.458" Bore Fast Twist

[Good Cheer]

I'm pondering getting a .458" bore with a fast twist. And, looking to pick folks brains before I do.
This will be a 1" across the flats GM barrel rebored to the new caliber.
If anyone has tried this please let me know. Would love to hear about the twist, chosen rifling pattern, barrel length, molds tried, powder charges and how those choices worked out for you.

My current plan is a modified TC Renegade with shotgun butt and the fore end trimmed back, glassed in 30" barrel turned octagonal to tapered round, tang ladder rear sight, sling. The RCBS 405gr and Lyman 475gr molds, card wad punch, rifle, barrel, sights and all the hardware are in hand. Still haven't settled exactly on the twist and rifling pattern. And haven't settled on which lock to use: Leaning heavily towards the L&R flint.

So, who's been working with a 46?

[Nobade]

I think you will find extremely short vent liner life using a flintlock with bullets. Platinum liners are going to be almost a requirement and make sure nobody is standing to the right of you when you touch it off.
Percussion bullet guns are a much better way to go, you get more out the muzzle and less out the side.

That said, I don't know what a rebore of that size would cost (Have you found anyone to do that? I would like to know who) but Kreiger makes barrels that size as regular production items. Last time I looked they had a couple in stock, though I don't think they were as long as you are looking for. I think that would make a dandy muzzle loader, with a 1:18 or possibly 1:16 twist for long heavy bullets. You will be generating some serious pressure though, it needs to be built way stronger than a ball firing gun. Pay attention to your breech plug design, don't use anything weak.

[Good Cheer]

It's a .40 GM percussion right now. Mr. Hoyt can do .458 bores and will be my first choice as I am happily familiar with his work (made my .62 sing!). And I'd really like to try a fast twist in a flinter.
Was leaning towards the .47 bore for a long time to use .475 pistol bullet molds and paper patching 45 rifle molds. But, thinking now that the .458 bore would be a better mouse trap.

One of the factors I'm really curious about with a flinter is shot to shot variation due to vent diameter. Been trying to get a .577 minie flinter barrel together on a Renegade...not yet.

[John Taylor]

I had a custom barrel made by Jerry at Orion barrel many years back, was supposed to be for a 45-70 with deep rifling. Turned out with a .450" bore and a .465 groove with 1 in 22" twist. I mounted it on a rolling block but never got around to finish it. Made a chamber reamer to take 45-70 brass and a .465 bullet. Latest thought it to take it off and build an under hammer action for it. It would still be 33" long after cutting the chamber off.
One of the things I played with years ago was making inlines from H&R shotguns. Made a couple in 54 cal with 1 in 22" twist and used a portion of the barrel to make a bullet sizer. Sizing the bullet through a shot piece of barrel that has been shrunk down .005" works great. You end up with a mechanical fit to the rifling and easy loading, plus good accuracy.

[Good Cheer]

Something else I should try...

Had wrapped up an old Renegade 54 flinter barrel to send it off for rebore to .58.
Before reboring I'm gonna try it out with the maxi-hunter and the REAL to build up some more data. Would like to see if there are any definable vertical stringing effects at 100yds with the flinter.

[idahoron]

I have one. Mine is a Green Mountain .458 with a 1-18 twist. I use a Lee 405 HB paper patched. It has a Lyman 57 SML peep and a Lee shavers globe with a level. It is a far speaker. Ron

http://i223.photobucket.com/albums/dd294/idahoron/458bennitmountainmag2.jpg

[475BH]

I'm pondering getting a .458" bore with a fast twist. And, looking to pick folks brains before I do.
This will be a 1" across the flats GM barrel rebored to the new caliber.
If anyone has tried this please let me know. Would love to hear about the twist, chosen rifling pattern, barrel length, molds tried, powder charges and how those choices worked out for you.

