GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: shorty on August 17, 2018, 07:52:47 PM
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Does a choked barrel really improve accuracy ?
I don't know....... >:( >:( >:( >:( >:(
All grouping at 25 yards on paper.
First gun was the 22 synrod with terrible barrel. Re-choked it and it shoots better than me with 14.66's and 21.14's ONLY. Laser straight.
Second was a FD PCP .177 cal (no Choke and did nothing besides put a target crown on it) and shoots every .177 cal pellet the same ( GREAT ).
Third was the 25 cal synrod with GM barrel ( did not do anything to it ). Shoots pretty darn good but not as great as the 22 and the FDPCP.
Forth gun Gauntlet 22 cal. Out of the box, great. Chopped 5" over barrel and re-crown, better than great with every 22 cal pellet in house.
So, when I say great I mean cover with a dime or nickle. When I say Ok, i's more like a quarter (min-10 shots). I really like the one holers but I can't hold it that steady or have a great scope on each of the guns.
What have you all experienced? Is a choke really worth it? From what I am seeing, I can shoot a larger variety of pellets without a choke more accurately than a chocked barrel.
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Michael just cut the choke off of his rainstorm II .25 and got better groups with pellets and bullets. I think it depends on how tight your barrel is (imho) if your going to get good accuracy with pellets after you cut your choke off. The choke plays advocate with pellets being different sizes. But.. makes bullet sizing more critical.
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Choking is starting to sound like a gimmick too me?!. ??? ??? ???
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It really depends on the platform and power level also. Ive had guns with no choke shoot great until i cranked them up then they shot all over the place and then choked them and they shot great on the other hand Ive had guns with chokes shoot great and just as well with no choke the only difference was the unchoked barrels had a tight bore.
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Choking is starting to sound like a gimmick too me?!. ??? ??? ???
Its not its helps resize the pellets as they exit so more uniform shots threw the whole Tin of pellets. Cut the choke off the green moutain and tell me what you think I bet you change your mind.
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the Rainstorm shot well, VERY well with JSB's but not so well with bullets. Once I found that the bbl. itself was very tight, ( bbl. .250/choke .251) I gathered up a bucket load of courage and cut and recrowned it.
The results were shocking. It went from a one holer at 36 yards with MK-II's to literally pellet size hole. All thru the pellet sized hole!
Bullets were very inconsistent with the choke. Regardless of sizing. Once the choke was removed, the groups were good. Not stellar, but good, with far less fillers.
I hand lapped the bbl. and the groups got better. But still not what they could be.
Late yesterday evening, I fire lapped the bbl. starting with 220 grit, followed by 360 grit, and finally 600 grit.
this is done by rubbing the oil mix of grit on a precision steel plate, and using a second steel plate, rolling the bullet between the two plates, which pressed the grit into the bearing surfaces of the bullet.
Proper way to use it is 10 shots with 220, 10-20 of 360, and finally 20+ of the 600 grit. I was very low on the grit, so 10 or 220, 15 of 360 and 15 of 600 grit were used.
The .25 Storm with bullets was a fine 36 yard performer, and fair 50 yard performer, but not so good at 80 yards.
Today, the test shows it is now a Squirrel Killer at 80 yards. Success at last!
Used a 1" target dot on my range, and the first NOE modded Ranch Dog, 50 grain bullet went exactly thru the tiny bulls eye of the target. Followed by two more tightly touching. Final two strung to the right. My bad, Seems I am too anxious to wait for the gust of wind to settle. GRRRR!
So here is something to think about. Choke at 80 yards, 8-9 inch groups. No choke ,2-3" groups. Hand lapped, 2 to 1/2" groups. Fire Lapped, under an inch at the same distance, same bullets.
Pictured is six shots of the 50 grainers, at apx 740 fps. ( Just received new hammer springs from Oneshot and the velocity jumped to 880 fps at lowest setting of adjustment from hammer spring screw). Have not tested accuracy yet with higher velocity. The bbl. is one in 14 twist, so should get even better with speed. FPPE jumped from 63-64 fpe to 86 fpe with nothing more than s simple spring change, Thanks to Oneshot. 8)
Knife 8)
Six Shots from magazine, first two thru the tiny bullseye at 80 yards. 6-8 SW Wind from left to right, with gust to 10-11 mph.
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Knife great results my friend!!! I’d advise those reading to not go chopping off your chokes it does work with certain barrels and that’s just how it is but not all. The most accurate barrel I’ve ever tested and this can be backed up by many many people on this forum is the Marmot Malitia HF 22 barrel and it has the tightest choke I’ve ever seen. Now I own a LW polygon barrel with no choke and it’s a laser so yes no chokes can work but most competition barrels are choked in FT and Bench rest tournaments so those guys are the top of the top as far as accuracy goes. JMHO
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Travis, I keep seeing Poly bbl's talked about, but not as much as when they first hit the market. Seems like there would be advantages to them.
What is your take on them, and any applications for slug shooting?
Thanks Sir!
Knife/Mike
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I can vouch for the MMHF .22 barrel. What a laser with soft lead. Not so much with hard lead for very long between cleanings. Can't use a .22 cleaning rod due to the tight choke.
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I have very limited experience as I have only hand lapped two rifle barrels besides reading lots of various opinions on the subject.
If a barrel has rough and/or tight and loose areas in the bore having a choke isn't going to help much. Mike It sounds like to me you cleaned up the barrel by hand lapping and then gave the bore a real good polish by fire lapping. Fire lapping by it nature tends to add a choke.
It seems that a consistent bore is more important than a choked one. Of course all of this coming from an armchair quarter back. ;)
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Does a choked barrel really improve accuracy ?
I don't know....... >:( >:( >:( >:( >:(
All grouping at 25 yards on paper.
First gun was the 22 synrod with terrible barrel. Re-choked it and it shoots better than me with 14.66's and 21.14's ONLY. Laser straight.
Second was a FD PCP .177 cal (no Choke and did nothing besides put a target crown on it) and shoots every .177 cal pellet the same ( GREAT ).
Third was the 25 cal synrod with GM barrel ( did not do anything to it ). Shoots pretty darn good but not as great as the 22 and the FDPCP.
Forth gun Gauntlet 22 cal. Out of the box, great. Chopped 5" over barrel and re-crown, better than great with every 22 cal pellet in house.
So, when I say great I mean cover with a dime or nickle. When I say Ok, i's more like a quarter (min-10 shots). I really like the one holers but I can't hold it that steady or have a great scope on each of the guns.
What have you all experienced? Is a choke really worth it? From what I am seeing, I can shoot a larger variety of pellets without a choke more accurately than a chocked barrel.
Hummmm.........whenever I chopped a HW barrel I re-choked it and the accuracy has been good every time. I first made a "choke clamp" that got placed on the muzzle and using a heavy vise I "squished" the muzzle in steps till the choke was the tightest part of the bore. Here is the "chop & choke" I did to a .177 Beeman R1 barrel to make it fit my R9 better after i sold the .20 barrel that came with the R9........
(https://i.imgur.com/pyLIXaEl.jpg)(https://i.imgur.com/UlVj0qAl.jpg)(https://i.imgur.com/E5xGWWOl.jpg)
On another "chop & choke job" I used a modified heavy pipe cutter to "roll in the choke". The modification was to replace the cutting wheel with a lathe turned roller. This worked however the muzzle finish was marred and the metal was upset like this so I used the "choke clamp" after that...........
