Please explain differences in M71 and 71/84 Mausers.

[W.R.Buchanan]

OK guys, I have a friend who has a M71 Mauser, and a 71/84 Mauser. Both are in .43 Mauser but apparently one has a much larger bore than the other. One shoot PP boolits great the other sprays them.

He has made cases out of .45-90 cases as recommended on the Case Forming Forum but they only fit in one of the guns.

He wants me to ream out the chamber so that these cases will fit both guns. I am not going to do this, but instead find out exactly what is going on that is different between the guns.

Can anyone give me some idea of changes in bore/groove sizes made between these 2 models. There is @.020 difference in the slugs of his guns. I need to know if this normal or if his guns have bad barrels. Bboth are pretty nice looking guns and the bores look nice and shiny.

He wants to be able to use the same loaded rounds for both guns, but I don't think that is going to happen. I certainly don't want to alter the chamber on one of these guns which would be a one way trip, and ruin the value of the gun and make it more difficult for the next owner to deal with.

Just need to know a little more about any differences these two models might have.

All info appreciated.

Randy

[Mk42gunner]

Silly me, I thought the only difference was the 71 is a single shot and the 71/84 is the repeating next generation. Here is a link I found the that explains the groove diameter change: http://www.militaryrifles.com/Germany/71-84Mau.htm

Robert

[Gunor]

http://castboolits.gunloads.com/showthread.php?5007-loading-for-the-43-Mauser-11mm-Mauser

See if this helps.

[W.R.Buchanan]

Robert: Thanks so much for the link. It explains the differences in the groove dia.

Wondering if the chamber area near the neck of the cartridge is smaller dia. on the 71/84?

This is what he wants to modify. His gun is in pristine condition and I am not going to be the one to change it, but hopefully I can talk him out of it.. He is 94 years old and shoots with us twice a month without fail and is highly intelligent. He was a Commercial Diver back in the day. I have found most divers that weren't all that smart,,, are now dead.

Randy

[StrawHat]

Here is my go to link for info on the 43 Mauser. Hope it helps.

http://www.riflemagazine.com/magazine/article.cfm?tocid=750&magid=56

Kevin

[W.R.Buchanan]

Guys I want to thank all of you who contributed to this post. I have got enough info to talk intelligently to this guy and talk him out of modifying his gun.

I had surmised that the intent was to have the BP bump the base of the boolit up to fill the very deep grooves.

With this in mind he will have to continue to make two different loads for these two guns. Which is the way it should be in the first place.

Randy