GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: nervoustrigger on June 06, 2016, 11:43:00 AM
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I have noticed a few reports recently of finding rifling damage on Crosman barrels at the muzzle, believed to be from the use of a non-floating pilot on a crowning tool. So for users who are struggling to get decent groups, I wanted to briefly explain a way to inspect for this potential damage.
Firstly, let me say I am not an expert on this and there may be a better way to do this inspection, and I invite the more experienced gunsmiths to comment.
So with that said, here we go. This is a fairly straightforward visual inspection. Start by cleaning the barrel. You don't want lead and graphite covering things up.
Then the trick is getting both a light source and your line of sight going down the end of the barrel at the same time. If you have the barrel off and can shine a flashlight through from the breech end, that works best. Otherwise you might be able to do it entirely from the muzzle end by playing around with lighting and angles. My big noggin kept getting in the way :) Anyway, as you look down the bore, what you're looking for is a change in the sheen of the rifling about 1/4" - 1/2" down. Basically what happens is the crowning pilot burnishes the rifling and gives it a different appearance from the rifling further down. If your barrel has this damage, it will be quite obvious because there will be a distinct ring all the way around the circumference.
GTA member deerfarm sent me a .22 Marauder barrel that he had given up on and replaced with an aftermarket barrel. On this barrel it was pretty easy to spot the damage. It is worth mentioning that the cotton swab test will not detect this type of damage. Also, it was not apparent from pushing pellets through. That may be due to the choke. I think if it weren't choked, it would have been possible to feel a change in resistance just before the pellets emerged from the muzzle.
Here are some examples provided by GTA members:
K.O. was the first I am aware of to present a photograph of a barrel from 2014:
https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681 (https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5487)
Oldnoob had the same type of damage on a Discovery purchased in March 2014:
https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685 (https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5486)
ACZan just got one around October 2017:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5488)
There are even examples of this damage on the newer Maximus, which Crosman confirmed they are manufacturing with their newly re-engineered process. Here's one from starlingassassin from May 2017: https://www.gatewaytoairguns.org/GTA/index.php?topic=126375 (https://www.gatewaytoairguns.org/GTA/index.php?topic=126375)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5499)
Lastly, here's another example of damage that looks different but has a similarly detrimental effect on accuracy. It is from a Discovery barrel that Ozarkairgunner sent me in November 2016. Shown here is the section I chopped off to get back to good rifling:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5317)
Pushing a pellet through met with a lot of resistance once it reached the damaged section. The pellet emerged with the entire circumference of both the head and skirt smeared. After removing the bad section and deburring the bore, pellets look much improved:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5318)
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Seen it on quite a few as well ... Sadly most with modest to heavy pilot damage never shoot very well even after extensive lapping and prep to "Try" and correct it.
Tho that said ... even with all the Bad Rap Crosman gets on there .22 & some .177 barrels, have seen / have some of these OEM barrels shoot good as the renowned LW barrels do !!
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Out of the 4 Crosman barrels I looked at, 2240, 1377, Disco and P-Rod, all had the rifling wiped off the map. I recrowned 3 of them, as I don't plan on using the 2240 barrel, and shot 2 of the 3, the 1377 barrel and the P-Rod barrel. Both barrels shot lights out after the rework. 3 of the 4 there was no rifling left. 1 was harder to see, but with a ground pin gauge it was easy to tell. Look down the barrel with a flashlight and you can see it fairly easily.
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I have been lucky only one of my barrels had the problem, a 2260 barrel which I had planned on shortening to 18" anyways...
it was pretty bad though...
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I bought a 24" disco barrel to use on my 1377. I did not notice any thing made by the crowning Pilot but I do have a line running the full length of the barrel. ???
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Interesting. I will have to check my 2260. I thought it was odd that the only pellet the 2260 will shoot is JSB 18.1 and I mean others are thrown all around. It doesn't even like 14.5grn crosman premiers in dome or hollowpoint. H&N Barracuda 21grn and Beeman Kodiak 21grns are thrown like curveballs at 15 yards. I will check my barrel later. Thanks for the heads up.
EDIT- my barrel looks fine, still weird to me that it won't shoot crossman, H&N, Beeman and RWS pellets. JSB's only for this one. May have to order an 18" from Baker airguns, I like the look better with the TKO on there.
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i have several crosman barrels i will check them. just tagging this thread for ease of locating again.
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I usually stuff a bit of fluffy white cotton down the bore (from the muzzle) about 1" and shine the light over my shoulder. The white tends to diffuse/reflect the light and allow a decent look at the actual surface of the bore.
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Interesting. I will have to check my 2260. I thought it was odd that the only pellet the 2260 will shoot is JSB 18.1 and I mean others are thrown all around. It doesn't even like 14.5grn crosman premiers in dome or hollowpoint. H&N Barracuda 21grn and Beeman Kodiak 21grns are thrown like curveballs at 15 yards. I will check my barrel later. Thanks for the heads up.
EDIT- my barrel looks fine, still weird to me that it won't shoot crossman, H&N, Beeman and RWS pellets. JSB's only for this one. May have to order an 18" from Baker airguns, I like the look better with the TKO on there.
you also need to check the leade (for a smooth transition to rifling rather than a sharp edge)...also about half my barrels had a burr at the transfer port that needed knocked down...
Jason has a thread on how he does his barrels but I lost my bookmarks...
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Interesting. I will have to check my 2260. I thought it was odd that the only pellet the 2260 will shoot is JSB 18.1 and I mean others are thrown all around. It doesn't even like 14.5grn crosman premiers in dome or hollowpoint. H&N Barracuda 21grn and Beeman Kodiak 21grns are thrown like curveballs at 15 yards. I will check my barrel later. Thanks for the heads up.
EDIT- my barrel looks fine, still weird to me that it won't shoot crossman, H&N, Beeman and RWS pellets. JSB's only for this one. May have to order an 18" from Baker airguns, I like the look better with the TKO on there.
you also need to check the leade (for a smooth transition to rifling rather than a sharp edge)...also about half my barrels had a burr at the transfer port that needed knocked down...
Jason has a thread on how he does his barrels but I lost my bookmarks...
Right about the time you posted this I did the Q tip test. It has a bur that is catching the cotton fibers. If anyone has the fix to this I would appreciate it if you could post it.
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Here is a link to my little barrel accurizing writeup:
http://www.gatewaytoairguns.org/GTA/index.php?topic=98836.msg925609#msg925609 (http://www.gatewaytoairguns.org/GTA/index.php?topic=98836.msg925609#msg925609)
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Matt, for what it's worth, I have one of the barrels with a line running down the bore and it shoots great :) It was a big surprise. I did recrown it and polished the leade but I did not polish the bore. I thought I would need to but it was printing 3/8" groups at 25 yards and that exceeded my expectations for a pumper so I never took it apart for that step.
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Matt, for what it's worth, I have one of the barrels with a line running down the bore and it shoots great :) It was a big surprise. I did recrown it and polished the leade but I did not polish the bore. I thought I would need to but it was printing 3/8" groups at 25 yards and that exceeded my expectations for a pumper so I never took it apart for that step.
That is great news! What pellets does yours like? I have only tried the 7.9 gr crosman pointed and it did not like those (no surprise). :D
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My particular barrel shoots the Air Arms 10.3gr best, followed closely by both JSB- and AA-branded 8.4gr. But let me qualify that by saying when it comes to finding the very best shooting pellets, the difference between pretty good and excellent seems to come down to the particular batch.
Also, the RWS Meisters group about 1/2" at 25 yards which makes a very effective house sparrow wrecking ball.
All this is at around 10fpe on a 24" barrel. I know it defies logic...a barrel that long and slender ought to be a harmonic vibration nightmare but the fact it shoots various pellets (i.e. different weights and velocities) well tells me it is pretty well behaved. FWIW, I did firm up the barrel band by shimming where it attaches to the end of the pump tube and there is a grub screw on each side coming up at an angle to bite into the barrel. Just carefully tapped the plastic and took care not to over torque them. POI has been rock solid from day to day, month to month.
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You can use a bore light, which is basically an angled flashlight, that uses a bent clear plastic rod to conduct the light. You can get one pretty cheap. Use the bore light at the breech and look down the muzzle.
