doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com Reloading question for 8x57jr pre-war Merkel

So I think I have this sorted out.

First off, I was making things harder than they needed to be, by simultaneously working with once-fired S&B brass that had been shot in my rifle, and a mix of loaded (by someone else) once-fired and new Norma brass and another handful of fired RWS brass that I had purchased.

By measuring the factory ammo before and after firing in my rifle I could see where cases had 'grown' during firing. There weren't appreciable differences between left and right barrel fired cases. Basically the body of the cases expanded in diameter, most appreciably by .002-.005" measured 0.75" up from the rim. And the shoulders moved forward in firing, by .0065". Cases expanded elsewhere, particularly the neck, right above the shoulder. The biggest increase as a percentage was how the neck immediately past the shoulder increased during firing (+1% in diameter.) Brass fired in my rifle still chambered in my rifle (no surprise).

But the handloads I had purchased and pulled down for the brass sometimes chambered but often would not. I couldn't tell why until I dumped the powder.

I pulled down the handloads I had bought because the bullets were 0.323" and my rifle is 0.318" What I found with those was a mix of previously fired brass, which wouldn't chamber, and new Norma cases with pristine case interiors (vs dark, obviously used cases). These new Norma cases would chamber without running thru my .318 sizing die, assuming I'd already pulled the bullets. (For what it's worth, the load appears to have been 170gr JSP over 43gr of 4895, which seems to be on the safe end of 8x57 loads, which start at 40.0 and work up to a max of 48.0grs of IMR-4895 for 170gr bullets (per loaddata.com)

Anyway, once I focused this previously fired empty brass that I knew wouldn't chamber I tried setting the Hornady dies have again. Initially I turned the sizing die, with the decapper/expander removed, into the press till it bottomed out on the shell holder. Resized cases still wouldn't chamber. Then I turned the dies a further 1/3 turn into the press and locked them down and resized...now these cases chamber correctly. (Not all the previously fired cases will chamber, but at the least those I had purchased loaded. I've got enough brass that works that I'll put the remaining problem cases aside for now.)

So I wasn't setting the shoulder back enough to match my gun's chambers.

The only other point to share is that my used 0.318" 8x57 dies came with a bullet sizer. I've been using that, and Imperial Case Lube, to size the 0.323" jacketed soft points down to the 0.318" diameter I need. Takes some force, but all the bullets resized without visible damage. (I also love the collet bullet puller from Hornady. So much easier to use than the Franklin kinetic puller!)

Now to reload some rounds with my own stash of powder and see how these compare to the factory S&B ammo, which is super accurate but seems a little hot for my rifle (primers look fine but rifle is slightly hard to open. Garmin has those at 2,400fps.)

Thank you all for your advice as I worked thru this.

Regards,
Chris