Barrel Problem

[BearGuy]

Need a little help here. I have a PBB barrel bought from LS Wild last year that might have a problem. Cartridge is 6 creed on a tikka action. When I first got the barrel I felt like the bolt was a little more difficult to close on some rounds then I thought it should be but it shot well and I didn’t really think much of it. I also don’t think I ever chambered a round that I didn’t fire as I was just practicing and getting as many rounds down the barrel as I could. Fast forward to the fall and after chambering a round that I didn’t fire, I noticed some “scratches” on the round. Kind of didn’t touch the rifle until recently after getting into hand loading. After shooting some rounds I was having pressure signs at 2.5 grains under book max. Then was noticing ejector marks on factory loaded brass as well. It seems to me that maybe the throat is a little short? I’m no wizard when it comes to all this stuff so any input is appreciated. 108 eldm and 95 tmk both show scratches.

 

[mtnbound]

Need a little help here. I have a PBB barrel bought from LS Wild last year that might have a problem. Cartridge is 6 creed on a tikka action. When I first got the barrel I felt like the bolt was a little more difficult to close on some rounds then I thought it should be but it shot well and I didn’t really think much of it. I also don’t think I ever chambered a round that I didn’t fire as I was just practicing and getting as many rounds down the barrel as I could. Fast forward to the fall and after chambering a round that I didn’t fire, I noticed some “scratches” on the round. Kind of didn’t touch the rifle until recently after getting into hand loading. After shooting some rounds I was having pressure signs at 2.5 grains under book max. Then was noticing ejector marks on factory loaded brass as well. It seems to me that maybe the throat is a little short? I’m no wizard when it comes to all this stuff so any input is appreciated. 108 eldm and 95 tmk both show scratches.

Did you use a Go-No-Go gauge when you spun the barrel on?

 

[BearGuy]

Did you use a Go-No-Go gauge when you spun the barrel on?

Yes. Bolt did not close on no-go. Bolt did close on the go gauge. Double check it the other day as well. I didn’t feel like there was any abnormal resistance on the go gauge either.

 

[mtnbound]

Yes. Bolt did not close on no-go. Bolt did close on the go gauge. Double check it the other day as well. I didn’t feel like there was any abnormal resistance on the go gauge either.

Ok, what's the OAL of the rounds? Does the bolt feel tight on all of the rounds, handloads, and factory?

 

[Caseknife]

Have you checked for a carbon ring. Looks like that on the bullet.

 

[BearGuy]

Ok, what's the OAL of the rounds? Does the bolt feel tight on all of the rounds, handloads, and factory?

Factory and hand load 108’s: 2.791
95 TMK: 2.770

Feels tight on all the 108’s if I go nice and easy. If I’m just shooting through a mag it isn’t as bad. 95’s don’t feel as tight.

 

[mtnbound]

Factory and hand load 108’s: 2.791
95 TMK: 2.770

Feels tight on all the 108’s if I go nice and easy. If I’m just shooting through a mag it isn’t as bad. 95’s don’t feel as tight.

I would rub a black Sharpie all over the bullet and casing neck and chamber a round, and see how bad the Sharpie is wiped/scraped off for a better visual.

 

[huntnful]

Those scratches seem abnormal to me, even if it’s cut with a shorter freebore.

The depth of the reamer itself must be correct based off your go no go gauge test. But something is off in that freebore area.

Are you aware what freebore reamer, or reamer in general that they used to cut the barrel?

I’d be curious to see inside there with a bore scope and if carbon build up in the throat area is scratching up your bullets like that.

 

[BearGuy]

I would rub a black Sharpie all over the bullet and casing neck and chamber a round, and see how bad the Sharpie is wiped/scraped off for a better visual.

95 tmk and 108 eldm

 

[BearGuy]

Those scratches seem abnormal to me, even if it’s cut with a shorter freebore.

The depth of the reamer itself must be correct based off your go no go gauge test. But something is off in that freebore area.

Are you aware what freebore reamer, or reamer in general that they used to cut the barrel?

I’d be curious to see inside there with a bore scope and if carbon build up in the throat area is scratching up your bullets like that.

I’m not sure. @hereinaz might know. I was going to take it to my local smith and have him look at it with a bore scope as my step one.

 

[huntnful]

I’m not sure. @hereinaz might know. I was going to take it to my local smith and have him look at it with a bore scope as my step one.

Keep us updated if you don’t mind . Any barrel cleaning done ever? Just a SAAMI 6 creed that’s only seen factory ammo?

 

[mtnbound]

95 tmk and 108 eldm

I would check things with an OAL gauge if you have one; if not, take it to a local smith and see if he can measure it for you.

 

[BearGuy]

Keep us updated if you don’t mind . Any barrel cleaning done ever? Just a SAAMI 6 creed that’s only seen factory ammo?

No cleaning ever done. Didn’t clean a lot to begin with then saw threads on not cleaning and solidified my position. And yeah saami and about 400 rounds of factory ammo and ~50 of reloaded ammo. I’ll definitely update the thread as I learn more. I called PBB today and the guy I talked to said it was probably a carbon ring… I’ve just read a lot of conflicting info on a carbon ring so idk what to think about that

 

[AKM]

I’ve had pressure signs w factory ammo. Blew my mind at first. Started checking cartridge dimensions and found the case shoulder was at the bottom of the saami range. Gave hard bolt lift, ejector swipe and ejector imprint on the bottom of the case. Came back w handloads using .002” bump using same brass and it was all gone. Any headspace measurements on cartridges or chamber?
I have also had pressure signs using factory nickel plated brass. Rifle would put two in a group and throw the rest by 2-3” @ 100yds. Switched back to brass cases and problem gone.
Another condition that will produce a similar condition is the oiled chamber. Want it clean and dry.

Interested to hear what the gunsmith finds.

 

[ResearchinStuff]

If this is on a Tikka, sometimes they just beat up the case head. My 6.5 puts a slight swipe on every shell that goes into it even if I don't fire it.

Whatever is going on in your freebore area is weird though.

 

[Dave Thomas]

If it didn't happen when new I would say probably a carbon ring. If I'm not mistaken the creedmoors have a tight freebore diameter. Add a little carbon on it and that happens. My 284 Winchester reamer has a half thousandth clearance over bullet diameter and I have the same problem.