Jap ammo 6.5 x 51

[vintage hunter]

Can we see a picture of the rifle ?...................

I'd rather see the case with the blown primer.

Actually if you round up the 6.5 jap. it would be 51 ie 6.5x50.8 !............

It depends on who's case you measure as to what length you get. A few thousandths one way or the other ain't gonna make no difference, 6.5 Jap is 6.5 Jap. As can be seen in Parashooter's photo at least some T38's lack a chamber step making an accurate determination of a standard case length difficult at best. The unfired cases I've measured(including a few WWII era Jap service rounds) range from 1.970'' to 2.00'' in OAL, the difference is in the neck portion only.
dlumpkin, regardless to what the gunsmith says you don't have an ammo problem, you have a problem with your rifle.

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[303tom]

I am going to go out on a limb here, if it is blowing out the primer, it`s a Head Space Problem !.............Here is 6.5 Jap. Service MeasurementsAttachment 62299

[toot]

primers backing out is a sign of excessive head space! a lot of JAP 6.5,s have it. no chrome bore like the type 99,s.

---------- Post added at 10:50 AM ---------- Previous post was at 10:47 AM ----------

a primer backing out is a sign of excessive head space, a lot of 6.5,s have it. no chrome boar like the type 99,s.

[ireload2]

Primers backing out are often a sign of low pressures. You see it a lot with 30-30 and 35 Remington fired cases.

Here is some long forgotten data that I recorded FWIW

I measured Norma 6.5 Jap ammo at 1.603 to 1.608 with the Stoney Point/Hornady tool and the .350 gage dia. (yes the ammo varies)

My Pacific 6.5 Jap form/trim die resizes cases at 1.630

I checked the headspace of my Lee Fl sizer die and it was 1.608 with a .35 Remington case using the .350 diameter ring in the Stoney point tool.

The Japanese Type I seemed to have headspace right at 1.608 to 1.610. The metal of this rifle is in mint condition. You can see the Lee die, Norma ammo and the rifle chamber all seem to be the correct length relative to each other.

I do not have multiple dies or gauges for this round. I do have another Type I but I have never checked the chamber on it.


Here is an old link to some discussion of Jap headspace
If you are not familiary with the Hornady Stoney point tool - you can substract 2 inches from the caliper readings in this thread and make more sense out of the comments.

http://castboolits.gunloads.com/arch...p/t-12630.html