Home Forums Lever Action Central Lever Actions - General Action strength and CUP, again.

I have been shooting lever action .44's and 45-70's for quite awhile and now have a Big Bore .356 Win. and a Mirkoru Mod. 71 in >348 Win. I have run across more conflicting information on the strength and ability to handle pressure of lever action rifles then with any other type of action. Some of it says a Big Bore .356 Win. can handle 52,00 cup and the Mirkoru made .Mod. 71 in 348 Win. can only go to 40,000 cup with one gun writer saying it is a 48,000 cup rifle. Others say a modern 1886 Win, is a 50,000 cup rifle and the modern 1895 Marlin 45-70 is a 40,000 cup rifle. It seems like no one will ever agree on what the "modern" rifles cup or psi rating is.

Why would the Mod. 71 Win. only be a 40,000 cup rifle if the Big Bore .356 and 1886 are rated to 50,00 cup or higher. I thought the Mod.. 71 was the pinnacle of lever action design in the opinion of many?

Gets confusing, if it were bolt actions or single shot rifles there would be a consensus, not so with even "modern" lever action rifles. I understand it when using "old" rifles with different steels and designs compared to today's "modern" versions. I also realize one should always follow the guidelines from a loading book, yet, even they have bigger differences with lever guns then with other types of actions.

Also, Starline makes rifle brass for the .348 Win. and 45-70, etc. Is it better then Win. brass in terms of strength and consistency? I now they charge a bunch for the .348 brass.

Read this just to make it more confusing for ya...


http://castboolits.gunloads.com/showthread.php?6998-Buck-Elliot-s-454-Casull-levergun-test-Part-1

Good read and I think I might have read it before. The real question for me is the strength difference between a "modern" Mod. 71 and 1886 Winchester. Is there a difference, does any one on earth really know? LOL......

And what about that .348 Starline brass?

I would think the 71 could go as high in pressure as the 1886, one limiting factor may be the larger case head area of the .348 and the increase in pressure against the bolt.

Hey Vic,

I think the .348 case head the same as the 50-110 that was chambered for the 1886? Also, lots of articles call the Mod. 71 a new improved and strengthened version of the 1886. That makes no sense to me if it operates at a lower pressure. So I really don't know how it is improved or strengthened. I doubt any Alaskan critter I put hole in will much care about any of this, but in this day and age I would think some where there is an answer,

Below is a link to an interesting discussion on action strength with comments from Doug Turnbull :

http://forums.accuratereloading.com/eve/forums/a/tpc/f/8721043/m/9481037881?r=5201049881#5201049881

The 71 has the locking blocks at a slight angle to the bore (like the 92) while the 1886 they are vertical to the bore. So... the 86 would be stronger between the two but since they are parallel if you get to hot you run the risk of seizing the action. I doubt anyone is going to blow either action anytime soon. Theres a guy on YouTube that has some hot loads for his 50-110 1886 (custom built on a Miroku frame).

Winchester said the slight (2 degree) angle of the locking bolts was to handle the increased pressure from the 348. Buck Eliot’s 454 has vertical locking bolts and he told me the angled bolts in my model 89 500 s&w were a mistake. The first one in built had angled bolts and I tested it. Like sticking cases in it which is over 100k psi according to my friend at Western powders.