8mm Lebel revolver

[Battis]

I made 8mm Lebel revolver cases out of 32-20 cases. I used an Accurate mold and a Lee bullet sizer (.326" - the bore is .323"). 2.8 grs Bullseye.
The gun is very accurate, not much recoil, average = 400 fps.
But, the fired cases are ballooned out, and some split. Loaded rounds fit sloppily in the chamber. I think the brass is undersized. Dummy round on left, fired on right.
I might buy some Fiocchi reloadable ammo for the brass, as long as it's not made from 32-20 cases.
Any suggestions on brass? (or whatever I'm not doing right)

[9.3X62AL]

The appearance of the fired case suggests that the brass below the full-diameter case mouth area was too strong to be expanded by the powder charge used to propel the bullet. 32/20 cases generally aren't real stalwart--were these parent cases made by Starline? SL tend to be sterner stuff than the usual run of W-W or R-P brass.

I think your Fiocchi ammo idea has merit. I don't mind reforming or developing brass when necessary, but if the hulls are commercially available get 100 rounds and give them a run. Your load of 2.8 grains of Bullseye also appears in Barnes' Cartridges of the World, 15th Edition and it seems like it should have fully-formed the fired cases. You might also do a Tale Of The Tape on the chambers and see if they are within spec.

[17nut]

[Battis]

Based on the specs of that cartridge case, my rounds are way undersized, everywhere except the case length and OAL. The loaded rounds rattle around in the chambers (which I plan on measuring).
So...the pressure slams into the base of the bullet in the case, and before the bullet is pushed forward, the pressure expands the brass under and around the bullet, right?
Once the bullet is in the barrel, it's fine - very accurate, so at least the bullet seems to be the right size. But the case takes a beating.
I have some Fiocchi ammo on the way.
Thanks for the info.

[9.3X62AL]

That drawing posted by 17nut is a big help. Many thanks!

A couple other thoughts occur to me here. Case loss issues--32/20 brass does not have a gentle lifespan if fired repeatedly. I have four firearms that chamber the caliber, and no two chambers are alike when it comes to shoulder location or radial diameter. W-W and R-P cases stretch unevenly every firing, and need to be trimmed at least every second firing; after every firing would be better. (Note--Starline brass is nowhere near as prone to stretching as these old-line cases are). So there is a lot of brass-working going on if they have been fired much. If the brass has been work-hardened, it might not respond to pressure as predictably as new or annealed brass case bodies might.

Another thought.......with much of the case undersized, I wonder if propellant gas got around the case neck and exerted itself against the exterior of the cases at the same time the gases were working on the case interior. Heckler & Koch uses a fluted chamber in their self-loading rifles to channel propellant gases into the chamber to prevent case adhesion under pressure in their rifles' roller-locked/recoil-operated systems. If your case sidewalls come out looking "charred", that is your clue. According to "COTW" data, the 2.8 x Bullseye load should produce about 720 FPS with 115 grain bullet. If your results were in the 400 FPS ballpark, then the propellant gas is going somewhere else and/or doing something else not planned for.

I think the 32/20 cases can be made into 8mm Lebel brass, but if I was to take the project on I would start with new/unfired brass--shorten/trim first--get a custom expander spud to open most of the length of the case closer to Lebel specs--then expand to accept the 8mm bullet. One of the case's most important roles is to seal the chamber against gas leaks--we may not be dealing with belted magnum rifle pressures in this application, but loose gas in any firearm causes issues.

[Battis]

I got the Fiocchi ammo - the cartridge specs are basically what 17nut posted above. The body of the brass case is wider all the way down compared to the cases formed from 32-20 brass. There's a 2.5 gr powder charge in the case.
The bore of my revolver measures approx. .323" which is why I sized the cast bullets to .326". The Fiocchi jacketed bullet's diameter is .328". I'm figuring that with the plus/minus aspect of my bore measuring, and the large size of the fired case mouths of the 32-20 formed cases, there shouldn't be any problems firing the Fiocchi ammo.

[Battis]

Yep, the Fiocchi bullets are too big. It almost made it out. The first 6 rounds were fine but very very slow.
At least I can reload the brass with cast bullets.

[Texas by God]

Yep, the Fiocchi bullets are too big. It almost made it out. The first 6 rounds were fine but very very slow.
At least I can reload the brass with cast bullets.

You couldn't duplicate that on purpose!

Sent from my SAMSUNG-SM-G930A using Tapatalk

[Battis]

The Fiocchi brass is ballooning out like the 32-20 brass in the above pic did, even though the Fiocchi brass is wider. Not every case, so I have to figure out which cylinder chamber is out of specs. If it is an out of shape or stretched chamber, how could that be corrected? For the heck of it, I wrapped some aluminum tape around a case just below where the neck balloons out, and the round still slid easily into the chamber.

[dubber123]

The only way I could think of correcting the original cylinder would be to sleeve the chambers and re-cut them to spec, which would probably be cost prohibitive.

[slughammer]

Maybe the uneven brass is because of hardness and uneven expansion. I would consider annealing a dozen cases about 1/3-1/2 of the way down. Use a band of that tape to center them in the chambers.

What diameter do the backs of chambers measure?

[Battis]

Some of the fired cases are not deformed. I'm going to load some rounds using the Fiocchi brass and my cast bullets (.326"). I'm going to mark and note each chamber and see if the problem is not in all of them. Annealing makes sense if all of the chambers deform the brass. I'll try aluminim...alimumin...metal tape.