MPA barrels/chamber question

[Pilotscrappy]

Hey guys quick question, I bought a new MPA b/a rifle this weekend and just started breaking it in.

First off I love the rifle it's awesome, I got the folding chassis and it has the Curtis axiom action and mpa match barrel. (6.5creed)

I just took it out today for first time and put about 40 rounds thru it. I loaded up virgin hornady brass with 40gr of reloader 16 and 140eld bullets.

My fired brass has markings on it from what I'm assuming is tool marks, or a rough cut from the chamber? It doesn't seem to affect accuracy as I'm. Already shooting under half inch @ 100.

My question is will this smooth out at all as the barrel breaks in? Or is it normal? And is there anything I need to pay attention to or can do to smooth it out?

This rifle is my first big rifle purchase (coming from rpr) and I just wanna make sure all is well. Thanks

 

[Steel head]

Are you talking about the necks?

 

[wade2big]

I don’t know what you are talking about either. If it shoots well, then it does.

 

[Pilotscrappy]

No I'm talking about the line twords bottom of the case. It's honestly not a big deal its just my ruger didn't do that so it's just different is all. It shoots great so far just wanted to check if the lines on the brass were normal

 

[Steel head]

No I'm talking about the line twords bottom of the case. It's honestly not a big deal its just my ruger didn't do that so it's just different is all. It shoots great so far just wanted to check if the lines on the brass were normal

Kinda looks like stretch line.
I’d check new case vs fired case growth from base to shoulder.
If it’s just a couple thousandths is a non issue.

I have had a few barrels and lots of brass with a similar mark but i know my headspace is GTG so I ignore it.

 

[King_beardsly]

Might just be the reamer they cut the chamber with was getting long in the tooth, but doesn't look like anything to concerning. If it chamber, extract smoothly and shoot constantly you're golden

 

[wade2big]

I’m definitely not an authority on the subject, but if nothing is bulging or indented then I wouldn’t worry.

 

[Pilotscrappy]

Might just be the reamer they cut the chamber with was getting long in the tooth, but doesn't look like anything to concerning. If it chamber, extract smoothly and shoot constantly you're golden

I'm thinking this cuz I can see some left over tool marks in the chamber, but there not that bad.

Rifle shoots great so far and I'm very pleased so I will move on and start load development after I get this brass once fired ?

 

[justwoody1]

If you can't feel it then dont worry about it.

 

[NamibHunter]

Most likely this is just a scratch mark inside the chamber. Looks very slight. If so, nothing to worry about. You can have it polished out, but i would not bother with that.

To be on the safe side, just cut one case open (a Dremel tool works well) and check if the brass is thinning near the case head. If so, you will need to check head space. Could also use an opened up paper clip with a 90 degree bend at the end to feel for a ridge on the inside of the case. Less reliable though.

As mentioned before, also get the correct gauge (Hornady gauge works fine) and check case head to shoulder length for both a fired and an unfired case for factory match ammo. If the delta is well over 0.002”, then there might be a stretch ring on the inside of the brass, which is a bad thing, as it can eventually lead to head separation.

However: This is a very unlikely outcome, as MPA is famous for doing a superb job chambering their rifles.