(https://i.imgur.com/X0sReKdl.jpg)
Here is a target shot sitting on a bucket resting the gun on cross sticks using the chopped and choked R1 barrel on my Beeman R9 when I lived in WV. LOL, doesn't seem that the "chop & choke" hurt the accuracy any.............
(https://i.imgur.com/daG1cT8l.jpg)
Anywhoo, more directly to answer your question concerning accuracy , IMHO, it all depends on the gun/barrel to begin with. I do know that the HW barrels I've owned have all had a constriction in the bore where the barrel was pressed into the barrel pivot block, plus an occasional constriction along the bore itself. My theory is that the choke on HW muzzles is simply to stabilize the pellet just before release by guaranteeing that the smallest part of the bore is at the muzzle after the pellet was re-sized by the various constrictions in the bore. As long as the bore is perfectly uniform from leade to muzzle I really don't know is a choke would help with accuracy, however for the HW bores I'm familiar with it does seem that accuracy should be improved bith choking and a good crown.
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Travis, I keep seeing Poly bbl's talked about, but not as much as when they first hit the market. Seems like there would be advantages to them.
What is your take on them, and any applications for slug shooting?
Thanks Sir!
Knife/Mike
I'm not speaking for Travis, of course, but I have a choked polygon in .22. I'm still working out what it likes, and at what speeds. I can say it seems to like speed. It is same hole accurate with a few pellets, and will shoot at least 10-12 of the different pellets I've tried under a dime at 30 yards. I tried some of the BBT 30 grain and 28 grain HP out of it, and it was only so so. They were about a nickel at 30 yards, which isn't good enough in my book. I tried them at 900-950fps. I think they may do better if they were sized slightly different, or in an unchoked barrel for sure. I can say the polygon is far more consistent in it's behavior than my last barrel, FWIW.
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I'll take unchokerd barrels any day.
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Gimmick was not the word i really meant. And I am not saying to cut off your choke or put a choke on. Just trying to figure out somethings and wanted to get a consensus on the matter.
I am currently at 50/50 and don't know why.
A few things are bothering me though. I have read alot about 22lr's having a choked barrel but, most people say here that running slugs in a choked airgun barrel doesn't group well. That's weird ain't it ? 22Lr barrels are choked and they only sling slugs.
I am still not getting it yet. Is it that a choked barrel increases a poorly made barrel ?
Could it possibly be that a long time ago someone decided to squeeze the end of their barrel choking it and got better grouping, then promoted it somehow as being the greatest thing for accuracy and now we just all assume you need a choke to have supreme accuracy?
I guess it can go the other way with slugs too.
I like everyone's opinions because I have a feeling there just might not be a technical paper on the matter.
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Just my 2 cents after following this thread. I can see the value of a choke to compensate for a less precision barrel or inconsistent non-match pellets.
I think that is why Michael got great results, after removing his choke, because he did a super job in lapping his barrel, which is now a precision barrel, plus the fact that he is casting consistent pellets.
In my PB 6mm BR and PPC bench rest days small groups could only be achieved with precision match unchoked barrels, sorted bullets and consistent concentric reloads.
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In my experience, the accuracy obtained from a given rifle depends on how all the variables are managed to work together. You change one thing, you may need to change two more to get the results you want. I have had very good shooting barrels with and without chokes, but mostly with.
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The muzzle must be the same or slightly choked for best accuracy. IF it is looser accuracy will suffer. I would call it possibly a crutch to make sure it shoots well. Most barrels will have a tight spot of two that will constrict the pellet/bullet. If it constricts more than the muzzle accuracy will suffer. Their is a reason that the highest end barrels cost $4-500, in a powder burner.
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All I am hearing is opinion and not hard faq.
Sloppy barrel design with choke improves but a well designed "built" barrel delivers.
I am starting think gimmick again and it P's me off. This is one of those situations that someone (bigger and "YOU LOOK UP TO" ) throws something out in the market and everyone thinks it's greatest thing from sliced bread.
Come on now... Where is the data that supports a choked barrel as being the best.
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I dont think all these companys are putting chokes on guns as a gimmick they are doing so to increase the pellet to pellet consistency. I doubt Daystate, FX, Crosman, WAR, Theobin and Raw etc etc are putting chokes on guns for the *(&^ of it. Chokes work period but in some cases they are not needed. If I was going to bet my life and had two identical guns one choked and one unchoked setting on the bench and had to put 5 on a dime guess which one Id pick up.
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Never had, nor have I seen a choked bbl in 22lr, or any other modern pb. There are bbl.s that are lapped by hand or fire lapped that are gradually tapered from breach to muzzle. But this is a totally different process than chokes. And quite extensive to manufacture or have done by hand lapping. Unless you know how to do it your self. It is hard arduous work. Trust me on that one. ;)
One poster wrote that fire lapping will give you a choke. Not true. If done to the extreme, you can end up with a tapered bore, or completely ruined.
Pellets, thru the years have had all sized in one cal. Different manufactures have used all kinds of specs. Still do to some extent. Especially in the .177 thru the years, and even more so in Europe. The only answer to have any kind of accuracy on average, with different brands, much less different lots is choking. Not much of a way around it. Have a barrel that is not all that pellet fussy, especially in .177, bet dime to donuts it's choked.
Knife
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All I am hearing is opinion and not hard faq.
Sloppy barrel design with choke improves but a well designed "built" barrel delivers.
I am starting think gimmick again and it P's me off. This is one of those situations that someone (bigger and "YOU LOOK UP TO" ) throws something out in the market and everyone thinks it's greatest thing from sliced bread.
Come on now... Where is the data that supports a choked barrel as being the best.
You mean facts like choked barrels almost always win the matches?? Just because YOU don't care to listen/believe does not make it a fact it is not true. It's not hard to fathom that if the bore is looser at the muzzle the pellet/ bullet will not perform well. Do you understand that barrel makers always mark the muzzle end of a barrel because it is tighter???
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All I am hearing is opinion and not hard faq.
Sloppy barrel design with choke improves but a well designed "built" barrel delivers.
I am starting think gimmick again and it P's me off. This is one of those situations that someone (bigger and "YOU LOOK UP TO" ) throws something out in the market and everyone thinks it's greatest thing from sliced bread.
Come on now... Where is the data that supports a choked barrel as being the best.
Seems to me, you offered some hard facts in your opening post. Those facts are: a good barrel can be made more than one way, and, no manufacturing process insures great performance. A precision made barrel that is essentially perfect from breech to muzzle will shoot well, regardless of choke or not, assuming the pellet is a proper fit. And therein lies the rub. As mentioned above, since the choke is a smaller diameter, it tends to make a barrel less fussy about pellet choice. It is, in effect, sizing your pellets. The success of some premium makers using choked barrels proves it works. The success of others using non-choked barrels proves it isn't the only way. Maybe one reason I have had better luck with choked barrels, I'm too lazy to size pellets. You may be offered your "hard facts" by both groups, and both will be right. The fundamental remains unchanged, good barrel and good pellet fit, however you can get it.
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There is a huge difference between a precision tapered barrel vs choking one .5" from the muzzle to make it better. I am not an idiot fudge nuts and don't treat me like that. >:( Yes you moorepower and travis )
I don;'t like being implied as an idiot or dumb as$.
