I need some info on the correct bullet size for the 38-55 Winchester. I had never considered it to be anthing other than .375 and I ASSUMED that the current crop of .375 diameter bullets would be correct for these reloads. My brother tells me that the correct bore size for the 38-55 is .378. Both of us are interested in 38-55 for our HandiRifles. Do any of you out there know the bore diameter of the current production of the H&R 38-55 barrels? BTW, we have looked on the H&R website and can't find this information.

Thanks for any help you can give.

My Winchester LF is .378 with best results using a .380 dia cast bullet.
I also custom built a Ruger No1 in 38/55 with a fast twist 1:14" barrel that is .375. I use a special 340gn .376 cast bullet in this one.

There is no CORRECT bore size. It is what it is - is the way it goes for .38-55s. Original rifles are usually an honest .380 or better. Modern .38-55s are usually .375" in the grooves, .366 across the lands.

Don't assume, measure.

Brent

quote:

Originally posted by Brent:
There is no CORRECT bore size. It is what it is - is the way it goes for .38-55s. Original rifles are usually an honest .380 or better. Modern .38-55s are usually .375" in the grooves, .366 across the lands.

Don't assume, measure.

Brent

Unfortunately for us, Brent is correct. I have a friend who recently purchased a NEW small Sharps from Dakota in this caliber, and they told him it is supposed to be .378"-.379". I haven't slugged it yet, but using new brass, the .380" expander plug causes an off-center bulge on the case neck even before a .380" bullet is seated.

It may be that once the cases expand from firing, by sizing down only a short section of the neck this can be eliminated. But it sure can't be good for accuracy.

In addition, need for such large bullets will effectively force us to use cast bullets for everything...... I had been hoping to be able to try some bullets like the 235-grain Speer .375" spitzers. Guess not.

The H&R barrel .38-55 Handi-rifle I got last year slugged out at .379. It also shoots very well with black powder loads and cast bullets in the 250- to 300-grain range. My daughter uses it for a BPCR silhouette rifle, and we have shot it out to 800-yards.

For what it's worth, I would buy another one.

Dave

Thanks to all of you. It looks like I may have to get into bullet casting. I've never done that but it looks interesting.

The .38-55 has been produced since the late 1800s. Manufacturing tolerances then weren't what they are today. Variations in bore and groove were common between makers and among guns from one maker. The SAAMI spec is .379 grooves. How they arrived at that number is probably not now known. The SAAMI case length is also shorter than traditional. I've read of .375 grooves on old guns. As was said, you simply have to measure your gun to know.