GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: UlteriorModem on September 22, 2019, 05:58:41 PM
-
Typically I use JSB Diabolo Exact Heavy's in my Gauntlet. There pretty consistent.
Today I was putzing around with the gauntlet and was running low on the Heavies. I had it zeroed in pretty good, 9's and 10's.
But I was running low so I opened up a new tin of the Heavies and woah! POI shifted a couple of inches (at 30 yards) to the left!
I don't know what the difference is between the two tins but I saved some from the previous tin to compare them to one another. Don't know if it is weight, head or skirt size, or all of those :o
-
Check the lot numbers on the tins that will also give some good information. Pellet swages ware larger as they are used so everything is subject to change.
-
Either you HAD spiraling ... or do now ???
Try changing speed and see what happens
-
Even all Mc'Donalds fries don't taste the same. Gonna be some difference in production runs.
Grouping is what counts.....
-
Even all Mc'Donalds fries don't taste the same. Gonna be some difference in production runs.
Grouping is what counts.....
X2 makes sense to me
-
Well I expected 'some' difference in 'flavor' but wow... 3 inches?
Also the grouping is not as good as it was, indeed it does seem to have some spiraling.
I did note however when putting the Gauntlet up the barrel shroud was loose so that may explain some of the wandering.
-
I had a similar experience... so I ran about 6 patches through the barrel to 'semi - clean' 'er out... and Voila: back to center.
Now I just clean the barrel (Mrod) about every 1.5 tins.
-
Could be something to that. I suppose the barrel could have leaded up with the previous tin and the new tin however different are affected by that.
I will give it a cleaning soon and check it out.
-
I found this works great for me with a little balistol:
http://patchworm.com/ (http://patchworm.com/)
-
I've been watching this thinking if I ever had this happen with me while standing to shoot. It is easy enough to tell since my steel targets are 1.5" in diameter, and no, never had a group suddenly shift as far as yours did.
While I think target shooters at rests can get into the weeds about POI shift and barrel cleaning I discount the idea your rifle needed cleaning and there is another culprit in the mix overlooked. I'd be wondering about loose screws and bumps you may have inadvertently encountered.
I'll get a flyer on occasion too few to mark as an accident and found out a can of pellets had a few pellets short of a happy meal, but to get a group going sideways hasn't happened, yet.
I can see where the pellets end up if I miss and by calling the shot before it hits I can tell whether it's the pellet or me.
I'm still waiting to see what you find out and wish the best!
???
-
Did the groups tighten up after you tightened the barrel shroud? I recently had a loose locking ring on a front globe sight put my groups in the toilet. Tightened up the ring and so did the groups. Harmonics do weird things with pellet guns. How many times have loose stock screws on springers gotten people crazy? Anything loose on the barrel is a hundred times worse.
-
I had a similar experience... so I ran about 6 patches through the barrel to 'semi - clean' 'er out... and Voila: back to center.
Now I just clean the barrel (Mrod) about every 1.5 tins.
LOL....I've read on the forums, including this one, that some NEVER clean their airgun barrels because they never need cleanin'. ::)
Glag I'm not the only one that found it necessary to occasionally clean my bores but I only shoot springers and we all know that they "don't shoot good" to begin with! :o
-
Ed, I am in that group that almost never cleans a barrel. My first PCP was bought in 2013. I cleaned the barrel at that time. My brother is shooting it now with proven success (bag limit kills.) To my knowledge, the barrel has not been cleaned since 2013. And I advised my brother to clean the barrel ONLY if the accuracy goes away.
"If it ain't broke, don't fix it!"
Side note: I have been shooting air guns since the 1940s.
-
Ed, I am in that group that almost never cleans a barrel. My first PCP was bought in 2013. I cleaned the barrel at that time. My brother is shooting it now with proven success (bag limit kills.) To my knowledge, the barrel has not been cleaned since 2013. And I advised my brother to clean the barrel ONLY if the accuracy goes away.
"If it ain't broke, don't fix it!"
Side note: I have been shooting air guns since the 1940s.
"If it ain't broke, don't fix it!"
LOL.....evidently my .177 HW95 was "broke" judging by this target so I "fixed it" simply by cleaning the bore........
(https://i.imgur.com/9CVD7jnl.jpg)
I did some work on a .177 HW97 for a friend of my brother and it evidently was also "broke" and was "fixed" with a bore clean..........
(https://i.imgur.com/D2uLwIOl.jpg)(https://i.imgur.com/t7myvjGl.jpg)
LOL.......perhaps we have a different definition of "broke". :o
-
No offense intended, Ed.
