.50 VS .54 Round Ball Accuracy

[waksupi]

For several years I used a CVA 54 caliber Hawken Hunter for competition and hunting. When I decided to make my own rifle I checked the NMLRA records to see what rifle won most of the time - answer, full stock, 40 caliber, caplock. Then I noticed the names of the winners. It seemed that it didn't matter what was shot, it was who did the shooting.
Good rifle, in a style and caliber that you're comfortable with, good load development, practice, have fun and don't take yourself seriously.

Yep. It ain't the arrow, it's the Indian!

[charlie b]

I had a question about this too. I am using my GPH barrel with PRB and am still working on loads. It seems to like lighter loads, as in 40-50gn rather than heavier. A 40gn load of 3f will get me around 2" at 50yd where 80gn is 4". I had always thought that the faster twist would want a slower bullet. The problem with the lighter load is the rainbow trajectory for 100yd.

And, yes, I am learning how to shoot PRB. Only shot one other rilfe with it, back about 30yrs ago. That was a KY rifle with slow twist. It was accurate with just about any load.

Anyone else do this? I am open to any ideas or experience.

[sharps4590]

GPH barrels are like 1-32 or 1-28, aren't they? The lighter load under a PRB showing the better accuracy is pretty much as it should be so yes sir, you are correct. You want higher velocity, flatter trajectory with a PRB with accuracy you'll need a slower twist. The PRB doesn't take a lot of stabilizing. Being the shortest projectile that will fit a bore it has the sectional density of a rock. Spin it too fast and it becomes less stable.

[charlie b]

Yep, that is what I thought. I figure on limiting my round ball shooting to 50yd or so, unless it is a really calm day.

[54bore]

GPH barrels are like 1-32 or 1-28, aren't they? The lighter load under a PRB showing the better accuracy is pretty much as it should be so yes sir, you are correct. You want higher velocity, flatter trajectory with a PRB with accuracy you'll need a slower twist. The PRB doesn't take a lot of stabilizing. Being the shortest projectile that will fit a bore it has the sectional density of a rock. Spin it too fast and it becomes less stable.

I just bought a brand new Lyman GPH in .54 Cal and it is 1:32 Twist, so is the .50

[sharps4590]

I thought that's what I read some where but wasn't certain. I'm the opposite of some of ya'll in that I have absolutely zero experience with fast twist ML barrels but, ballistics is ballistics....

[mooman76]

Charle B,
Try a tighter patch and you should get better accuracy, especially with slightly heavier loads. Examine you fired patches they tell you allot. They should be in good enough shape to use again. If they are shredding or getting burned out, accuracy will suffer.

[54bore]

I thought that's what I read some where but wasn't certain. I'm the opposite of some of ya'll in that I have absolutely zero experience with fast twist ML barrels but, ballistics is ballistics....

That's me starting this thread, i have ZILCHO experience with Round Ball? I Shoot Paper Patched and sized bullets exclusively making the Fast Twist barrels my specialty. This thread has been REALLY interesting to me, i had no idea the slower the twist the more powder it takes? I would have never guessed that

[Squeeze]

GPH barrels are like 1-32 or 1-28, aren't they? The lighter load under a PRB showing the better accuracy is pretty much as it should be so yes sir, you are correct. You want higher velocity, flatter trajectory with a PRB with accuracy you'll need a slower twist. The PRB doesn't take a lot of stabilizing. Being the shortest projectile that will fit a bore it has the sectional density of a rock. Spin it too fast and it becomes less stable.

I think, the bigger the bore, the slow twists come in more. When you go tiny, It seems a faster twist in a .32 is better for roundball. A little .32 drops off the charts for formulas and specifics. Ive always went with the theory that a .40, and a .54 are a sort of sweet spot caliber for roundball accuracy. They just seem to consistently outshoot everything else.