But to say,
I have a choke is better just ain't true and point me in the direction of those barrels that are winning matches. Please. I am sure there is more to it than a choke " .5 inches from the muzzle".
This is a discussion... Not knocking a choke as I have had to put one on my .22 synrod to make it shoot better.
Show me and i will listen.
Knifemaker makes a great point and it has to do with precision barrel manufacturing. A taper is completely different than (just the ) muzzle being choked.
Like I said,
This is just a discussion about chokes in general. Not a bar fight as I am getting too old to keep defending myself on this site.
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Never had, nor have I seen a choked bbl in 22lr, or any other modern pb. There are bbl.s that are lapped by hand or fire lapped that are gradually tapered from breach to muzzle. But this is a totally different process than chokes. And quite extensive to manufacture or have done by hand lapping. Unless you know how to do it your self. It is hard arduous work. Trust me on that one. ;)
One poster wrote that fire lapping will give you a choke. Not true. If done to the extreme, you can end up with a tapered bore, or completely ruined.
Pellets, thru the years have had all sized in one cal. Different manufactures have used all kinds of specs. Still do to some extent. Especially in the .177 thru the years, and even more so in Europe. The only answer to have any kind of accuracy on average, with different brands, much less different lots is choking. Not much of a way around it. Have a barrel that is not all that pellet fussy, especially in .177, bet dime to donuts it's choked.
Knife
I agree with everything you said Knife. Just no way around mass production and pellet variations with out a choke to compensate for it. Now custom guns can certainly be made to shoot without a choke
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There is a huge difference between a precision tapered barrel vs choking one .5" from the muzzle to make it better. I am not an idiot fudge nuts and don't treat me like that. >:( Yes you moorepower and travis )
I don;'t like being implied as an idiot or dumb as$.
But to say,
I have a choke is better just ain't true and point me in the direction of those barrels that are winning matches. Please. I am sure there is more to it than a choke " .5 inches from the muzzle".
This is a discussion... Not knocking a choke as I have had to put one on my .22 synrod to make it shoot better.
Show me and i will listen.
Knifemaker makes a great point and it has to do with precision barrel manufacturing. A taper is completely different than (just the ) muzzle being choked.
Like I said,
This is just a discussion about chokes in general. Not a bar fight as I am getting too old to keep defending myself on this site.
Not sure why you think Im treating you like and Idiot or how you came to that conclusion so Ill bow out good luck Tim. https://youtu.be/Z1-xGuEkdLw
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Trust me, I did a LOT of mixing of pellets and bullets BEFORE I removed the Choke. I wanted to made "dang" sure there were very good,and concentric land and groove markings in both bullets and the bullets I wanted to shoot.
It sht JSB's far too well to monkey with it on the hopes it would perform with the bullets without checking first.
The base of the skint was very deformed when pushed thru the choke. With all the lands causing extrusions al the way around.
With the pellets pushed thru all the way to be just short of the choke as measured, the markings were sublime. NO deformation at all, but with clear, and well defined rifling marks all the way around, and very even. This made the decision for me.
Still gave me pause, but I pinned my ears back and went for it any way. LOL! ;D (If it failed I guess I could alway save my money for a while and order a replacement bbl.). Grrrrr!
Knife
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One poster wrote that fire lapping will give you a choke. Not true. If done to the extreme, you can end up with a tapered bore, or completely ruined.
I guess that would be me ;D Absolutely true what you said. I guess I've always assumed if the bore at the muzzle is smaller than the rest of the bore it is choked. I see the difference between a taper, just getting lucky and having the tight spot be at the muzzle vs the breech and of course a manufacturer rolling a constriction on the end.
None of the guns I have purchased have been high end, so it is less scary to work a barrel over. Whoops made a mistake, darn just lost $30.
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LOL! ;D
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Would be hard to get real definaitive results...and would need to be repeated with several barrels.
Would need ONE barrel that could be progressivly choked, tested, and the retested with the next degree of choke. Not changing the crown or shortening; would want only the choke to be the variable.
Likely have to retest all the pellets, as the favorite pellet of one degree of choke might not be the favorite of the next degree of choke.
Just working on one barrel wouln'tprove anything universal about chokes...esp. if other variables were manipulated along the way (barrel length/crown/attached weights/etc).
Also likely,would be mixed results...but likely by chewing up the 10th barrel, would get an indication (maybe a 70% confidence level?).
Doubt if anyone really knows or can put independent (not connected to any airgun maker/barrel maker) experiemntal data out there.
This much I do know...if the pellet barrel is going to have a slight tight spot, the only place it WON'T hurt is if it is at the muzzle end.
And under that flag, offer antecdotal tales (which certainly isn't proof of anything...just what happened in one or two instances).
Pretty picky about accuracy, even with cheap barrels. Have had a couple of early QB barrels that were terrible. All the usual cures didn't help.
One I did find a slight tight spot about 17" down the barrel. Cut the barrel , made the tight spot the end of the barrel, and I still shoot that barrel today. Was it the slight choke? Was it somehow a better crown? Was it the length/stiffness of the shorter barrel?
Don't know...don't really care. Goal was to try and make that one barrel accurate enough to keep. May not be the "ultimate" that that barrel COULD be, but I'm not likely to tell the differences.
As for the other problem child barrel....it's doing duty as a tent stake.
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So, Tim, you're querying if choked barrels improve accuracy, or if they are just a gimmick. it's a gimmick, it's the longest running most widely practiced gimmick on the planet
The short answer, yes they do to, depending on two things in my experience. If the barrel likes its choke (some can be extremely aggressive, while others are barely there at all), & the factory consistency of the size of the ammo you chose to shoot. Because 4.51 mm ammo isn't always 4.51 mm, not even in the so called match grade ammo used for international competition. There will be a some at 4.52 & some at 4.53, some at 4.50 & some 4.49 might even get a few 4.48
Want the ultimate accuracy? Questioning the choke likely won't get you there unless it's a really aggressive choke. My advice would be that you could start checking the size of the choke on your articular barrel against the bore size, I consider anything more than .04 smaller than bore aggressive. If that's not your cup of Earl Grey then move on to with sizing your pellets, or do what most match competitors do, which is find that magic pellet the gun absolutely loves & get the batch number, & buy all the pellets that were made in that batch that you can.
Good luck.
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Does a choked barrel really improve accuracy ?
I don't know....... >:( >:( >:( >:( >:(
All grouping at 25 yards on paper.
First gun was the 22 synrod with terrible barrel. Re-choked it and it shoots better than me with 14.66's and 21.14's ONLY. Laser straight.
Second was a FD PCP .177 cal (no Choke and did nothing besides put a target crown on it) and shoots every .177 cal pellet the same ( GREAT ).
Third was the 25 cal synrod with GM barrel ( did not do anything to it ). Shoots pretty darn good but not as great as the 22 and the FDPCP.
Forth gun Gauntlet 22 cal. Out of the box, great. Chopped 5" over barrel and re-crown, better than great with every 22 cal pellet in house.
So, when I say great I mean cover with a dime or nickle. When I say Ok, i's more like a quarter (min-10 shots). I really like the one holers but I can't hold it that steady or have a great scope on each of the guns.
What have you all experienced? Is a choke really worth it? From what I am seeing, I can shoot a larger variety of pellets without a choke more accurately than a chocked barrel.