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My particular barrel shoots the Air Arms 10.3gr best, followed closely by both JSB- and AA-branded 8.4gr. But let me qualify that by saying when it comes to finding the very best shooting pellets, the difference between pretty good and excellent seems to come down to the particular batch.
Also, the RWS Meisters group about 1/2" at 25 yards which makes a very effective house sparrow wrecking ball.
All this is at around 10fpe on a 24" barrel. I know it defies logic...a barrel that long and slender ought to be a harmonic vibration nightmare but the fact it shoots various pellets (i.e. different weights and velocities) well tells me it is pretty well behaved. FWIW, I did firm up the barrel band by shimming where it attaches to the end of the pump tube and there is a grub screw on each side coming up at an angle to bite into the barrel. Just carefully tapped the plastic and took care not to over torque them. POI has been rock solid from day to day, month to month.
Thanks! Mine is cut down to 16".
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Well a couple days ago I took a .22 cal nylon brush and made about 15 passes through my bore with Mpro7 cleaner. Then ran about 6 patches through until clean. Today I just shot the best five 5 shot group on a card that I have ever shot at 15 yards. Four out of five groups were a ragged hole with one going just over 1/4 inch. I think I need to credit a lot of it to the pellet packaging from Airgun depot, I really like the foam cut outs they package the pellets in. Unlike Amazon with their rather sloppy packaging, I could not find one damaged pellet skirt in the 500 tin of JSB exact 18.1grn. I also did not shoot as quickly today. I should recheck how it shoots Crosman premier domes but if it will consistently shoot the JSB's this good then I will be quite happy.
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I said I would report back when the .177 Disco barrel arrived and it did today. I was pleased to see no evidence of a crowning pilot having been used, however it does have the line running down the bore very much like one I got over 2-1/2 years ago. I went ahead and gave it a full manicure and pedicure and swapped it onto the 2240 HPA. It was almost 1am by the time I got finished and sighted in with the aid of a flashlight so it wasn't under the best of conditions. Nonetheless it was hitting the smaller spoons (1") at 25 yards every single time using the cheap RWS Basics wadcutters (830fps / 10.7fpe). I tried two other types of pellets and they had a similar POI which is usually a good sign. So far so good with this one!
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Hey guys, I'm curious. Does anyone know why the .177 barrels have the line down the bore?
I assume it is a seam from the manufacturing process of the raw tubing. My understanding is that DOM (drawn over mandrel) tubing is commonly used and therefore some speculation on the forum that is likely what Crosman uses. Prior to today, I thought it was a seamless process but it turns out it isn't. Apparently it's just that the seam is "almost invisible" according to this article:
https://www.metalsupermarkets.com/difference-between-erw-dom-and-seamless-tube/ (https://www.metalsupermarkets.com/difference-between-erw-dom-and-seamless-tube/)
In a nutshell, it explains that the manufacturing of DOM tubing starts just like ERW (electric resistance welded) tubing, it's just that it gets finished up differently which yields better dimensional tolerances and conceals the seam. So I guess the degree to which the seam is "almost invisible" can vary.
I've never seen this type of seam on any other barrels except from Crosman. But even more curious is that it's only on the .177 barrels, not the .22. At least from the handful of each that I have seen.
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I have a brand new Marauder and it kinds blows LOL.
I tried doing a recrown and it did improve things a little bit, but still there are a still a number of flyers and the groups are large compared to my disco, which is like a scalpel.
I did see something in my marauder barrel that looks like the pic in this thread. Should I just send Crosman a pic if those marks and ask them to replace it? I suppose I shouldn't have done the recrown before talking to them. So what is the solution if they don't replace it? Chop the barrel and recrown?
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It needs to be cut off so you have rifling to the end of the barrel.
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I thought this was interesting so figured I'd share it. Prior to doing the J-B Bore treatment, I pushed a pellet through and then again afterwards. The striations in the rifling marks are dramatically reduced so it's easy to see how it helps reduce the tendency to strip off lead.
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5319)
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Thanks, Jason!
Cool pic. Very illustrative. I haven't yet done the barrel port or leade treatments yet, but I'll do a before and after pellet also.
But I did lop off the last 1/4 to 3/8" of my Marauder barrel (the least amount I could cut to get all the pilot tool damage out) with an angle grinder and recrowned using a dremel stone to give a bit of recess at the end of the barrel. Then i used a brass screw and valve grinding compound to cut the crown. I think I could even do a little better with the crown as I can't quite clearly see the rifling as well as I'd like to. BUT...the rifle shoots straight now! I went from shooting half dollar sized 10-shot groups at 30 yards to shooting sub-dime sized ragged holes at 25 yards with 3 out of 5 of the pellets I tried. Really happy about it.
So thanks SO much for you excellent barrel smithing write-up with the great picture of the leade-bore area. And for the pic showing the before and after on the pellets. Can't wait to see how well it will get after giving it the full treatment ;)
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That's great, Ray! I love reading a success story. I need to give credit to Kirby for the excellent photos of both the rifling damage in this thread and of the leade in the linked thread. Hopefully yours shoots even better after deburring the barrel port and knocking off the sharp edge at the start of the rifling. Fortunately those two things a pretty quick and easy compared to a chop and crown.
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That's great, Ray! I love reading a success story. I need to give credit to Kirby for the excellent photos of both the rifling damage in this thread and of the leade in the linked thread. Hopefully yours shoots even better after deburring the barrel port and knocking off the sharp edge at the start of the rifling. Fortunately those two things a pretty quick and easy compared to a chop and crown.
Well a big thanks to you AND Kirby, then! :D
So pulled the barrel yesterday and dealt with the barrel port and the leade. But since I have the gun apart and it's going to rain cats and dogs here today, I figured I'd have a try at the j-b bore paste and bore bright treatment (I ran a few pellets through the barrel before starting the work yesterday and one after. I'll do more after the j-b treatment also)
To that end,I went and picked up some j-b bore "compound". I am assuming this is the new product name for j-b bore paste for which I find nothing when searching Google. Can you confirm this is the right product? Also, they didn't have the j-b bore bright, so I got some Flitz Polish...I assume that's an OK substitute for bore bright, let me know if you think I am wrong about that.
But my biggest question about this portion of your barrel treatment regimen is the cleaning rod. I only have the cheap multi-section aluminum kind that scews together and has a non ball bearing plastic handle. Some of the forum threads on using j-b bore paste mention the need for a stainless steel cleaning rod with a ball bearing handle. I can't seem to find any online that don't have some kind of coating on them. Would a plain old Hoppes Elite like this do the job?: http://www.cabelas.com/product/HOPPES-ELITE-ROD/2044699.uts (http://www.cabelas.com/product/HOPPES-ELITE-ROD/2044699.uts)
Any advice you have on the paste and rod I mentioned above would be greatly appreciated.
Thanks!
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Hi Ray, yes it sounds like you have the right stuff. The label reads "non-embedded bore cleaning compound". J-B bore paste just seems to be the popular term for it.
I'm not really sure where Flitz falls in terms of fineness of polish in relation to the two J-B products. I have heard of folks using it in place of the J-B bore paste but that only loosely implies it is more similar to that one. I think it would be fairly easy for you to find out. Put some of each on a cotton cloth (old T-shirt scrap) and scrub a highly polished piece of metal. If the J-B dulls the surface and the Flitz preserves the mirror finish, then you know. Might be able to substitute a piece of glass for the polished surface. It would be easy to compare any dulling.
Regarding the cleaning rod, I checked the Cabelas link and that one looks fine to me. Firstly, it is a ball bearing type. Secondly, J-B is non-embedding and you're working from the breech end so the rod material isn't super important. For example, for .177 I have a brass rod. Brass is relatively soft which means abrasives can embed into it. I definitely wouldn't want to use it to clean from the muzzle end or where there is any opportunity for small microscopic grit to get introduced. But I have no qualms about working from the breech end with J-B.
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Hi Ray, yes it sounds like you have the right stuff. The label reads "non-embedded bore cleaning compound". J-B bore paste just seems to be the popular term for it.
