doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com mystery caliber 9.3x??

we have lift off.

Ordered a 4d reamer and re-cut the chamber, you guys were right it was a slight diameter/taper difference. Cut and checked the chamber with two live cartridges. Cut, extract, clean, drop round in... I didnt have to go full depth with the reamer. I stopped with 1/8" or so of the rim cutting portion behind the barrel face. I did it by hand and held the barrel in a bench vise

I definately recommend you to use a lot of cutting fluid and clear chip every 2 full rotations. Test fired two shots, measured the brass, no deformation, bulges ect. They measure very close to new brass. However it does seem the gun is off face as the primers definately show signs of flow. I'll post pics of those later

journeymen,
I apologize for not making it clear that I have a reamer for the "N" version of 9.3x72R. It threw me off when you said you had ordered Cerrosafe. Since you live within driving range, I could have saved you time and the cost of a reamer.
Mike

Der Ami, no harm no foul. I was worried that i'd screw something up and liquify the solder holding on the barrel lug.

This is what the primers looked like. I talked with our gunsmith at work and he said it might be the jacketed bullets causing a higher pressure, given it was proofed for black powder.



The gun is also off face. It will readily close on a .003" shim. I assume ideal is .001" to .0005"?

journeymen,
The 193gr normal bullet for the 9.3x72R doesn't raise the pressure significantly because it was especially made for use in older rifles (basically has a thin jacket that is undersized except for a short "driving band"). This bullet is not common in the US and there is no way to know what bullet the rifle was fired with, in the past. Bullets intended for the more powerful 9.3s(such as 9.3x62 or 74R) could very well raise the pressure. I believe current ammo is loaded to about 18,000 C.U.P., older ammo may have been loaded to 12,000 but I don't know for sure. I do have a couple boxes of ammo marked " Schwach Ladung"(weak load). I don't know the pressure nor velocity (too rare to shoot over the chronograph), but it does have the jacketed bullet. You can have a lot of fun shooting it with cast bullets from Lyman mold #355408(origional or shortened to about 200 gr) or 358315(200gr) or 358318(250gr) or RCBS 200-35(200 gr) which ever stabilizes in your rifle at appropriate velocity for a black powder proofed rifle. The single locking lug underlever rifles such as this one were not intended for high pressures.
Mike

I'm out of my depth on this one. I know the lockup is out. I dont know what surfaces i should add material to or if thats the correct course of action to bring it back to face. The small red circle is around what i think is a clearance cut on the barrel lug

journeymen,
I don't think the "problem" is as devastating as you seem to think it is. I would be hesitant to do any welding to "correct" it. If it were mine and I was concerned about it, I would concentrate on the wear of the hinge "pin" and/or the underlever "pin". You could check to see if this would help matters by making up simple straight pins a couple "thousandths" larger, before making up new screws and or reaming the holes "round". You should be able to use it the rest of your life with 12,000 psi loads normally and 18,000 psi loads only for hunting.
Mike

Journeyman;

See PM I just sent you.

Regards;
Stephen Howell

Journeymen, what does the breech face look like? Hard to tell from the pics but looks more like just a corroded surface abound the firing pin hole that lets the primer center enter the "potholes" and then get smoothed off when the action is opened. If so, no biggie.

Another thing, what is the rim thickness on those S&Bs?