Interesting thread so I actually did a "bore map" of my spare .177 HW95 barrel by pushing through a new 7.9 grain CPL from my pellet pouch that had been head sized to 4.50mm using my home made pellet sizer. Here is the "map"............
(https://i.imgur.com/qYyHXeCh.jpg)
Setting the pellet in the leade with pellet skirt flush with the face of the barrel pivot block I started pushing a new pellet through the bore noticing the tight and loose spots.
1. The initial push to engrave the pellet required a "hard push" on the pellet.
2. The push was still "tight" but looser than the "initial push" till the pellet got past the area where the barrel was pressed into the barrel pivot block.
3. Then the push was an "easy sliding push" which became a TAD "lighter".
4. Then the pushed pellet encountered another slight constriction in the bore till the pellet entered the choke.
5. This particular .177 HW95 barrel had a very tight choke requiring about the same force as it took to push the pellet into the rifling at the leade.
Here are the results after pushing a couple CPLs through the bore, one CPL only head sized and one CPL full sized.
1. Pellets pushed past the"tight patch" at the barrel pivot block. Notice that the rifling lightly marked both the pellet head and skirt of the head sized CPL but the skirt of the full sized CPL was VERY lightly marked...........
(https://i.imgur.com/7RURTnCh.jpg)
2. Two new pellets pushed through the bore and out of the choke, one head sized only and one full sized. Notice that both pellets had the rifling heavily engraved into both the heads and skirts after exiting the choke..........
(https://i.imgur.com/ZZ4UDn2h.jpg)
Anywhoo.....both of my .177 HW95 barrels had similar constrictions along the length. My other .177 HW95 barrel had a bit looser choke, however the barrel that I used for these "pellet pushes" was a bot more consistent as it pertains to the degree of tightness/looseness. As far as accuracy is concerned, when I shot groups with the barrel "other less consistent" barrel on my HW95 in the pic "from bucket and sticks" I have to say that they were excellent............
(https://i.imgur.com/8SZm6IEl.jpg)(https://i.imgur.com/v6Ug0yHl.jpg)(https://i.imgur.com/Uxcy31Rl.jpg) (LOLonly 4 shots the last group) ::)
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Nced,
That's some interesting stuff there you did. I am glad it got your interest (like me) to do some testing.
Been reading alot about this lately for a couple days. Just like Knifemaker did with the lapping, It seems like a beautiful taper from the breech to the muzzle is the most idea condition and choking a barrel like I did (wedding band method) and Motorhead showed is just a "fix/hack-improvement" from a barrel that is not performing. Although, doing this does not work or improve all the time due to barrel quality and other things are needed to fix it.
I can clearly see where a clean taper from the breech to the muzzle is the key.
Next questions I keep asking myself is, how do you do this in a precision repeatable automated way and be able to show ACTUAL evidence of a conforming taper to a specification.
I would love to be able to do this but, I just can't afford or get permission from the wife to go into a journey of this magnitude.
So I will share my thoughts on how someone may do this if they ever get into precision lapping barrels to a taper.
Linear slide - 170 bucks
4 axis cnc controller accepting G-code - 260 bucks
Stepper driver and power supply - 25 bucks
Silly wiring - ???
This really cool ID air gauge for tight tolerance ID measurements so that the barrel can be provided with an actual dimensional report of the bore.
https://www.amazon.com/FUYU-Linear-Actuator-Motorized-Stepper/dp/B077Q8LVLW/ref=sr_1_4?ie=UTF8&qid=1534682255&sr=8-4&keywords=linear+slide+with+stepper+motor (https://www.amazon.com/FUYU-Linear-Actuator-Motorized-Stepper/dp/B077Q8LVLW/ref=sr_1_4?ie=UTF8&qid=1534682255&sr=8-4&keywords=linear+slide+with+stepper+motor)
https://www.amazon.com/RATTMMOTOR-Linkage-Controller-Handwheel-Engraving/dp/B075HBB8VJ/ref=sr_1_4?ie=UTF8&qid=1534682299&sr=8-4&keywords=cnc+controller&dpID=51q8lWReLmL&preST=_SY300_QL70_&dpSrc=srch (https://www.amazon.com/RATTMMOTOR-Linkage-Controller-Handwheel-Engraving/dp/B075HBB8VJ/ref=sr_1_4?ie=UTF8&qid=1534682299&sr=8-4&keywords=cnc+controller&dpID=51q8lWReLmL&preST=_SY300_QL70_&dpSrc=srch)
https://www.westerngage.com/air-probes-for-precise-measurement-of-internal-diameters/ (https://www.westerngage.com/air-probes-for-precise-measurement-of-internal-diameters/)
I am also curious to know if any barrel manufactures provide an internal dimensional report for their barrels as I have not seen or found one yet.
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I can clearly see where a clean taper from the breech to the muzzle is the key.
& this would basically make the entire length of the barrel into a choke, a long low degree choke.
I am also curious to know if any barrel manufactures provide an internal dimensional report for their barrels as I have not seen or found one yet.
iirc a few older barrel manufacturers used to, but I can't recall which ones. Most check to make sure their bores are within certain tolerances along the length but dont publish that info. It's more for their own internal use to let them know when there are issues with materials, tooling wear etc
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LW is the only manufacturer that publishes that information to my knowledge
https://www.lothar-walther.de/163.php (https://www.lothar-walther.de/163.php)
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how clean was the barrel before you pushed the pellets through ?
I have an mrod with a very temperamental barrel
it gets leaded up fairly easy and the leading causes a lot of friction
kinda like rubbing a crayon on a glass surface is much stickier than rubbing on paper
one can easily think that the barrel has a physical tighter bore in areas but it could very well be lead deposits
Interesting thread so I actually did a "bore map" of my spare .177 HW95 barrel by pushing through a new 7.9 grain CPL from my pellet pouch that had been head sized to 4.50mm using my home made pellet sizer.
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There is a huge difference between a precision tapered barrel vs choking one .5" from the muzzle to make it better. I am not an idiot fudge nuts and don't treat me like that. >:( Yes you moorepower and travis )
I don;'t like being implied as an idiot or dumb as$.
But to say,
I have a choke is better just ain't true and point me in the direction of those barrels that are winning matches. Please. I am sure there is more to it than a choke " .5 inches from the muzzle".
This is a discussion... Not knocking a choke as I have had to put one on my .22 synrod to make it shoot better.
Show me and i will listen.
Knifemaker makes a great point and it has to do with precision barrel manufacturing. A taper is completely different than (just the ) muzzle being choked.
Like I said,
This is just a discussion about chokes in general. Not a bar fight as I am getting too old to keep defending myself on this site.
[/quot
You ask for opinions, I gave you widely known information and you tell me it's just opinion and you want some facts. There is a reason you get the responses you do, and being an idiot is not words I would use as to why that is. ::) I am done with your..... question
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I can clearly see where a clean taper from the breech to the muzzle is the key.
& this would basically make the entire length of the barrel into a choke, a long low degree choke.
I am also curious to know if any barrel manufactures provide an internal dimensional report for their barrels as I have not seen or found one yet.
iirc a few older barrel manufacturers used to, but I can't recall which ones. Most check to make sure their bores are within certain tolerances along the length but dont publish that info. It's more for their own internal use to let them know when there are issues with materials, tooling wear etc
The BSA SuperSport barrels are hammer forged with a taper from breech to muzzle................
https://www.youtube.com/watch?v=bnnBoann6CY (https://www.youtube.com/watch?v=bnnBoann6CY)
https://www.pyramydair.com/product/bsa-supersport-tactical-air-rifle?m=3209 (https://www.pyramydair.com/product/bsa-supersport-tactical-air-rifle?m=3209)
http://www.airgunmagazine.co.uk/tests/gun-test-bsa-supersport-se/ (http://www.airgunmagazine.co.uk/tests/gun-test-bsa-supersport-se/)
From the above.........