I'm not really sure where Flitz falls in terms of fineness of polish in relation to the two J-B products. I have heard of folks using it in place of the J-B bore paste but that only loosely implies it is more similar to that one. I think it would be fairly easy for you to find out. Put some of each on a cotton cloth (old T-shirt scrap) and scrub a highly polished piece of metal. If the J-B dulls the surface and the Flitz preserves the mirror finish, then you know. Might be able to substitute a piece of glass for the polished surface. It would be easy to compare any dulling.
Regarding the cleaning rod, I checked the Cabelas link and that one looks fine to me. Firstly, it is a ball bearing type. Secondly, J-B is non-embedding and you're working from the breech end so the rod material isn't super important. For example, for .177 I have a brass rod. Brass is relatively soft which means abrasives can embed into it. I definitely wouldn't want to use it to clean from the muzzle end or where there is any opportunity for small microscopic grit to get introduced. But I have no qualms about working from the breech end with J-B.
Ok, great. Thanks for the reply. I'll pick one of the rods up and will test the flitz as you suggest. I'll report back on the results when I have them. :D
Ray
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Me I have been a bit lazy about it... I fire lap with jb using a paper q-tip tip dipped in JB bore paste in front of a crosman pellet... cpums for the slightly larger head size... on a couple I did it with toothpaste...
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Kirby, I don't know about that being lazy. Sounds like more work to me ;D
Every patch that gets oil and J-B gives multiple passes back and forth through the bore. Each pellet gives only one. To achieve a similar finish, I think it would take me 5 times longer to do it with fire lapping. :)
Which reminds me, I watched a Youtube video by Sean Pero a while back where he poured a lead lapping slug I've been thinking about trying that soon, or perhaps substitute a pellet with multiple driving bands (e.g. heavy Eun Jin). Thus far I've been using VFG pellets in .22 and .25 cal, or a jag and cotton patches for .177. I'm happy with the results but of course I wonder if I could achieve any better results with a different method. Any suggestions from the experts?
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well its usually just one loaded with qtip in front then 4 or 5 just bare pellets after then clean and repeat if I feel it needs it... some I only did once... the one with some tooling marks and the line in it I did about 30 pellets... seems to work well... Me I am just trying to make sure if there is any roughness to the bore/grooves that it get knocked down and all micro features/tiny burrs point towards the muzzle... ???
I load the qtip(.177) pretty heavy with JB...
On .22 and .25 I add/twist on cotton ball to build up the size of the qtip.
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pouring a lead lap in .177 is next to impossible...lol its a right pain in the butt lemme tell you.... first you have to remember with a traditional poured lap you need to keep it indexed(technically it should NEVER leave the bore completely) and you will need to figure out a way to "bump" it back to size as its used.... and the jag you need to make will be so tiny it will be fragile..
While I am absolutely guilty of using a mop and bore paste to "lap" a barrel its really not preferred method of lapping unless your going for a fast polish.... the mop and paste method will round out the edges of the lands which is not a good thing... a traditional lead lap will polish and even remove material(taper lapping or "choke" ) while still maintaining nice crisp edges....
it MIGHT be easier with a little planning to use a pellet as the lap in the smaller calibers.... I have daydreamed about it but never tried to apply any of my ideas lol
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One of these days I just might fire lap the snot out of a crosman barrel and see what happens if it is possable to over lap and how long it would take.. ;)
Being that these are very light subsonic rounds and I have had a 66 straw barrel that only had "ghost rifling" that still shot very well... I tend to think that it does not take much rifling with most pellets...
Now if I was trying to send the 50g BBT out of my Trail 725 .25 barrel (modded for disco/13xx breech) at 950fps the shallow rifling could be a prob allowing it to skid down the barrel..?
But for pellets well even if it wiped out the rifling some at the breech end and put a slight taper in the barrel I bet it would send the pellets out very well... think almost smooth twist... just as long as the pellet head engagesthe walls thru out...
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Thanks Michael, those are some well reasoned points about using a poured lap. Keeping it indexed, compressing it back to a firm fit as it is used, and difficulty of doing that in .177 cal.
I did wonder about the crispness of the edges of the lands when using a compressible lap. That's one of the reasons a ball bearing rod is needed, so the lap (whether rigid or compressible) can follow the rifling. It does seem like at some level a softening of the edges could become a problem, but normally we're removing so little material that I suspect in practice it isn't really an issue. I think we can see evidence of that when lapping. For example, I use a Sharpie to mark a couple of lines on my cleaning rod so I can easily see that it is following the rifling. So as long as a compressible lap reliably follows the rifling, I have to assume the somewhat rigid head and skirt of a pellet will follow it as well. That is, the soft lap can more easily give way and jump the rifling as compared to a pellet.
Granted, a pellet gets a sharp slap on the rear end when it is fired, so intuitively it seems like there's some opportunity for it to "jump the rails" a bit before it picks up the spin of the rifling. Can't say I've seen any evidence of that when looking at the skirts of recovered pellets, though. And Kirby, your reference to the smooth twist design reminds me that accelerating a pellet and then stripping it through a rifled section isn't necessarily a bad thing.
It's often helpful for me to think of what happens when something is taken to the extreme. So if I went super aggressive on the lapping and ended up radiusing the snot out of the edges of the rifling, what would happen? The rifling would no longer be square cut. Instead it would basically look like round bumps spiraling down the length of the barrel. Assuming the apex of those bumps were still about the same height as the original rifling, meaning offering about the same depth of engagment, would the pellet achieve the proper spin? Or would it skitter down the barrel and fail to pick up a stabilizing spin?
In terms of aerodynamics and turbulence, might it even be advantageous not to have sharp cuts around the circumference of the head?
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I have a TKO off of a barrel right now. If I can find a brass screw in the garage, would toothpaste be alright for a quick crown touch up?
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I have a TKO off of a barrel right now. If I can find a brass screw in the garage, would toothpaste be alright for a quick crown touch up?
Well depends on the toothpaste.. ;)
honestly if you have auto rubbing compound would work quicker...imo
I have used RC to fire lap and it works about the same as JB imo. I just avoid stuff with carbide in it... I did add baking soda to the toothpaste on one of the barrels also did not cause anything bad...
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OK, old topic, I know. But I did finally try the barrel treatment and pretty much wrecked the thing. Shoots terrible now. I recrowned, still bad. Chopped the barrel to just under the existing crown to try and get a fresh edge (I've only removed about a half inch total so far) and recrowned a third time. Still terrible.
Seems like, no matter how much I go at it with a brass screw, one side of the barrel just won't get where I can see the grooves and lands clearly cut into the edge of the crown when looking straight down the barrel (although they are clearly visible leading up to the crown when looking sideways into the barrel). Maybe I abraded too much. Not sure if I just didn't have a good enough stop near the muzzle or what. Or maybe my technique was bad...it was surprisingly difficult to do, the cleaning rod kept wanting to bend. I'm usually pretty handy...
Anyway, pretty frustrated now. I had it shooting very nicely and liking more pellets from just chopping off the piloting tool damage and recrowning. Id definitely recommend that to anyone who gets the 177 Marauder. It was awesome after that.
Not sure what to do now. Maybe i should chop off another 1/2" and recrown again? I might even be willing to fork out some $ for a better drop in barrel and be done with it, but it appears marmot militia only sells 22 barrels now... didn't see any 177 on their site.
Any suggestions on what to do next are welcome!
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Ray,
I used bench grinder and then progressively finer grits of sandpaper for mine. 100 turns clockwise and 100 turns counterclockwise for each grit from 60 to 2000.
http://www.gatewaytoairguns.org/GTA/index.php?topic=112013.msg1087227#msg1087227 (http://www.gatewaytoairguns.org/GTA/index.php?topic=112013.msg1087227#msg1087227)
Is it possible the bore of the barrel is not centered and that is why you're slightly off?
Taso
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Seems like no matter how much I go at it with a brass screw, one side of the barrel just won't get where I can see the grooves and lands clearly cut into the edge of the crown when looking straight down the barrel
Ray, are you moving the drill in a random figure eight pattern as you go? It's counterintuitive but that will give a more uniform result than attempting to keep the drill straight. For example, I swing the drill out to angles as much as 30-40°.