My current plan is a modified TC Renegade with shotgun butt and the fore end trimmed back, glassed in 30" barrel turned octagonal to tapered round, tang ladder rear sight, sling. The RCBS 405gr and Lyman 475gr molds, card wad punch, rifle, barrel, sights and all the hardware are in hand. Still haven't settled exactly on the twist and rifling pattern. And haven't settled on which lock to use: Leaning heavily towards the L&R flint.

Wouldn't you need to have a false muzzle and starter made also?

[idahoron]

No false muzzle would be needed if the bullet and paper is sized correctly. I have several rifles that all shoot paper patched bullets no false muzzles needed. Ron

[Good Cheer]

I have one. Mine is a Green Mountain .458 with a 1-18 twist. I use a Lee 405 HB paper patched. It has a Lyman 57 SML peep and a Lee shavers globe with a level. It is a far speaker. Ron

http://i223.photobucket.com/albums/dd294/idahoron/458bennitmountainmag2.jpg


Hey Ron.
Could you tell the rifle weight (32" barrel?) ?

[DIRT Farmer]

Just for the smart allack factor, I have been wanting to build a flint bullet gun. From my experiance using a 45 cal bullet gun as a poor boy long range gun, stainless nipples have a life of as little as 5 shots to auto half cock. My 54/28 ga trade gun loaded mostly with 1 oz of shot over 75 grains of ffg will toast a touch hole liner a year.
I still want to build a flint bullet gun, will use a Grean Mtn. 45 1/18 barrel set for PP after I talk to the guy about the possibility of building a platium touch hole liner.

[Good Cheer]

Fellas, while we are on the topic, is there any reasons why you would recommend another bore diameter other than .458?
I've worked with the .50 LRH from GM (and will probably never really be done entertaining myself with it) and pondered .470, .510, .520... any opinions are welcome.

[NickSS]

I hhave an acquaintance who shoots long range with a ML Parker Hale Volunteer rifle. It is 45 caliber and the bore measurs .451 accross the lands and .458 groove diameter. He shoots sized Lyman 480 gr pure lead bullets over 130 gr of FG. His twist rate is 1 in 20. I have seen him shoot a 48 out of a possible score of 50 at 1200 yards with that combo. He drops the powder down a long drop tube, follows it with a card wad then a lubed felt wad then the bullet. The bullet is lubed and slides easy down a clean bore. He whips the bore after each shot before reloading.

[rhbrink]

Just my .02 cents worth I think that Nodade is right. I know that the English built some fine shotgun flinters which shot a similar charge weight wise but those were much larger bores. The smaller bore the more pressure and the few that I have worked with it seems to take a serious charge to make a 45 boolit work in a muzzleloader. I just feel that you will treading on a dangerous situaton with a touch hole large enough to make a flinter fire consistantly and all that pressure building behind it. If it stayed together I for sure wouldn't want to be within a 100 feet of that lock side.

Another thought and I hate to even get started on this just because it gets beat to death and is for the most part totally stupid but to me a Flinter and round patched balls just go together like beer and brats. So I'm going to say it is if anything a flintlock should be kept "Traditional" if you want to experiment with a capper go for it.

I think the bore size would be just fine plenty of molds to work with no problems there.

Good luck with whatever you chose to do please let us know how it works out.

Richard

[Good Cheer]

Just my .02 cents worth I think that Nodade is right. I know that the English built some fine shotgun flinters which shot a similar charge weight wise but those were much larger bores. The smaller bore the more pressure and the few that I have worked with it seems to take a serious charge to make a 45 boolit work in a muzzleloader. I just feel that you will treading on a dangerous situaton with a touch hole large enough to make a flinter fire consistantly and all that pressure building behind it. If it stayed together I for sure wouldn't want to be within a 100 feet of that lock side.

Another thought and I hate to even get started on this just because it gets beat to death and is for the most part totally stupid but to me a Flinter and round patched balls just go together like beer and brats. So I'm going to say it is if anything a flintlock should be kept "Traditional" if you want to experiment with a capper go for it.

