Proof barrel gas port defect

[Diesel Pro]

Looking for opinions from those more educated than I regarding a gas port flaw in a new Proof CF barrel. To me it is pretty sad and never should have left the factory. The barrel came on a Cobalt Kinetics SPR Elite in 6 ARC that I recently purchased new at $3k+. I have not done any precision shooting for groups due to weather etc. I have only done chrono load development and zeroing with a thermal. I did some ladder testing, but only with a first focal 1-6 LPVO so nothing that I would consider precise point of aim or even consistent loads, but it does seem to shot well. On the target pic keep in mind 100yds range large dot in reticle, temps in single digits, portable bench and there are 30rds for each of the right 2 groups. The left groups were Vmax and they don't seem to fly like the ELDX. There are 3ea at 10 different charges plus I did not anneal my brass at that time so neck tension varied.


One pic is the Proof and the other is a cheap CMMG for comparison.

Cobalt said that they would work to facilitate a warranty replacement with Proof, but that would likely take 12 weeks. Knee jerk reaction is shove it up and break it off, but I don't have a lot of experience with these things.

 

[AleksanderSuave]

Looking for opinions from those more educated than I regarding a gas port flaw in a new Proof CF barrel. To me it is pretty sad and never should have left the factory. The barrel came on a Cobalt Kinetics SPR Elite in 6 ARC that I recently purchased new at $3k+. I have not done any precision shooting for groups due to weather etc. I have only done chrono load development and zeroing with a thermal. I did some ladder testing, but only with a first focal 1-6 LPVO so nothing that I would consider precise point of aim or even consistent loads, but it does seem to shot well. On the target pic keep in mind 100yds range large dot in reticle, temps in single digits, portable bench and there are 30rds for each of the right 2 groups. The left groups were Vmax and they don't seem to fly like the ELDX. There are 3ea at 10 different charges plus I did not anneal my brass at that time so neck tension varied.


One pic is the Proof and the other is a cheap CMMG for comparison.

Cobalt said that they would work to facilitate a warranty replacement with Proof, but that would likely take 12 weeks. Knee jerk reaction is shove it up and break it off, but I don't have a lot of experience with these things.

Unusual gas port erosion was one of the primary reasons Proof just replaced a brand new 6 arc barrel for me. 100 rounds down the pipe, if that.

Accuracy was dogshit as well. 1.5" groups at 100 yards with hornady eld match.Replacement took about 2 months. If I was to do it over, I would have just ordered one of the newer Centurion 6mm arc barrels.

I also dont have the carbon fiber option, just plain stainless steel..so your choices are a lot more limited if you want identical specs.

 

[Diesel Pro]

I just sent pics to Proof. I like the Cobalt and I like the carbon barrel concept, but the upper/lower fit could stand to be more secure and the irregularity in the barrel are concerning. The light weight of the CF is awesome. I just wish I'd have had my borescope and looked inside when new.

 

[AleksanderSuave]

I just sent pics to Proof. I like the Cobalt and I like the carbon barrel concept, but the upper/lower fit could stand to be more secure and the irregularity in the barrel are concerning. The light weight of the CF is awesome. I just wish I'd have had my borescope and looked inside when new.

I just looked up the price of that rifle. For that price it better damn well fit right securely

 

[ZA206]

Looks like a simple gas port burr from metal migration. Your gas port is almost entirely in a groove (ideal). How many rounds do you have down it? Have you tried decoppering the burr? I have a Proof CF 16” 223 Wylde and it got a gas port burr after about 10 rounds and wouldn’t group any better than 1.5” with match loads. I ran it hard with blaster ammo for about 150 rounds. After that, I cleaned it really well with Wipeout and JB’s+ Kroil.

After that, it settled down and became a laser. 1/2” 5 shot groups are common, fantastic turn around.

On the other hand, I had a WOA that had the gas port totally cutting through a land (terrible QC). It never shot anything smaller than 1.5“ with probably 300-400 rounds on it. I sent it back and got a replacement on WOA.

 

[Diesel Pro]

Unusual gas port erosion was one of the primary reasons Proof just replaced a brand new 6 arc barrel for me. 100 rounds down the pipe, if that.

Accuracy was dogshit as well. 1.5" groups at 100 yards with hornady eld match.Replacement took about 2 months. If I was to do it over, I would have just ordered one of the newer Centurion 6mm arc barrels.

I also dont have the carbon fiber option, just plain stainless steel..so your choices are a lot more limited if you want identical specs.

How many rounds have you put through the new one and how is it looking and performing?

 

[Diesel Pro]

Looks like a simple gas port burr from metal migration. Your gas port is almost entirely in a groove (ideal). How many rounds do you have down it? Have you tried decoppering the burr? I have a Proof CF 16” 223 Wylde and it got a gas port burr after about 10 rounds and wouldn’t group any better than 1.5” with match loads. I ran it hard with blaster ammo for about 150 rounds. After that, I cleaned it really well with Wipeout and JB’s+ Kroil.

After that, it settled down and became a laser. 1/2” 5 shot groups are common, fantastic turn around.

On the other hand, I had a WOA that had the gas port totally cutting through a land (terrible QC). It never shot anything smaller than 1.5“ with probably 300-400 rounds on it. I sent it back and got a replacement on WOA.

Yes the copper is out. This picture was was a bit back. I'd say close to 300 rds now. I have the 90ELDX and 103ELDX charges dialed in (assuming things don't go nuts when it warms up. Still need to explore seating depth.

Just stepped up my reloading game working through ladders for nodes rather than just shooting varying charges for groups. Getting my SD reduced through annealing etc. I plan to start shooting the CMMG a bit more so I'll see what that one does at the gas port. It's got a low round count and plenty of chatter marks to burnish out.

 

[ZA206]

Is the rifle shooting well? Are you a good enough shooter to tell the difference?
In your OP, you mentioned shooting off a portable bench with a 6X LPVO with a large center dot.

Not exactly the recipe for precision.

If the rifle is shooting well, I would be happy and not complain, regardless of what the gas port looks like though a borescope. All gas ports get erosion on the muzzle side... the CMMG will do it too once you get some rounds on it.

 

[Diesel Pro]

For comparison here is my Springfield Saint Victor that has at least 2x the rounds down it

 

[Diesel Pro]

edited duplicate post

 

[Diesel Pro]

Is the rifle shooting well? Are you a good enough shooter to tell the difference?
In your OP, you mentioned shooting off a portable bench with a 6X LPVO with a large center dot.

Not exactly the recipe for precision.

If the rifle is shooting well, I would be happy and not complain, regardless of what the gas port looks like though a borescope. All gas ports get erosion on the muzzle side... the CMMG will do it too once you get some rounds on it.

Yes that was my disclaimer. I haven't yet shot with my typical optic which would be a 14x second focal plane. The portable bench is setup is solid. I have a better rear bag now. I can shoot sub 1/2 MOA with relative ease with my Sako 204. On a good day I can cover 10 holes with a dime at 100yds and I have upped my reloading game substantially just recently. The load I use for the 204 shoots great, but I'm sure it's on an island and not in a node nor was my neck tension consistent as I was not annealing until just recently.