Otherwise the biggest issue I see (based on helping a few people by phone and personal messages) is applying too much pressure in an attempt to make the process go quicker. What that does is push steel into the bore and leaves a burr. The idea is to apply just enough pressure to keep the brass head in contact with the crown. Let the abrasive do the work.
To confirm there is no burr, push a couple of pellets through. If you can feel even the slightest resistance as the head emerges from the muzzle, it needs to be reworked. Now of course if the muzzle is choked, there will be some resistance for the last inch or so but there should be no increase in resistance as the head emerges.
Or maybe my technique was bad...it was surprisingly difficult to do, the cleaning rod kept wanting to bend.
Please explain. Unless you are referring to pushing pellets through, I don't know where a cleaning rod comes into play.
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Taso, since Ray is using the brass screw technique, it should not matter if the bore is slightly off center to the OD. Running the drill in a random figure 8 will help develop a uniform bevel.
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Taso, since Ray is using the brass screw technique, it should not matter if the bore is slightly off center to the OD. Running the drill in a random figure 8 will help develop a uniform bevel.
Jason,
Good to know!
Thank you,
Taso
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Ray,
I used bench grinder and then progressively finer grits of sandpaper for mine. 100 turns clockwise and 100 turns counterclockwise for each grit from 60 to 2000.
http://www.gatewaytoairguns.org/GTA/index.php?topic=112013.msg1087227#msg1087227 (http://www.gatewaytoairguns.org/GTA/index.php?topic=112013.msg1087227#msg1087227)
Is it possible the bore of the barrel is not centered and that is why you're slightly off?
Taso
Hey, taso.
Thanks for the reply. Funny, i think we have similar tools ;)
I too lopped off just enough of the barrel to get rid of the crowning tool damage from the factory using an angle grinder held by hand. Then I trued up the end to 90 degrees using my bench grinder like you did. From there I used a dremel tool stone in my drill to get the initial recess and a brass screw with grinding compound after that to cut the actual crown. Looks 90 to me and it worked for me initially. I just messed it up trying to give it the j-b bore paste and bore brite treatment. I've repeated the crowning twice since using the same methods. I just can't seem to get a clean groove/land in one area of the barrel. I'm afraid I may have worn away too much of the rifling one one side of the barrel.
Ray, are you moving the drill in a random figure eight pattern as you go? It's counterintuitive but that will give a more uniform result than attempting to keep the drill straight. For example, I swing the drill out to angles as much as 30-40°.
Otherwise the biggest issue I see (based on helping a few people by phone and personal messages) is applying too much pressure in an attempt to make the process go quicker. What that does is push steel into the bore and leaves a burr. The idea is to apply just enough pressure to keep the brass head in contact with the crown. Let the abrasive do the work.
To confirm there is no burr, push a couple of pellets through. If you can feel even the slightest resistance as the head emerges from the muzzle, it needs to be reworked. Now of course if the muzzle is choked, there will be some resistance for the last inch or so but there should be no increase in resistance as the head emerges.
Or maybe my technique was bad...it was surprisingly difficult to do, the cleaning rod kept wanting to bend.
Please explain. Unless you are referring to pushing pellets through, I don't know where a cleaning rod comes into play.
Thanks :D
Yes, I am moving the drill around as you suggest and was able t get a good crown using the same method earlier. As to the cleaning rod, I was referring to when I was giving the barrel the bore paste and bore brite treatment. In doing so, I found the long cleaning rod would sometimes bend as I would push the patches into the barrel. Not sure it matters,but just mentioned it.
I'm wondering if my stop at the end of the barrel during the barrel treatment wasn't good enough and I got too close to the end and wore away the rifling there. I've redone it twice now and the issue is in the same spot. I would think if it was my technique causing a not-round crown I wouldn't see the same lack of clear lands/grooves in the same spot twice. But next time I take it apart I'll run some pellets through it to see if they snag at the end... thanks for the tip!
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Ray,
Try and see if you can view the actual rifling in the spot you think you may have worn. I was lucky to get my smart phone to get some good pics. It's not easy getting the lighting and focus right.
That would be the only way to make sure. When I use the JB bore paste I don't let the brush out the end of the rifle. I keep my finger on the muzzle and reverse when the brush hits it. I normally only do about 20 stokes.
I use a nylon bristle brass wound core brush with a patch wrapped around the circumference. I then cover the exterior of the patch with JB paste. Just enough paste to color the patch.
I feel the nylon bristles won't scratch and the bristles may apply a more even pressure to the lands and grooves. I feel that a patch and jag setup puts more pressure on the lands.
It isn't a perfect solution as the lands are taller, the bristles poke through the patch and probably skid off the lands and into the grooves.
I'd love to hear other peoples solutions. :)
Thanks,
Taso
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MY nitro venom dusk came with a crown problem. Never even got to break it in, now it just sits because im too lazy to send it in since its a couple years past warranty...
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"Hey, taso.
Thanks for the reply. Funny, i think we have similar tools ;)"
Ray,
"Necessity is the mother of invention."
I don't have access to a machine shop so I have to figure out how to get things done with a little ingenuity and what I have on hand. Just like MacGyver! ;D
Taso
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Ugh. I give up. Just ordered a new barrel from crosman, asked them to inspect the muzzle for damage before sending. Maybe I'll get lucky and it'll be good out of the box. Otherwise I'll chop off the damage again and forego the bore paste / bore bride treatment.
Oh well...my MacGyver skills were lacking this time. Moving on ;)
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OK, old topic, I know. But I did finally try the barrel treatment and pretty much wrecked the thing. Shoots terrible now. I recrowned, still bad. Chopped the barrel to just under the existing crown to try and get a fresh edge (I've only removed about a half inch total so far) and recrowned a third time. Still terrible.
Seems like, no matter how much I go at it with a brass screw, one side of the barrel just won't get where I can see the grooves and lands clearly cut into the edge of the crown when looking straight down the barrel (although they are clearly visible leading up to the crown when looking sideways into the barrel). Maybe I abraded too much. Not sure if I just didn't have a good enough stop near the muzzle or what. Or maybe my technique was bad...it was surprisingly difficult to do, the cleaning rod kept wanting to bend. I'm usually pretty handy...
Anyway, pretty frustrated now. I had it shooting very nicely and liking more pellets from just chopping off the piloting tool damage and recrowning. Id definitely recommend that to anyone who gets the 177 Marauder. It was awesome after that.
Not sure what to do now. Maybe i should chop off another 1/2" and recrown again? I might even be willing to fork out some $ for a better drop in barrel and be done with it, but it appears marmot militia only sells 22 barrels now... didn't see any 177 on their site.
Any suggestions on what to do next are welcome!
wish I lived closer and had a before and after look on your barrel... just lapping should not be that kind of prob... these barrels are soft but are still pretty hard... but some crosman barrels have pretty light rifling... in the end you have to evaluate what each barrel needs individually...
How many pellets have you sent down range after lapping... is it bad with all pellets... heck are the .177 barrels choked..? check all the other things that it could be like an injured barrel o-ring leaking or the transfer port not sealing... maybe a loose barrel grub screw...
when you shortened the barrel how did you mod the shroud and cones is it clipping now..? check all the things that can change while removing and installing the barrel...
when you lapp the muzzle end gets very few few strokes it is the breech end that the rifling would be worn...
?
there is a Hammer forged .177 barrel that might be able to be modded for the Mrod if that is what you want but not cheap and the I think not cheap to have it machined to fit the Mrod...
http://www.airgunspares.com/store/product/16155/BSA-Buccaneer-.177-Rifle-Barrel-Part-No.-16-9382/ (http://www.airgunspares.com/store/product/16155/BSA-Buccaneer-.177-Rifle-Barrel-Part-No.-16-9382/)
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wish I lived closer and had a before and after look on your barrel... just lapping should not be that kind of prob... these barrels are soft but are still pretty hard... but some crosman barrels have pretty light rifling... in the end you have to evaluate what each barrel needs individually...