Please understand, it was explained to me some years ago that, because the air is clean going down the barrel (as opposed to burning powder), the only thing left behind is a coating of lead from the pellets. The next pellet wipes away and leaves a new coating. So unless that coating is contaminated, the barrel stays accurate. Possible contamination might come from oil attracted dirt and grit. Then, YES, the barrel will need cleaning. Maybe we could call the barrel "Sick" instead of "BROKE".
-
No offense intended, Ed.
Please understand, it was explained to me some years ago that, because the air is clean going down the barrel (as opposed to burning powder), the only thing left behind is a coating of lead from the pellets. The next pellet wipes away and leaves a new coating. So unless that coating is contaminated, the barrel stays accurate. Possible contamination might come from oil attracted dirt and grit. Then, YES, the barrel will need cleaning. Maybe we could call the barrel "Sick" instead of "BROKE".
LOL...a difference of opinion certainly isn't an offense to me! ;)
" The next pellet wipes away and leaves a new coating."
Not necessarely! Sometimes different pellets (like hard lead Crosman Premiers) can foul the rifling with lead and the following shots only pack the deposit tighter in the rifling while depositing another layer of fouling on top.
Along with the pics I posted showing before and after bore cleaning groups, I also have a story from a couple decades ago when my brother's .177 R9 started shooting patterns instead of groups at 30 yards.
Here are a couple 3 shot "powder burner style groups" my brother shot from a bench using his R9 and 10.5 grain CP heavies........
(https://i.imgur.com/QDfRViZl.jpg)
Since he shot these two 3 shot groups "back to back" I figured that the two groups were at least as valid as a single "airgun 5 shot group". After a while the same R9 stopped grouping and no amount of pulled patches would improve the accuracy. Using his bore scope he saw the rifling at the "choked muzzle" literally disappeared under a layer lead polished by pulled patches. To correct this issue he soaked his R9 bore with Hoppes #9, then after some time he used a .177cal brass brush on his cleaning rod to scrub out the packed in fouling. After the bore "soak & scrub" he once again had one hole groups. It was at that time that we (brother and I) started the search for a pellet lube that would keep the CP lead from "soldering" itself to the rifling lands. We first tried FP10 and while it worked OK it seemed to cause the Crosman pellets to oxidize when stored in a leather pellet pouch made from a Good Will coin purse. Next we tried aerosol Slick50 one lube and have been using it to lube pellets ever since. After starting to lube our Crosman pellets we never had another occurrence "packed in fouling" and bore cleaning when needed was/is a simple matter of pulling through a few patches.
I've read that pure lead pellets like the Air Arms domes don't foul bores as readily as the hard lead alloy Crosman pellets, however I still lube my AA anyway.
-
Cleaning barrel 'discussion' aside, I did get a chance to clean the barrel and tighten the shroud. I ran a few patches down the barrel with a bore snake and the first few came out black as coal! Pretty sure it is residue from whatever they put on the pellets after production or maybe mold release. It probably was not hurting anything but it makes me feel better :D
About 3 or 4 patches later they started coming out clean.
However I have not had a chance to try again.
It is still bleeping 96F with an RH of over 80% so it will have to wait a while. 8)
-
I would think because it was a sudden decline in the POI with the new tin, and if nothing else changed between shot #500 of the old tin and shot #1 of the new... it is the pellet.
I was going to suggest if you have some of the old pellets, to shoot them and see if you are back to zero.
But now that you have cleaned the barrel you have added another variable.
Not saying it was wrong to do so, just muddy's the water.
Now if you shoot the old tins remains and everything is back home you can assume the barrel cleaning had no effect.
Yet if the new pellets shoot closer, you may think it helped.
Short answer, If the new pellets group well, re-zero. You will never get the old ones back.
-
Yea I hear you about too many variables. Add tightening the shroud to the mix too :P
I shot it a little some yesterday in the hot day. The JSB's were wandering around a bit so I decided to try some AA field heavys. They did pretty good at first but after about 20 rounds they too started wandering.
I think I am having some spiriling issues. Perhaps the regulator has changed some after several hundred rounds. Need to break out he chrony and tune her down just a bit.
-
Well here is an update.
Got off work early today and decided to check things with the Chrony in spite of the sweltering heat. The results were surprising. I had expected to have to back off the fps but just the opposite proved to be the case.
First couple of shots I did not change anything. The FPS had fallen off from the last time I tweaked it and was in the 780 fps range with a pretty good spread from 765 to 785 over 5 shots. Shooting JSB Jumbo Heavys in .22 cal or 18.3 grain.
