7.65x53 Argy Brass from 8MM Mauser?

[Tom in Pittsburgh]

Anybody have experience making up 7.65x53 Argentine brass from 8MM Mauser brass? I have plenty of 8MM Mauser brass and would prefer to use some of it up instead of buying in new Argentine brass. Could I get away with just buying a 7.65Mauser trim die and using it to reform my 8MM Mauser brass in it? I have a Rockchucker, so the press is strong enough.

TIA

Tom

www.vingage-gunlore.com

[Maven]

Tom, There are two ways of doing this. (1) Simply run the lube 8 x 57mm brass into the 7.65 x 53mm die, trim to length, bell the neck via the Lee Univ.- or Lyman M die, and anneal. (2) Use a 7.65 x 53mm trim die, and then FL size. The rest of the prep. is the same. Btw, although I have the trim die, I still FL size brass I've reformed.

[FrankG]

I used milsurp 30-06 brass . Full length resized in 7.65 arg die and trimmed to length. The milsurp doesnt have any caliber designation on it .

[Multigunner]

I used milsurp 30-06 brass . Full length resized in 7.65 arg die and trimmed to length. The milsurp doesnt have any caliber designation on it .

I wonder how difficult it would be to restamp a case head to indicate the true caliber of converted cases?

Electro penciling might do the trick, but would be difficult to do neatly in the limited space.

[adrians]

Tom, There are two ways of doing this. (1) Simply run the lube 8 x 57mm brass into the 7.65 x 53mm die, trim to length, bell the neck via the Lee Univ.- or Lyman M die, and anneal. (2) Use a 7.65 x 53mm trim die, and then FL size. The rest of the prep. is the same. Btw, although I have the trim die, I still FL size brass I've reformed.

Yup ,i use method ( 1 ) in Mavens tutorial, Lymans "M" die is my expander of choice,either work well.
one little "heads up" ,when i resized for the first time the shoulder on the reformed case was not set far enough back (so to speak.) so i took others advice and ground a little off the shell holder and set my die ( Lyman) down a turn more in the press and it works, now the cases will chamber allbeit with a little extra umph!!! on the bolt handle ,that will not be a problem after fireing.
have a great weekend..

[Larry Gibson]

Tom

I've formed 7.65 cases from '06 cases (and a few similar cases) and also from factory R-P 8x57. The 8x57 was the easiest because the 7.65 FL die can be used and then a regular trimmer trims easily enough. The nice thing about forming your own cases is there is not headspace issues as the shoulder can be set back to match the chamber.

I've no problems with the headstamp and actually use it to keep the such formed 7.65 seperate from my 8x57 as I use WW cases for 8x57 loads.

Larry Gibson

[Tom in Pittsburgh]

Good advice from everyone -- thanks.

It looks as if I will end up having to buy a 7.65 Argentine FL die set (anyone have a used set they would like to part with?). I will then be able to reform my 8x57 brass and trim it in my Forster case trimmer.

Will it be necessary for me to anneal the necks of the trimmed and reformed brass?

BTW, the reason for all of this is that I am acquiring an interesting GEW88 which has apparently been rebarreled for the 7.65 Argentine cartridge.

Last question: I'm a long-time NRA member, too -- how are you guys showing that with your board signatures?

Thanks again.

Tom

www.vintage-gunlore.com

[Maven]

"Will it be necessary for me to anneal the necks of the trimmed and reformed brass?"

Tom, Yes, the reformed brass should be annealed. Also, you want to check the fired brass for the "dreaded doughnut," which develops at the neck-shoulder junction. If so, you need to remove it via a .314" Forster [inside] neck reamer.

[adrians]

Mavens advice on annealing the necks is sound advice.
i bought some ( once fired ) LC brass at a gun show one time ,i formed 06 to 8mm and ended up with a bunch of split necks after seating the boolits, i was $%#@&! at myself for not annealing the stuff first.

[Fredx10sen]

I used milsurp 30-06 brass . Full length resized in 7.65 arg die and trimmed to length. The milsurp doesnt have any caliber designation on it .

Yep +1

[Larry Gibson]

I've not had to anneal 7.65 cases formed from new commercial 8x57 cases until 8-10 firings. Forming cases from fired milsurp requires annealing as mentioned.

Larry Gibson

[jonk]

I've made hundreds of 7.65, 7.7, and 8mm from cut down once fired USGI 30-06 cases. I haven't annealed one yet and haven't lost any due to reforming problems.

