Actual experience only please! Fast twist rate for 58 cal

[chorizo]

I am going to have a Renegade barrel bored out to 58 cal, moderate depth rifling (unlike the more common shallow rifling on the Zoli or T/C) and cut to 24" in length. For a twist rate I am looking at 1:40 or 1:38. Does anyone have actual experience with this twist rate for the 58?

I plan on shooting the 580 grain .575 Maxi-ball with OP wad at whatever powder load it takes to achieve 1400 to 1500 FPS MV so I can play around to find the best accuracy in that range..

No PRB shooting EVER with this gun, No 1:48 twist recommendations please. I have those barrels and they are less than satisfactory for my needs. Yes, this will recoil. I have a stock specially bedded and prepared for this barrel so it should be up to the task.

When Mr. Hoyt starts taking barrels again after March, I will have this conversation with him and get his recommendations, but until then exploring twist options so I can have a beginning point of discussion.

 

[chorizo]

Point of reference: I believe guns are tools besides being works of art. I am also a carbine fan.

I have 50 cal with fast twist and 21" barrels, I have 54 cal, fast twist from 21" to 26" barrels. This rifle will fill the top end 58 cal niche with a fast twist and 24" barrel.

All are conical shooters.

 

[villagelightsmith]

Chorizo, I too am putting a .58 Caliber together. A custom underhammer (maybe 2!) with a choice of sights. from peep and ladder to long brass and glass. I, too, need to pick the brains of other shooters about twist for big, long, conicals. I am getting kinda long in the tooth, so I no longer have the time to make all the mistakes by myself. If anyone has any actual experience with these not-quite-big-bore front-stuffers I would sure like to benefit from your experience.
I've been fooling around with blackpowder for the last 60 years, but this will be my first .58 cal. Probably a Chunk Gun for long range conicals. Please, real experience or observation only!
I have seen too many people who will chime in from their inexperience and depth of ignorance. If that's what I needed I'd do it myself. I already know that round balls use different twist; how fast for the big conicals?
My other smokepoles range from .32 to a .69 smoothbore, a couple of shotguns and a 1.75" golfball bore (O.D.4") "signal cannon" that takes about 1/4# of the Righteous Black every time I light the fuse. It's a lot of fun, much giggling and laughter as the fuse burns down, and "Fun!" is the reason we shoot these stovepipes. I recommend it highly. But if you could spare a minute or so to lend me a starting point for the twist, I would be most appreciative. Thanks!

 

[chorizo]

I am heading out today to do some accuracy checks. I will pm you on Saturday with some ideas, calculations and what I have so far. I am burning powder for a couple of days putting some theories to test

 

[longcruise]

I suggest applying the Greenhill formula and go abit faster than indicated for the longest bullet you would anticipate shooting. It's definitely not an etched in stone formula.

There won't be many here with hands on experience with this.

 

[tenngun]

Is .58 a good idea for this?
That would be a whumper of a bullet. However even if you ‘load for bear it’s going to be on the low end of velocity. Drop will be a killer. You will have a killer at two hundred yards but would over shoot a hundred or drop off the paper if hundred is your zero.
I note that when about .58 was THE choice for military minnie guns but their long range ‘snipers’ were in the .45 range. Faster and flatter even though over an ounce
No I have NO experience for big fast tweist guns, I’m a dedicated round ball shooter and have went the opposite direction then you, but just a thought experiment noting how the old military found.

 

[Uncle Miltie]

My 35 lb .56 caliber slug rifle shoots a 977 grain paper patched bullet quite accurately with a 1/18" uniform right hand twist.

 

[Dobegrant]

Another Thumper in the making, have no input that would help but I also like short barrel rifles. I do not have any custom ones, my favorite muzzle loader is my Lyman Deer stalker in .54 cal

 

[64Springer]

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[chorizo]

Well, short note as it is late. Mixed bag today. The 58 was showing excessive pressure signs with the 560 grain bullet.. Hammer blowback, so it was set aside. I am afraid I will have to go back to a lighter bullet. The 54s gave me some good groups but it was a bit of a chore getting there. More tomorrow on a seperate thread on accuracy

 

[Rifleman1776]

Is .58 a good idea for this?
That would be a whumper of a bullet. However even if you ‘load for bear it’s going to be on the low end of velocity. Drop will be a killer. You will have a killer at two hundred yards but would over shoot a hundred or drop off the paper if hundred is your zero.

Tenn covers a lot of territory with that reply. Yes, a smaller round ball will kill 'em just as ded as your proposed whomper stomper. Yes, the recoil will be very uncomfortable. Yes, aiming in the field with a heavy bullet is a very iffy matter. Personally, I see no logic in your choice. But......this is a do yer own thang game. I wish you luck.

 

[Pukka Bundook]

Chorizo,
A lock with a vee spring would help prevent the hammer blowing back, but still it will be a thumper in that stock.
My thoughts would be a good bit faster twist, but as this project may be set aside, this is academic.

