Chamber out of round?

[Damartin95]

So I bought a second hand custom rifle in 300 prc. Got some factory hornady ammo to mess around with before I handload. This is where I had the first issue, about 1/3 of factory shells where very tight closing in the rifle due to bullet contacting the Lans( colored the cartridge with blue and you could see heavy marks on bullets. Not a big deal, just thought I'd seat the bullets alittle deeper. So I went ahead shot a few of the loads that chambered easily so I would have a few pieces of once fired brass. The problem is that the once fires brass will only chamber when the brass is oriented a specific direction. I'm assuming this is the direction it was fired in, leading me to believe the chamber may be out of round.

The brass wasn't deprimed, cleaned or set back in any way, just fired once and then attempted to rechamber. I did check the gun with go/no go gauge and check the brass with calipers to see if I could find any spots out of round.( I couldn't but they doesn't mean it's not there)

So my question is anything else It could be of that I should check?
Also if I plan on full length sizing the brass(which i do) does it really matter?
Trying to find a way not to have to rebarrel the gun I just bought lol

 

[memtb]

I got nutt'n for you, except…….Welcome from North Central Wyoming!

There are quite a few very knowledgeable folks here that will be willing to give some good advice!

Good Luck! memtb

 

[Radman]

So I bought a second hand custom rifle in 300 prc. Got some factory hornady ammo to mess around with before I handload. This is where I had the first issue, about 1/3 of factory shells where very tight closing in the rifle due to bullet contacting the Lans( colored the cartridge with blue and you could see heavy marks on bullets. Not a big deal, just thought I'd seat the bullets alittle deeper. So I went ahead shot a few of the loads that chambered easily so I would have a few pieces of once fired brass. The problem is that the once fires brass will only chamber when the brass is oriented a specific direction. I'm assuming this is the direction it was fired in, leading me to believe the chamber may be out of round.

The brass wasn't deprimed, cleaned or set back in any way, just fired once and then attempted to rechamber. I did check the gun with go/no go gauge and check the brass with calipers to see if I could find any spots out of round.( I couldn't but they doesn't mean it's not there)

So my question is anything else It could be of that I should check?
Also if I plan on full length sizing the brass(which i do) does it really matter?
Trying to find a way not to have to rebarrel the gun I just bought lol

I HAVE seen chambers out of round but it was on .22 single-shot break-actions, (where the closing of the loaded action always pushed the rounds upward on the chamber - thus the visible egg shape). How your chamber got out of round who knows? JMO

 

[E4aker]

I'd bet it's a 5 groove barrel that wasn't chambered with the proper technique.

The freebore can actually be cut smaller due to reamer pushoff in a 5 groove groove barrel with a 6 flute reamer if it's not supported correctly. There are certain things a riflebuilder can do to prevent this problem.

I've had custom rifles like this come in my shop built by "gunsmiths". If you bore scope it the lead will actually look like a pentagon

There is no reason the factory ammo should need the bullets seated deeper to chamber.

Who built the rifle and what barrel?