.43 Mauser in the 71/84

[Jeffjmr]

Mixed results on my first outing.

Casting the Lyman 446110, and they drop right at .446. My bore measures at .446 as well, so wish I could get another thou or so. Beagling?

Anyway, loaded 16, 17, and 18 grains of Trail Boss. Nearly powder puff recoil, lousy accuracy until the 18 grains then not bad. I know folks are going to 20 grains, and I may work my way up there unless I find a sweet spot lower.

All my fired brass will rechamber easily, so I will probably just run them through the M die and then seat and crimp. Problem is my Lyman dies clearly oversize (size the brass too small). So if and when I find the best load is a bit higher pressure and I need to resize, is there a .43 Mauser die set that is a bit less aggressive than the Lymans, or is there a reasonable way to open up the Lyman? I am also concerned about the shoulder shape and location. At $3+ a pop, I need this brass to last.

Thanks,
Jeff

[Der Gebirgsjager]

You're doing better than I am! About 12-15 years ago I bought two 71/84s fairly inexpensively, said to be the last of the last and somewhat the bottom of the barrel, supposedly from the German Navy. In all fairness the ad did say they were wall hangers of historical interest, but not to shoot them. Well, the first one's magazine tube was rusted solid, and when I tried to remove it from the stock for cleaning it disintegrated and left chunks of the tube rusted into the wood. The only way I could get the stock off of the rifle was to cut it in half, which I did, and then sent the halves to a stockmaking company with an order for a new duplicate stock. I figured I could use EMT to replace the magazine tube. When the stock came back the company had glued it together to use as a pattern for the new stock, but had failed to drill a hole for the magazine tube in the new stock. I set it aside and turned my attention to the second rifle and found that a round would not chamber. It appeared that the chamber had been sleeved for an unknown cartridge, but when I tried to get a cerrosafe casting of the chamber it was so rough that it wouldn't let go of the cerrosafe and I had to melt it back out (twice!). Then the opportunity came up to buy one that appeared V.G. externally with an excellent bore, so I bought it and loaded up 20 rds. of previously fired Bertram brass with some suitable bullets made by Buffalo Bore with incrementally increasing IMR 4895 loads and headed for the range. Click. Click. Wouldn't fire. Primers showed several little marks on each, but no dent--not enough to fire. The tip of the firing pin protrudes through the bolt face and looks like it should, but I'm suspecting that at sometime in its past a bit broke off the tip and it was polished a little. Anyway, something "just ain't right"! So now, the next plan is to swap in a firing pin from one of the other two and return to the range. At least yours is shootin' !

[Larry Gibson]

Checked my old notes, some years back helped a fellow load for his 71/84 who had a similar problem of the dies over sizing the cases. Solved the problem for him by lubing the case necks and neck sizing using an RCBS .308W seating die just running the necks up into the die. Worked perfectly for his bullet (sorry, did not record the diameter) giving .002" neck tension. If you have a .308W seating die you might try it. My notes say a 30-06 seater put too much taper on the neck.

Larry Gibson

[haak48]

Checked my old notes, some years back helped a fellow load for his 71/84 who had a similar problem of the dies over sizing the cases. Solved the problem for him by lubing the case necks and neck sizing using an RCBS .308W seating die just running the necks up into the die. Worked perfectly for his bullet (sorry, did not record the diameter) giving .002" neck tension. If you have a .308W seating die you might try it. My notes say a 30-06 seater put too much taper on the neck.

Larry Gibson

Did this as well (still do). The Lee dies for this caliber size correctly IMO, and I have a number of other makers which really oversize the case. I have always used the as cast 446110 bullet with 4759 and have had good results. I had Starmetal make me a .4465" die for my Star lube-size; works great. JH

[jrmartin1964]

My own experience with the 11mm 71/84 demonstrated that the chamber in my rifle is a bit more generous in dimension than the RCBS dies I purchased, particularly in the body and shoulder area. Two broken shell holders and more than a couple of cases stuck in the sizing die later, I chucked my FL die in a lathe, mounted a sacrificial case painted with lapping compound on a mandrel, and lapped the die to better match my rifle's chamber. Probably a bit extreme, but I haven't had another stuck case, or broken shell holder, in almost 17 years. At least not from the 11mm.

For a boolit, I chose RCBS's 44-370-FN. Cast from COWW, it drops from my mould measuring 0.4485", which allows me to size it at 0.446" to match my rifle's groove. I tried a number of smokeless loads, but in my rifle nothing has ever quite equaled the accuracy of a full charge of BP. And, I'll have to admit I'm kind of a fan of the low, resonating BOOM that only comes from BP!

[Jeffjmr]

My own experience with the 11mm 71/84 demonstrated that the chamber in my rifle is a bit more generous in dimension than the RCBS dies I purchased, particularly in the body and shoulder area. Two broken shell holders and more than a couple of cases stuck in the sizing die later, I chucked my FL die in a lathe, mounted a sacrificial case painted with lapping compound on a mandrel, and lapped the die to better match my rifle's chamber. Probably a bit extreme, but I haven't had another stuck case, or broken shell holder, in almost 17 years. At least not from the 11mm.

For a boolit, I chose RCBS's 44-370-FN. Cast from COWW, it drops from my mould measuring 0.4485", which allows me to size it at 0.446" to match my rifle's groove. I tried a number of smokeless loads, but in my rifle nothing has ever quite equaled the accuracy of a full charge of BP. And, I'll have to admit I'm kind of a fan of the low, resonating BOOM that only comes from BP!

