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Contributing Member
Factory Second Bullets 303 Caliber and 7.7mm Japanese
I'm finally getting around to loading up some ammunition for the Arisaka Type 99 carbine I bought in March of 2023. It came with 100 once-shot Norma brass just needed some projectiles.
I was looking around MidwayUSA and noticed they had Factory Second Bullets 303 Caliber and 7.7mm Japanese (3105 Diameter) 174 Grain Full Metal Jacket Boat Tail for $35.00 for 100.
Being the couruios type, Aka Test Engineer, I am I wanted to see what the deal is with these bullets. I was curious about what makes them 2nds. Not knowing who the manufacturer limits what I can learn since I have no reference bullet or complete manufacture specification to compare what the projectiles are.
So really, all I can learn is what the variance is;
1.) In weight
2.) In Diameter
3.) In Ogive to Base
And, of course, after working up a decent load, how well do the bullets work (out of my Arasaka)
So far, I have learned:
1.) Only 43 of 100 projectiles weight are within the advertised 174.0 grains (+/- in 0.1 Grain)
2.) The Average Ovige is 0.618" (+/- 0.0001)
3.) The Diameter is almost a 50/50 split 0.3106"/0.3107" and more than the .0.3105" advertised by MidwayUSA.
So what does it all mean so far?
- For enjoyment shooting (plinking), these projectiles should work just fine; how much they vary in the three measurements should have little impact on the accuracy of my rifle at my intended shooting distance of 100 yards.
- These seem to be an excellent deal for the price, and I'm glad I bought two boxes.
- I can't wait to see how these perform.
Last edited by usabaker; 02-18-2024 at 06:10 PM.
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02-18-2024 05:55 PM
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Legacy Member
After test shooting many different loads in over 200 T-99 rifles , I found that bullet to be about the worst for accuracy .
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Legacy Member
Thanks for posting. I look for 7.7 Arisaka postings because I have been working on such test loads myself. Please let me know what your results are. These look like 174gr Hornady bullets. I'm testing with these bullets as well. But, my the time start fine tuning my loads, I have to change powders! I am trying AA4350 now. A few months ago, I acquired 100 Norma cases like yourself and am resizing them now. I size my cases and trim them to just under chamber length so the bullet ogive can touch the lands. Use a Sinclair chamber length gauge. Instead of using the sizing button, I size the case and use a mandrel. Are you using an unaltered rifle or do you have s sporterised rifle with a scope? Mine is unaltered and I use a large radiation sign triangle to line up my sights.
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Legacy Member
It's the "boat-tail". (and the bullet diameter.
.303Mk7 and 7.7 Jap did NOT have "boat-tailed" bullets. The bullets were (generally more than .3105" as well. I have not "sampled" many Arisakas, but, the "nominal 7.7mm indicates a BORE of approx .303". This is not surprising, as the Imperial Japanese Navy was heavily based on BRITISH practice and equipment. Their first "proper" machine-guns were chambered for .303, but the local product was designated 7.7mm. In front of me right now is a specimen of this rimmed "7.7" cartridge that looks exactly like a Mk Vll .303, complete with "stab" crimps on the neck, the headstamp is the giveaway, as is the slightly domed primer cup. the "discolouration on the case indicates that it spent a LONG time, possibly a wet time, in a metal "strip' as used in Hotchkiss" based MG designs.
If anyone has a good Type 99 rifle or one or more of the 7.7mm machine-guns lurking about, it would be nice to get some "GROOVE" diameter readings.
See also the ballistically similar 7.65 Belgian / Argentinian. I am not really a cartridge "collector, so, I do not have samples of the other two (rimless and semi-rimmed) Japanese 7.7mm cartridges.
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