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Discussion Starter · #1 ·
I have a recently bought series 23, Kokura. 7.7mm It has matching bolt/receiver, chrome barrel/bolt. The rifling is strong; there is no pitting.

I finally got it out to the "range" up the canyon and set up some 100 yard targets. The real range was probably around 85 yards. No wind.

I shot 20 rounds of PCI, 150 grain FMJ and 20 rounds of Hornady 150 gr soft point.

There were a few cartridges in both brands that were FTF on the first strike, but there's a Wolff 18 lb solution to that problem.

Neither brand was erratic, but the Hornady grouped a bit better and was a bit higher on paper. I expected that. However, the general group with the Hornady was about 2 inches low at 85 yards. I think that's weird. I expected about 2 MOA of accuracy, but not a consistent 2" low.

For giggles, I flipped up my sight ladder and leaving that at the lowest setting (bottom of the ladder), I fired a 4 round group at each target. My "raised" groups were about 3" above the center of the targets. Those results seem reasonable.

Thoughts about a non-permanent method to raise my grouping? My rifle is no collector's prize, but I don't want to do anything like file down the front sight post.
I'm thinking that if I put a dab of elmer's glue along the top of the rear aperture sight ring, theoretically, that should force me to raise my barrel a bit to recenter the top of the front sight post.

Suggestions appreciated.

thanks
 

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I believe before I modified my sights, I'd just try to remember to aim 2" high with that rifle and ammo. But that's just me. ;)

Seriously, you might need to work up the correct load for that rifle by "rolling your own". I've had several rifles over the years which didn't perform well with factory loaded ammo, and took some work finding the correct powder type & load and bullet weight & type to perform consistently.
 

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I'm thinking that if I put a dab of elmer's glue along the top of the rear aperture sight ring, theoretically, that should force me to raise my barrel a bit to recenter the top of the front sight post.

Suggestions appreciated.

thanks
If you add glue to the top of the hole (instead of the bottom) you will shoot lower than you did before. You will be raising the rear of the barrel which equals lowering the muzzle.

It sounds like the Japanese military ammo might have been hotter or had a lighter bullet. As said, using Hornady just aim 2 inches high at 100 meters.
 

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Don't complain about 2" low, most will be 4 or 6" high!
 

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Discussion Starter · #6 ·
geladen:
If you add glue to the top of the hole (instead of the bottom) you will shoot lower than you did before. You will be raising the rear of the barrel which equals lowering the muzzle.
B47: yes, a bit of scotch tape proved that my theory was 180 degrees backwards. Thanks for clearing that up.

Big Ed:
Get a chrongraph and see what your bullet speed is.
B47: yes, reloading is the long-term plan, but for now, aiming 2" high will be the solution.

03man:
Don't complain about 2" low, most will be 4 or 6" high!
B47: "Besides Col. Arisaka himself, Don, you're probably the only guy whom I would believe when someone says "most Arisakas"... lol.
My T38 carbine was 2" high, so I guess that it's all working out on average.
Thanks for the help and suggestions.
 

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biff47,

Going from memory Japanese MILSPEC is flat base 174 gr Rifle or the Boat tail 203 gr (IIRC) T99 LMG ammo. That is one factor. Another could just be the rifle. Again, going from memory, with the flip sight down it is calibrated for 100 meters, flip it up and it starts at 200 meters and works it way up from there. I've had great point of aim groups with various .3105 or .311 150 gr FMJBT using a 6 o'clock hold. I also like pulled 7.62R COMBLOC 174 heavy ball as well. I am not sure that is any help, but my 2 cents.

Shannon
 
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