How many pellets have you sent down range after lapping... is it bad with all pellets... heck are the .177 barrels choked..? check all the other things that it could be like an injured barrel o-ring leaking or the transfer port not sealing... maybe a loose barrel grub screw...
when you shortened the barrel how did you mod the shroud and cones is it clipping now..? check all the things that can change while removing and installing the barrel...
when you lapp the muzzle end gets very few few strokes it is the breech end that the rifling would be worn...
?
there is a Hammer forged .177 barrel that might be able to be modded for the Mrod if that is what you want but not cheap and the I think not cheap to have it machined to fit the Mrod...
http://www.airgunspares.com/store/product/16155/BSA-Buccaneer-.177-Rifle-Barrel-Part-No.-16-9382/ (http://www.airgunspares.com/store/product/16155/BSA-Buccaneer-.177-Rifle-Barrel-Part-No.-16-9382/)
Thanks, Kirby.
It shoots bad with all pellets. Shot well with most just after chopping the initial factory damage off the end and recrowning. Then I did the barrel treatment and it has sucked since, despite multiple tries at recrowning. I have inspected the baffles to see if it was clipping (it appears they are fine) and the transfer port seems to be well sealed. I suppose I could chrony it again and see if I'm still getting the same readings I was initially. I have checked that the screws are all tight.
Honestly I got the marauder during the 25% off sale at PA, so even now that I'm investing $47 for the barrel I'm still $50 under the normal price. I am going to compare the new barrel's rifling to the one I currently have to see if it was something I did. If I end up with an extra barrel, I'll find some project to use it on ;)
I'm now just at the point I want to be able to shoot the thing. I'll play around with tinkering more down the road...
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I live really close to you Ray, but unfortunately I have never done much barrel work. If you need another set of eyes or moral support though, just let me know.
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I live really close to you Ray, but unfortunately I have never done much barrel work. If you need another set of eyes or moral support though, just let me know.
Thanks, Jerry :D
We'll see what happens with this new barrel and take it from there. I'm hoping the next one will just work. I explained my situation to the customer service woman at Crosman (very nice lady, I think her name was Angel) and asked to have them check the muzzle for damage before sending out. Keeping my fingers crossed.
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Just a quick update. A GTA member recently sent me a .177 Crosman barrel to work over. On receipt I quickly noticed it had the subject damage to the rifling near the muzzle. The owner reported that it wouldn't group any of the pellets he had tried. I chopped off 1/2" from the end of the barrel to reach good rifling and kept the cutoff section. Then the other night I played around with my camera settings and lighting and finally managed to get a decent picture of the damage so figured I might as well post it in hopes it may help others identify it:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5317)
This picture has also been added to the original post so new readers don't have to trudge through the whole thread to see it.
Pushing a pellet through met with a lot of resistance once it reached the damaged section. The pellet emerged with the entire circumference of both the head and skirt smeared. After removing the bad section and deburring the bore, pellets look much improved:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5318)
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Great pics Jason and very telling. Huge difference in the two pellets.
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Just read this thread and immediately checked my older .177 Remington Genesis and new Benjamin Trail .22 NP2.
Sure enough the Genesis looks just like your photos at the muzzle. It may explain why I only have fair accuracy with the Genesis.
I must say though, the barrel on the Trail NP2 looks great. The barrel and crown are very nicely done. I have much better accuracy with the Trail over the Genesis. I have read that Crosman has taken the barrel quality much more seriously lately, and it shows.
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I have a thread in the Crosman Benjamin forum, but I am following up my post in this thread also.
I decided to order a new barrel for my .177 Remington Genesis. Crosman was quick to send the new barrel, and it came last night. I opened the box to check it out.
To my surprise, it was not a finished barrel. I expected a blued barrel ready to install, and it was bare steel. Yes, the crown was good, but why was it not blued? It has a rough oiled steel finish with traces of surface rust starting.
Naturally it arrived too late on a Friday to call, and now I have to wait till Monday to call them.
I would not have wasted my time buying another barrel if I had known. Was I wrong to think the barrel should have been blued?
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They screwed up. No way should they be selling unfinished parts. They'll make it right for you.
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Crosman came through. They are shipping out a new barrel, and it will be blued. They apologized for sending out the first one, someone must have pulled it from the wrong bin. It can happen during the Holiday rush. On top of that, they told me to keep the non-blued barrel.
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Hello Enthusiasts,
I just received two barrels and was surprised to see one had good rifling at the end and the other had the pilot crowning tool damage. Here are two good focused photographs of the two barrels. These were manufactured at roughly the same time frame.
So, be sure to inspect the barrels when you purchase the rifle or a replacement barrel.
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It looks like this topic started off with warning about this defect and how to look for it.
What I originally did was shine a light down the bore from the other end and roughly inspect it with my jeweler's loop (used for inspecting gems and jewelry). I moved closer and further away to move my focus area along the bore. I saw the damage and pulled out the digital camera.
What I did was change the camera for close up shots and point at an angle into the bore. I then focused on the end of the barrel locking in the focus there (partial depressing of shutter button on automatics), but then moving the camera slightly closer to move the focus down into the bore. I have a background in photography, too. So, I pulled out some of my tricks on that to get good documentation of the defect.
I just noticed that the two barrels have a different shapes, one with a longer chamfer and deeper countersink. The other has a smaller chamfer and countersink.
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Hi Chris, thanks for the photos and report. Do you mind sharing some details on when and where they were purchased? Assuming they came direct from Crosman's parts department, it would give us of how recently they have shipped bad barrels. Just within the last few weeks?
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Here is a before and after pic of a re-crown I did on a .177 last week, as per Jason's instructions. The difference in accuracy is dramatic.
https://imgur.com/QLckcNc
https://imgur.com/9t0V2Gv
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Wow. Best thread I have read on here. After reading it my friends and I put a fiber optic light down our .177 Marauder barrels. Three had massive chipping of the rifling in the last 1/2" to 1" inch of the barrels. Gouged-out chunks of metal actually. One did not, but did look like the original picture. And I mean MASSIVE chipping, all the way around the rifling. Ours makes the original picture's damage look insignificant in comparison. No way this should have happened. Sadly, all but mine are out of warranty.
Cut off the ends? If so, how far back?
Better yet, is the Marauder .177 FT barrel available yet as a part that they could order? Or must you purchase the whole gun from the custom shop?
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Marauder barrels are choked so it's hard to say whether cutting off the affected portion at the muzzle would work satisfactorily. Kinda depends on how large the bore is. If it's not oversized, it may work just fine...but logically you can imagine why the bore dimensions may be held to lesser tolerances when the pellet is expected to exit through a choke.
Either way, it would only cost you time to try it.
If you're up to it, push a couple of pellets most of the way down the barrel, stopping short of the choke. Then push them back out again, the way they went in, and snap a close-up shot and post it. I recommend doing it with both a soft pellet (e.g. JSB) and a hard pellet (e.g. Crosman).
You really have me wondering about the tearout in the rifling. Although button rifling is something of a brute force thing, the steel is normally pretty ductile so I wonder why it tore. Maybe it was near the seam. I know with some Crosman barrels you can actually see the seam, not on the exterior but on the interior.
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Thanks Jason. It's just nasty in there. Already talking to aftermarket barrel makers/suppliers to find a better route, but I would still like to attack this. I will post up pics in a couple of days. I used a pick glass like used in textile industry to see it. Easy enough with eyes, but impossible with a camera. So it is time to buy a USB barrel scope. Can anyone direct me to one with O.D. small enough to go down a .177? Hopefully on Amazon? If I knew which one it would be on order already. Prime will have it here quick. I want you guys to see this. Damnedest thing I have ever seen in over fifty years of pulling triggers. All the way around the circumference of the bore, not just in one place. You know, we all discussed it, and we all agreed: These were tack drivers the first twenty shots or so, darn near same hole at 20 yards then performance fell off and the groups opened up. Been chasing it ever since. Thanks to this thread we looked down the barrel, and now we have something that might be the culprit. Not wasting another pellet or any more of my time shooting it until this is resolved. 1000 shots ain't gonna' shoot this out of it. Lapping won't either. I suspect I'm going to cut mine off, its toast anyway. Please post the links to good directions I should follow in cutting and recrowning a Marauder.
