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Twist rates on single action .45 revolvers
redice
Member Posts: 1,550 ✭✭✭✭✭
I have an uberti liberator in .45lc with like a 4.5 or 5inch barrel and I have another .45 its an Italian knockoff with a 6 or 6.7 inch barrel, now the longer barreled gun is much more accurate for 200 225 even 250 grain bullets, and I believe this is mainly due to it having a little more twist because of the length of the barrel if not just due to it having a totally different twist in the first place.
Now comes the crap part I hate the knockoff, but like the Uberti the only problem being the uberty doesn't hold up to my standards of accuracy unfortunately, I have thought about trying to reload lighter loads for it like 165 grn but I really hate having a gun that needs to be reloaded for to be accurate.
So my question is is it most likely the twist rate difference that is causing my accuracy woes? and if so what are some other single actions that are better at stabilizing the .45lc in 200+ grain bullets in this same length of barrel say 4.5 or 5"
Now I also have a marlin lever gun in .45lc and I assume that will take the heavier bullet weights gladly and be more accurate because of them just because the rifling has more time to stabilize the bullet in such a long barrel, is this also true?
Thanks guys.
Now comes the crap part I hate the knockoff, but like the Uberti the only problem being the uberty doesn't hold up to my standards of accuracy unfortunately, I have thought about trying to reload lighter loads for it like 165 grn but I really hate having a gun that needs to be reloaded for to be accurate.
So my question is is it most likely the twist rate difference that is causing my accuracy woes? and if so what are some other single actions that are better at stabilizing the .45lc in 200+ grain bullets in this same length of barrel say 4.5 or 5"
Now I also have a marlin lever gun in .45lc and I assume that will take the heavier bullet weights gladly and be more accurate because of them just because the rifling has more time to stabilize the bullet in such a long barrel, is this also true?
Thanks guys.
Comments
A 1:20 is a 1:20 regardless of weather it's 2" long or 24" long
You slug the barrel and cylinder to determine actual size and select a bullet accordingly. Have your favoite gunsmith do the work if this is something you don't feel comfortable doing yourself.
Twist rate and barrel length are two completly different things.
A 1:20 is a 1:20 regardless of weather it's 2" long or 24" long
I know that however I believe both revolvers have simmilar rate but the one haveing a longer barrel gives it more time to use that rate/a fuller twist, thus a faster rate of twist in the shorter barrel would possibly help to stabilize a heavier bullet if I understand this correctly whereas the slower rate of twist better stabilizes lighter bullets??
Basically I was told something on these lines and I looked down each barrel and followed 1 rifling on the shorter revolver it gets around 1/4 turn on the longer it gets 1/2 of a turn i.e. on the longer barrel the rifling starts at the bottom at the breach and ends at the top at the muzzle the shorter barrel revolver the rifling only goes half that.
SOME PISTOL ACCURACY ISSUES;
A short barrel has a shorter sight radius. It is harder to hold the same sight picture with short barrels vs. long barrels. .003 sight missalignment on a 5" barrel is the difference between a 10 and a 9 on the NRA slow fire target at 50 feet.
A forcing cone issue or muzzle crown issue is most likely the true accuracy problem, if it is a mechinical issue.
Having each pistol shot in a ransom type rest is the only repeatable way to determine the accuracy of each gun you have.
Handloading will also help create ammo that each gun likes and is tailored to it.
......but the one haveing a longer barrel gives it more time to use that rate/a fuller twist, thus a faster rate of twist in the shorter barrel would possibly help to stabilize a heavier bullet if I understand this correctly whereas the slower rate of twist better stabilizes lighter bullets??
You understand incorrectly, Barrel length affects velocity only.
Basically I was told something on these lines and I looked down each barrel and followed 1 rifling on the shorter revolver it gets around 1/4 turn on the longer it gets 1/2 of a turn i.e. on the longer barrel the rifling starts at the bottom at the breach and ends at the top at the muzzle the shorter barrel revolver the rifling only goes half that.
[/quote]
1/4 turn in 4" is the exact same thing as 1/2 turn in 8" IE both will rotate the bullet once every 16".
As bpost1958 already pointed out...Sight Radius has much to do with accuracy. A longer sight radius (longer barrel) will usually be more accruate then a short sight radius (shot barrel) Any variation in the Sight Picture of your short barreled revolver will have a great affect on group size at the target. The lock time - hammer fall of you pistol also plays into the picture. Single Action Colt SAAs and clones have a VERY long lock time. You must keep the sight aligned and follow through with the shot.
Its not a sight radius issue.
ok so the twist rate is the same but the difference in velocity from one barrel to the other would that make a significate difference in accuracy? like a highter velocity bullet would be spinning faster than a slower velocity bullet in the same barrel conditions. So in that case would a lighter bullet weight improve accuracy by increasing the velocity and thus spin?