Long story short I 'tightened' up the Hajimoto mod hammer spring adjustment a few times and settled in at right at 830fps and was much more consistent with the chrony displaying like 3 duplicates in a row. Spread of 834 to 836 much better!
Put out a 30 yard target and shot quickly a 197 out of 200 with 8 X's. The gauntlet is back in stride again :D
What the velocity change has to do with a different tin of pellets, probably nothing aside from they just made the inconsistency stand out enough for me to look into it.
Thanks for your patience and suggestions. I'm a better shooter thanks to you :D
-
This makes me wonder what brand, type, weight (velocity) pellets the "cleaners" shoot, VS the "never cleaners".
Based on anecdotal evidence, Crosman Premier hard lead pellets need occasional barrel cleaning, while JSB, H&N and RWS more often don't.
Is this an over simplification?
I can see that barrel smoothness and choke dimensions could also play a big role. As well as muzzle velocity. Some say expect leading over X FPS. So the power and pellet weight would factor in.
-
Add lubed pellets, or not to the cleaning question...
-
This makes me wonder what brand, type, weight (velocity) pellets the "cleaners" shoot, VS the "never cleaners".
Based on anecdotal evidence, Crosman Premier hard lead pellets need occasional barrel cleaning, while JSB, H&N and RWS more often don't.
Is this an over simplification?
I can see that barrel smoothness and choke dimensions could also play a big role. As well as muzzle velocity. Some say expect leading over X FPS. So the power and pellet weight would factor in.
"Some say expect leading over X FPS"
I've wondered if shooting "loosies" are partly responsible for rapid barrel fouling. There was a time years ago when boxed 7.9 grain Crosman Premiers (around die#7) had "pellet head size QC issues" and some would fit loosely in the leade. Experience proved that a loose fitting CPL would be a flier so I would shoot the "loosies" into the ground. I theorize that when shooting the combination of hard lead CPLs (antimony in the alloy), loose fit in the bore and R9 tuned to shoot at 910fps caused the rifling to strip lead shavings from the pellet head since the loose head wasn't "engraved properly" by the rifling. "Way back when" I was shooting dry hard lead CPLs (including the "loosies") I would find visible flecks of lead on cleaning patches pulled through the bore. After I started lubing the hard lead CPLs the interval between needed bore cleaning (when accuracy fell off) was reduced and I stopped seeing lead flecks on pulled patches. Also, the bore clean was much simpler because only a couple pulled patches were needed to restore accuracy instead of a thorough bore scrub.
As far as "pure lead" pellets like the JSB Exacts, I really don't know if they would foul my bores like the CPLs since almost all of the supposedly 4.52mm Exacts fit my R9 leade inconsistently loose (even had some flip out of the leade when relatching my break barrel) because there were simply too many fliers to be useful so they weren't used very much and I sold the remaining 9 tins of Exacts I owned.
Anywhoo....I personally believe that shooting loose fitting pellets will foul the bore more quickly as the velocities are pushed higher, however I don't know if the same thing would happen when "properly snug" fitting pellets are shot at higher velocities
-
.
-
This makes me wonder what brand, type, weight (velocity) pellets the "cleaners" shoot, VS the "never cleaners".
Based on anecdotal evidence, Crosman Premier hard lead pellets need occasional barrel cleaning, while JSB, H&N and RWS more often don't.
Is this an over simplification?
I am of the noncleaning (old)school, unless something changes. After the initial once over for factory oils. And i have similar pellet opinion. Cheap pellets=dirty=the guns the need it sometimes, expensive=better q.c. .... it's how it seems to go. But I won't discount rattlers contributing now that it's been mentioned. It still fits my experiences for the past 30yrs. I have a semiauto FX gun that cycles air from the LDC back to the reciever, so wiping down inside is infrequent but regular maintenace to avoid problems. FX recomeds only JSB for good reasons. Cleaning out after shooting CPUMs is just plain messier.
To original poster, I just noticed, while ordering a bunch, that Pyramyd now specs the head size of Exact Jumbos at 5.52mm not 5.5 as in years past, not sure since when cause i'm just finishing the last of sleeves bought back in 2007. That much difference from old molds getting bigger is gonna change POI for me I'm sure.