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Recommended method for cutting and recrowning will depend on your tools. Cut off the offending section with a hacksaw and then if you have a lathe, use that to face off the end square. I don't have one so I use the procedure described here with a drill press:
https://www.gatewaytoairguns.org/GTA/index.php?topic=55681 (https://www.gatewaytoairguns.org/GTA/index.php?topic=55681)
For the actual crowning part, that article goes into it a little bit but my updated article here describes it better.
https://www.gatewaytoairguns.org/GTA/index.php?topic=130555 (https://www.gatewaytoairguns.org/GTA/index.php?topic=130555)
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Excellent. Thanks. Fresh out of lathes, but got everything else.
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Hi NervousTrigger,
Now, I have to be careful how I phrase my comments as to not offend anyone at Crosman. The person who personally help me with getting good replacements after two bad barrels has been good to me. However, I might have already offended him when I sent the photographs of the damage and kindly asked to get it replaced.
From what I can best tell is that these barrels had to have just been manufactured within the past couple of weeks up to a month. I asked why one looked very good while the other had noticeable damage. Wonder why defects like these are not quality controlled to be removed from production.
Don't have an option to cut my barrel short. It needs to be at least 24 inches. I have been considered purchasing a Lothar Walthar barrel and have it machined the same as the Crosman barrels.
Tonykarter,
I was fortunate enough to know how to manipulate the camera for the photos I posted. But, those are difficult to attain and only view less than an inch into the bore. One thing I need to do is get a bore scope. I would like to get one of the USB bore scopes, but I saw too many bad reviews. The USB bore scopes would be best, especially when documenting the inspection. I need to find a higher quality one than the Chinese scopes I have been seeing. The least expensive one I can find does not have video/image capturing capabilities and only has 0 degree direction of view. I have been talking to the folks at FiberScope to find a scope which can do the 0 degree view with angle mirror attachments. Think the minimum would be over $1,300 for what I need. I might consider buying the Portable Flexible Fiberscope.
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Does anyone know anyone who has machined a Discovery barrel out of a blank? Obviously, the receiver end has the most work. Would be nice to have the drawings of the receiver end to use for machining a new barrel.
Guess I could have one of my old bad barrels cut for a cross section and reverse engineered for the dimensions.
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I may try with my HD camera and see if it lucks out. Mine is so bad that it MUST be sawed off. You guys are not going to believe how bad it looks. You would think I've been shooting carbide pellets.
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Tonykarter,
What barrel is this that you have? Was it the original on the rifle or a replacement?
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ACZan,
If you need to keep your 24" barrel length you could figure out how to cut out the bad rifling in the center but leave the exterior of the barrel intact. I can see how you could do that with a lathe but I haven't figured how to without.
Taso
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"cut out the bad rifling in the center"? Where did that come from? Your comment didn't make any sense. If the barrel is bad in the middle, it needs to be completely replaced. Unless, good short pieces can be re-purposed for pistols and such.
This topic is was primarily discussing the defects created by the pilot for the crowning process with Crosman barrels. For others, they found more than the pilot crowning tool damage.
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ACZan,
I have attached a picture of what I'm trying to explain. You can keep the same barrel length but remove the defective rifling from the center of the bore outward. Or I guess drill out the end of the barrel. I apologize if I can't properly describe what I'm thinking. lol
Taso
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Sorry. Didn't mean to hijack the thread. Will start another when I can get the pics of the damage.
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Ray, no worries. Feel free to post here. I think your findings are very relevant. I'm more than happy to expand the scope of this topic to include what you found, and with your permission, summarize it and include your photos in the original post.
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I know exactly what Tasco1000 is talking about. It's called counter boaring. It can work very well too. Many old military rifles with wallowed out muzzles can be restored to good accuracy in this manor. A boaring bar on a lathe can do this or a piloted counter boar would work too. The pilot would have to be exact to the barrel and nicely smooth to not cause a problem. .
n.h.schmidt
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Ah, I see what you are talking about, TAS1000. Thanks for the drawing, that helps a lot. I thought you were talking about the actual middle of a 24 inch barrel, 12 inches towards middle. Was trying to figure out how you were pulling off that Houdini. If I was really desperate, I might try that. With my engineering background, I am a bit more particular.
Tonykarter indicated his bad rifling was much further down the length of the barrel than what I had on my bad barrel. I would like to see what images of the defect he will upload to the site. I am really curious about what he has going on in the bore.
NervousTrigger,
I forgot to mention that both of the barrels in my photos were purchased at the same time. Not sure if I made that clear in the earlier post.
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Okay, the pictures I was able to take do not do the damage credit, but the video I shot does. Educate me please. Which file sharing site uploads vids the fastest and is GTA friendly?
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If not Youtube, upload it to Dropbox and post a link.
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https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be (https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be) Best I can do for now. A buddy of mine will be in tomorrow to do some hunting at Venado Creek Ranch. He's bringing his Nikon. I bet he can shoot some very good pictures. I'll post them up too.
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https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be (https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be) Best I can do for now. A buddy of mine will be in tomorrow to do some hunting at Venado Creek Ranch. He's bringing his Nikon. I bet he can shoot some very good pictures. I'll post them up too.
It says "This video is unavailable".
You might have to go into the YouTube settings and change it to "Public".
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Okay guys, Chris' recent experience getting a bad barrel from Crosman prompted me to go back through some old posts and see how far back this stretches.
K.O. got one way back in 2014:
https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681 (https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5487)
Oldnoob had the same type of damage on a Discovery purchased in March 2014:
https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685 (https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5486)
And of course ACZan just got one in the last few weeks:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5488)
Let that sink in for a moment.
Here we are over 3 years later and Crosman is still shipping barrels with damaged rifling at the muzzle.
What does it take to fix the root cause? The right tools. 3 years wasn't enough.
What does it take to perform damage control? To inspect barrels and cull the bad ones so their "valued customers" don't have to assume the role of quality control technicians? It would take a tech with a flashlight about 10 seconds to spot the damage. Yet in 3 years they couldn't be bothered to do that.
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Agreed 100%. Here is the YouTube link again. It is set as public access. https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be (https://www.youtube.com/watch?v=C07zyWg3PgQ&feature=youtu.be)
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To keep the 24" length why not get a Maximus barrel and trim it down?
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Tonykarter,
Hopefully, your friend has a good Nikon with a lens capable of macro focus. The way your are lighting the barrel might be sufficient. Your friend would then need to zoom in on the area and focus to it, manually, not auto-focus. Videos is a bit rouch to see details. However, a rough image is basically what I was seeing, while I used a standard incandescent 75 watt bulb at one end and a jeweler's loop at the other.
I am just going to have to break down and purchase that Portable Flexible Fiberscope at FiberScope dot com for $275.00. Unfortunately, there is no way to capture the image with this device. It is only a 0 degree direction of view.
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Douglasr,
A Maximus barrel was suggested by Crosman. They said I would need to get a Maximus breech, but Crosman warned I would lose FPS on the shots. Think the ports are smaller. I would imagine the Maximus barrel would still work with a standard Discovery .22. Without drawings and dimensions, exchanging parts is a gamble on results.
If I am going to swap out for a different breech, might as well put a BNM repeater on the rifle. Going spring for a Lothar Walther blank barrel and have it machined for the BNM breech and TKO suppressor. Shouldn't have any issues with a LW barrel at all.
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NervousTrigger,
Nice presentation. I thought I heard that Crosman completely changed there process for the barrels when the Maximus was introduced to there line. Five years is way to long to allow a defect like this to persist, especially at a critical point, the muzzle.
It looks like the pilot without a doubt creates a groove 3/8 to 1/2 from the end, which definitely damages the lands. Others, look like it might also flatten the lands to the point where the rifling is gone.
You're right the customer shouldn't be performing the quality control for any end product.
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Hi Chris, yeah we had it on authority from a Crosman employee about a year ago that they were in the process of re-engineering their barrels, and implied that the manufacturing and QC aspects were being revamped accordingly. But he also qualified it by saying something about it applying to their premium products. I don't know where that line was being drawn but he gave an example that they were testing a springer that was getting great results out to something like 70 yards. So surely it applies to the Marauder but not a 760 pumper, for example.