Greenhill formula as already mentioned, is a very good place to start!

 

[chorizo]

Tenn covers a lot of territory with that reply. Yes, a smaller round ball will kill 'em just as ded as your proposed whomper stomper. Yes, the recoil will be very uncomfortable. Yes, aiming in the field with a heavy bullet is a very iffy matter. Personally, I see no logic in your choice. But......this is a do yer own thang game. I wish you luck.

No round ball shooting..not interested at all in that,; no, recoil is not very uncomfortable, it is no worse than a high base 12 ga load and the reason the 58 might be a poor choice is the dearth of conical bullets without skirts in the low 500 gr range that I will be able to push to the velocities I need.

Aiming in the field with a heavy bullet is just like a light bullet. Know what your ballistics are and aim appropriately.

As for logic, thanks for your input. I will give it due consideration since you don't understand my logic therefor you can't follow where I am going. Thanks for the good luck wishes....as with anything like this there is certainly a bit of luck involved because no matter how much calculating and programs you run, shooting is where the rubber meets the road! If I could find a conical in the Plains style in 510-525 grain I think it would work, but as I am not willing to cast my own, I am stuck with the commercial offerings which are slim pickings at best.

But as I can achieve what I want with the 54 cal, the 58 cal might just be a fool's chase and an answer to a problem that doesn't exist!

I do have two more barrels coming with 1:32 twist in both the 54 and 58 in 22". The 58 might be relegated to shooting 440 gr REAL bullets, but that provides me with no advantage over the 54 cal.

 

[Sun City]

You're in for a good learning session!!

 

[chorizo]

Chorizo,
A lock with a vee spring would help prevent the hammer blowing back, but still it will be a thumper in that stock.
My thoughts would be a good bit faster twist, but as this project may be set aside, this is academic.

Greenhill formula as already mentioned, is a very good place to start!

On review of what went down, I believe the blow back was caused by the nipple letting go as it appears the threads were rusted out. Inserts coming and I will tap and thread and put a carbon steel insert in and give it another try.

I concur on twist and I have a 58 cal 1:32 twist barrel at Bobby Hoyts as we speak and the 54 22" 1:32 twist will be here on 20 Mar....it is in the mail

If you go about things analytically and plan, document and try things, you are damn right, it is a learning session. I don't think it is a lost cause yet. I get the nipple repaired and I will start a slower approach and see what I get.

I am not done with it yet!

 

[villagelightsmith]

You're in for a good learning session!!

That's what they told me when I got a mule instead of a horse!

 

[chorizo]

That's what they told me when I got a mule instead of a horse!

Having used both on the ranch growing up, I would rather work with a mule than a horse any day. Just got to approach them like a thinking animal, unlike a horse, that rarely thinks and each experience they have is like the first..

 

[chorizo]

Is .58 a good idea for this?
That would be a whumper of a bullet. However even if you ‘load for bear it’s going to be on the low end of velocity. Drop will be a killer. You will have a killer at two hundred yards but would over shoot a hundred or drop off the paper if hundred is your zero.
I note that when about .58 was THE choice for military minnie guns but their long range ‘snipers’ were in the .45 range. Faster and flatter even though over an ounce
No I have NO experience for big fast tweist guns, I’m a dedicated round ball shooter and have went the opposite direction then you, but just a thought experiment noting how the old military found.

Yeah, but they weren't using modern powders, modern design conicals and were looking for a fast loading military style gun......all of those things I am not. Different set of parameters and different goals and uses. Not convinced that the military requirement would ever give me what I want, so I am only tangentially using their designs.

I see no reason yet to give up on a 58cal....but it is looking like a 54 cal will provide me what I want with a greater variety of bullets to choose from.

 

[Old Hawkeye]

A 580 grain bullet @ 1500 fps? Like Sun City said, you are in for a "good learning lesson".

 

[tenngun]

Yeah, but they weren't using modern powders, modern design conicals and were looking for a fast loading military style gun......all of those things I am not. Different set of parameters and different goals and uses. Not convinced that the military requirement would ever give me what I want, so I am only tangentially using their designs.

I see no reason yet to give up on a 58cal....but it is looking like a 54 cal will provide me what I want with a greater variety of bullets to choose from.

Well I was thinking the long range sniper rifles, that weren’t built for speed loading.
I don’t know that our powder is much better than that used during the WBTS.
Based on ballistic test then with pendulums and today with chronographs velocities are the same. And we see the marked drop in powder charges even though the fat minnie was in flintlock musket ball part weight
I didn’t mean to be disparaging of your idea. A gun that makes you smile when you shoot is what you need. There is no crazy idea with a fun safe gun
I have no use for a blunderbuss, or a cannon, I’m not to much in to pistols. But they’re all neat, I like to see them even though I wouldn’t own one, ant their owners get a ‘blast’ out of them….. and that’s what counts