-
Ed,
Your loose pellet leading theory has definite "traction" with powder burners. There, a less than groove diameter driving band bullet causes a significant volume of hot gas to leak past the projectile, that then melts and solders lead to the barrel (more of a problem with hard alloys because the degree to which bullet base diameter can "bump up" to seal off hot gasses is reduced). Now, spring airguns do not have the heat of powder burners, but they do heat the air beyond the melting point of lead early on in the firing cycle...
Shooting slugs from a PCP that are well below groove diameter to reduce friction (and allow less distortion in the choke) is not a leading risk, because the air leaking by the slug is "cold". It is cooled via expansion; rather than heated in the gun via compression.
Do you "wash" pellets before lubing them? If so, this would remove a lot of lead flakes that would be of a size that could be melted and re-condense on the steel. If you don't "wash" pellets, or you find a significant difference in leading with one type of lube over another, then that suggests it is the lube itself that is the major contributor to keeping lead from sticking to the bore.
I am of the opinion that cleaning any barrel to the point of stripping all fouling, grease and oil down to bare steel before shooting is asking for lead to solder to the barrel... I deliberately leave a thin film of oil, or only lightly wipe out from storage before shooting ( I look through to see shiny bore, with no cleaning patches left in it). That way, whatever "dust" remains in the bore after a few shots cannot strongly bond to the steel. Even better, if that oil or lube is replaced with each shot.
With springers, oil lubed pellets are dicey due to the propensity to burn the oil via dieseling. Certainly, one does not want a drop of oil in the pellet base. Just a hint on the narrow bearing surfaces. Else, a wax or some other lube that is harder to light is better. Here, your experience in lube choices is most useful.
Patching dry is much more important with centerfire rifle cartridges. Here it is the chamber that should be dry (so the case can grip the chamber walls), rather than that the bore being absolutely bare steel, on the first shot.
That said, all un-jacketed lead PB projectiles are lubricated to prevent leading. This includes pure lead for muzzle loaders, and "hard cast" for centerfire handguns.
-
Ed,
Your loose pellet leading theory has definite "traction" with powder burners. There, a less than groove diameter driving band bullet causes a significant volume of hot gas to leak past the projectile, that then melts and solders lead to the barrel (more of a problem with hard alloys because the degree to which bullet base diameter can "bump up" to seal off hot gasses is reduced). Now, spring airguns do not have the heat of powder burners, but they do heat the air beyond the melting point of lead early on in the firing cycle...
Shooting slugs from a PCP that are well below groove diameter to reduce friction (and allow less distortion in the choke) is not a leading risk, because the air leaking by the slug is "cold". It is cooled via expansion; rather than heated in the gun via compression.
Do you "wash" pellets before lubing them? If so, this would remove a lot of lead flakes that would be of a size that could be melted and re-condense on the steel. If you don't "wash" pellets, or you find a significant difference in leading with one type of lube over another, then that suggests it is the lube itself that is the major contributor to keeping lead from sticking to the bore.
I am of the opinion that cleaning any barrel to the point of stripping all fouling, grease and oil down to bare steel before shooting is asking for lead to solder to the barrel... I deliberately leave a thin film of oil, or only lightly wipe out from storage before shooting ( I look through to see shiny bore, with no cleaning patches left in it). That way, whatever "dust" remains in the bore after a few shots cannot strongly bond to the steel. Even better, if that oil or lube is replaced with each shot.
With springers, oil lubed pellets are dicey due to the propensity to burn the oil via dieseling. Certainly, one does not want a drop of oil in the pellet base. Just a hint on the narrow bearing surfaces. Else, a wax or some other lube that is harder to light is better. Here, your experience in lube choices is most useful.
Patching dry is much more important with centerfire rifle cartridges. Here it is the chamber that should be dry (so the case can grip the chamber walls), rather than that the bore being absolutely bare steel, on the first shot.
That said, all un-jacketed lead PB projectiles are lubricated to prevent leading. This includes pure lead for muzzle loaders, and "hard cast" for centerfire handguns.
A few "personal opinion only" comments.
"Now, spring airguns do not have the heat of powder burners"
Bore fouling with my HW springers and loose fitting pellets has NOTHING to do with heat. It's simply that shooting pellets that are too loose at too high of velocity strips off some lead if the pellet doesn't spin with the rifling. Then the following pellets will pack the lead particles tightly into the rifling grooves, so on and so forth with each "loosie".