"it does boast BSA’s world-famous cold-hammer-forged barrel – a carefully crafted spout that’s renowned for its accuracy."
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I could be wrong, but I believe those tapered barrels are referred to as a "full choke" barrel.
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Steyr had hammer forged barrels and were always on the top of list for accuracy
mine is an LG100 and the hammer forged barrel is a treat to shoot
don't know if they still do hammer forged or not
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I could be wrong, but I believe those tapered barrels are referred to as a "full choke" barrel.
No Sir, full choke is a shotgun term. These taper bore barrels have been used in competition for decades and are called Taper bore. Quite common in high end bench guns. They were also used in old black powder barrels such as some Sharps used in long range competition. It isnt' a new concept.
Speaking of this, another variation of a hammer forged bbl, is the FX system. However, rather than using a mechanical driven set of anvals, (hammers in rotation), it instead used hydraulics to press the outer dia into the bore. Which is a smooth bbl until the last part of the barrel which is now somewhat rifled. But very shallow marks. Imparting much less disturbance to the projectile.
the new X Barrels are an extension of this process. What was old, is new again. 8)
Knife
While a Taper bore can be obtained by skilled hand lapping, it is more commonly done usually done as a result of using a tapered mandrel in the hammer forging process.
Knife.
Knife
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I can clearly see where a clean taper from the breech to the muzzle is the key.
& this would basically make the entire length of the barrel into a choke, a long low degree choke.
I am also curious to know if any barrel manufactures provide an internal dimensional report for their barrels as I have not seen or found one yet.
iirc a few older barrel manufacturers used to, but I can't recall which ones. Most check to make sure their bores are within certain tolerances along the length but dont publish that info. It's more for their own internal use to let them know when there are issues with materials, tooling wear etc
The BSA SuperSport barrels are hammer forged with a taper from breech to muzzle................
https://www.youtube.com/watch?v=bnnBoann6CY (https://www.youtube.com/watch?v=bnnBoann6CY)
https://www.pyramydair.com/product/bsa-supersport-tactical-air-rifle?m=3209 (https://www.pyramydair.com/product/bsa-supersport-tactical-air-rifle?m=3209)
http://www.airgunmagazine.co.uk/tests/gun-test-bsa-supersport-se/ (http://www.airgunmagazine.co.uk/tests/gun-test-bsa-supersport-se/)
From the above.........
"it does boast BSA’s world-famous cold-hammer-forged barrel – a carefully crafted spout that’s renowned for its accuracy."
If you slug a BSA barrel you will notice that there's no taper, just a choke. They are exceptionally accurate though unless you get a bad one.
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Here is an airgun discussion concerning "tapered bores" and "choked bores"...........
https://www.pyramydair.com/blog/2011/12/choked-bores-and-tapered-bores/ (https://www.pyramydair.com/blog/2011/12/choked-bores-and-tapered-bores/)
I do take exception with a couple statement from above.........
"But spring guns don’t need a choke, since the act of firing swells the pellet skirts. However, some spring guns do have the same resistance near the muzzle that is felt in better pneumatics. This is an accident of swaging-in the dovetails for the front sight attachment. Weihrauch guns that have front dovetails all have this and we have called it a choked bore. It’s really just an accident of the manufacturing process and is as random as can be. But it’s there and some shooters feel it helps accuracy. Even though the choke doesn’t wrap all the way around the bore, they feel that it still provides the same stability that an intentionally-choked bore does."
1. "spring guns don't need a choke".
After pushing several CPLs through both of my .177 HW95 bores I found that the "fit to the bore" became very loose once the pellet traveled 3 1/2" from the breech (just past the area the barrel was pressed into the breech block). The pellet fit only became "snug again" when being pushed through the choke. Seems to me that if the choke and last 4" of the barrel were removed the loose pellet fit to the bore wouldn't help stabilize the pellet at the muzzle. I guess that if the bore were "perfect" with no internal variations the choke wouldn't be needed but no HW barrel I've owned had a perfect bore but the factory choked .177 HW barrels are noted for being accurate (I've read this isn't so for the HW .22 bores)!
2. "This is an accident of swaging-in the dovetails for the front sight attachment."
Hummmm...really? Perhaps this whole "accidental choke" is true, however I have worked a HW98 break barrel that had no "front sight dovetails" and I don't think the barrels was "accidentally choked". ::) The gun was very accurate as this 50 yard group shot sitting on a bucket resting the gun on cross sticks shows .........
(https://i.imgur.com/d5v1VdPl.jpg)
I found this to be an interesting hammer forging video.................
https://duckduckgo.com/?q=bsa+hammer+forged+barrel+taper&t=canonical&atb=v129-5_j&ia=videos&iax=videos&iai=oALJDh43K3I (https://duckduckgo.com/?q=bsa+hammer+forged+barrel+taper&t=canonical&atb=v129-5_j&ia=videos&iax=videos&iai=oALJDh43K3I)
https://www.ar15.com/forums/ar-15/Do-All-CHF-Barrels-Have-a-Tapered-Bore-/118-707524/ (https://www.ar15.com/forums/ar-15/Do-All-CHF-Barrels-Have-a-Tapered-Bore-/118-707524/)
From the above..........
"Originally Posted By col_hapablap:
As the title reads, is a tapered bore (or rather a tapered mandrel) a necessity for removal of the mandrel after the forging process? I've read a bit on the CHF process, but I have never found and answer to this particular aspect.
1) As stated above, steel is elastic it springs back.
2) Even if the mandrel is tapered, the largest diameter of the mandrel will be the diameter of the bore, remember, the mandrel is only about 6 inches long and the barrel is pulled over the mandrel and beaten to shape. The barrel is complete when the mandrel comes out the other end.
3) Barrels are allowed some taper, usually one tenth of a thousandths of an inch (0.0001") over the entire length, but only tapering from breech (largest) to muzzle (smallest)."
and
Question........."So for clarity, the CHF bbls that are advertised as taper bore are designed to have a taper bore and that feature is not merely an artifact of the production process? Can a bore taper more than a few ten thousandths over its length?"
Answer........"Yes, they can, but not a whole lot of taper is needed."
Concerning BSA "tapered mandrels"........
https://www.solware.co.uk/air-rifle-pellet-gun/bsa-rifles (https://www.solware.co.uk/air-rifle-pellet-gun/bsa-rifles)
From the above.........
"The tapered mandrels are made from specially formulated tool steel"
Very interesting thread that prompted some entertaining research on my part even though the "final ruling" won't affect my accuracy shooting from "bucket and sticks"! ;D
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I could be wrong, but I believe those tapered barrels are referred to as a "full choke" barrel.
No Sir, full choke is a shotgun term. These taper bore barrels have been used in competition for decades and are called Taper bore. Quite common in high end bench guns. They were also used in old black powder barrels such as some Sharps used in long range competition. It isnt' a new concept.