I DID find with the Argie that I had to neck turn them to get them to chamber.

[oscarflytyer]

OK - just DUH... For some stupid reason, never thought about reforming brass for both my 7.65 and my 8 MM... From all the above, sounds fairly simple.

Since I have never done this, would someone be willing to post the complete step by step process, including any special notes/aspects/gotcha's?

Buying/reforming brass for these two from 06 brass should be a lot less expensive and allow me to finally get some ammo in quantity for the Mausers. Thanx

[leadman]

I have been forming brass for the 7.65 Arg for 30 years. Started out with a Lee die set and it did work but the die starting getting wear in it. I bought a new die set and an RCBS trim die. The trim die is open topped, goes in your press and is so hard a hacksaw won't hurt it.
I lube the case lightly, size a little at a time with 3 or 4 strokes to get the brass all the way in. I found this is easier on the brass and there is less springback.
Once the brass is all the way in with the shellholder touching the die trim the excess with a fine toothed hacksaw. Unless your chamber is oversize this works well, if oversize adjust the die to get the correct headspace.
Remove, deburr slightly, relube, size to your chamber in a full length die, trim to length and deburr. You are ready to load.

I use mil-surp and commercial brass as the chambers of my 2 91s are a little different. I have annealed but find it is not really needed. I have not had to turn a neck either. I have not found it necessary to fireform this brass either.

I have some of my first reformed brass from about 30 years ago that I still use.

[oscarflytyer]

I bought a new die set and an RCBS trim die.

Leadman - to clarify - you are using the Lee loading dies, plus the RCBS trim die, correct? And thanx for the reply.

[adrians]

leadman has it down by using the rcbs trim die, but i'm cheap and can't really afford the coin right now for dies in the cals i reform for (although the 7.65 is on my list).
so my way of doing it is i bought a Harbour Freight mini bench saw ( $20 something ) and i cut the 06 down close enouth to get it within specs and then i give it a final run (after sizing) in my redding case trimmer.
i glued a wood "backstop" on it for 06 to 8mm and just slid a q-tip in there for 7.65.
not as good as using the trim dies but it gets me in the ballpark the redding takes care or the details, and as mentioned i'm cheap....

[bruce drake]

I wonder how difficult it would be to restamp a case head to indicate the true caliber of converted cases?

Electro penciling might do the trick, but would be difficult to do neatly in the limited space.

I've got some small-size Brownells stamp marking set that I picked up on clearance a few years back and will give it a shot tonight and report back. Shouldn't be hard to mark the brass, just need to figure out how to hold the case steady to tap the mark.

Thanks for the idea. I've got a ton of reformed cases (from 30-06, 25-06, 270 Win) for my arisakas and mausers.

Bruce

[Char-Gar]

I have a file trim for that caliber and have formed cases from both 8mm and 30-06 cases. It works just fine. Just lube the cases good and run them into the die and cut on anything sticking above with a fine tooth hack saw. A couple of swipes accross the top of the die with a double cut file and you are done...well maybe.

The RCBS file trim die is cut to the FL sizing specs, so there is no need to FL size except to expand the necks to receive the bullets. As a cast bullet person, I just use an M die and that is that.

The Redding file trim die is cut larger than a FL sizing die. So when you are done you will have to FL size the case.

Which die you use depends on what you want to do. I prefer the RCBS for case forming and triming cases I would FL size anyway. I prefer the Redding for routine trimming so I don't FL size cases I only want neck sized. To solve this, I just buy the Redding and then FL size formed cases in a regular FL die. If I just want to trim, then I don't mess up my fire formed cases.

Both dies are of good quality, but will give different results. Knowing that going in will help you make the right choice for you.

[leadman]

I am using a set of RCBS dies now, the first set were Lee. I have an original 91 that has chrome furniture and a high gloss varnished stock. Also numbers stenciled on the buttstock. Was told it might be a school rifle.
Anyway the headspace on this rifle is alot tighter on my 91 sporter so I do have to full length size after the RCBS trim die. I have a shellholder I took a couple thousands off to make it work.

When I use the Lee full length sizer die to reform with 30-06 I would size it aways then cut it off as the neck would bottom in the die. I tried cutting the case off first and it gave me problems as the neck did not want to form and the case would bend. It could have been just that set of dies also, so try it which ever way and use what works.

[Char-Gar]

Any cases reformed into another caliber are kept in plastic ammo boxes and clearly labeled what they are. If time is taken to read what is written, there is never a problem. I would not store reformed cases bulk into a box or bag.