I think the bore size would be just fine plenty of molds to work with no problems there.

Good luck with whatever you chose to do please let us know how it works out.

Richard

Yep, those are many considerations that I myself have been going over.
This being a TC Renegade, the published TC data is being looked at. Here's what my TC pamphlet says for max loads in their flintlocks. This of course is with their hardware, not a GM rebored to a different twist and groove.

45 Percussion & Flintlock
100 grains FFg with 320 grain bullet, 1612FPS

50 Percussion & Flintlock
100 grains FFg with 470 grain bullet, 1416FPS

54 Percussion & Flintlock
120 grains FFg with 540 grain bullet, 1396FPS

58 Percussion & Flintlock
120 grains FFg with 560 grain bullet, 1331FPS

Wow. My 54 maxi-hunter mold weighs in at only 430 grains.
And, the max load info TC gave for all their calibers is really pretty remarkable when thought of in terms of BP cartridge performance.

A major consideration is indeed how much powder it would take to get a given bullet to percolate in the chosen twist. The less the better. After having worked with fairly rapid twists in muzzleloading I have reservations about a 45 with an 18" twist. An open sight hunting rifle just doesn't need an 18" twist suited to 1000 yard target shooting. Punch .46 caliber with a 1" long slug into a Greenhill formula calculator; a 30" twist works.

However, as may concern the concept that flintlocks should only be used with round ball...as an interest in muzzleloading I specifically wish to learn how well flintlocks can perform with minies and solid based bullets.

[idahoron]

GC, my renegade weighs 9.750 pounds unloaded. The rate of twist you will need depends on the type of bullet you want to shoot. I like the Lee 405 HB they are 1.048" long. I think they are at the short end of what this twist is good for. Here are a couple of pictures of groups with that bullet.

http://i223.photobucket.com/albums/dd294/idahoron/6shotgroup100yardsTC458.jpg
http://i223.photobucket.com/albums/dd294/idahoron/11-24-07--45-70.jpg


I also have the Lyman "whitworth" mould. Those bullets weigh 475 gr and I have had good luck with them both paper patched and naked.

http://www.hunt101.com/data/500/22507-7-07_whitworth_2_5.jpg
http://www.hunt101.com/data/500/22507-7-07_whitworth_1_5.jpg

[Good Cheer]

Thanks for the info Ron. Reckon I can whip out the calculator and figure the weight change for thirty inch and transition to tapered round.

That .54 Renegade flinter barrel I was going to try out with REAL's and maxi hunters to check for vertical stringing... unwrapped it and tried it out. It was as rough as I'd thought it was. No wonder I boxed it up. Off it goes to be reborn as a handily abbreviated .58.

[John Taylor]

Another thought. Does the person doing the rifling have the size cutter box for the size you want? Most barrel smiths have the sizes for standard bores but to do an odd size requires a special cutter box be made for that size. A 50 cal would use a size .500" and cut grooves out to about .520" To do a barrel with a bore size of .458 would require a box that size, most 45s would need a box that is .440, .444, .446 or .450 depending on if it is for a pistol or rifle.

[Good Cheer]

Another thought. Does the person doing the rifling have the size cutter box for the size you want? Most barrel smiths have the sizes for standard bores but to do an odd size requires a special cutter box be made for that size. A 50 cal would use a size .500" and cut grooves out to about .520" To do a barrel with a bore size of .458 would require a box that size, most 45s would need a box that is .440, .444, .446 or .450 depending on if it is for a pistol or rifle.

Yep, he does.

[Boz330]

Just for the smart allack factor, I have been wanting to build a flint bullet gun. From my experiance using a 45 cal bullet gun as a poor boy long range gun, stainless nipples have a life of as little as 5 shots to auto half cock. My 54/28 ga trade gun loaded mostly with 1 oz of shot over 75 grains of ffg will toast a touch hole liner a year.
I still want to build a flint bullet gun, will use a Grean Mtn. 45 1/18 barrel set for PP after I talk to the guy about the possibility of building a platium touch hole liner.