Thanks JR. If I can't continue to get away without sizing, I think I'll use your method to bore out the die as well. There is a thread on another board of a fellow getting under two minutes of angle with his 71/84 using Trail Boss. That is what I'm after, realizing that that is a long shot with this gun and iron sights and cast bullets and my eyes!

I get the BP attraction. If only I could get past the cleaning routine and using WATER to clean my 130 year old STEEL rifle! Its a phobia! Irrational fear. I know.

Jeff

[upnorthwis]

My Lee dies also do way too much sizing. Bought a 9/16-18 bolt that fits another die body and made an expander/belling tool out of it. Since this method still does a lot of brass work, I too will try to bore out the sizer die. I'm beagling the 446110 with 8 BHN COWW over 24 gr. 5744. Requires a Dacron wad to keep powder against primer to avoid hangfires. 1115 fps.

[Reverend Al]

From memory I shot my .43 Mauser 71/84 with the Lyman bullet as cast over about 25 to 27 grains of SR4759 with very good results. Another gun that I need to get out to shoot more ... :-(

[Gewehr-Guy]

I gave up using my Lee dies, after tearing the rims off two shell holders , now I just hand seat the RCBS bullet in the unsized cases and it works great. Guess I got lucky with with case dimensions and bullet dia. Had good accuracy with RL-7 and IMR 4198 but I really need to try with Black Powder.

[ascast]

just a quicky before I fall off- the RCBS bullet is bigger and will work better. Beagle your dies, maybe get a Lee die to work up, or buy .44-77 Sharps die. If you must use that bullet, try it very soft with black or pistol powder, like Unigue. keep us posted

[dogmower]

"Casting the Lyman 446110, and they drop right at .446. My bore measures at .446 as well, so wish I could get another thou or so. Beagling?"
try powder coating. usually adds a couple thousandths for me (harbor freight black).

[dogmower]

btw,
have any of you guys had luck with forming brass from another, less expensive, caliber?
if so, please expound.
thanks
john

[Der Gebirgsjager]

"The Handloader's Manual Of Cartridge Conversions" suggests using Bell brass. Just about as scarce and expensive.

[Denny303]

I am gearing up myself to load for a 71/84 and have been researching a lot, anyways I found this youtube video useful for using the Winchester magnum family of cases. https://www.youtube.com/watch?v=m0E_Hly-uE0 I have also read of guys using 45-70 and 45-90 brass as well, and wrapping two wraps of masking tape around the base to center the brass until fireforming, as it is undersized to start with.

[ascast]

I think I'll write a book on this one day. If you plan to really shoot as opposed to a just a few shots for fun, buy modern factory brass. Now get the die situation worked out. American makers use Barnes as a reference and as such, build dies to handle a .439 bullet. They ( he) don't take into account that it was paper patched, two wraps -- so add about 10 thousands to the bullet or .448-.450. Even using the Lyman 446110 is too big for the .439 expanded in 11mm dies. Ultimately your brass will start to stretch on the weak side to the point that our bullet/neck is not concentric the the case body. This will continue until your loaded round won't chamber. Ouch ! I got some 44-77 C&H dies. They are not right, but they are WAY better than off the rack 11mm Mauser dies. The RCBS 44-370 is a better bullet or Lyman 446187. NEI has some in the right range. keeps us posted. ps don't take that rifle apart without guidance

[ascast]

on brass the 11mm uses a "Mauser A base" type of brass. the base is very thick and sort of two diameter. the bolt face of a 71/84 matches this edge profile. 45-70 cases may not go in to contact bolt face on firing so over time they may get convex (bent outward). now they may not fit back into your shell holder and your primers are a tad exposed. this is not an issue with a '71 Mauser as the bolt face is flat. same cartridge, different gun. Lee dies will get you started and Lyman 439186 cast soft, fast powders. but you will SOON not be happy. The shell holder will break. You need a Lyman M style expander. and your brass will wear out.
Dominion brass is OK but will crack on you sooner or later. German stuff from the 1870's is good stuff but you will need to invest in a Berdan priming/depriming rig, and Berdan primers and a seater.
Buy a box of modern stuff from Graf or Midway or Buff Arms

[Jeffjmr]

That would explain why the Lyman FL die wants to neck down so severely, but does't explain why it wants to squeeze the body down just as severely. My chambers neck measures .470. My fired brass measures .466. It still chambers easily. My Lyman M die barely expands the fired neck and puts a very slight bell so I can seat my .446 bullet without shaving. Thus I am experiencing very little working of the brass so I don't expect any cracks anytime soon. I did however anneal the necks and shoulders. So far so good, and when the weather warms I'll chrono and test my 18.5 grain and 19.0 grain Trail Boss loads. If they turn out as accurate or better than the 18 grain load, and I can continue to reload without resizing, I'll consider this problem solved. And the powder coat idea is a great one to get me another thou or so of bullet diameter, or I'll beagle the Lyman 446110. But I hesitate because it is throwing the most perfect bullets of my 6 or 7 molds I use.

[ascast]

I am glad it's working for you. Perhaps your dies are sizing so much is just a general thing; i.e. they want there product to work, the dimensions are not a modern standard, most folks would be happy to fire a few rounds. PM me in a couple months if you want. I can send you a sample of bullets. be safe