SPR barrel life

[RTH1800]

One of my HCS Mk 12 rifles is dropping off in accuracy. (my favorite of course). It is now approaching 1MOA which is well over twice the new barrel group size. I do no rapid fire, mag dumps etc. I do occasionally get into a pack of coyotes and fire 5-10 rds fast, but not often enough, of course. About half of the rds were fired at game, the other half on the range. RD count is just over 3K. All RDS were 77 grain SMK @ 2725-2750. MK262 or TAC handload. All firing has been suppressed. Bore is eroded, but not too badly. What are your experiences with barrel life on the HCS builds?

Thanks!

RTH

 

[maggitas]

RTH,

I do not have any experience with the round count of an SPR barrel but that seems a bit low. Have you tried removing the copper out of the barrel with Boretech bore cleaner or Sweets 7.62?

 

[Pusher591]

I too suggest a real good cleaning. Bore tech is phenomenal. FYI, don't use any bore foam, it can get into the gas tube and create pressure issues once your up and running again.

If cleaning it doesn't work, make sure inspect the crown for dings or dents. I highly recommend taking the flash hider or brake off and cleaning the crown and thread area well. Nothing rough, just the crown soak in a non-abrasive cleaner for a little bit, then clean with a soft brush. Let us know if anything works out.

 

[ORD]

Even with all 3k round being shot suppressed...that's a VERY low round count with a 5.56/.223 running even hotter, heavier loads through it. What specifically do you mean by "Bore is eroded...?" If so, which portion? Chamber end or muzzle? Throughout?

As I'm sure you are aware, running the rifle suppressed throws all kinds of @#$% back into the receiver, throughout the gas system, etc., etc. I too recommend an extremely thorough cleaning and inspection of the rifle from top to bottom. You might also have a look at your can, because while I doubt its the culprit (God forbid!!), you could have some damage to it or at least considerable fouling/crud build-up in the suppressor causing/contributing to your decline in accuracy.

Once you have everything cleaned up and inspected, assuming you don't find anything afoul with your crown, can, etc., just remember that you'll likely have to foul the bore somewhat before it will settle in and your accuracy will return (assuming of course that it was excessive fouling/deposits in the barrel in the first place causing your accuracy woes).

Good luck and God speed! Be sure to post a follow-up once you have a chance to re-evaluate.

 

[BCP]

Could be coppered up.

2750 is a somewhat hot load for 18" 223 and most stainless barrels start to drop off about 3000. Maybe play with seating depth and charge weight? About 6000 you should see it drop to around 1-1.5MOA no matter what you do and past 10k it'll be a plinker barrel.

 

[MSTN]

Good advice you're getting here.

You might check to ensure the barrel collar for the Ops-Inc 12th Model is secure on the barrel shelf and the suppressor is getting at least four full threads of engagement on the muzzle device.

I'd like to add there is sometimes a problem with carbon building up in front of the chamber area that does not get removed effectively with normal cleaning. A size larger bore brush with carbon solvent (I like KG-1!) rotated gently in the throat area is all it typically takes to knock it out.

A trip down your barrel with a borescope would answer a lot of questions.

I know that HCS uses excellent barrels turned out by Gene Barnett from Douglas blanks. A steady diet of Mk 262 does have a reputation for being hard on throats, regardless of the quality of the barrel. Maybe you could find an accuracy node 100 FPS slower.

 

[RTH1800]

Thank you for the replies.
I also had a reply from Kevin at HCS to an email. He stated 6k was about the trouble area for accuracy and some go to 10K but accuracy is off a good bit.
Borescope shows erosion in throat. Those Douglass barrels never look as smooth as a Krieger or Bartlien but shoot great. I have cleaned it, suppressor is fine. I am quite picky about accuracy and this rifle shot under 4" at 750 meters in the past. No wind, of course. I will try it again. It must be under 1MOA or it will be re-barreled. Thanks for the input.