Speaking of this, another variation of a hammer forged bbl, is the FX system. However, rather than using a mechanical driven set of anvals, (hammers in rotation), it instead used hydraulics to press the outer dia into the bore. Which is a smooth bbl until the last part of the barrel which is now somewhat rifled. But very shallow marks. Imparting much less disturbance to the projectile.
the new X Barrels are an extension of this process. What was old, is new again. 8)
Knife
While a Taper bore can be obtained by skilled hand lapping, it is more commonly done usually done as a result of using a tapered mandrel in the hammer forging process.
Knife.
Knife
Thanks for the clarification Knife. I didn't know tapered barrels had different names. My shotgun does have a full bore and is tapered down all the way to the muzzle. Just has no rifling.
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Lets all step back and take a fresh perspective ....
Lead dust, we see it in our LDC's most because that's what they do ;) Where does it come from ? ... we did not load the pellet with lead dust all over it that's a fact !
IT COMES from the pellet eroding / wearing away lead as it travels the length of bore. Which tells us the pellet when loaded EXITS at muzzle SMALLER ???
Yes indeed it does ... so while going down the bore the pellet fit to bore is getting looser and said pellet can start to gently side to side rock / tilt and become YAW destabilized.
Rougher the bores surface finish, greater is the abrasion on the soft lead pellet, Smoother less so. Depth & width of land / groove also come into play.
CHOKES simply are nothing more than a short section of barrel that tightens up the bore to COUNTER the lead loss and looser fit of the pellet when it gets to muzzle end.
By snugging up the bore to 'Worn" pellet fit you get a YAW stabilization right as pellet is exiting.
So, have a nice smooth barrel with shallow land & groove rifling And / Or shoot harder alloy lead the down sizing issue of the pellet may indeed be fine having pellet exit without YAW wobble & shoot accurate without a choke.
Start out with under size pellets ( Common problem ) Just have a mass production so so quality barrel ( VERY common ) you'll be near guaranteed pellets going to get at the muzzle end of bore and NOT be in firm contact with bore any longer !!! CHOKE ME PLEASE 8) 8) 8)
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Scott, thanks, that is a great explanation.
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Lets all step back and take a fresh perspective ....
Lead dust, we see it in our LDC's most because that's what they do ;) Where does it come from ? ... we did not load the pellet with lead dust all over it that's a fact !
IT COMES from the pellet eroding / wearing away lead as it travels the length of bore. Which tells us the pellet when loaded EXITS at muzzle SMALLER ???
Yes indeed it does ... so while going down the bore the pellet fit to bore is getting looser and said pellet can start to gently side to side rock / tilt and become YAW destabilized.
Rougher the bores surface finish, greater is the abrasion on the soft lead pellet, Smoother less so. Depth & width of land / groove also come into play.
CHOKES simply are nothing more than a short section of barrel that tightens up the bore to COUNTER the lead loss and looser fit of the pellet when it gets to muzzle end.
By snugging up the bore to 'Worn" pellet fit you get a YAW stabilization right as pellet is exiting.
So, have a nice smooth barrel with shallow land & groove rifling And / Or shoot harder alloy lead the down sizing issue of the pellet may indeed be fine having pellet exit without YAW wobble & shoot accurate without a choke.
Start out with under size pellets ( Common problem ) Just have a mass production so so quality barrel ( VERY common ) you'll be near guaranteed pellets going to get at the muzzle end of bore and NOT be in firm contact with bore any longer !!! CHOKE ME PLEASE 8) 8) 8)
LOL, I also want a choked barrel on my .177 springers, however I also think that shooting undersized unlubed pellets will contribute to bore fouling along with general gunge and "dust created by the sliding pellet" you mentioned! When I shot supposedly 4.52mm JSB Exacts most were loose fitting to begin with, but MANY were exceptionally loose fitting. Using 4.52mm exacts (marked on the tin) I had two dry fires with my .177 Beeman R9 at a field target match, and I would have had three dry fires if I didn't notice the Exact flipping out of the leade when relatching the barrel. I'm thinking that the edges of shallow rifling engraved on an undersized pellet can "strip off" in the bore (as well as dust & crud if the pellet is dirty), then residue gets packed tightly into the rifling after shooting "normal size pellets".
In the past I've posted this "sordid tale of woe" sniff sniff :-[
My brother's .177 Beeman R9 fouling packed so tight that no amount of pulled patches would remove it. He was shooting unlubed hard lead 7.9 grain Crosman Premier lights at 910fps and the Die #7 CPLs included a lot of "pee-wees and swarf" in the box. Whenever a CPL felt loose when loading it was simply shot into the ground which exaggerated the fouling. Using a "bore light" and seeing the rifling at the choke was buried under a layer of polished lead the issue was solved using Hoppes #9 and a bronze brush. This also started a search for a suitable pellet lube that would keep the "dust" from packing in the rifling and resisted plus the loose fitting pellets were tossed instead of shot. Using lubed and "proper fitting" CPLs (tossing the loose fitters rather than shooting them) only a few patches were needed to restore accuracy, plus the time between required bore cleanings was increased.
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My Marauder has a stock choked barrel that shoots JSB 10.3gr pellets like a laser at 891 fps. Any slower (below 875) and the groups are not great.
Attached is a 50 yard target that I shot last week. This rifle can shoot dimes anytime at 50 yards if the wind is light (below 5 mph).
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One method of choking for .22 long button rifled Match Barrels... I think it would work well for combo (pellet/boolit) barrels... If you used ~.22 pellets
https://www.anschutznorthamerica.com/store/p36/1907_Target.html (https://www.anschutznorthamerica.com/store/p36/1907_Target.html)
wonder if they are stress relived before boring/honing and then after buttoning before profiling... also wonder about bore growth of differing steels used for barrels...
I wonder how green mountain chokes the .25 mrod barrels... mine show no sign of being swaged like the Lothar Walther barrels...
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Scott, thanks, that is a great explanation.
+1.
Tapered barrel may the best ?
I am thinking that the much longer pellets/bullets/slugs need much less YAW stabilization at the end of barrel .
I also read that they not like any choke at all.
Why ???
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Scott, thanks, that is a great explanation.
+1.
Tapered barrel may the best ?
I am thinking that the much longer pellets/bullets/slugs need much less YAW stabilization at the end of barrel .
I also read that they not like any choke at all.
Why ???
Pellets are supported within the bore on TWO narrow bands of contact ( pellet head and skirt tail ) which not only wears away quickly but also offers little resistance in crushing smaller via the choke.
Bullets & even those with bands have far greater contact area to the bore and while they too slough off lead via rifling contact there generally not loosing enough to become yaw destabilized.
With so much more contact area with the bore, forcing a bullet threw a choke slows it down far to much and can cause massive lead smear ( leading ) within the choked portion of the barrel ... not good.
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Scott, thanks, that is a great explanation.
+1.
Tapered barrel may the best ?
I am thinking that the much longer pellets/bullets/slugs need much less YAW stabilization at the end of barrel .
I also read that they not like any choke at all.
Why ???
Pellets are supported within the bore on TWO narrow bands of contact ( pellet head and skirt tail ) which not only wears away quickly but also offers little resistance in crushing smaller via the choke.
Bullets & even those with bands have far greater contact area to the bore and while they too slough off lead via rifling contact there generally not loosing enough to become yaw destabilized.
With so much more contact area with the bore, forcing a bullet threw a choke slows it down far to much and can cause massive lead smear ( leading ) within the choked portion of the barrel ... not good.
