Determining chamber without casting.

[clemens]

Can a clambering of a rifle be determined without chamber casting,?
(Ex)- using a snap cap of suspected chambering. Would bolt close correctly if cap was correct?

 

[Mikecr]

Fully fire formed brass(in the chamber) measures out at chamber minus springback.
As far as basic go/no-go fit, a head space gauge shows that much(to the shoulder).
I wouldn't hold any faith in a snap cap fit.

 

[clemens]

I have the worst luck. Found a real nice 90% turn key rifle. At first was thought to be a 338LM. Well found out today that it is not LM but possible 338 rum or edge. Was just hoping maybe could get a snap cap to see if that would work. Cause not really wanting to pay for the rifle and be 338 edge.

 

[Bob Wright]

It's really easy to do a casting. Did one on my 7RM to determine neck dia. Can the person selling it not want to do it?

 

[waspocrew]

I have the worst luck. Found a real nice 90% turn key rifle. At first was thought to be a 338LM. Well found out today that it is not LM but possible 338 rum or edge. Was just hoping maybe could get a snap cap to see if that would work. Cause not really wanting to pay for the rifle and be 338 edge.

I could be totally wrong in my thinking, but the Edge is based on the slightly longer 300 RUM case. You could try chambering a piece of 300 RUM brass - if it chambers, would suspect it's an Edge. If it doesn't chamber, I would suspect it's likely a 338 RUM. Just a thought.

 

[clemens]

It is in Pawn shop. So not much I can do. I do know someone who has 300rum I could get case from.

 

[XSIVSPD]

Bring a peice of any magnum brass and see if it fits the bolt face properly. If it does, it's not any version of a 338 lapua. Or even better, bring a peice of 338 lapua brace as there's no way it will fit in a mag bolt face at all.


Or just bring calipers and measure it

 

[clemens]

They told me today that it is definitely not a 338lm. Was told they tried chambering LM and no go. So it is either Rum or edge.

 

[clemens]

Guess could just build one on donor action I have.

 

[Mram10us]

Borrow a go gauge for 300 rum. If it doesn't close, it's a 338 rum. If it closes, it's an edge ... assuming it was headspaced correctly
edit: what waspocrew said above

 

[clemens]

Great idea

 

[nmbarta]

I hope it's cheap with all the unknowns. There is a lot of weird stuff out there that wasn't done right.
I personally wouldn't want to a "custom" if I didn't know who the builder was.
Lot's of back yard builders doing stupid stuff.

 

[XSIVSPD]

It is in Pawn shop. So not much I can do. I do know someone who has 300rum I could get case from.

Do this then. There's enough difference between the 338 rum and 300 rum that that would tell you. Bring a 300win and a 338win just in case lol (if both chamber it's a 338-300 of some sort. If the 300 doesn't then it's a 338win mag)

 

[redleg1013]

Can a clambering of a rifle be determined without chamber casting,?
(Ex)- using a snap cap of suspected chambering. Would bolt close correctly if cap was correct?

Uh... not to pick nits or anything but I'm pretty sure that the chambering has to be listed, by law [27 CFR 478.92 (a)(1)(ii)(B)], on the rifle, like on the barrel... might want to start there.

Now that aside, I wouldn't buy a pawn shop rifle that I couldn't identify the chambering of. Why you ask? Because I know there are people that think after a couble of youtubes that they are gunsmiths, eff up their project and sell them off at pawn shops...