Where to start with 7.7x58 JAP

nemesiss45 · July 22, 2014, 03:39 AM

My dad gave me a few rifles today as he is trimming his collection (making room to buy more). Among them are a .303 Enfield no.5 jungle carbine, 1903 Springfield, a Columbian Mauser, and a model 99 Arisaka.

I also got a crate plus 2 bandoleers of .303 and can of 30-06, so that leaves me with no ammo or brass for the Arisaka. A quick search looks like Norma is the only source for new ammo or brass. Is there something I can form to work? Is there any source for less expensive ammo or brass?

Thanks, as always, for any insight.

nemesiss45 · July 22, 2014, 03:52 AM

I've read up on forming 30-06. anyone do this? any drawbacks to it?

Blindstitch · July 22, 2014, 04:38 AM

There are videos on Youtube about how to do it. But Privi i believe makes 7.7 brass for $55.

http://www.grafs.com/retail/catalog/...roductId/12653

F. Guffey · July 22, 2014, 09:22 AM

Quote:

Thanks, as always, for any insight.

I would suggest purchasing a 308 W forming die, rational, it is short. Being short allows a reloader that can keep up with the numbers/gap between the bottom of the die and shell holder for forming cases that are longer.

After forming/establishing the shoulder use the full length 7.7 die for final sizing. And remember, there is no excuse for having head space issues when you are in charge if adjusting the die.

I have formed cases for the 7.7, with my dies and 30/06 cases I paid 7 cents each for I formed 80 cases for $5.60. I do not suggest using cases that have been fired more than twice unless the cases are annealed.

F. Guffey

Jim Watson · July 22, 2014, 09:31 AM

Some people worry about forming 7.7 out of .30-06 because of the Jap's larger head diameter/chamber diameter which leaves a lot of room for the 06 brass to expand.

Some people say, no problem, they do it all the time.

Some people say they wrap a turn of tape around the 06 case so the bulge is uniform.

All I know is what I read on the internet, I don't do much with surplus guns.

tangolima · July 22, 2014, 10:40 AM

I have been shooting 7.7 jap formed out of 3006. No problem, but my load is not hot.

Forming is not that hard. I only have the Lee full length die. Go slow, use good lube, and anneal. Turn the neck too.

-TL

**44 AMP** · July 22, 2014, 10:51 AM

On paper, the .30-06 is listed as having a .470" head and .473" rim. The 7.7mm Arisaka is listed as having a .472" head and a .474" rim.

this is not an insurmountable obstacle. Also remember that tolerances vary somewhat, and in a type 99 the chamber could be a bit on the "loose" side.

I have made 7.7mm cases from 06. Simply trim the 06 to the right length, run through the 7.7 sizer die, and measure. Possibly trimming again, likely not, if you did it right the first time.

The 7.7mm Jap military loads are in the 2400fps range, and operate at about 43,000psi. At this pressure level the slight difference in case size (06 vs 7.7) has not given me any issues. And, I never really noticed any "bulge".

Graf & Sons often has 7.7mm brass. And, it might just be on the brass dealer's table at gun shows, being an uncommon caliber, they don't sell a lot, so they might still have some....

In performance, the 7.7mm Jap is a rimless .303 British. Same diameter bullets, same speeds. You can make acceptable ammo from 06 cases and moderate loads of mid burning rate powder (IMR 4064, 4320, or the classic 4895). Don't try to make a magnum out of it.

While blowup testing has shown the Arisaka to be a very strong action, the rest of the rifle might not like it. One Type 99 I had, using moderate loads, had the stock separate after about 8 rnds or so. Not break, it came apart at the forend joint. original 99 stocks are often 3 pieces, plus the handguard, and after all this time, might not be in really good shape, as far as the glue that holds them together.

If you can get some, pony up the cash for 7.7mm brass, get a 100 and enjoy shooting the old relic. If you can't get purpose made 7.7, make some out of 06 brass and enjoy shooting the old relic.

F. Guffey · July 22, 2014, 11:12 AM

Then there is unsupported case head and case head protrusion. The first .125" of the case head is not sized, it protrudes from the shell holder. The deck height of the shell holder is .125" then there is the radius.