Also very believable/logical explanation - THANKS
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Neither yes nor no.
If you get a choked barrel that shoots great, then you belive in chokes.
If you get a non-choked barrel that shoots great,then you belive in no-choke.
Darn few of us will take a great shooting choked barrel and "unchoke it" on a hunt for greater-greatness (or choke a non-choked great barrel in the same search).
Generally, we'll try adding or reducing/removing the choke in barrels that don't shoot as well as we hoped. Are hoping to salvage a less than great barrelby changing it rther than risking an already great barrel in hopes of improving what already works.
So 99% of the choke work is done (adding or removing) with a barrel that didn't work out as well as we hoped...a kind of salvage operation with no real down-side (worst would be crappy gets crappier).
Right about here, am going to call "NOT IT".
Just how many of us would seer at a 1MOA barrel and decide to choke it (or un-choke it) in hopes of a magical 1/2MOA barrel? If you FIRMLY belived in chokes, you'd choke that non-choked MOA barrel (or unchoke it if you firmly belived in no-choke)....but darned few of us (which is why the "not it") are willing to do that kind of thing to an already amazing barrel...so evidently we are not "true belivers" in one system over another.
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Personally I put all of mine through a 'sizer' of a size which suits after a the barrel test with all available head sizes, then wash and dry them after which they get a light lube. All the crown does is to resize them on the way out and is the get around for manufacturers to hide their not so accurate ammo production. Even the most expensive 'match' types are not 100% immune to the differentials in head size.
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Personally I put all of mine through a 'sizer' of a size which suits after a the barrel test with all available head sizes, then wash and dry them after which they get a light lube. All the crown does is to resize them on the way out and is the get around for manufacturers to hide their not so accurate ammo production. Even the most expensive 'match' types are not 100% immune to the differentials in head size.
"not 100% immune to the differentials in head size"
Hummm.... my three HW barrel bores have tight spots along it's length which will "size down" a pellet so it "kinda rattles" down the looser portions before being "stabilized" by the choke. My HW barrels are still very accurate as long as I don't shoot "loose fitters.
Regardless of the pellet head size from the tin, as long as the pellet head is large enough to be "sized" when loaded into the "first tight spot"....the leade all pellets exiting the choke will be similar. The issue comes when the pellet tins have excessively small heads. This situation happened when I was try in to use 8.4 grain JSB Exacts for a field target match using my .177 R9 which has a slightly larger bore than my newer .177 HW95. Here is a .177 HW95 barrel where I noted the "tight and loose sections" by pushing through a new pellet. My other HW95 barrel and my "looser leade" Beeman R9 barrel had "tight and looser sections" similar to this.............
(https://i.imgur.com/qYyHXeCh.jpg)
LOL.......IMHO, as long as the pellet head is large enough to be "sized" when loading into the leade, a couple "silly little 1/100th mm of head dimension" doesn't matter...........every pellet when shot will be the same size after exiting the choke! Without a choke the pellet can "rattle it's way" down the loose sections of the bore and perhaps be a bit skewed when exiting the crown.
I have no experience with PCPs at all, and it doesn't seem to me that a couple 1/100th of mm in pellet size, or slight skewing at the crown from a PCP wouldn't matter very much and perhaps a "perfect bore" or a choke isn't necessary to maintain accuracy, I really don't know.
IMHO, with the smaller .177 cal pellets I use it's either a "perfect .177 cal bore" (doesn't happen at my price point) or a simple choke that does work with less than perfect .177 cal bore as long as the pellet head isn't undersized to begin with.. The main reason I buy .177 cal 7.9 grain boxed Crosman Premiers is that they have relatively large 4.53mm-4.55mm heads so they all get "sized simply by loading into the leade". Even though they are "sore finger tight" when loaded into my HW95 the die lot marked and dated boxed CPLs are extremely accurate (when seated properly) I did go the extra step to make a pellet head sizer/skirt expander that eases the loading of a 4.52mm hard lead CPL as opposed to a 4.55mm unsized CPL head.......
Random unsized CPLs from the 1250 count box.........
(https://i.imgur.com/qbrnYqjl.jpg)
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nced there is a problem with measuring pellets with electronic vernier calipers... at best they are only accurate to +/- .001... the resolution may be .0005 but all that means is it will display to 5 tens not that it is accurate to .0005...
here is an old vid about fixing some accuracy probs caused by under-size heads in 2014 when the Mrod .22 barrels(and my disco barrels) among having other probs could be as large as ~.219"... my different .22 crosman barrels in that time varied in size from about .217 to .2185+ with faint to decent rifling... not to sure about his measuring technique with the mic; seems to measure a bit small but...
the 7/32(.21875") ball seat is what did the work in my opinion... it let the head be bumped up in size enough that the choke gave some accuracy...do not think it was the skirt size... but do think consistent skirts can matter...
So I do think yes because of manufacturing tolerances a choke can do a lot at times to even things out giving more consistency to groups with pellets and give more consistency across differing pellet types/brands... still think that a taper lapped barrel with very consistent pellets is best tho...
https://www.youtube.com/watch?v=dwg_cqC1y-M (https://www.youtube.com/watch?v=dwg_cqC1y-M)
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I am glad this turned out to be a good discussion. ;D
Been giving this a lot of thought still and I keep hearing (repeatedly) loose and tight spot with in the barrel PLUS leaving the barrel with a uniform squeeze.
So, what about the rifling. If the rifling is a .002" to .005" deep, and the bore fluctuates +/-.001", then the projectile is still riding the barrel without slop (right?). It should just feel tighter or looser but still be in contact.
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nced there is a problem with measuring pellets with electronic vernier calipers... at best they are only accurate to +/- .001... the resolution may be .0005 but all that means is it will display to 5 tens not that it is accurate to .0005...
here is an old vid about fixing some accuracy probs caused by under-size heads in 2014 when the Mrod .22 barrels(and my disco barrels) among having other probs could be as large as ~.219"... my different .22 crosman barrels in that time varied in size from about .217 to .2185+ with faint to decent rifling... not to sure about his measuring technique with the mic; seems to measure a bit small but...
the 7/32(.21875") ball seat is what did the work in my opinion... it let the head be bumped up in size enough that the choke gave some accuracy...do not think it was the skirt size... but do think consistent skirts can matter...
So I do think yes because of manufacturing tolerances a choke can do a lot at times to even things out giving more consistency to groups with pellets and give more consistency across differing pellet types/brands... still think that a taper lapped barrel with very consistent pellets is best tho...
https://www.youtube.com/watch?v=dwg_cqC1y-M (https://www.youtube.com/watch?v=dwg_cqC1y-M)
A couple comments.........
Hummm.....I agree that a perfectly tapered airgun bore MIGHT be a better way of "choking the pellet", however I really don't care what the final "choke diameter" when the pellet leaves the barrel. The tightest constriction in the bore my .177 cal HW springers is indeed at the muzzle and those barrels are accurate enough for my purposes............
(https://i.imgur.com/8SZm6IEl.jpg)(https://i.imgur.com/v6Ug0yHl.jpg)
Concerning using digital Calipers to measure due to tolerances and such...........
When using my iGaging caliper to measure my micrometer test bar I believe this accuracy is close enough for measuring lead pellet heads with enough accuracy to sort pellets!
