PRB in 1 in 28 twist

[Blacky Montana]

Happy New Year,

Hey guys, although I am not new to muzzleloading, I have never fired a PRB in my life. My Austin & Halleck Mountain rifle has a fast twist of 1 in 28 with a 32 inch heavy barrel, so I have always shot conicles and a few sabots. I have considered trying PRB's, but never have cause I know most PRB barrels have a slower twist of 1 in 66. How does a PRB handle with such a faster twist? Will it be just as accurate as the long heavy conicles? I have read here on the forum where all you guys say PRB's are just as lethal on deer as conicles, so I am willing to give this a try. Please forgive my lack of knowledge, but the only other ML shooters I know all use the new in-lines. I'm the only one still using a side lock Hawkens, so I'm not around anyone who can offer me help. Any info would be deeply appreciated. Almost forgot, my A & H is a 50 cal.

Thanks,
Blacky Montana
SASS #19953

 

[Brik847]

I have a fast twist too - White Mt. Carbine .50 that I am working on for round balls. My last trip to the range I tried 60 grs. 3f powder, a .490 ball, and pillow ticking and mink oil lube. I shot 8 shots into a 4" square at 50 yds. My patches were in good shape after firing. I also use a felt over powder wad. What I'm going to do next is same set up with more lube on the patch and I'm going to lube the barrel with a swab after I load.

My next thing to do is try a .495 ball. I also made up some moose juice patches for something else to try.

My twist is 1:21 with a 21" barrel. With that barrel length I am limited on powder I can burn in it. I can't go much more. With your slightly slower twist and longer barrel, you should be better off to begin with. I am not discouraged. I'm just going to keep working at it. I love shooting balls.

Good luck, let us know how it goes.

 

[MikeChapin]

The fast twist rifles will shoot round balls alright but you have to use a reduced charge. For a .50 I would start at about 30 grains and see how it groups. Go up 5 grains and shoot another group and so on. With the fast twist it should be pretty dramatic when you hit the sweet spot. A five grain difference will shrink the group from four or five inches to an inch or so at 50 yards.

Once you have found the sweet spot for the light load, there should be another sweet spot at a little under twice the light load. If you found the rifle groups well with 35 grains, go up to 60 grains and work around there in 5 grain increments until you find the second sweet spot.

 

[bart_anastasi]

I have been shooting a fast twist barrell .54 cal for years and no problems. Use a 425 grain maxi for a conical and a .535 RB around 235 grains of lead.

If you look in the TC traditional load data owners manual for ML's available on their web site you can down load a wealth of caliber specific information.

That info is for 2F powder and for RB's I would reccomend you keep to that most specifically with a heavy round ball.

The max load for my 54 shows and I am working from memory here the following.

120 grains of 2F with a 425 grain maxi yields 1550 fps and 2200 foot pounds of energy. That by the way is about what you get from a 12 gauge 2 3/4 inch shell.

120 grains of 2F with a 235 grain RB yields 2000 fps and 2000 foot pounds of energy.

The point is that if you are shooting a .50 the load data is pretty good to. Do not be affraid to give it a try.

A good tight patch and a good quality RB remember to keep away from bargin bassement RB. Every once in a while they will have a flat spot that gives you a flyer.

 

[Walks with fire]

I have a 1/28 twist GM barrel on one of my rifles and shot it one time at the range with 80 grains of 2f Goex; .495 ball and .017 pillow tick patch at 50 yards. It shot one big hole for 3 shots; I will test it more eventually but it did group.

 

[roundball]

I have a 1/28 twist GM barrel on one of my rifles and shot it one time at the range with 80 grains of 2f Goex; .495 ball and .017 pillow tick patch at 50 yards. It shot one big hole for 3 shots; I will test it more eventually but it did group.

Excellent...I put the constantly repeated theme that high power PRBs in fast twists (ie: 1:28")won't shoot accurately in the same category of the other constantly repeated theme that high power PRBs in medium twists (ie: 1:48") won't shoot accurately.

 

[BrownBear]

I experimented quite a bit with PRBs in a fast twist 54 cal. Once I got above 50 grains of 3f or Pyro P, accuracy declined quickly. But at or below 50, it was entirely reasonable for mashing bunny heads out to 50 yards. 35 grains turned out to be the best load, with shots nearly touching at 50 yards.

Based on experiences using both 50's and 54's I'd "interpolate" that to mean that your top charge with a 50 cal would be around 40-45 grains and your most accurate load would come in at 25-30 grains.

Those certainly aren't big game velocities for a PRB, but they're a real hoot for plinking and small game hunting.

 

[Walks with fire]

I talked with a guy one time that was in my opinion quite knowledgeable about bp barrels and even made quite a few in his time. We talked about twist rates, groove depths and designs, calibers and charge rates. Anyway; his opinion was that the faster twist barrels with shallow depth grooves could shoot roundballs just as well as slower twist barrels. He even felt that a 1/48 twist was ideal for roundballs in a .50 caliber and 1/56 was ideal for .54 calibers.

He went on the explain that shallow grooved fast twist barrels required a close to bore diameter ball and that the barrel must be swabbed extremely clean between shots. I have not tried them extensively in my barrels yet but shot a few of my standard 1/66 twist load/patch combination in the 1/28 twist. The only thing was that they hit left of center about 2" of my conical loads.

 

[Blacky Montana]

OK guys,
I deffinately see where I will have to decrease my powder load by as much as half of what I use with conicles. I am normally using 90 grains of Goex FFg to push a 435 gr White Rifle's Power Punch conicle. This load/conicle combination is devastating on deer and extremly accurate. My new conicle question would be, how much powder do I need behind a PRB to be effective on deer out to around 75 yards? I realy do want to try using PRB's in my A & H fast twist, but I would like to be able to use it for deer hunting as well.

Thanks,
Blacky Montana
SASS #19953

 

[Rebel]

I would say at least 60 grs of 3f and 70 would be better.

 

[roundball]

Just experiment with a few shots each...clean barrel, over powder wad, tight fitting patch ball combo, etc, for every shot...run it right on up the chart and see what it'll do

 

[BrownBear]

Rebel's #'s reflect my own impressions. I'm currently using 90 grains in 54 cal and 80 grains in 50, both 3f or Pyro P. Seems to be power to spare in both. I shoot a lot in the 50-60 range with both for plinking and target. While I'm sure the right shot would still do the job with either, I nudge it up a bit "just to be sure."