1:32 inch projectile?

[jonk]

I have a .50 cal Navy Arms inline with a 1:32" twist. I note that it does only so-so with a minie or sabot; what about a round ball?

Of course, the proof is in the pudding and the firing, but I guess what I'm asking is what is the best nominal projectile for that twist rate?

[mooman76]

It would probubly shoot RB but only at low powder charges with that twist. You might try a maxie and see how that does. Yours is a tight twist more for the Sabot or a minie/maxie. There are allot of different sabot's and minie/maxies you might need a different size one like a little tighter. Probubly not the answer you want but every gun is a little different and you have to try different things. Also you didn't mrntion the powder charge you were using. Maybe someone else here will answer that has a gun similar to yours that has some comb that works. What are you calling so-so?

[jonk]

I've tried 1 and 2 pyrodex pellets and FFG from 50 to 100 grains.

[Bad Flynch]

Well, I own a Ruger ML and IIRC, it also has a 1 in 32" twist. That gun loves the 370 grain T/C Maxiball with 90 grains of FFFg.

[Digital Dan]

L = 130 x D^2 / twist

Where:

L = bullet length in inches
D = diameter in inches

130 is a suitable constant for variations of the Greenhill formula at BP velocities. Your answer will provide stability within useful range for this class of arm. Minie balls do not thrive on high pressure or perhaps shallow rifling which may be your circumstance....that's a guess on my part. Can't speak to the matter of sabot performance in your gun. If you use the Greenhill calculation the bullet length is what matters, not the sabot. In your shoes I'd be trying the Maxi Ball mentioned above with about 90 grains of FFg.

[Rattus58]

Hi Digital...

I called some statistician one time about this, greenhill uses 150. This gentleman suggested 120 for low velocity, 180 for hyper velocity.

Aloha... :cool:

[jonk]

Hmm. I shot the gun a fair amount this week. I will buy some Maxis and try those this coming weekend. However, so far as it goes-

The gun didn't show a preference between minie balls and sabots. Ergo, I shall of course shoot the cheaper and more satisfying minies- unless the maxis shoot much better. Nor did it show a preference for black powder or pyrodex, though it didn't do so great with pyro pellets. It actually did a bit better (could be coincidence) with crisco lube vs. bore butter- hey that's fine too, crisco is dirt cheap.

The surprise came at how well it actually shot a patched round ball with a reasonably stout charge of 80 gr of FFG. Granted I was only at 50 yards but it managed a 3 shot 2" group. Come to think of it, everything it shot was about a 2" group, with a few flyers- my bad, some of my minie balls weren't quite filled out at the base.

So I'm about 80% of the way there; I'll finish sighting it in this coming weekend (as well as try the maxi balls).

[versifier]

Try loose Pyrodex RS if you are looking for better accuracy than with pellets. "Minute of deer" is easy with the pellets and they are MUCH faster to reload with in the field, but the "sweet spot" for accuracy may well be with an intermediate charge. (Many hunters will load the loose powder for optimum accuracy for the first charge, then reload with pellets in the field for a second shot.) MaxiBalls, MaxiHunters, and REALs all should be on your test program, and you should be moving out to 100yds. Groups at 50 only tell you so much. Many projectiles that look fine at 50 pattern like shotgun pellets at 100. The only way to find out is to test them as results with other rifles, even of the same twist, are only general guides. Your rifle will tell you what it prefers, but you have to ask it.

[jonk]

Yeah, one more round at 50 then out to 100. A 6" group at 100 would be acceptable to me. Minute of deer indeed- if I center it on the vital mass area a 3" spread in any direction for a 6" group in total would be perfectly fine. I wouldn't be taking a shot at over 100. Mind you I shoot 200 and 300 yard range matches all summer long, but those are with cartridge rifles.

Anyhow, we'll see what's what this friday.

[Junior1942]

My 1 - 32 Lyman Great PLains Hunter likes the Lee 320 gr REAL bullet.

[macvcallsign]

My experience with fast twist barrels is that a hard lead is needed. Just a thought.

[jtaylor1960]

My Great Plains Hunter shoots round balls very well.I shoot 100grs. of 2F powder.

[Rattus58]

My experience with fast twist barrels is that a hard lead is needed. Just a thought.

I shoot 1-20 twists and softest lead is still best for ACCURACY.

Aloha... :cool:

[KCSO]

A friend got a Jaeger rifle from Dixie and the flintlock had a 1-32 twist. As we DON"T shoot bullets we tried the rifle to see how a ball would stabalize. We ran increasing charges up to 90 grains of powder. The gun shot best with 55 grains of FFg and a 530 ball and a 17 thou patch lubed with bear oil. BUT... The gun would still group into 4" at 100 yards with 80 grains of FFG. So give a r/b a try it might just work.