Rifle Twist ?

New here and have a conumdrum I could use your opinions with ”¦
I have a .50 short barrel 34 inches. Fast twist at 28. I believe this is made to fire .50 sabots with a .45 bullet. Made by a really good maker I met at Dixons years ago. Couple years ago I had him build this sporting rifle. Guess I took a fancy to this short rifle. Presently advert. on Comtemp. Longrifle. Anyway, since it is not very traditional I was thinking of changing to a .50 ball barrel at the same length. Question is, will a 28 twist deliver any accuracy in this length barrel ??

Thanks for sharing, P

Accuracy? Yes, with a sabot, as described :redface: . Or, with low powder charges it may produce the decent accuracy wanted. A short barrel won't like heavy charges.....I mean it will burn some powder after the PRB leaves the barrel... Try it out and let us know what you find?

First 34" is a rather long length for a rifle.
Second 28 twist is most definitely a sabot or conical twist.
Third this twist is also probably quite shallow as well as fast which would doubly make it very unsuitable for patched roundball.
For shooting patched roundball you would do well to find a rifle with a much slower twist and much deeper rifling that will be able to grip the patch.
Fourth as to length anything over 25"-26" will perform equally well, as the only gain with any extra length is the greater distance between the sights (a finer sight radius).

Toomuch
............
Shoot Flint

While we don't discuss "plastic wrapped pistol bullets" on this forum I will try and keep my answer to things we can discuss.

1:28 is pretty fast in a 50 cal. It was most likely designed for shooting those unmentionables.

You could try a rather long paper patched bullet or some of the conicals that designed for 50's by T/C or Lyman (as an example).

If you do want to try round balls I would suggest you pick up a pack of "Hard Balls" from Hornady.

I believe they go for about 10 or 15 bucks for 20, so "not cheap" by any means but the ball is held in a small shot cup so it shoots like one of those plastic wrapped bullets.

It is Hornady's attempt to answer the need to shoot a round ball in a fast twist barrel for those area's that do not allow "other than roundball".

Maybe worth a try.

(as to accuracy - my Mod 94 with a 20" barrel has a 1:12 twist - it's not the twist and barrel length that determine accuracy to any significant degree - however, the "average shooter" will be more accurate the longer the barrel is. Think "pistol" with a 5" barrel - one minuscule twitch and the bullet is a couple feet off target by the time it gets there. With a 48" barrel some would say you are "half way to the target", even a minor hand tremor may still allow you to stay very close to the bullseye)

Only based on stuff I have read and have no personal experince with ...a fast twist and shallow groves can give exelent accuracy with a ballprovided its shot in subsonic velocities. A tight combo should not strip if the speed is kept slow. Some fine match guns made for ball had some fast twist but were not made to be 'magnums'.
And you will have fun playing with it even if it wont be 'ol' tack driver'.

First 34" is a rather long length for a rifle.
Second 28 twist is most definitely a sabot or conical twist.
Third this twist is also probably quite shallow as well as fast which would doubly make it very unsuitable for patched roundball.
For shooting patched roundball you would do well to find a rifle with a much slower twist and much deeper rifling that will be able to grip the patch.
Fourth as to length anything over 25"-26" will perform equally well, as the only gain with any extra length is the greater distance between the sights (a finer sight radius).

Toomuch
............
Shoot Flint


You were right on until the last statement. Up to a point we haven't discovered (44" barrels were the longest ones tested) the longer the barrel, the greater the velocity, and lesser the dB level at the shooter's ears.

Theoretically, that .50 cal. 34 inch barrel should be able to burn as much as 77 grains of black powder efficiently. However, a 1:28 twist rate is way too fast for that much powder. You will need to start with a charge of somewhere around 40 or 45 grains and work up in 5 grains increments until you find the sweet spot where it will give you the best accuracy. Quite often, but not in every case, a .50 cal. rifle will give good accuracy with a load of around 80 grains. I would bet that you will find that your rifle will do best somewhere around 60 grains. But, only actually working up a load as I described will tell you what your rifle wants. If you want to use the heavier charges, you will need a barrel with a slower twist rate. I would suggest nothing faster than 1:48.

GriscomRun,
28" twist isn't too fast for round ball if the rifling is of geometry suitable for round ball in that fast of a twist.
I know, that's a great big if. Yah just gotta try it to find out.

Now, got to tell you this blows me away. I literally just came back from the post office. Mailed off a barrel with instructions to make it .52" bore with 28" twist and rifling for paper patching off the shelf molds. However, mine is percussion. If you paper patch with your flinter please post the results. I've been puzzling over how well the same set up would work with flint.

If you want to shoot round balls ,switch barrels. If you want yo shoot buff,moose, elk and such have a conical mould made!
Nit Wit

It's the depth of the rifling and not the twist that will determine whether or not it will shoot ball accurately. If the grooves are very shallow a prb can skid across the rifling and give lousy accuracy. If the grooves are reasonably deep the prb will "catch" the rifling and shoot quite well with hunting loads.

Toomuch said:

First 34" is a rather long length for a rifle.
Second 28 twist is most definitely a sabot or conical twist.
Third this twist is also probably quite shallow as well as fast which would doubly make it very unsuitable for patched roundball.
For shooting patched roundball you would do well to find a rifle with a much slower twist and much deeper rifling that will be able to grip the patch.
Fourth as to length anything over 25"-26" will perform equally well, as the only gain with any extra length is the greater distance between the sights (a finer sight radius).