"Shooting slugs from a PCP that are well below groove diameter to reduce friction"
I have no idea what happens with a PCP, I'm only reporting my findings with the springers I use. I do know however that some PCP shooters at the ft matches are satisfied that a 30fps velocity variation has little to do with accuracy out to the 55 yard max target distance. On the other hand I TRY to keep my velocity variation prom pellet to pellet at no more then 10fps. For some reason even a 20fps velocity variation from my recoiling piston guns does affect the accuracy at longer distances. I really don't know why but I suppose the way springer recoil "flips the pellet when shot" weighs into the mix due to greater or lesser "muzzle flipping" if the velocities aren't relatively consistent. I tried using Chair Gun ballistic software to determine the ballistics of my pellets but gave up. The reason was that unless I played with the BC numbers in the software the "puter results" weren't very close to "real world" and I had to shoot at actual distances to determine the pellet trajectory. I've READ that some PCP shooters were able to take the computer calcs and actually use the data for plotting trajectories. Perhaps the motion of piston guns introduce "dynamic variables" in ways that can't be computed so I've always shot some targets at actual distances to verify the "puter results". LOL....I needed to shoot pellets for verification so I decided to skip the "puter calcs" and simply shoot real targets like this one. LOL....it was even shot sitting on a bucket resting the gun on cross sticks like I do when squirrel hunting or shooting hunter class field target because I get different results if I shoot from a bench..........
(https://i.imgur.com/5ko3WLgl.jpg)
Do you "wash" pellets before lubing them?
Only if they're dirty, have too much parting compound on them, or there is a lot of swarf in the box. I couple cases of Crosman Premiers that I've bought a few years ago were washed due to "gunge in the box" but the cases bought for in the last few years have been clean without swarf in the box or on the pellets.
"lube itself that is the major contributor to keeping lead from sticking to the bore."
Yup....exactly which is why I started lubing my CPLs in the first place.
"I deliberately leave a thin film of oil, or only lightly wipe out from storage" and "Even better, if that oil or lube is replaced with each shot. "
Shooting lubed CPLs the bore is "oiled" by every pellet shot. ::)
"With springers, oil lubed pellets are dicey due to the propensity to burn the oil via dieseling."
Definitely true and there needs to be some care when lubing to insure that only the "rifling surfaces" are lubed. Basically, don't spray lube directly on the pellets. To assure this I spritz a tiny amount of Slick50 OneLube in the bottom of a dedicated pan, then spread the "oil film" around evenly over the bottom of the pan, dump in a box of CPLs, stir pellets gently so a thin film of lube is transferred to the rifling surfaces, then dump the pellets back into the box (or pellet pouch) for storage. If there is a Greyhound Bus stop smell when shooting OR EVEN more than a slight sheen on the loading fingers the pellets were excessively lubed. Here is a box of CPLs being lubed........
(https://i.imgur.com/hgxRz0rl.jpg)
"That said, all un-jacketed lead PB projectiles are lubricated to prevent leading."
Over the years I've found that there is very little "powder burner lore" that applies to shooting pellets. For example, when chronying some .22 rimfire bullets I've had velocity variations as much as 100fps. On the other hand, after tuning my springers and a few dozen "fouling shots" (yep, my springer bores do need some fouling to be consistent) I check the velocity consistency.
I recently (last week) checked out the velocity of my .177 R9 and .177 HW95 and here were the results indicating no abnormal dieseling even though both pellet brands were lubed.......
.177 Beeman R9.....7.9 grain CPL 849,844,849,850 8.4 grain Air Arms domes 839,839,836,833
.177 HW95.............7.9 grain CPL 881,881,884,887 8.4 grain Air Arms Domes 856,859,860,862
-
Wow, Ed. If the pellets can skid in the rifling they really are loose. Too loose. Makes me think of this guy: Toulouse Lautrec :)
I think you are correct that velocity variations with springers affect POI, not because of a difference in pellet drop over range, but because of differences in barrel whip timing and muzzle placement on leaving the bore. That said, such a small velocity variation between shots suggests no dieseling in your springers at all.
-
Wow, Ed. If the pellets can skid in the rifling they really are loose. Too loose. Makes me think of this guy: Toulouse Lautrec :)
I think you are correct that velocity variations with springers affect POI, not because of a difference in pellet drop over range, but because of differences in barrel whip timing and muzzle placement on leaving the bore. That said, such a small velocity variation between shots suggests no dieseling in your springers at all.
If there is dieseling it's only because some OneLube may have gotten inside the pellet skirt. My springers were both stripped of all petroleum lubes and then relubed with non-dieseling Dupont Krytox GPL205 grease. I have found that as long as my velocity doesn't vary much more than 10fps I can't tell and accuracy difference with my equipment and shooting skills sitting on a bucket resting the gun on cross sticks.