(https://i.imgur.com/GP6G6Grl.jpg)
There is a "method to measuring", however I'm really not concerned if a pellet head is EXACTLY 4.52mm (or whatever), only that the pellet head diameter is consistent from one pellet to the other. I choose to start with boxed CPLs because the heads are indeed larger than most (4.53ish mm - 4.55ish mm) and after a trip through the sizer all have the same pellet head without "ovality". Here is an example of pellets that were head sized with my 4.48mm die and the pile on the right heads small enough to drop through the sizing ring of the die without pushing with the "ram"..........
(https://i.imgur.com/mb6213sl.jpg)
Whatever the actual size of the pellet heads before and after sizing, there were quite a few in the 750 count tin with undersized heads. Here is the measuring method I use since it's accurate enough. Matter of fact, I can get repeated readings on the same pellet and the accuracy is good enough to determine if a pellet head is "oval" and many are indeed oval before sizing.........
(https://i.imgur.com/JkExcWJl.jpg)
Back when I used a digital caliper with less resolution than my current caliper I got these pellet head measurements of supposedly 4.52mm H&N FTS straight from the tin.........
(https://i.imgur.com/iutV3tGl.jpg)(https://i.imgur.com/f1F71oPl.jpg)
I think that we could both agree that even the ole caliper was accurate enough to sort within a .005INCH accuracy (smallest .174, largest .179) regardless of the "unit round off".
Before I started sizing pellet heads I was sorting pellets into "size lots" and then shooting the larger size lots. Without sorting the H&N FTTs and JSB Exacts there was always a large variation of "pellet fit in the leade" and I knew from experience that a much looser fitting pellet wouldn't fly to the same point of impact as a properly fitting pellet. After sorting pellets into groups I learned that even the rather crude measuring you mentioned (tolerances & such) that the sorted pellet heads fit the leade consistently. The smaller head size sorts could be distinguished simply by the pressure needed to seat the pellet and I found that the "smaller size groups" that were a "real easy push" also weren't as accurate as the larger size groups that needed some resistance to seat the pellet in the leade.
LOL.....there wasn't much I could do to "adjust" the head size of the CPL on the left straight from the box..........
(https://i.imgur.com/tA9SX7kl.jpg)
What I find interesting is that there are shooters that go through the hassles of sorting pellets using "precision holes in a plate" and reporting good accuracy gains doing so. Well....knowing that many pellet heads are a bit oval (due to the die parting line?) it does seem to me that the ACTUAL pellet head size isn't as important as the fit in the leade because I've measured pellet head "ovality" as much as .02mm.
Anywhoo......I'm still of the opinion that as long as a pellet head is "re-sized a bit" when loaded into the leade it will be the same size when shot regardless of the "silly little 1/100th mm difference" before loading. The problem comes when the pellet head is too small to be sized when loading.
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Anywhoo......I'm still of the opinion that as long as a pellet head is "re-sized a bit" when loaded into the leade it will be the same size when shot regardless of the "silly little 1/100th mm difference" before loading. The problem comes when the pellet head is too small to be sized when loading.
correct.
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I noticed "Ted`s holdover" in his vlog channel said when he was testing the wildcat mk2, he did not sort pellets anymore, as the effort was not worth the gain, in that gun. The reason being the barrel was choked.
But he also said it absolutely make a difference in other kind of barrels. So if what he say is true, a choke should be a benefit as I see it, as it makes the barrel less picky about the actual size of the pellet.
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Correct Aslak
A choke makes every pellet that exits the muzzle the exact same diameter as the one before it & after it. That is, once the pellet that is discharged has a head & skirt diameter that were larger than the choke.
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What Ted said was the fx bbl, with a choke doesn't need his attention of sorting. But other brands ,with chokes do. He is shooting the new SX bbl.
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If what Ted said about the choke is true then, the choke length only has to be the length of the pellet ( Right? ). I am not sure about that one but, if you think about it, that's all the choke length you really need if we are talking about that little sizing before the pellet leaves the barrel.
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I think the answer is that it "could". It "could" also make a gun less pellet picky without improving accuracy overall, or maybe even make it less accurate with what used to be it's favorite pellet but generally accurate with a greater selection of pellets. It could also outright ruin accuracy. Gotta be done right by somebody that really knows what they are doing, and still may not improve anything.
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I have been under the impression that the choke also provided more spin on the pellet and that my explain some of the choke length.
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I looked at his video again, to see what he actually said. He did not actually say it was because the barrel was choked, but rather that the barrel reshaped the pellet. I know the smooth twist, and the standard smooth twist-X are choked. So at least on those particular barrels it should have less benefits of sorting pellets.
But I know from my experience with a wildcat mk2 in .177, undersized pellets will fly bad, probably in any gun.
I did switch from a box of 4.52mm 8 grains exact (which probably was smaller than their size), to a box of 4.53, and did see great improvements. To confirm the difference I pushed pellets true the liner with a rod, and looked at how much "dents" the pellets had. On my particular sample the 4.52 had litle marks on the pellet, while the 4.53 did have noticeable more. So had i sorted out the pellets with the biggest head on my 4.52 sample, it would probably made a difference.
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If what Ted said about the choke is true then, the choke length only has to be the length of the pellet ( Right? ). I am not sure about that one but, if you think about it, that's all the choke length you really need if we are talking about that little sizing before the pellet leaves the barrel.
The thing is with .177 pellets while they might come with slight differences in head diameter, some are very short, while others are very long for their caliber.
Most chokes aren't very long though. Longest I've ever encountered was around about 0.75"
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I always thought that a choke (if done properly) acted like a funnel... to square an undersized pellet to the bore. I might be wrong and I apologize to others if they have said the same thing. I did read most of the thread (I think).
I have about 25 LW barrels - most are choked. The choked LW barrels have the choke starting about 1" to 1-1/4" from the muzzle. The bore diameter reduction is about .0015 to .002". They are a straight-line taper from the start of the choke to the muzzle. They shoot the undersized pellets almost as well as the perfectly sized pellets. In contrast, the un-choked LW barrels will send the undersized pellets to a POI that is detached from the main group. The un-choked barrels will group just as well however, if all of the pellets are perfectly sized to the bore. This is just my experience - I haven't found a lot of info on this...
Wyo
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I always thought that a choke (if done properly) acted like a funnel... to square an undersized pellet to the bore. I might be wrong and I apologize to others if they have said the same thing. I did read most of the thread (I think).
I have about 25 LW barrels - most are choked. The choked LW barrels have the choke starting about 1" to 1-1/4" from the muzzle. The bore diameter reduction is about .0015 to .002". They are a straight-line taper from the start of the choke to the muzzle. They shoot the undersized pellets almost as well as the perfectly sized pellets. In contrast, the un-choked LW barrels will send the undersized pellets to a POI that is detached from the main group. The un-choked barrels will group just as well however, if all of the pellets are perfectly sized to the bore. This is just my experience - I haven't found a lot of info on this... Wyo
Makes a lot of sense and explains a lot.
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I am speculating that since the smooth twist X barrel on the wildact mk2 does not have common groves and rifling, the pellet will not spin properly before the choke. The choke might make the pellet a litle smaller, but it will not be able to start spinning it. That 4.52 sample I tested was "very" small compared to other pellets. RWS superdome, stoeger x-field ,JSB heavy was all bigger, and did shoot better than the underzided JSB pellet. The JSB heavy are also labeled 4.52 but are bigger.