Experiment: 458 Win Mag case with lead bullet and black powder?? Doable??

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  • Last Post 03 September 2010
corerf posted this 06 June 2010

Contemplating rebarreling a 300 win mag mauser I own to 458 win mag and shooting 500 gr cast over black powder, a poor mans 45/70. I am stuck with the mag bolt face and dread shooting the poor performing 300 win mag. So the 458 win mag has much data for 500 gr bullets and larger using 5744 for powder, the typical BP substitute for low and slow shooting.

So what if I dedicated the rifle to BPCR and shot some big 500gr cb's over 100 gr of BP??

Theres certainly no pressure issues with rifle, chamber or brass. I dunno twist rate that's best but the adams and bennett barrels are 1-14".

Would the 1-14 blow out at 1600 fps and strip being too fast, since a 45/70 is normally “around” 1-20??

Anyway, I would like to take the beater and do a simple rebarrel and I either go back to a new 300 win mag, which unless I become a mil sniper as new occupation, will go UNUSED.......  or I change it to a 45 cal that the bolt face will match and shoot big cast but I really want a BPCR to play with. Worst case is if the BPCR doesn't work, I'll load 5744 and shoot cast anyway, low and slow and lob them in just the same.

Any thoughts??

Thanks in advance

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tturner53 posted this 06 June 2010

I can't offer any useful advice, but it sure sounds like a good idea to me. One of those just for the hellovit projects. I'm going to try my new H&R .444 Marlin barrel with bp, why not? I don't even know if the .458 is a bottle neck, but if so that may be a consideration. Don't see how you could exceed factory ammo pressures though. Funny, but I have an old Rem 700 in 7mm magnum, thought about going to the .300 Winchester to have a more useful chambering, like military sniping for instance. You could always sell the .300 and buy a 45-70. Lots of different ones available, all price ranges.

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Dennis Jorgensen posted this 06 June 2010

Get Paul Matthew's Book 40 Years of rifles. You can find some of your answers.

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corerf posted this 06 June 2010

TT,

the belted mag case is a 65kpsi case. I can't imagine ever exceeding (with proper case filling) that pressure. But you mentioned the bottle neck. It's not a bottle neck, just tapered.

Looks like your 444 marlin but twice as BIG

I hate to loose a GOOD K98 mauser to trade to a BPCR. But your right, thats an option.

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Daryl S posted this 07 June 2010

You can shot BP easily and effectively in any straight or almost straight large bore ctg.

My Sharps .45 has an 18” twist and works well with any lead bullet and black powder. You .458 will too.

Grooved lead, jacketed or paper patched?

With jacketed bullets to 500gr., you will get comparable accuracy or better accuracy than the gun shoots with smokeless powder. No wiping necessary.

With cast grooved or paper patched bullets, if a proper lube and enough of it is used, you should be able to shoot up to 20 consecutive shots without having to wipe the bore, and the first dry patch should push ALL the fouling out the muzzle. You might have difficulty getting more than about 85gr. of 2F in the case along with the requisite wads and bullet.

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JetMech posted this 07 June 2010

With the 458 case, you effectively have a 45-90, a great cartidge in it's own right. Capacity of your case is about 2% less. 1:14 twist will handle any of the heavy weight 45 bullets, so you should have a good combination.

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corerf posted this 07 June 2010

45-90, thats a nice comparison. I wanted more than a 45-70 but on a bolt action.

Now I read an article (last night late) about the 458 LOTT on a ruger #1 used with BP, overcame any taper in 458 WM and holds more powder. I can rechamber the 458 WM mauser to the slightly longer 458 LOTT, supposed to be the ultimate 458 ..... with any powder. The author started with 458 WM in mind but them went for the LOTT to improve the cartridge.

I know I cant cycle that long a case thru the bolt or magazine, it will be effectively neutered into a S/S rifle, but thats the point.

I think this is doable and I sure appreciate all your help folks.

Thanks

Mike

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argie1891 posted this 07 June 2010

i built a 458 mag on a mag. mauser action that was given to me. it was in 7mm mag and someone had bent the blr. i really don't like magnum rifles so i call mine a 45-90 belted express rifle. i have only shot a few with black powder but it is fun to shoot and recoil is very manageable. i have lyman 457124 457191, and 457406 for moulds. I will never shoot a round approaching top loads as i don't really like recoil. for loading i filled the case and let the bullet compress the 2f black powder so far i haven't really tried to shoot great groups just kinda plinked with it. i plan on spending some time working up some accuracy loads soon. it should work well for sage rats as they weigh about the same as the bullet. Joe Gifford

if you think you have it figured out then you just dont understand

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RicinYakima posted this 07 June 2010

Come on Joe! You know that they weight at least 10 times as much as the bullet and have sharp teeth and charge like tigers!

