Winchester Model 94 Sporter .38-55

[RonL]

I just bought a new Winchester (Miroku) Model 94 Sporter in .38-55. Does anyone know what groove diameter Miroku puts in these rifles? I need to get the correct slug to slug the bore and also do a chamber cast.
Anybody have experience with the new Winchesters in .38-55?

[RonL]

I just spent several hours searching the web. I found several people on the web who indicated that they had slugged their Miroku built .38-55's and came up with .376 to .377. I had sent an email inquiry to Winchester Customer Service. They sent an email reply that their chambers were SAAMI standard and that the groove diameter was 9.550. Translated from metric that gives .375984252. Basically .376.

[RonL]

My one inch mike disappeared (stolen). I splurged and ordered a Mitutoyo set that included a one inch mike and a six inch dial indicator. I did a rough check of the bore at the muzzle with the inside caliper of the dial indicator and got a reading of .376. I'm going to push a .380 lead ball down the bore and get a more precise measurement.
Looking at the 2015 SAAMI specs for .38-55 it gives a cartridge length of 2.085 and a chamber length of 2.1182, which seems to call for the shorter Starline brass. However, in a note it gives a tolerance of + .015 on the chamber length, which indicates that it would accommodate the longer length Starline brass. The specs call for a .373 bore and a .379 groove.
It seems that one has to precisely measure each rifle to match one's load to that particular rifle.
And so it begins.

[BFJ]

Slug the bore. This will determine which size bullet to use. I had to do all 3 of the 38-55, I have owned. Older and newer can be very different bore diameter.

[Texas by God]

When you get it all lined out, I would love to see pictures and a range report please. The 3855 is one of my new favorite cartridges.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[skeettx]

Use a .379 cast bullet if the cartridge will chamber

For my Ruger #1 and my Marlin Cowboy, I use a .382 diameter cast boolit

Mike

[CamoWhamo]

I did a Cerrosafe cast of mine and measured my bore at .377.

I cast and size the Accurate Molds 38-250B to .379.
Note, that Starline make 2 sizes of brass. 2.080" and 2.125"
My rifle takes the 2.080" brass. I could not get the longer brass to chamber.

[pietro]

I just bought a new Winchester (Miroku) Model 94 Sporter in .38-55.

Does anyone know what groove diameter Miroku puts in these rifles?

I need to get the correct slug to slug the bore and also do a chamber cast.

Welcome to the board !


FWIW, there's no "correct" slug...……………..

Since pure lead is soft, just locate a fishing sinker that's about bore size, support it from one end of the barrel with a cleaning rod, then upset/expand the lead with a square-ended drift (dowel, brass rod, etc, etc).

I usually do all this near the muzzle, to make it easier to push the expanded slug from the rear of the barrel for measurement.

Cerrosafe is a good material for making a chamber cast.


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