Yeah, cleaning the throat for carbon is usually the most efficient way to investigate/solve the problem. Sometimes the effort investigating is way more than just cleaning to see.
Use a good carbon solvent, those rings are stubborn.
Barrel Problem
- Thread starter BearGuy
- Start date
Use a good carbon solvent, those rings are stubborn.
^^Buy a borescope on Amazon and scrub the carbon ring out before you do anything else. I will be pretty surprised if you don't have a carbon ring. But def report back.
kswaterfowl
WKR
- Joined
- Apr 3, 2020
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- 476
Sounds like it was a tight chamber to start with.
Castle Rock
WKR
- Joined
- Mar 28, 2020
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Update on this. Just took everything to the smith to get it borescoped and see if anything is going on. Definitely some carbon ring buildup but nothing was too crazy. He cleaned the barrel and then took a chamber cast. The cast showed everything to be to spec. The only thing that wasn’t checked was freebore or throat. Came back and chambered some rounds and there is maybe one very very slight scrape on the bullets but it’s honestly hard to tell.. I haven’t shot it yet so I will report back and see if I still have any pressure problems. I’m gonna probably be able to shoot tomorrow and see what happens.
Willie IV
Lil-Rokslider
- Joined
- Mar 6, 2019
- Messages
- 202
I built a 6cm tikka that was chambered by my local smith. I had the same issue and it was a carbon ring. Now that I've used some once fired brass in reloads it seems like less of an issue so I'm not sure if factory case lengths were on the short end of tolerance. Anyhow, I fought it thru 200 rounds of factory ammo. Boretech C4 and a mop and let it sit in the throat area for 15-30 minutes. Clean it often is what I found to be best.
Update 2:
The picture below is what the rounds looked like after my smith cleaned for an hour or so and then I shot about 10 rounds through it. Pressure signs weren’t there like they were beforehand. But given the scraping I decided to send it to preferred to see what they said. They loaded dummy rounds and couldn’t really get the same result I was getting. He then cleaned and lapped the barrel and gave it to their smith so he could polish the throat and smith said no issues with the chamber. They sent it back today and said dummy rounds were feeding perfectly with no scraping and it should be good to go. Going to shoot it as soon as I can to but PBB said all should be well. In anyone’s opinion, is this enough information to say that a carbon ring alone was affecting the performance or is there other factors to check off the list?
The picture below is what the rounds looked like after my smith cleaned for an hour or so and then I shot about 10 rounds through it. Pressure signs weren’t there like they were beforehand. But given the scraping I decided to send it to preferred to see what they said. They loaded dummy rounds and couldn’t really get the same result I was getting. He then cleaned and lapped the barrel and gave it to their smith so he could polish the throat and smith said no issues with the chamber. They sent it back today and said dummy rounds were feeding perfectly with no scraping and it should be good to go. Going to shoot it as soon as I can to but PBB said all should be well. In anyone’s opinion, is this enough information to say that a carbon ring alone was affecting the performance or is there other factors to check off the list?
Attachments
Also to note, my plan moving forward is to just go forward and shoot. If it happens again, I’ll cross that bridge when I get there but I’m just gonna keep shooting.
Also, I can’t speak highly enough of Mason at PBB and the CS there. He never once made me feel like I was crazy and he was asking good questions to make sure he was understanding and doing all he could. The fact that he couldn’t replicate what was happening but still took the necessary steps to send it to the smith was impressive to me. They started working on it the day they got it and communication was constant and clear.
Also, I can’t speak highly enough of Mason at PBB and the CS there. He never once made me feel like I was crazy and he was asking good questions to make sure he was understanding and doing all he could. The fact that he couldn’t replicate what was happening but still took the necessary steps to send it to the smith was impressive to me. They started working on it the day they got it and communication was constant and clear.
Are you getting the same bullet scraping since it came back from PBB?
They sent the barrel today so I’m gonna check when I get it all put back together. They said none of the dummy rounds showed any scraping
Final Update:
Got everything back from PBB and got it all put back together. No more scraping of bullets. I’ve shot factory and hand load ELDM’s through with no issues. 40.6gr H4350 gave me 2890 through the 20” barrel. Didn’t seem to have any pressure signs whereas before i had faint ejector marks. I then loaded some 116 TMK’s to 39, 39.5, and 40gr H4350 at 2.840 COAL. Heavy bolt lift and ejector marks at 40gr. 39.5 seemed a little tough on the brass but no heavy lift, ejector marks, or flattened primers. After ready through some of the other loads with 108’s, 95’s and 116’s, I feel like my chamber just might be on the tight side because all of my loads for those 3 rounds are quite a bit lower. Getting about 2790 with the 116’s so I’m just gonna shoot the crap out of the rifle with that load and get a new barrel whenever that time comes.
Got everything back from PBB and got it all put back together. No more scraping of bullets. I’ve shot factory and hand load ELDM’s through with no issues. 40.6gr H4350 gave me 2890 through the 20” barrel. Didn’t seem to have any pressure signs whereas before i had faint ejector marks. I then loaded some 116 TMK’s to 39, 39.5, and 40gr H4350 at 2.840 COAL. Heavy bolt lift and ejector marks at 40gr. 39.5 seemed a little tough on the brass but no heavy lift, ejector marks, or flattened primers. After ready through some of the other loads with 108’s, 95’s and 116’s, I feel like my chamber just might be on the tight side because all of my loads for those 3 rounds are quite a bit lower. Getting about 2790 with the 116’s so I’m just gonna shoot the crap out of the rifle with that load and get a new barrel whenever that time comes.
Did they say what they did?
Cleaned and lapped the barrel and then sent it to their smith and he polished the chamber throat area
It wouldn't hurt to try a different powder, but I agree, just shoot it till it doesn't shoot anymore.
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