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corerf posted this 07 June 2010

Joe, thats awesome, a report of success.

I think the LOTT is out due to additional cutting to get even a single round to feed and extract properly. I may try it with 458 WM brass and then see if the Hornady Belted mag Basic brass could get me another 1/10 inch of case length and I'll wildcat my own case length. It's just a reamer push a bit further.

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argie1891 posted this 07 June 2010

i almost went with the 458 2 inch as i think less is more when working with a case this big. a 45/70 is 2.1 inches long the 458 2 inch should be a belted 45/70. joe gifford

if you think you have it figured out then you just dont understand

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argie1891 posted this 07 June 2010

ric. i had to shoot one because he was making obscene gestures at me. I shot him with a 30/06 wih the rcbs 180gr. fp. and 19 gr. of 4759. at least i taught him to fly when the bullet hit him. joe

if you think you have it figured out then you just dont understand

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Vassal posted this 07 June 2010

This is a pretty nice idea. 458 win mag with cast! I love this forum, and the CBA:cba::cba::cba::cba::cba::cba::cba::cba::cba:

Good job guys thanks for the thread.

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Daryl S posted this 11 June 2010

Now - if you have a bolt gun in .458 2", and desire a bit more ooomf - I used a .450 Alaskan reamer to re-chamber a 2". I turned the rims off to .532", cut a new extractor groove - a 20 second job per case on a small lathe with re-ground tool to cut the rim groove. I called it a .458 Alaskan. At 2.1", any length bullet, including 600gr. can be used in a standard action.

The resulting case has slightly more capacity than a .458 Winchester. 2,200fps with 500gr. was easily accomplished & cast shot as well as jacketed - sub 1” at 100 yards - you just have to learn to hold it steadily. Oh yeah - due to the barrel having a long straight section ahead of the action, I set the barrel back after a year of heavy recoiling bliss and re-cut the chamber back to .458 2". I “loved” that round. Not as high velocity as handloads in a .458 Mag, but easily did 2,060fps with 500gr. jacketed & cast - of course, anything lower in speed shot splendidly as well, including as light as 300gr. cast.

After 15,000 rounds in the .458 2", torn cartilage front and back in my right shoulder, I sold the .458 to a buddy for his guiding rifle and swore to stay with my .375/06IMP as my 'heavy' rifle, for cast and jacketed.

The .450 Alaskan & .458 Alaskan, both with 500gr. Lee W/GC - solid 7/8” to 1” @ 100 meters @ 2,000fps - straight WW alloy.

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Mnshooter posted this 03 September 2010

Most people are confusing cartridges over rifle types. A long range BPC rifle will boast a barrel of about 30+ inches, often 34 inches with 1-18 twist and rifling designed for cast bullets. Slower twist for fouling. A modern gun like a bolt 458 has a short barrel and jacketed bullet rifling. When I tried a 8mm Mauser with BP I could get it to work, but was not impressed by the performance. The old 303 BP load was for the Lee Metford rifle with metford rifling. Using BP in a modern rifle depends upon your expectations. You may get passable accuracy, but it may not be near what you can get with a gun designed for BP.

Mnshooter.

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Ed Harris posted this 03 September 2010

If you shoot blackpowder or Pyrodex, the narrow lands and shallow rifling form of most .458 Win. barrels doesn't cope with BP fouling well. You would need to wipe between shots. If you shoot smokeless loads at normal cast velocities, the .458 works just fine for that. You want a 400-520 grain flatnosed bullet with large diameter bore-riding forepart to take the rifling. Great idea for next CBA-LBT group buy!

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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corerf posted this 03 September 2010

Ed, I sold the rifle. I have purchased a large estate in whole and have been filtering thru the keepers and the movers. There were NO BPCR's, that may be a good thing. I probably don't need a shoulder crusher anyway.

Additionally, I have missed see your input on the forum. It's nice to “read” you again. I know you have been “here” but haven't seen so many post recently.

Hope all is well with you./ Mike

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