What im seing on paper and its quite repetable is the longer barrel revolver is holding under a 4" group at 20 feet and the shorter barrel revolver is well over a foot with the exact same ammo both have 6 land rifling and aparently the same twist rate both muzzle crowns are fine and apear to be similar if not the same forceing cones apear to be fine however thats just from coursery examinaton but both guns are basically new so it should not be a problem.
I did have a little bit of luck pulling the shorter barrel revolver groups in by moveing up to 250gp bullet however it wasnt enough to bring it into what I concider good enough accuracy wise. And the longer barrel revolver's accuracy was degraded by moveing up to the 250 to the point it was shooting like the shorter. I think the reason why the 250 gr may have helped the shorter revolver would be because of a longer bullet from my reading it sounds like bullet length correlates somewhat to weight and its really the length that affects accuracy more.
Anyhow I gues I just want to know if I get a pistol that has a 5" barrel but has a faster twist than what my uberty has would it better stabilize 200-250gr projectiles and if yes what are some good choices?
I do plan to reload however I never want a gun that the only way I can shoot it accuratly is to reload for it.
quote:A lot of the cowboy shooters are using one of the many SAA clones. However, the problems encountered are not limited to these Italian imports. The foremost problem that is encountered, across the board, is the lack of a proper forcing cone, and a proper cylinder to barrel gap. In just about all the pistols, the forcing cones are roughly formed and generally not square to the bore. A properly cut forcing cone is essential to accuracy and to reducing lead build up in the bore. In most examples, the forcing cones are found to be non-concentric with the bore, very rough, and not cut at the right angle. The bullet upon leaving the charge hole, in the cylinder, will not be correctly guided into the barrel. Bullet distortion and unwanted vibrations will occur. If the cone is not polished smooth lead will build up fast. As the lead builds it causes shot to shot variations and is not conducive to good groups.The most common problem found with the cylinder gap is really not what you would expect. The gap is generally within tolerance but usually not cut square to the bore. This also causes the bullets to enter the bore, upset.Also, in this area of the firearm, the other problem encountered is the lack of lead into the rifling. This, I believe, is all proof that the forcing cones are formed when the barrels are made and not cut during assemble.
The angle to which the forcing cone is cut and the size of the cylinder gap can be a point of many debates.Different manufactures have promoted the merits of different angles on different firearms over the years. We can find 5, 11 and 18 degrees among the most common.Ruger has touted the merits of the 5 degree while 18 degrees is the most popular. 11 degrees is generally considered to be gentler on the bullet and causing it less distortion. After the cone has been cut and polished to the right depth and the end of the barrel cut square to the cylinder, I recommend just breaking the edge of the cone with an 82 deg. cutter.
Or just buy yourself a 1:16 twist barrel (for your psitol) like the Marlin and have at it.
You might need the services of a good Gunsmith
quote:A lot of the cowboy shooters are using one of the many SAA clones. However, the problems encountered are not limited to these Italian imports. The foremost problem that is encountered, across the board, is the lack of a proper forcing cone, and a proper cylinder to barrel gap. In just about all the pistols, the forcing cones are roughly formed and generally not square to the bore. A properly cut forcing cone is essential to accuracy and to reducing lead build up in the bore. In most examples, the forcing cones are found to be non-concentric with the bore, very rough, and not cut at the right angle. The bullet upon leaving the charge hole, in the cylinder, will not be correctly guided into the barrel. Bullet distortion and unwanted vibrations will occur. If the cone is not polished smooth lead will build up fast. As the lead builds it causes shot to shot variations and is not conducive to good groups.The most common problem found with the cylinder gap is really not what you would expect. The gap is generally within tolerance but usually not cut square to the bore. This also causes the bullets to enter the bore, upset.Also, in this area of the firearm, the other problem encountered is the lack of lead into the rifling. This, I believe, is all proof that the forcing cones are formed when the barrels are made and not cut during assemble.
The angle to which the forcing cone is cut and the size of the cylinder gap can be a point of many debates.Different manufactures have promoted the merits of different angles on different firearms over the years. We can find 5, 11 and 18 degrees among the most common.Ruger has touted the merits of the 5 degree while 18 degrees is the most popular. 11 degrees is generally considered to be gentler on the bullet and causing it less distortion. After the cone has been cut and polished to the right depth and the end of the barrel cut square to the cylinder, I recommend just breaking the edge of the cone with an 82 deg. cutter.
Or just buy yourself a 1:16 twist barrel (for your psitol) like the Marlin and have at it.
Thanks thats the most usefull reply I have read all day.