JP HP AR10 bolt finish durability issues

[exoto1225]

Does anyone running a JP HP bolt notice the finish durability issue? I used this one in my AR10 for ~2 months, only shot about 400 rounds, and the lugs are now completely just naked metal, the body of the bolt also shows tiny spots where finish wearing off. All these look like chemical erosion of the DLC finish, but the only cleaning solvent I use is Hoppe's No. 9.
This in fact is the replacement bolt from JP because I had same issue with my first one. In the email, they said this is not normal. I wonder if anyone had similar experience? will JP's Chromium Nitride finish be more durable? thanks

 

[scott5456]

I get the chrome polished ones because they are so easy to clean and very slick. A couple notes, are you sure your upper and barrel extension are lined up? Yes I know if has a pin but typically there is a bit of slop in the pin to move one way or another. Does your charging handle have any wear on it? Do you clean inside your barrel extension? Might check the finish on the inside of the barrel extension with a bore scope, some people have had to lap them a bit to get the high spots or rough finish to even out.

 

[dtma42]

The one I have in my factory-built LRI-20 got dings on the lugs after 300 rounds and I emailed JP about it. According to them it's normal. Don't know why they're telling us differently.

 

[Billiam1211]

Here’s mine, its paired up with a Proof Research 6.5 Creedmoor barrel and also has ~ 300 rounds on it. Looks like your bolt is wearing much more aggressively than mine. I’m running 41.7gr H4350 with 140 ELDs. I did also bed the barrel into the upper to align it perfectly because my Aero upper had a tiny bit of slop.

 

[Aftermath]

Post some pics of fired cases.

 

[exoto1225]

Here’s mine, its paired up with a Proof Research 6.5 Creedmoor barrel and also has ~ 300 rounds on it. Looks like your bolt is wearing much more aggressively than mine. I’m running 41.7gr H4350 with 140 ELDs. I did also bed the barrel into the upper to align it perfectly because my Aero upper had a tiny bit of slop.

I run 40.5 gr H4350 with 140 ELDM on seekin SP10 with a PROOF CF barrel. My first JP bolt worn like this at 100 rounds. JP replaced that one, then this one lasted 400 rounds and I got same result. I'm also pretty sure that it is not physical/mechanical wear but chemical erosion of the finish. All lugs have no scratch marks at all (Except for area from the rear end of the lug), just discoloration. it looks to me that JP's "DLC coat" finish is not chemically stable towards the residue generated from burned gun powder, but I could be wrong.

 

[HerCoStarNTheBeaverPictur]

I have not had this issue. Also a proof barrel but factory ammo

 

[Bigjake83]

I run 40.5 gr H4350 with 140 ELDM on seekin SP10 with a PROOF CF barrel. My first JP bolt worn like this at 100 rounds. JP replaced that one, then this one lasted 400 rounds and I got same result. I'm also pretty sure that it is not physical/mechanical wear but chemical erosion of the finish. All lugs have no scratch marks at all (Except for area from the rear end of the lug), just discoloration. it looks to me that JP's "DLC coat" finish is not chemically stable towards the residue generated from burned gun powder, but I could be wrong.

No that's about right, my JP bolt that I use in my Proof 6.5CM barrel has a fair amount of wear at around 600 +/-
It's purely cosmetic and has no bearing on the bolts performance. I don't see what the problem is? And if for some reason it does create a mechanical issue JP will replace it.

I also clean my bolts on a soft wire wheel so that may have expedited some of the wear, regardless she's still shooting in the .3's

All my other JP Bolts still look new, so yeah I'd say if a fair assumption they had a batch go out and the coating is a bit weak on them.