It's pretty clear the Maximus isn't what would be considered part of their premium line but the reports from owners have been very favorable for the most part, so I thnk that led folks to speculate that Crosman was making the barrels under the new design and processes. Looking for evidence of that, I posted a thread here asking owners of both the Discovery and Maximus to compare their barrels--depth of rifling, number of lands and grooves, ratio of size of lands and grooves--anything that might indicate they are manufactured differently. However so far I haven't seen conclusive evidence of it.
For what it's worth, I have an absolutely stellar .177 Discovery barrel...and a completely mediocre LW barrel that came on a custom shop 2400KT. So I have no doubts that Crosman can produce excellent barrels. It's just consistency that's been their bane. I know it's not easy to manufacture precision machines at the market price points where they play...what I would call the mainstream market. But surely we can agree they are doing themselves no favors by mutilating rifling over a span of years. So I'm sure my criticisms of their products seem harsh at times but it's not because I have a beef with them. Rather, it's that I see a potential for them to be the hands-down one to beat in the mainstream market and it just pains me to see them displaying this degree of incompetence or apathy.
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Hi Chris, yeah we had it on authority from a Crosman employee about a year ago that they were in the process of re-engineering their barrels, and implied that the manufacturing and QC aspects were being revamped accordingly.
....It's pretty clear the Maximus isn't what would be considered part of their premium line but the reports from owners have been very favorable for the most part, so I thnk that led folks to speculate that Crosman was making the barrels under the new design and processes.
...... Rather, it's that I see a potential for them to be the hands-down one to beat in the mainstream market and it just pains me to see them displaying this degree of incompetence or apathy.
Actually Tom Gaylord stated in his review on the Maximus that it was a new patented process that would make a very accurate barrel.
The Crosman employee stated here on this forum that they were going to manufacture the barrels here in the US.
What we don't know is do they do this or are the barrels still made in china and shipped to the States.
Either way, there doesn't seem to be sufficient quality control standards in place in order to assure the consumer a quality product.
I do fully agree with you...this is a missed opportunity for Crosman to separate themselves to ship a quality product to consumers.
Most PCPs and many springer products that Crosman has their name on retails over $150 so we aren't talking about chump change here.
IMO, there is no reason why they can't deliver a quality product for that amount of money...even though I presume most of the gun parts are made in china.
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Douglasr,
A Maximus barrel was suggested by Crosman. They said I would need to get a Maximus breech, but Crosman warned I would lose FPS on the shots. Think the ports are smaller. I would imagine the Maximus barrel would still work with a standard Discovery .22. Without drawings and dimensions, exchanging parts is a gamble on results.
If I am going to swap out for a different breech, might as well put a BNM repeater on the rifle. Going spring for a Lothar Walther blank barrel and have it machined for the BNM breech and TKO suppressor. Shouldn't have any issues with a LW barrel at all.
Well that is not right about the breech it is the same as the disco and has the same part # 1761-019... the bolt might be different have not checked..
As far as being slower well maybe but probably not... my .22 Maximus barrel is tighter than all my other .22 Crosman Barrels... Also the rifling seems taller and the bore /groove ratio look to be 50/50 and My older Crosman barrels seemed to be about 70/30 bore/groove.
The barrel transfer port on the Max was just over .125 (drill bit shank (checked with a mic) at .125 and fit very slightly loose) very easy to open up and de burr... so if the disco port is bigger it is easy to open up...
those marred lands sometime do not affect accuracy as much as you would think... also some really mess it up... I feel all crosman barrels need the leade done any ways and that helps them a bunch... so it you create a burr opening up the barrel port well it will get knocked down when the leade gets done...
Here is a Varmint barrel with the same prob... did well at 18 yards...
https://www.gatewaytoairguns.org/GTA/index.php?topic=105939.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=105939.0)
here is an old Dianna Barrel that has left over marks from the boring process... probably caused the barrel to lead up enough to kill accuracy... fire lapping probably cleaned out the lead and maybe smoothed the muzzle side of the ridges... so maybe helping it not lead up as quick...
https://www.gatewaytoairguns.org/GTA/index.php?topic=77016.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=77016.0)
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Okay guys, Chris' recent experience getting a bad barrel from Crosman prompted me to go back through some old posts and see how far back this stretches.
K.O. got one way back in July 2012:
https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681 (https://www.gatewaytoairguns.org/GTA/index.php?topic=80859.msg771681#msg771681)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5487)
Oldnoob had the same type of damage on a Discovery purchased in March 2014:
https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685 (https://www.gatewaytoairguns.org/GTA/index.php?topic=64067.msg612685#msg612685)
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5486)
And of course ACZan just got one in the last few weeks:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5488)
Let that sink in for a moment.
Here we are over 5 years later and Crosman is still shipping barrels with damaged rifling at the muzzle.
What does it take to fix the root cause? The right tools. 5 years wasn't enough.
What does it take to perform damage control? To inspect barrels and cull the bad ones so their "valued customers" don't have to assume the role of quality control technicians? It would take a tech with a flashlight about 10 seconds to spot the damage. Yet in 5 years they couldn't be bothered to do that.
Hey Jason I think that was a 2014 barrel... just for truths sake... I know it was about a year after I joined the forum... I looked and I joined 3/13... camera date is inaccurate...
I still think the same as before in that thread... that yes they should do better...
But it is mitigated by the fact that they will work to fix the prob or accept returns and the fact that they cost much less than any other barrel... 5 times less than a LW blank that then needs machining... My Maximus .22 has a very very light chatter mark not enough to matter... I did have a Miss cut chamber though... I could have returned it but chose to fix it...
I also think that they need to cut the chambers with a tool that create a leade also... even the .25 green mountain barrels have no leade just hard edged rifling... I mattered more on one of mine than the other... JSB Kings worked great at 50 yards on both but one did not like the Benji 27g at all... worked on its leade and now they work almost as well as the JSB...
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Even the Powder barrels need inspecting and work some times...
Am also a believer that lapping should be done after drilling and prior to hammer forging, cutting, broaching, or buttoning the barrel blank...
https://www.google.com/search?q=boring+marks+in+barrel&tbm=isch&tbs=rimg:CZoJ7nPAfKuDIjiJvfzUXCKVnt6JEUZigxcnXg0AmoP4ix9VadCez37xFkI1yU_11Jh-bIMYY0lfPD-X1ddIf2yf9PyoSCYm9_1NRcIpWeEeTUogDcrqdfKhIJ3okRRmKDFycRkgiIB5nc0-wqEgleDQCag_1iLHxHYcHVFIz6YoSoSCVVp0J7PfvEWEdhwdUUjPpihKhIJQjXJT_1UmH5sRzIgD5WwaXNYqEgkgxhjSV88P5RHmfIJFkZaVeSoSCfV10h_1bJ_10_1EfuR8LuvEzSt&tbo=u&sa=X&ved=0ahUKEwjopKS0iPvWAhVK12MKHVr7AvkQ9C8IHw&biw=1366&bih=662&dpr=1#imgrc=_ (https://www.google.com/search?q=boring+marks+in+barrel&tbm=isch&tbs=rimg:CZoJ7nPAfKuDIjiJvfzUXCKVnt6JEUZigxcnXg0AmoP4ix9VadCez37xFkI1yU_11Jh-bIMYY0lfPD-X1ddIf2yf9PyoSCYm9_1NRcIpWeEeTUogDcrqdfKhIJ3okRRmKDFycRkgiIB5nc0-wqEgleDQCag_1iLHxHYcHVFIz6YoSoSCVVp0J7PfvEWEdhwdUUjPpihKhIJQjXJT_1UmH5sRzIgD5WwaXNYqEgkgxhjSV88P5RHmfIJFkZaVeSoSCfV10h_1bJ_10_1EfuR8LuvEzSt&tbo=u&sa=X&ved=0ahUKEwjopKS0iPvWAhVK12MKHVr7AvkQ9C8IHw&biw=1366&bih=662&dpr=1#imgrc=_)
https://www.google.com/search?q=lapp+a+barrel+before+hamer+forging&rlz=1C1GNAM_enUS688US688&oq=lapp+a+barrel+before+hamer+forging&aqs=chrome..69i57.28568j0j7&sourceid=chrome&ie=UTF-8 (https://www.google.com/search?q=lapp+a+barrel+before+hamer+forging&rlz=1C1GNAM_enUS688US688&oq=lapp+a+barrel+before+hamer+forging&aqs=chrome..69i57.28568j0j7&sourceid=chrome&ie=UTF-8)
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Hi Kirby, thanks for the correction on the time. I was indeed going by the camera's date. I will go back and fix the references this evening.
