7.7 Jap., which brand of 30-06 brass?

[wallenba]

I need to make some 7.7 Japanese cases from 30-06. I shoot .314 sized cast 185 grainers. Before I order brass, which brand has shown the best results with case thickness after forming? I'd really like to avoid neck turning as my previous attempts at it were dismal.:-?

[junkbug]

If I were to order brand new brass today for my Type 99, and Graf's 7.7mm was still out of stock, I would order some of their 8mm Mauser brass. Less trimming, and your new neck wont be part of the old shoulder.

http://www.grafs.com/retail/catalog/product/productId/12659

But its up to you.. I have lots of range salvage 30-06, I'm sure some of it would have to be inside neck reamed to work right for the 7.7x58mm.

Huningtons shows some, don't know if they have any left in stock.

http://www.huntingtons.com/cases_graf.html

[wallenba]

[QUOTE=junkbug;1342039]If I were to order brand new brass today for my Type 99, and Graf's 7.7mm was still out of stock, I would order some of their 8mm Mauser brass. Less trimming, and your new neck wont be part of the old shoulder.

That's the problem I'm getting with range brass, a little "love handle" on the neck. I have 8mm Mauser but I need them for my K98. I'll go look at the Graf's stuff.

[Will]

Midway shows they have 7.7 in stock. Kinda pricey but I would go with the real thing.

[Surplus Shooter]

Any decent quality brass would work.

[dualsport]

Seems like I read a warning somewhere about making 7.7 from 30-06. I think it was Huntington's catalog. Something about base dimensions, or I may be confused. I'll have a look see, ...... yep, RCBS says don't do it, base size for Jap is bigger than 30-06 family. (page 52/53 Huntington's 2011 retail catalog), not a safe conversion. I'm not the fireforming police, do what you want, just passing along a bit of info I ran across while looking for a die to do just that so's I could feed my Arisaka. No die available from RCBS for that one.

[nicholst55]

Seems like I read a warning somewhere about making 7.7 from 30-06. I think it was Huntington's catalog. Something about base dimensions, or I may be confused. I'll have a look see, ...... yep, RCBS says don't do it, base size for Jap is bigger than 30-06 family. (page 52/53 Huntington's 2011 retail catalog), not a safe conversion. I'm not the fireforming police, do what you want, just passing along a bit of info I ran across while looking for a die to do just that so's I could feed my Arisaka. No die available from RCBS for that one.

While I agree totally with you, RCBS used to say the same thing about 6.5X55 Swedish Mauser - don't form it from .30-06 because the head diameter is too small. That was before Remchester brass was made in this flavor with - you guessed it - standard .30-06 head diameter. Not sure if RCBS still goes by that seemingly outdated policy or not.

[Hip's Ax]

I made some out of Lake City, they worked fine but really long and boring trimming all that excess off. I annealed them as well. I bought Graf's after that.

[Pavogrande]

Many moons ago, I made my 7.7 from what was then plentiful - WWII 06 brass - A wrap of scotch tape around the base took care of the size difference and kept the case centered for the first firing -- Not needed for subsequent firing -- At that time neck/throat differences were not thought about, but did not seem to cause any problems --

[jonk]

While I have occasionally had a case head seperate after dozens of firings, this is usually just an extraction problem- it doesn't usually douse you with gas and the Arisaka has a good gas shield. Ergo, I have no issue with the conversion.

I use whatever I have on hand. Most of mine is LC 69.

[Safeshot]

I like Lake City, CMP Danish, CMP Greek, and any available boxer primed military 30/06 cases (in reasonable quantity to have a good "lot size"). I like to use the military cases because the head stamp is NOT stamped 30/06. I especially like head stamps with a 77 date - add a punch mark between the 7's and it is "almost" a perfect head stamp for the 7.7 mm Japanese case. Just one approach. I like to save the commercial 30/06 with the correct head stamp for use to reload 30/06 ammo. I may have a large neck diameter in my rifle's chamber, I have never had any problems with "thick necks". If anything, the slightly thicker necks might help. The "love handles" on the reformed neck seem to "iron out" with the first firing or "fire forming" and after the next full length resizing. Safeshot

[0verkill]

It may just be my method, but out of the "big 3" Winchester seems to form easiest with the fewest ruined cases. I've never formed any that had to be reamed, but that could just be my chamber.