[54bore]

I think, the bigger the bore, the slow twists come in more. When you go tiny, It seems a faster twist in a .32 is better for roundball. A little .32 drops off the charts for formulas and specifics. Ive always went with the theory that a .40, and a .54 are a sort of sweet spot caliber for roundball accuracy. They just seem to consistently outshoot everything else.

Squeeze, I plan to shoot the heck out of a couple of my stock 1:48 twist .54 Cal TC barrels with round balls when the snow gets gone here and i can actually get anywhere without getting stuck! I hope i can find accuracy in them, i have 3 different barrels to work with.

[mooman76]

Some guns have a really slow twist like 1-92(I believe) or slower. They usually take over 100gr to really shoot their best. Yes it is fact that the larger the caliber, less twist is needed to stabilize the round. It also depends on the length of the projectile being the longer projectile needs a faster twist to keep stable. RBs are RBs so the length thing goes out the window of coarse.

[charlie b]

Charle B,
Try a tighter patch and you should get better accuracy, especially with slightly heavier loads. Examine you fired patches they tell you allot. They should be in good enough shape to use again. If they are shredding or getting burned out, accuracy will suffer.

I think the patches are fine. They are indeed almost good enough to be used again, just the rifling marks on them. The rifling marks are nice and crisp.

One reason I was leery about trying PRB is the rifling on the Hunter barrels is shallow, like a breech loader, not the deep grooves most people look for with PRB. The slow twist barrels do have the deeper rifling.

[sharps4590]

The amusing and ironic thing about this entire thread is that all this was hashed out and known nearly 160 years ago. Forsyth, Baker and others had it all figured out. Sadly, unless a fella learns about and digs around to find their old writings, which are not all that easy to come by, it's almost as if it's lost knowledge and we get to re-invent the wheel. Saw the same thing when BPC's started getting popular. All those tricks and knowledge the old timers knew and took for granted we were ignorant of.

[Squeeze]

The amusing and ironic thing about this entire thread is that all this was hashed out and known nearly 160 years ago. Forsyth, Baker and others had it all figured out. Sadly, unless a fella learns about and digs around to find their old writings, which are not all that easy to come by, it's almost as if it's lost knowledge and we get to re-invent the wheel. Saw the same thing when BPC's started getting popular. All those tricks and knowledge the old timers knew and took for granted we were ignorant of.

that is so true. Guys like Whitworth, and Rigby had barrels and loads all figured and had already tried about all the possibilities. Now our mindset with all the technology is that history couldn't have matched our knowledge. But there's so much ancient historical finds, That we still don't know how it was built, and probably couldn't be replicated today. Even WITH the help of technology and machinery

[charlie b]

So, how did that knowledge get passed on? By people asking questions and reading books. Same as what is going on here now.

[54bore]

So, how did that knowledge get passed on? By people asking questions and reading books. Same as what is going on here now.

Gets lost over time/generations, then when it takes back off you start over. Not so much now days with the internet etc. the internet is a good, and bad thing, their is tons of good info out there, but also plenty of twisted garbage to go with the good. I personally enjoy trying new things, or 'new to me' things, Maybe it was done years ago, maybe it wasn't? I enjoy it regardless

[Fly]

Charlie. Why would you shoot a PRB in the GPH barrel in 1-32 twist? I have both barrels in GPR 1-66 & GPH in 1-32.
That makes no sense. My GPH shoots a conical much more accurate than a PRB?


Fly

[charlie b]

Because I want to. Yes, I shoot paper patched bullets too. Just nice every now and then to shoot some 'light' loads.

I don't have both barrels. I may get a second one, or even a second rifle, in the future to shoot PRB, but, right now the GPH is what I have.

I also like to see if I can 'stretch' what a firearm will do. Like mouse loads out of my M1 Garand or Mod 94 .30-30

[Fly]

OK I understand, get the GPR barrel some time in the future, you will love it also my friend.

Fly

[charlie b]

I might get a new barrel. But, then again, I have had a hankering for a flintlock so I may just wait and get a flinter for round ball shooting. Heck, I might even follow in rfd's footsteps and get a kit