3 years is still really disappointing though :)
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K.O.,
Crosman stated the Discovery is a 100% USA Made product. The Production Manager explicitly stated the Discovery barrels are coming off their production line in NY.
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Just got confirmation from the Production Manager at Crosman that the Maximus barrel production is a completely different process and separate from the Discovery barrel production line. Maximus barrels would most likely have the newer patented process which has been mentioned in the forum.
Too bad that they can't upgrade the Discovery barrel production line.
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Luke, Chris, Kirby, thank you guys for clearing things up about the Maximus barrels. I thought that was the case but I remember FuzzyGrub commenting he had bought 4 of them and they all had the same "chicken scratch" rifling as the typical Discovery barrel. That seemed to suggest they were having them manufactured in a couple different places or via a couple of different processes. Maybe that was an early production thing.
So why isn't it a Maximus barrel won't interchange with a Discovery barrel? Same diameter but different transfer port locations?
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Hang on, I am actually in a middle of the same topic conversation with the Crosman Production Manager on the difference between the barrels and how they fit with the upgraded breech which would be needed to put the Maximus barrel on the Discovery rifle. I'll have the answer for you hopefully tonight. If not, it will be tomorrow. May also have to look back through my emails on details of the subject.
But, it has been a long day will be calling it a night soon.
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Was looking back through my email correspondence. This came from the Crosman Production Manager.
"All of our PCP barrels are manufactured in the US."
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Ah, I found it.
"You don’t want to switch to the Maximus transfer port because it will reduce your velocity. The discovery has a larger transfer port."
Crosman Production Mgr
Now I can sleep tonight.
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Ah okay, thanks. Looks like his terminology is a little off though. The transfer port is a small bushing that sandwiches between the valve and barrel. I assume he's referring to the barrel port. If indeed that is the only difference, it's a difference that's exceptionally easy to remedy. I'm going to go ahead and order one in the near future and give it a try.
By the way, apparently in spite of the Maximus barrel being manufactured stateside, they've still managed to jack up the muzzle on at least a few. I had forgotten about this thread that starlingassassin opened (https://www.gatewaytoairguns.org/GTA/index.php?topic=126375) a few months ago but he got a Maximus with the damage:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5499)
And another member, Vance H, received two with this damage.
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=5500)
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Just a quick note that I updated the date on Kirby's example, and reworked the original post to include all the photos supplied by GTA members.
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Crosman's apathy is disconcerting. I am not one to speculate but what is Crosman's logic? Instead of recalling all the defective barrels they are choosing to only replace the ones where customers complain? If that's the case then I think its a bad long run business strategy.
I've shunned Marauders because I didn't want to play the barrel lottery in not having to buy a $200 LW replacement barrel. In all honesty I did pick up a .25 Marauder because I thought the price was good and it has a Green Mountain barrel. I'd like to get one of Travis's shorter aluminum tubes and make a Marauder carbine. ;D
Taso
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NervousTrigger,
It is a good possibility I have my parts mixed up. Below is the quote from the production manager.
"You don’t want to switch to the Maximus transfer port because it will reduce your velocity. The discovery has a larger transfer port."
Do you know if the port on the Maximus barrel is actually smaller than the Discovery barrel. You did mention the Maximus is 0.125"
From what I found out from Crosman, the difference between the standard Discovery breech (part #1761-019) and the steel upgrade breech (part #2240SBPK) is the barrel sleeve groove. As for the small bushing which fits into the port, someone will have to clarify the differences.
It has been really hard to get dimensions and specs from Crosman. They are very reluctant to give out any of that information. If I had drawings in hand, I would have the definitive details to figure out what is what.
So, are the Maximus barrels, which produced by a new and different process, having the same pilot crowning tool damage? I could have sworn I saw a photo of the same damage on a Maximus barrel doing Google image search with the word "crowning" in the phrase.
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Hi Chris, sorry, I don't have the sizes of the Disco and Maximus barrel ports. Must've been someone else that gave the Maximus at 0.125".
And I guess you missed the part a few posts back where GTA members starlingassassin and Vance H both received Maximus rifles with the damage. I'm hoping that was an early production thing. Otherwise they worked hard to re-engineer their barrels only to ruin them on the last step.
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Jason, please clear an Inbox space. Been trying to send you one for a couple days. ;D
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Oops, sorry Jerry. Just cleaned out some messages!
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NervousTrigger,
I have accumulated several bent/bad Discovery .22 barrels along with some very accurate ones. I'll measure those ports and report back on this topic on my findings. I never got the statement from Crosman that the two barrels have the exact dimensions. 'They were basically the same', is what I got from them. That's too vague for me. Here are the differences I know at this point.
Discovery has machined flats for the rear and front sights. Maximus does not.
Discovery is 24 inches long. Maximus is 26 inches.
Discovery is 0.437 inches in diameter. Maximus is _???_
Discovery port is _???_ inches in diameter. Maximus is 0.125 inches as you said.
I thought that a couple replies on this topic mentioned some bad Maximus barrels. Would like to see some photos of those.
The impression I got from talking to Crosman was that the new barrel manufacturing process was introduce along with the Maximus model. If this is the crowning issue on those barrels as well, then they are using the same pilot crowning tool on both models' barrel. Would that be a logical deduction on that?
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Thanks for the details on the Discovery and Maximus barrels.
A couple of things you mentioned lead me to believe you did not see my post on Sun Oct 22. Starlingassassin took a picture of the muzzle damage to a Maximus barrel. I copied it to the original post for reference. Also you credited me for a second time for the info on the Maximus barrel port diameter. Wasn't me :)
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Seems like the easy(er) work around is to get a maximus just for the longer barrel, knowing some of it will get chopped off.
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Sam,
I thought exactly the same thing.
Taso
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Believe me, I wanted to go the Maximus route, because I use a scope. Have no need for the machined flats for the rear and front open sights.
Crosman told me if I went to the upgraded steel breech #2240SBPK, which doesn't have the machined grove for the barrel/front sight sleeve, I would experience a drop in fps. At that point, I didn't get any information on what was responsible for drop or what to do about it. So, the Crosman manager focused on locating a good Discovery barrel. He personally checked them for straightness and accuracy. Unfortunately, one with the pilot crowning tool damage slipped through. The barrel shot accurately with the damage at a range of 10 yards. But, I can't take a risk on the defect. Damaged rifling is damaged rifling, even worse if it is at the muzzle.
The only way I can find out what is the difference between the two breeches and barrels is to have them in hand with micrometer. Unless, someone has already gone down that road.
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Okay guys. Here is the another barrel I received. I actually detected a slight amount of pilot crowning tool damage. Base on the number of barrels I have, the ratio appears to be 1 out of every 2 will have some degree of pilot crowning tool damage. I outlined the slight damage in the uploaded photo. You have to click on the image to enlarge it and to see better what I outlined. It is in the same spot as all the others.
Fortunately, this did not affect the test shots.
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Sorry NervousTrigger,
That was K.O. who gave the 0.125 inch measurement on the port.
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Guys,
I have a big correction to make. The first two barrels are 26 inches long with a flat machined for the rear and front open sights. The third barrel is 24 inches long, which means it is an actual Discovery barrel. The first two are a version of the Maximus rifle barrel for open sights, not the Euro version. I didn't bother to measure them, until I put them side by side.
Simple enough to cut off the bad section of the one bad Maximus barrel.
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I have a 177 Maximus l purchased sometime this year cleaned the barrel installed an ffh and reg shot ten different pellets ten shots each and got ten holes😳 I figured had to be a bArrel issue ordered another barrel all good now at least out to 30 dime sized groups. Now got me wondering about the bad barrel and the new one. I kept the old barrel and I won’t be able to inspect the barrel and my other crosman guns until I get back from the Philippines in March