[psj12]

Do a search for Hornady 7.7. I think Sportsman's Paradise has it cheap.

[shastaboat]

I have made 7.7 brass from any 30-06 but it is not advisable. Since 7.7 brass is available
http://www.grafs.com/retail/catalog/product/productId/12653

also Norma brass is available. I would reccommend you buy commercial brass...expecially if you shoot any high pressure jacketed loads.

[0verkill]

If you're having to buy brass anyway, yeah go ahead and buy actual 7.7 brass. The big point of using 30-06 for me is that I can get it for free as long as I'm not too lazy to bend over and pick it up off the ground. I bet this is the reason a lot of others use it to form other cartridges. In the 2 months before deer season it seems to sprout from the ground like mushrooms in spring.

A little tip, most of the metric or European calibers Hornady sell is PRVI brass, go to Grafs.com and get PRVI cheaper.

As to the whole 30-06 being slightly smaller, the drawing in the Hornady 7th edition lists the base of 30-06 base as .470 and the rim at .473. It lists 7.7 with a base of .471 and a rim of .470, not a big diffrence. Lee,s modern reloading 2nd edition lists the 30-06 with a base of .470 and arim of .473, the 7.7 is listed as having a base and rim .003 larger at .473 and .476. I think the big deal is that there is no SAAMI spec on 7.7 Arisaka which would explain why the 30-06 measurements match and the 7.7 dont. Measure most any factory new brass against dimensions given in a reloading manual and the actual brass will usually come out quite a bit smaller. Federal brass seems to be especially bad for this.
Long story short, if the measurements listed above sound like too much difference to you, don't do it.

[shastaboat]

Hornady's dimention for 7.7 brass is wrong. [I] have seen many references where apparently they just copied those dimentions. I have seen the rim diameter listed to as high as .478. My inhand reference which is Ken Howell's DESIGNING AND FORMING CUSTOM CARTRIDGES list the head diameter as .4743 and the rim diameter as .4760. I measured the head diameter of some of my 7.7 fired (unsized) brass and they measure .476. I would recommend that a 7.7 shooter buy factory 7.7 brass of whatever brand they can find. PRVI brass is cheaper and well made.

[dbldblu]

In the 2 months before deer season it seems to sprout from the ground like mushrooms in spring.


Thanks for that, it made me laugh. I have pounds and pounds of 30-06 brass liberated from terra firma but I picked up 20 Norma 7.7x58 cases off of Fleabay which satisfied my needs.

[0verkill]

Hornady's dimention for 7.7 brass is wrong. [I] have seen many references where apparently they just copied those dimentions. I have seen the rim diameter listed to as high as .478. My inhand reference which is Ken Howell's DESIGNING AND FORMING CUSTOM CARTRIDGES list the head diameter as .4743 and the rim diameter as .4760. I measured the head diameter of some of my 7.7 fired (unsized) brass and they measure .476. I would recommend that a 7.7 shooter buy factory 7.7 brass of whatever brand they can find. PRVI brass is cheaper and well made.

Is that Norma or milsurp?
I would bet that the reason for the small size listed could be from measuring surplus cartridges that were out of spec, being manufactured during wartime and all.

[Japlmg]

Guys, making cases for the 7.7x58 Japanese out of 30-06 brass (any 30-06 brass) is 100% safe.
I have been doing so for 45 years, and I have yet to have a case split at the base.
I feed a couple Japanese machine guns with said reformed brass, and MG chambers are normally cut larger than rifle chambers.
Yes, the base of the 30-06 case buldges out a bit, but it is no big deal.
Norma 7.7x58 brass is considered to be excellant stuff.
Well I hate to tell you this, but Norma brass is undersized at the base, as the 7.7 Japanese Norma makes is nothing but a shortend 30-06 case.
Don't believe me, well then measure a unfired Norma 7.7 Japanese case and compare it to a unfired 30-06 case.
So lets put this 30-06 to 7.7x58 myth to bed!
I personally now use 8x57 Mauser brass, as there is no case trimming required, just resize and load.
The 30-06 requires 5 mm of trimming (about .200 inch), and that is a lot of trimming to do.
Gregg

[Wayne Smith]

Only one personal experience. Arisaka99's rifle is rechambered with an 06 reamer. This leaves the 06 cartridge base expanded a little. We found this out when he was neck sizing the first cartridges he fired. With the 06 die screwed out he was still slightly resizing the case maybe 3/8" up from the base as it entered the base of the die. Not enough to matter, but enough that he lightly lubed the rest of the cases.