For those that do not measure case head thickness, my surplus 30/06 military cases have a thickness of .200". My R-P case head thickness is .260" from the bottom of the cup above the web to the case head.

What ever problems reloaders think they have when forming 7.7 from 30/06 has to be up inside the chamber. And unless they get careless they are not going to upset the case head thickness.

F. Guffey

nemesiss45 · July 22, 2014, 12:42 PM

thanks for the replies. I'll probably start off trying some -06 brass and see how it goes.

I pulled down one of the .303s I got last night to check the powder and weigh the bullet to see if I could use it for the Arisaka. I was shocked at my first encounter with cordite... for a moment I thought someone stuffed the case with spaghetti, lol. the bullet looks like it will fit the bill, so I may pull down 10-20 of those for the bullets.... one I get a die, that is.

I will definitely not be shooting hot loads out of it. I only shoot my old military rifles with the bare minimum to preserve them as best I can.

**44 AMP** · July 22, 2014, 06:43 PM

The 7.62x54mmR the 7.7x58mm Arisaka, and the .303 British all use the same bullets. (.310-.312" nominal).

While not as common as the US .30 cal (.308) bullets they are out there on the market, as surplus (in small lots) and as regular commercial sporting bullets from all the major makers.

If you are just going to shoot them with the bare minimums, you might consider (eventually) going to cast bullets.

While the initial up front costs for casting and sizing bullets is large, once done, you will never have to buy bullets for casual use, as long as you can get lead, tin, & etc.

Or, there are several custom casters around the country that can make what you want, for less than jacketed slugs. Just watch out for the shipping, lead is heavy!

There is a little more work involved for loading cast slugs into bottleneck cases than loading jacketed bullets, but you might find it worthwhile, in the long run.

tangolima · July 22, 2014, 08:47 PM

I am interested in knowing the custom casters. You have info on those that you can share? Thanks.

-TL

nemesiss45 · July 22, 2014, 11:29 PM

Yeah, I cast .45 acp and .308 now, so it will just be the cost of a mold and an expanding die... but I need an expanding die for my .308 anyway.

T. O'Heir · July 23, 2014, 03:11 PM

"...the Jap's larger head diameter..." Only 3 thou. Real issue is the difference in length of .210". Actual case dimensions are here. http://stevespages.com/page8d.htm
Allegedly only needs the '06 run though an FL die then trimmed though.
http://www.milsurps.com/showthread.php?t=36845
Grafs lists Prvi brass at $54.99 per 100.
Norma is way over twice that from Midway. $39.03 per 25 from MidSouth Shooters Supply.
Dies are fairly easy to get and not stupid expensive. Hornady, RCBS and Lee all make 'em.

tangolima · July 23, 2014, 04:03 PM

I tried going straight to full length resizing die, and it didn't work well. The Lee die doesn't have enough room for the neck. Have to cut the neck short first.

Trimmer works but not practical. There is too much brass to trim. Cut first, with pipe cutter or hacksaw, then trim.

The formed brass could have neck wall too thick as it comes from the shoulder of the donor brass. I always turn the neck and anneal.

-TL

**44 AMP** · July 24, 2014, 12:14 PM

I have RCBS dies, and they will handle forming the full length 06 case before trimming, BUT it is MUCH easier to rough cut first (hacksaw or tubing cutter) THEN size. Then check length and finish trim (of needed) and chamfer.

You can use a case trimmer, but unless you have one of the powered ones, it takes a LOT of cranking to do the whole job....

kilimanjaro · July 24, 2014, 02:26 PM

Sure seems a lot simpler to just go to a show and buy some brass or even a box or two of vintage commercial ammo. Here, there is always one or two vendors selling estate ammo, and I recall seeing 7.7 Jap on his table, it was right beside the. 375 H&H I wanted.

F. Guffey · July 29, 2014, 09:36 AM

Trim .210" from 100 cases is 21.00" inches of trimming. Rather than complaining about trimming I find better ways, I use a 308 W forming die with a hack saw. If I had one forming die it would be a 308 W forming die. if I had two the second forming die would be a 243 W forming die.

