Japanese Ammuntion and Rifle Testing

[jmoore]

Part the First:

This thread is an extention of another on the Ammunition and Reloading forum (ETA link below):

6,5mm Japanese Arisaka Ammuntion Dimensional Revelations (Photo Heavy)

See Post #21 (Et al.?) for specifics on this session.


Expect both to be sort of an on-going work.

As for 13 May 2011, a tiny initial test session to get things started.

Warm up:

M1a 134918 a thoroughly abused and monkeyed with rifle that's back to a surprisingly conventional configuration.

TRW USGI barrel witth several thousand rounds through it that I know about (because I did it).
SAI "plump" stock that has a favorite "feel". -Note: no bedding(!), but good fore end tension and trigger group clamping pressure.
Leupold Ultra M2 10x on an old ARMS 18 and 19 mounting set.
Std GI flash hider (not reamed)
Modded trigger hsg and hammer as posted elsewhere on other old threads.

Not very Japanese so far, but it shot so well after having JUST been thrown back into the wood stock from a JAE unit, that details might useful before I forget them....

No rezero, no warm up sighters, just ten rounds:


Note the fancy bench rest set-up. Operator was wearing two T-shirts (a little cool) and fired LH.


1st five rounds fired after stock swap.




Next five. Note that the zero was previously spot on with this ammo whilst in the JAE stock. Mighty good group for a tired chrome lined bored rifle. But it isn't unusual! I don't deserve it, but...

So with that baseline established, the real test:


Same fancy shooting gear. Some Hornady, Federal/Norma, and some brass bulleted milsurp ammo.


Nagoya Series 27 Type 38 with a great bore, and matching bolt, etc.


O-rings


O-rings were reused until cut beyond servicability, usually 3-5 cycles.


Target 1J: Again first round on paper was "cold bore". As expected, it was high, so the following 9 rounds were fired whilst aiming somewhere around the "X" superimposed on the photo. Seems a little left correction is needed. (Fired LH)
Ammo: Hornady 139gr SP.

Max spread (9 rounds): ~5 1/4", but the best 7 were in ~3 1/2".

As a disclaimer, front sight focus was VRY tough! Allergies, presbyopia, and old lenses, sorry! But we gotta start somewhere.

For maximum gas protection, and better sight focus, the next five rounds of brass bulleted milsurp ammo was fired RH.

No O-rings used, nor were they needed! The primer crimps made closing tha bolt an effort. Fortunately, the "interrupted thread" locking face geometery was of great assistance. (Photo of case base to follow.)


Only three hits! Report was louder, recoil greater, and impact higher. 4" spread, for what it's worth.
One long hang fire, with reduced report and recoil-sights were on target, but no hit.
One misfire, but it turned out to be an odd duck round in the charger. (loose, not from one of the sealed boxes.)

Due to pierced primers (two or three), testing was suspended using this ammo. Firing pin tip damage is certain with continued use, and salt laden gases being blown through the action are undesirable.

Type 97 results coming- time pressures force an interruption.

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.

[jmoore]

Well, due to a rather longer delay than anticipated (going through withdrawal pains and anxiety there for a few hours!) this will be rather shorter than planned:

T97:







Rifle #342, scope #S/N I forgot- will add later, maybe.

Had a hard time for some reason with getting a good view through the scope, so whilst fighting the view there were seven rounds of Hornady on one target and three on another... Phooey! Didn't actually appear to scew the results particularly, but the group surely wasn't stellar- nor was it much worse than normal.



The other three:


Changed the aiming "point" for the preliminary Norma group- The first five went well under 2"- possibly under 1 1/2", but I did nothing but enlarge the group after that. Still, it was better than expected. Perhaps the O-rings helped a little, but overall, I would DEFINITELY recommend NOT trying to combine case forming and group shooting like this! Very distracting- dealing with O-rings, getting the rounds chmbered with the O-rings, checking each case after firing for primer setback, etc.

Anyway:





As mentioned in other threads, I've not yet found a really accurate 6,5mm Japanese rifle or carbine. The T99s do as well or better (if in good shape) -even the really crude fixed sight jobs.
So, this is just establishing baseline expectations.

More details coming- and maybe some new glasses! (gotta quit buying ammo...)

---------- Post added at 09:25 PM ---------- Previous post was at 09:19 PM ----------

Eh, another reticle photo:


T97 2.5x (for 6,5mm ammo) reticle photo

[onlycrimson]

Very interesting. The different reticles are cool

[jmoore]

Very interesting. The different reticles are cool

Thanks. This is apt to be a long, drawn-out affair.

The Type 97 2.5x scope reticle makes sense to me, even if the "vertical" graticule shows a lot of bullet drift.

The Type 99 4x reticle seems a bit "Hollywood".



T99 4x reticle (for 7,7mm ammo) photo


But that's a whole different subject! Going to try to sort the 6,5mm first.

[P-07ShortLee]

What did you do about the pierced primers?

[jmoore]

I stopped shooting the old ammo! I think I'd rather pull bullets and use new cases.

Too much work and produce gathering for much shooting lately. Plus, I'm trying to completely redo the reloading area(s)- it's entirely too spread out (in two counties, even!), and cramped all at the same time. Took the fun right out of it.

[muffett.2008]

Interesting experiment JM, keep them coming.

[jmoore]

Thanks! I'm not done with this one, but I'm slow. For one thing, the reloading area is in a state of reconfiguration and won't likely get up and running again for a couple of months. Too many things happening at once...

[rayg]

I've shot my 97 sniper and I found that scope w/o adjustments is terrible to use because you need to try to focus on the same sight picture each time and that sight picture might be where there are no cross lines/hairs, (+) use as a cross reference to the same point each time. I wonder what lines a matching they zeroed a matching scope to? Ray

[jmoore]

I've shot my 97 sniper and I found that scope w/o adjustments is terrible to use because you need to try to focus on the same sight picture each time and that sight picture might be where there are no cross lines/hairs, (+) use as a cross reference to the same point each time. I wonder what lines a matching they zeroed a matching scope to? Ray

The scope CAN be zeroed, but it's a giant pain in the rear unless you have an actual fixed vise at the firing point. After shooting a group you clamp the rifle in the vise and adjust the entire unit so the the reticle is directed at your aiming point. Lock everything down. Then remove the teeny grub screws that fix the objective lens in place and use the special spanner to turn the lens 'round and 'round until the reticle now points at the group center. It's wierd and hard to cipher how the eccentric inside won't repeat in one turn, but it doesn't. The bother is you will have to do it over for ammo and weather changes, so it's only exact (maybe!) on the day of the zeroing. (Hopefully tightening the grub screws back won't throw it off too badly, also!) Mine's off zero a bit agin, which makes testing a bit more challenging.

As a complete novice, what were the O rings for? Smaller case in a larger bore?

Smaller case in a bigger chamber. The Arisaka chambers run on the largish side for reliability, and the cases often swell unevenly at the first firing. The o-ring trick was developed to negate headspace issues with rimmed cartridges (it pushes the case hard against the bolt face), but I hoped it would work to also center the cartridge in the chamber for it's first firing. More uniform primer ignition and some theoretical accuracy gain due to better bullet to bore alignment were intended.