[curiousgeorge]

I know that you can make 7.7 brass from .30-06 because I have done it.

I also know that it is not 100% safe, UNLESS you are shooting fairly mild loads because I had 2 cases to rupture, maybe split or crack would be a better description, right above the head on the first firing and several others looked really bad. Was it a bad gun or bad chamber? I don't know, and at the time I didn't care. I quit while I was ahead and bought some Norma 7.7 brass. No more problems. The gun that I had was not safe with the .30-06 cases. Just for info purposes, the cases that failed were all once fired Winchester.

The above being said, if I were planning on shooting nothing but light cast loads, I would use military brass. Maybe I am wrong, and if so I appologize in advance, but they seem to be the toughest stuff around.

Steve

[Multigunner]

A 7.7 Jap with a chamber cut at minimum or nearly so, and not noticably worn, may have no problem with reformed .30-06 brass, but another 7.7 Jap rifle otherwise I dentical but having a slightly looser cut or worn chamber might have problems.

The potential for case blow outs was recognized long ago, when these rifles were occasionally rechambered for the .30-06 cartridge.
Use of a full house .30-06 sporting load, or a M1 Ball cartridge with its slightly higher pressure, in one of the looser chambered of the rechambered rifles might result in more stress on the brass than a well below maximum load in '06 brass reformed to 7.7 and fired in a 7.7 chamber.

They used to recommend that only mil spec '06 cases be used for reforming to 7.7, due to tougher brass and thicker case walls.

An old trick to avoid un necessarily lopsided expansion of a case a tad small for the chamber is to wrap a turn or more of a narrown strip of cigarette paper or some other thin material around the base above the extractor groove for first firing of the reformed case.
Besides insuring even expansion to reduce stress, centering the case for first firing then neck sizing only insures a near dead center firing pin strike, and presents the bullet to origin of rifling without cant that can affect accuracy.

I always mark the rim of my .303 cases and rotate 180 degrees on second firing. I found these well centered cases reduce group size by half compared to first firing.
Another trick is to size only 2/3rd of the meck. The still evenly expanded portion of the neck centers the neck in the chamber neck, further insuring presentation to OR without cant.

While many older sources state that a well centered pin strike has little or no effect on accuracy, these sources usually are repeating results of experiments done when sensitive large dia mercury compound berdan primers were the norm.
The smaller dia, less volatile compund, and much smaller anvil, of modern day large rifle primers seem to benefit more from a well centered firing pin strike.
Probably not always true with all combinations of primer, action, etc, but ever rifle and pistol I've worked on to insure a well centered strike showed noticable improvement in group sizes immediately.

[Guesser]

I had a five gallon bucket full of once fired FA 58 NM that I have been using, no crimp and after annealing it is easy to form, trim, and fire form. It seems to last a long time. I don't keep track of how many times it is loaded.

[303Guy]

Looking at Steve's pages it seems that the 7.7 Jap is almost identical to the 8x57 Mauser. Surely those would be easier to reform to 7.7?

[Multigunner]

Looking at Steve's pages it seems that the 7.7 Jap is almost identical to the 8x57 Mauser. Surely those would be easier to reform to 7.7?
A member of another board who has collected and restored many Japanese rifles once posted that he had deliberately fired a 7.92X57 cartridge in a 7.7 Jap chamber just to see what would happen. So apparently its possible to get a 7.92 in the chamber and close the bolt (though probably requiring some effort to close the bolt). Could be that this is only the case when a chamber is badly worn or headspace far out of specs. IIRC The rifle he tested, in a proper remote test firing booth in his gunsmithing shop BTW, was a non restorable piece sacrificed for the experiment.
I forget the exact results but I believe the action was ruined.

