Cimmaron 1885 38-55

[slow poke gear]

Has anyone checked the bore diameter of their rifle if so what did if mic out at?

Having a had time getting even factory rounds to chamber in mine.

 

     Thanks

                  Slow poke 

[WymoreWrangler SASS 46187L]

I bought a 1894 Uberti clone in 38-55, accuracy was horrible, had the barrel miked at .380, HSM ammo was all over the place, some were at .370, after I had someone change the bullets to .380 the rifle worked...

[Sedalia Dave]

First there are two different chamber lengths for 38-55. 2.080" and 2.125". Second the SAAMI spec for 38-55 is strange to say the least. Note that the max bullet diameter is .377" -.003" yet the groove diameter is .379" +.002". Also notice the specification only covers the shorter brass.

 

 

 

Now read this.  https://www.starlinebrass.com/articles/loading-with-correct-38-55-winchester-cases-38-55-rifle/

 

This means that 38-55 chambers are all over the place.

What I did with all of mine is ream the chambers with a custom cut reamer so that I could shoot properly sized bullets that I cast from a mould that was custom made to cast a bullet of the proper dimensions..

 

I also realize that no factory ammo will ever shoot accurately in any of my rifles.

Edited March 18 by Sedalia Dave

[slow poke gear]

7 hours ago, WymoreWrangler SASS 46187L said:

I bought a 1894 Uberti clone in 38-55, accuracy was horrible, had the barrel miked at .380, HSM ammo was all over the place, some were at .370, after I had someone change the bullets to .380 the rifle worked...

That's actually the ammo I am having the hardest time using. It doesn't seem to want to chamber even

[Mad Dane, SASS#5536]

Mine slugged at .3785- use .380 bullets and got great accuracy.

[Texas Red]

New to me Uberti 1885 Highwall 38-55.  Slugged barrel, .3765, using .380 bullets and trialing .381 Shoots Great.  .377 were Horrible.

TR

[Reverend P. Babcock Chase]

Howdy Fellers,

 

Based on my limited experience, it seems that at some point in the last century manufacturers decided to ignore the original dimensions for the 38/55 and go to .380" bore. I don't know who started the trend, but I noticed it when working on an Italian made replica. Would not shoot cast bullets worth a damn with "handbook recommended" .378-9" bullets. Turns out the bore was .380". Got one with "correct" dimensions (old spec.) bore and it shot fine.

 

So what! If most new guns are the larger bore, we will have to go to larger bullets and hope (or ream) for new overall neck diameter. 

 

There's my complete mastery of the obvious.

Rev. Chase

["HH" (a.k.a. Dave)]

My Mirouku built 1855 Highwall slugs out at 0.377 groove diameter.  I use bullets ranging from 0.379 - 0.380 in diameter, which are readily available in cast, Hi-Tek and Polymer Coated forms in various weights.  Badman Bullets, Cheycast Bullets, Bearcreek Supply are just three examples.  I've used all three in addition to home-cast bullets found in an estate sale.  In the latter case, my buddy sizes and lubes them at 0.379 for me.

 

Go to Starline Brass website and read the tech note they have on the .38-55 wcf cartridge for more information, but essentially, the best answer is to slug your own barrel to confirm what your gun's groove diameter is.  In cases of the .38-55 wcf guns, vintage up to modern production, they are not all equal and have a wide range of differing groove diameters.  Slug your barrel first, then go bullet hunting.

[Red River Rudy, SASS #8490 LIFE]

SD, that is not two different cartridges.  That is a diagram of the case and the chamber.

[Sedalia Dave]

2 hours ago, Red River Rudy, SASS #8490 LIFE said:

SD, that is not two different cartridges.  That is a diagram of the case and the chamber.

Yes I know. It is to illustrate that the cartridge dimensions do not correspond to the chamber dimensions. 
 

There are two different case lengths and both have the same head stamp. SAAMI only publishes a specification for the shorter brass. 
 

Another Gotcha is that the 357 Winchester cartridge is the same dimensions as the short 38-55 brass. However the max chamber pressure for .375 Winchester is about double that of 38-55. 

Edited March 19 by Sedalia Dave

[Rancho Roy]

I use .381 in my Uberti 1885.......Shoots fantastic......9g Unique with 3/4 x 3/4" toilet paper wad stuffed down to hold powder against primer...under any 250g bullet. Recoil like a 22 Magnum and shoot lights out to 300 yds! I and others using my loads have won many competitions with this load in various 38-55 rifles. Pull trigger, eat a ham sandwich and wait for the "ding!"

[Hoss]

2 hours ago, Rancho Roy said:

I use .381 in my Uberti 1885.......Shoots fantastic......9g Unique with 3/4 x 3/4" toilet paper wad stuffed down to hold powder against primer...under any 250g bullet. Recoil like a 22 Magnum and shoot lights out to 300 yds! I and others using my loads have won many competitions with this load in various 38-55 rifles. Pull trigger, eat a ham sandwich and wait for the "ding!"

I use a similar load. 10.0 Unique. No toilet paper tho. I’ve never found Unique to be position sensitive.