I have both with an additional 12 forming dies. The 308 W forming die can be used to form 257 Roberts, 8mm57, 7mm57, 7.7 Japanese etc. I can be told 'all you have to do is use a full length sizer die', I form first then fire.

F. Guffey

July 22, 2014, 03:39 AM	#1
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	Where to start with 7.7x58 JAP My dad gave me a few rifles today as he is trimming his collection (making room to buy more). Among them are a .303 Enfield no.5 jungle carbine, 1903 Springfield, a Columbian Mauser, and a model 99 Arisaka. I also got a crate plus 2 bandoleers of .303 and can of 30-06, so that leaves me with no ammo or brass for the Arisaka. A quick search looks like Norma is the only source for new ammo or brass. Is there something I can form to work? Is there any source for less expensive ammo or brass? Thanks, as always, for any insight.

July 22, 2014, 10:51 AM	#7
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,850	On paper, the .30-06 is listed as having a .470" head and .473" rim. The 7.7mm Arisaka is listed as having a .472" head and a .474" rim. this is not an insurmountable obstacle. Also remember that tolerances vary somewhat, and in a type 99 the chamber could be a bit on the "loose" side. I have made 7.7mm cases from 06. Simply trim the 06 to the right length, run through the 7.7 sizer die, and measure. Possibly trimming again, likely not, if you did it right the first time. The 7.7mm Jap military loads are in the 2400fps range, and operate at about 43,000psi. At this pressure level the slight difference in case size (06 vs 7.7) has not given me any issues. And, I never really noticed any "bulge". Graf & Sons often has 7.7mm brass. And, it might just be on the brass dealer's table at gun shows, being an uncommon caliber, they don't sell a lot, so they might still have some.... In performance, the 7.7mm Jap is a rimless .303 British. Same diameter bullets, same speeds. You can make acceptable ammo from 06 cases and moderate loads of mid burning rate powder (IMR 4064, 4320, or the classic 4895). Don't try to make a magnum out of it. While blowup testing has shown the Arisaka to be a very strong action, the rest of the rifle might not like it. One Type 99 I had, using moderate loads, had the stock separate after about 8 rnds or so. Not break, it came apart at the forend joint. original 99 stocks are often 3 pieces, plus the handguard, and after all this time, might not be in really good shape, as far as the glue that holds them together. If you can get some, pony up the cash for 7.7mm brass, get a 100 and enjoy shooting the old relic. If you can't get purpose made 7.7, make some out of 06 brass and enjoy shooting the old relic. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

July 22, 2014, 06:43 PM	#10
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,850	The 7.62x54mmR the 7.7x58mm Arisaka, and the .303 British all use the same bullets. (.310-.312" nominal). While not as common as the US .30 cal (.308) bullets they are out there on the market, as surplus (in small lots) and as regular commercial sporting bullets from all the major makers. If you are just going to shoot them with the bare minimums, you might consider (eventually) going to cast bullets. While the initial up front costs for casting and sizing bullets is large, once done, you will never have to buy bullets for casual use, as long as you can get lead, tin, & etc. Or, there are several custom casters around the country that can make what you want, for less than jacketed slugs. Just watch out for the shipping, lead is heavy! There is a little more work involved for loading cast slugs into bottleneck cases than loading jacketed bullets, but you might find it worthwhile, in the long run. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

July 23, 2014, 03:11 PM	#13
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...the Jap's larger head diameter..." Only 3 thou. Real issue is the difference in length of .210". Actual case dimensions are here. http://stevespages.com/page8d.htm Allegedly only needs the '06 run though an FL die then trimmed though. http://www.milsurps.com/showthread.php?t=36845 Grafs lists Prvi brass at $54.99 per 100. Norma is way over twice that from Midway. $39.03 per 25 from MidSouth Shooters Supply. Dies are fairly easy to get and not stupid expensive. Hornady, RCBS and Lee all make 'em. __________________ Spelling and grammar count!

