[oldred]

I am looking to barrel a replica 1885 Highwall with a 45/70 barrel but the only barrel I can find to my liking is a Green Mountain Black powder cartridge barrel, I want an octagon with an 18" twist. Shilen has one that I might also consider but it is round with a 20" twist and is also for black powder cartridges. My question is if I use one of these are they the same from a standpoint of strength as the barrels sold for smokeless cartridges? The Green Mountain barrel is made from 4140 and is a heavy barrel but should it, or the Shilen, be limited to black powder 45/70 pressures? I am NOT looking to hotrod this thing I just would like to be able to use the same less than max loads that I use in my Marlin but I certainly don't want to take chances. Is there any real difference in strength for a BPC rifle barrel?

I know I could just ask the manufacturers but I had a friend do just that and he could not get a straight answer, liability reasons I guess and basically they just said that BPC barrels are best used with black powder or BP substitutes.


These barrels I am considering are not actually "45/70" but are un-chambered 45 caliber BPC blanks.

 

[tacklebury]

Many folks who own the BPC sharps knock-offs use mild trapdoor level loads in them with smokeless. I currently make some trapdoor level loads using Reloader7 which is a good .45-70 powder and my favorite. I get good accuracy and clean bore shooting it. I load for a .45-70 Buffalo Classic which is a modern, but my wife cannot stomach my 46.7 gr. RL7 loads, so I load up 325gr. FTX bullets behind 34.3 gr. Reloader7 for her, which represent a very close approximation to trap door speeds. With the Reloader7, it's more of a push then a kick, even in the higher power loads. It is my opinion that the lower level loads like my trap door load of 34.3gr. would be fine. Just keep in mind that the lock/action is the second portion of your rifle's strength and if you are making one, you need to be sure that your action can handle what you intend to do. Good luck and be safe.

 

[crazydave]

What was the original caliber of the gun? I ask because I've seen "replica highwalls" in modern, high-pressure chamberings. If the gun is/was chambered by the maker in modern calibers, I'd have no issues with using a BPCR barrel blank for standard .45-70s if it was mine. FWIW....

 

[oldred]

Actually it is a new receiver that has been machined from 4140 HT and while it probably is as strong as a modern factory replica, maybe even stronger than some of the imports, I would never attempt to chamber it for a high pressure round like a 458 Win for example but I have no worries about the receiver handling 45/70 loads for the Marlin however. I was just unsure about the barrels and why they are listed for BPCR rounds when they also list somkeless barrels for the same 458 bore. I guess the reason could be due to the different twist rate but since that is just a guess I needed to do some research and find out for sure. I could just use a blank that is sold for the 458 Win but the twist rate of 1-14 is probably to fast for the 45/70 and the lead bullets I intend to shoot most often.