With typical oversized mil spec chamber necks and bores such catastrophic results might not have been the case if the older 8X57J cartridge were used.

Due to the legendary strength of the Arisaka action many a wanna be P O Ackely has hammered the bolt shut on unsuitable cartridges just to brag about their Arisaka not blowing up.
Hatcher's Notebook mentioned a incident where a teenager managed to fire two .35 Remington rounds in a 7.7 without apparent damage, the third shot shattered the action and sent fragments deep into the young man's head. He survived surgery.

[bruce drake]

what 303Guy was suggesting and I do this out of preference for loading for my 7.7 Arisaka is to use 8mm BRASS and then reform the case to 7.7 specs. What you are left with after the reforming is a 7.7 Arisaka Case with a neck 1mm shorter than the official specs (8mm is 7.92x57mm while 7.7 Arisaka is 7.65x58mm).

The first time you neck the case down from 8mm, you'll have a false shoulder from where you are moving down from .323 to .312. With cast boolit loads, the first firing will fire-form the shoulder to match the chamber and its good to go for further shooting.

Bruce

[303Guy]

Yes, I was meaning the brass for reforming to 7.7 Jap. Although I have heard rumors of the strength of the Arisaka action. Forgive my lack of clarity.:oops:

A 8x57 round forced into a 7.7 Jap chamber would likely push the bullet back into that case. That plus the oversize bullet would surely be catastrophic!

[Multigunner]

Yes, I was meaning the brass for reforming to 7.7 Jap. Although I have heard rumors of the strength of the Arisaka action. Forgive my lack of clarity.:oops:

A 8x57 round forced into a 7.7 Jap chamber would likely push the bullet back into that case. That plus the oversize bullet would surely be catastrophic!

It was my own lack of clarity.
I'd meant that since the fellow I mentioned had managed to chamber a 792X57 in his 7.7 then the cartridge cases should be very close in configuration so the 7.92X57 case should work well if reformed to 7.7 specs.

If there is any remaining slack near the base one could use milspec 7.92 cases which were usually extra tough for use in the LMG. A thick side wall near the base should prevent blow outs.

A reformed case without a recognizable headstamp other than number codes would be easier to mark in some way as being for the 7.7 rifle. To avoid confusion at a later date.
Electric pencil should do the trick.

[Me not you]

I've used 8mm Mauser for 7.7 Arisaka loads with no problems at all. What I normally do for the first firing (in a bolt rifle only) is load the Hornady 100gr 0.312 pistol bullet over about 12 gr Unique. I also lube the cases. On firing, the lube helps the case slide back against the bolt face. The case is then nicely fireformed to the chamber with no stretching. This load is also pretty accurate, good for rabid raccoons in the yard etc. After that I neck size with a LEE collet die.

[psj12]

I make, and have made, brass for the 7.7 from 30-06. I find I need to ream the neck to remove the thicker brass where the sholder is pushed back. After fireforming I only neck size to reduce wear on the cartridge base. I think 8mm would work better. I just have lots of 30-06 and the tools to do it.

[0verkill]

I always mark the rim of my .303 cases and rotate 180 degrees on second firing. I found these well centered cases reduce group size by half compared to first firing.
Another trick is to size only 2/3rd of the meck. The still evenly expanded portion of the neck centers the neck in the chamber neck, further insuring presentation to OR without cant.

I'll have to try that with my 303.

As to the 7.7 I think it all depends on your situation. 8x57 will be easier to reform, but 30-06 is probably more abundant to most of us. How tight your chamber is may limit your ability to use reformed cases. A lot of these were wartime production rifles so a chamber cast may be in order to see if '06 brass or others can be reformed.

[BeemerMark]

Hornady now sells loaded rounds for a reasonable price. I bought a few boxes and then reload it. Cheaper than then the 20 rounds of Norma brass. Used to do the 30-06 route but not only is it was too much work but I did not like loaded rounds of 7.7 labeled 30-06.

[0verkill]

Is the hornady 7.7 PRVI ? (PPU headstamp)