July 24, 2014, 12:14 PM	#15
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,850	I have RCBS dies, and they will handle forming the full length 06 case before trimming, BUT it is MUCH easier to rough cut first (hacksaw or tubing cutter) THEN size. Then check length and finish trim (of needed) and chamfer. You can use a case trimmer, but unless you have one of the powered ones, it takes a LOT of cranking to do the whole job.... __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

July 22, 2014, 03:52 AM	#2
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	I've read up on forming 30-06. anyone do this? any drawbacks to it?

July 22, 2014, 04:38 AM	#3
Blindstitch Senior Member Join Date: April 14, 2013 Location: Milwaukee, Wisconsin Posts: 2,693	There are videos on Youtube about how to do it. But Privi i believe makes 7.7 brass for $55. http://www.grafs.com/retail/catalog/...roductId/12653

July 22, 2014, 09:31 AM	#5
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	Some people worry about forming 7.7 out of .30-06 because of the Jap's larger head diameter/chamber diameter which leaves a lot of room for the 06 brass to expand. Some people say, no problem, they do it all the time. Some people say they wrap a turn of tape around the 06 case so the bulge is uniform. All I know is what I read on the internet, I don't do much with surplus guns.

July 22, 2014, 10:40 AM	#6
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,828	I have been shooting 7.7 jap formed out of 3006. No problem, but my load is not hot. Forming is not that hard. I only have the Lee full length die. Go slow, use good lube, and anneal. Turn the neck too. -TL

July 22, 2014, 11:12 AM	#8
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Then there is unsupported case head and case head protrusion. The first .125" of the case head is not sized, it protrudes from the shell holder. The deck height of the shell holder is .125" then there is the radius. For those that do not measure case head thickness, my surplus 30/06 military cases have a thickness of .200". My R-P case head thickness is .260" from the bottom of the cup above the web to the case head. What ever problems reloaders think they have when forming 7.7 from 30/06 has to be up inside the chamber. And unless they get careless they are not going to upset the case head thickness. F. Guffey

July 22, 2014, 12:42 PM	#9
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	thanks for the replies. I'll probably start off trying some -06 brass and see how it goes. I pulled down one of the .303s I got last night to check the powder and weigh the bullet to see if I could use it for the Arisaka. I was shocked at my first encounter with cordite... for a moment I thought someone stuffed the case with spaghetti, lol. the bullet looks like it will fit the bill, so I may pull down 10-20 of those for the bullets.... one I get a die, that is. I will definitely not be shooting hot loads out of it. I only shoot my old military rifles with the bare minimum to preserve them as best I can.

July 22, 2014, 08:47 PM	#11
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,828	I am interested in knowing the custom casters. You have info on those that you can share? Thanks. -TL

July 22, 2014, 11:29 PM	#12
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	Yeah, I cast .45 acp and .308 now, so it will just be the cost of a mold and an expanding die... but I need an expanding die for my .308 anyway.

July 23, 2014, 04:03 PM	#14
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,828	I tried going straight to full length resizing die, and it didn't work well. The Lee die doesn't have enough room for the neck. Have to cut the neck short first. Trimmer works but not practical. There is too much brass to trim. Cut first, with pipe cutter or hacksaw, then trim. The formed brass could have neck wall too thick as it comes from the shoulder of the donor brass. I always turn the neck and anneal. -TL

July 24, 2014, 02:26 PM	#16
kilimanjaro Senior Member Join Date: November 23, 2009 Posts: 3,963	Sure seems a lot simpler to just go to a show and buy some brass or even a box or two of vintage commercial ammo. Here, there is always one or two vendors selling estate ammo, and I recall seeing 7.7 Jap on his table, it was right beside the. 375 H&H I wanted.

July 29, 2014, 09:36 AM	#17
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Trim .210" from 100 cases is 21.00" inches of trimming. Rather than complaining about trimming I find better ways, I use a 308 W forming die with a hack saw. If I had one forming die it would be a 308 W forming die. if I had two the second forming die would be a 243 W forming die. I have both with an additional 12 forming dies. The 308 W forming die can be used to form 257 Roberts, 8mm57, 7mm57, 7.7 Japanese etc. I can be told 'all you have to do is use a full length sizer die', I form first then fire. F. Guffey