94 Winchester/Miroku 38-55 Bore diameter

Bowie

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Hi,
I’m wondering if any owners of the newer made Winchester/Miroku 94 rifles in 38-55 have measured the bore diameter? I’m curious if they kept the .379-.380” bore or are tighter (.375”)?
Thanks in advance.
 
The original post does have a bit of dust on it.

Best information I could find: Bore: .373" Groove: .377" (SAAMI)
Expect some variation...likely between .376"-.377"

Standard bullet diameter for factory-loaded .38-55 jacketed ammo is .377".
Newly manufactured Winchester 1894 rifle grooves are essentially .376" (.37598"). With the expected slight bore variations normal in any rifle.
So, the Winchester info wasn't that far off.

For cast bullets: .378"-.379" should be fine. Pretty much the same as vintage bores.
Of course, slugging the bore is the only way to know for certain.

Al
 
Last edited:
Hi,
I’m wondering if any owners of the newer made Winchester/Miroku 94 rifles in 38-55 have measured the bore diameter? I’m curious if they kept the .379-.380” bore or are tighter (.375”)?
Thanks in advance.
Mine (Miroku) was .377. I shot .379(ish) cast and .377 barnes bullets. .375 Sierra jacketed bullets also shot just fine in it. Never tried the Barnes .375, but I'd be willing to bet that they'd be fine too.

Bullets "Obturate" under the pressure of combustion gasses behind them. They expand and seal against the bore wall. You will still find that one of .375 or .377 are more accurate for you. All I'm saying is that it's safe to shoot either in that Miroku - try both out and see what it likes best.

The next, and more important question is brass thickness and chamber length (gotta love loading for the the 38-55).

I found the shorter brass was fine, but the long worked too. However (related to your original question) a .377 bullet was tight and required the thinner Starline brass to cycle and chamber smoothly. A .375 bullet wasn't fussy about brass, so I could use Winchester or whatever else I had lying around.

Good luck
 
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