That ought to be cheap. That little tiny piece of platinum in the nipples is $50+. You will have as much in the liner as what the barrel costs.

Bob

[DIRT Farmer]

BOZ, I can get away with telling my wife I am buying up platium to have some jewlery made for her. (right)
Wish I could be in Oak Ridge this weekend.

[Good Cheer]

http://i791.photobucket.com/albums/yy192/SNARGLEFLERK/45-70molds.jpg
Would like some input fellas.
With 45 rifle bullets with these lengths, how slow of a twist can you get by with?
Do you go by the barrel contact length only?
I'm hoping to go with the very slowest twist that will work. Past experience has shown that the very fast twists used for typical "long range" rifles are what is required for extreme long distance shooting and not bullets that would be considered medium weight for the bore size.
So, what say ye? What's the best way to figure the twist that will be needed?

[rhbrink]

I'm sure that you have looked at the Green Hill formula? I pluged in some numbers and came up with the maximum length of 1.12 inches. I don't think the green Hill formula is all that accurate because it doesn't take velocity into account but it might get you into the ball park. That would give you a boolit weight of about 425 grains more or less I wouldn't go any slower that a 28 inch twist for myself.

[Good Cheer]

Yeah, I think you're right.
Any way I go about it, it comes up as around 28" twist to be safe with these molds in hand. Greenhill, comes up as about a 33" twist for the longer mold and 37" for the short one.
It is all a matter of trade offs, getting the RPM's needed and also trying to avoid excessively fast twist as much as possible.

The more I look at this...I keep coming back to the first project path, a .47" bore to use with paper patched .46" rifle molds, .476"/.480" pistol molds sized to be used as maxi's without paper and .465" tight patched round ball with light loads. Would probably work quite well with a 28" twist, .47" bore, seven or eight lands and grooves of equal width. Probably would get a rifle mold tweaked by Erik to bring the diameters up with straight lead.
Ah, decisions, decisions.

[rhbrink]

All very interesting I like the idea of having the barrel bored to use existing boolit designs makes for a lot of sense to me. I really think that if you were to go with the 28" twist that it would work just fine from .460 to .500 boolit diameter for a hunting weight boolit. Now if you were to shoot long range different story. Hope that you keep us informed of the results.

Richard

[Good Cheer]

Well, I finally stop agonizing and settled on a design. Just printed out the letter to accompany the order.
Of the two molds intended to use, the heaviest is the Lyman 457121P that drops out at 0.453" diameter with straight lead. That will be my paper patch bullet. The other is the RCBS 405 grain.
Rather than rebore the 38" long Green Mountain barrel and chop it to be a .47 shooter hunting rifle on a Renegade, my old south paw .54 New Englander with the QLA is going to be sleeved. It's 1.06" at the breech and 0.915" at the muzzle.
0.458" bore diameter.
0.470" groove diameter.
Seven grooves, round bottom, equal with lands.
1:24" twist.
And that's the plan for my brassless 45 hunting rifle...unless I decide to make the barrel longer instead of just using a liner.

[idahoron]

That Lyman 457121PH is the mould I have that I called the "whitworth". If you look at the Lyman web page they recommend at least a 1-20 twist for that bullet. I have had good luck with it in my 1-18 twist .458 Renegade. I have not shot it in my 1-28 twist because it is a .451. Ron

[Good Cheer]

Well, Ron, thank you for the information. Reckon I'd better crank her up to 20"?
I puzzled and pondered the relative merits of different twists and convinced myself that 24" would be quick enough. But, you don't know until you get there.
She's already in the mail now to get rejuvenated but there's nothing that says I can't change the twist.

[Good Cheer]

It's here! Yippee!
Time to fire up the lead pot.

[rhbrink]

Well where's the report hows it shoot?

[Good Cheer]

Manana amigos!
Think it needs a TC tang peep.