Toomuch
............
Shoot Flint

Click to expand...

Its really never as simple as those absolutes. 1. Rifle Barrels over 34": Members of my traditional muzzle loading gun club shoot rifles with barrels up to 48" in length. Don't tell the chunk gun shooters that barrels over 34" are too long for a rifle. At 60 yards 10 shot groups are often less than 1" using the long barreled guns. Chunk gun shooting is firing at an X target from a prone position with the rifle resting on a chunk of wood. Check out rifles used at matches such as the Alvin York match or the Bevel Brothers' Championship match.

2. Rifling developed for early jaeger rifles used a twist of 1 turn in the length of the barrel. These short barreled jaegers had barrel lengths of 28 to 30 inches. The twist was 1 turn in the barrel length. Often the bore size was large with the ball of 0.62" or greater. They were intended to shoot round ball.

That said, I think for present day use of a 50 caliber rifle barrel, a 1 in 28" twist is too fast for that sized round ball unless the velocity is kept low.

This Jaeger has a 22 inch barrel with a 1 in 14 twist. It shoots round balls and conical minie hollow base better than I can. Targets were 32 yards off hand.

Good shooting and it shows that good loads can be found to deliver outstanding accuracy.

Yes there are a great many variables.

In Barber's book, Instructions for the Formation and Exercise of Volunteer Sharp Shooters c. 1805 it mentions the German use of very fast twist rates in some of their rifles used for target shooting in the age of the patched, round ball. For example (iirc) as much as 1.5 turns for the length of the barrel, which, in say a 36" barrel would be a twist rate of 1:24 and in a 42" barrel would be 1:28.

So fast twist rates were known, what isn't known is the depth of the rifling, nor it's width, nor number of gooves or the powder charges used as well as the calibers.

LD

Col. Batguano said:

You were right on until the last statement. Up to a point we haven't discovered (44" barrels were the longest ones tested) the longer the barrel, the greater the velocity, and lesser the dB level at the shooter's ears.

Click to expand...

You are correct, I submit to your addition.

Toomuch
...........
Shoot Flint

Its really never as simple as those absolutes.

Click to expand...

That is the only absolutely correct statement made in this entire thread.
Just stop and consider why fast twists are rarely seen in ml rifles.

"the longer the barrel, the greater the velocity, and lesser the dB level at the shooter's ears."

I find this statement very interesting. On the face of it, it sounds counterintuitive. Higher velocities but lower noise levels at the shooter's ears. Higher velocities would seem to indicate a more efficient use of the available powder and this would seem to indicate a higher breach pressure. Higher pressures would result in greater noise levels. The longer barrel would place the muzzle farther from the shooters ears but it would be only a matter of inches and that would be highly unlikely to result in lower noise levels at the shooter's ears. How was this noise level determined? I need to ruminate on this a bit. :hmm:

Grenadier1758 said:

Its really never as simple as those absolutes. 1. Rifle Barrels over 34": Members of my traditional muzzle loading gun club shoot rifles with barrels up to 48" in length. Don't tell the chunk gun shooters that barrels over 34" are too long for a rifle. At 60 yards 10 shot groups are often less than 1" using the long barreled guns. Chunk gun shooting is firing at an X target from a prone position with the rifle resting on a chunk of wood. Check out rifles used at matches such as the Alvin York match or the Bevel Brothers' Championship match.

2. Rifling developed for early jaeger rifles used a twist of 1 turn in the length of the barrel. These short barreled jaegers had barrel lengths of 28 to 30 inches. The twist was 1 turn in the barrel length. Often the bore size was large with the ball of 0.62" or greater. They were intended to shoot round ball.

That said, I think for present day use of a 50 caliber rifle barrel, a 1 in 28" twist is too fast for that sized round ball unless the velocity is kept low.

Click to expand...

1: As I explained the longer barrel offers the finer sight radius, thus drawing a finer bead. Also, as the Col. added the longer barrel offers more velocity which further stabilizes the ball.

2: Although these rifles had a faster twist, the rifling was also cut MUCH deeper which enabled it a positive grip on the patch. Also the larger ball will perform much better with a faster twist than the smaller calibers.

Toomuch
...........
Shoot Flint

Another option is to slow down the ball with lighter powder charges, that MAY improve accuracy. As has been mentioned, there were some fast twist barrels on original guns.

The longer barrel would place the muzzle farther from the shooters ears but it would be only a matter of inches and that would be highly unlikely to result in lower noise levels at the shooter's ears. How was this noise level determined?

Click to expand...

B&P, it does make considerable difference at the ears of the shooter. A 20" shotgun barrel can sound like a major explosion to the shooter compared to the same load from a 24" barrel.
And, in our game, a short barrel under roof at the range can be a major difference in sound perception. My wife used to shoot an H&A Buggy rifle. Short barrel jobby. It was .45 cal. and she used moderate loads. But when it went off at the range it sounded like the world was being blasted off it's axis because the muzzle did not protrude past the roof line. Perception or real? I dunno. :idunno: But, I do know it would tightent up the rear facing orifice sumptin' awful. :shocked2: