Lapping a barrel

[JDY]

What type of lapping compound would I use for lapping a new SS barrel that coppers up (after only 4-5 shots) in the last 2-3 inches at the muzzle. The barrel has 150 rounds fired and cal. is 6.5-284. Shooting a 140 A-Max @ 2800 fps.
THANKS
JDY

 

[watercam]

Brownells offers excellent lapping compounds. I keep 120, 240, 400 and 600 grits around. I would try ten passes with 240 grit on a slightly undersized patched BRUSH. Start with ten passes, then clean and try ten more of 400 and stop and shoot again.
If you have a bore scope you can look after the first ten passes and see if the tooling marks or burrs have smoothed out. Be careful as it is possible to over lap a barrel to the point of lowering pressures (ie velocities).
Have fun,
Mike T.

 

[blawton]

Goodson valve lapping compound in 120 240 and 400 grit is what you will need.

I have also used this smooth kote with success to help with coppering problems. you can find it in the armorers kit at www.sentrysolutions.com.

 

[spclark]

Besides lapping with compound and a lap, there's something called fire-lapping which is done with abrasive-coated bullets.

David Tubb sells kits of bullets in several calibers, each kit having several bullets coated in graded abrasives to be used depending on the severity of the problem:

http://www.superiorshootingsystems.com/RELOADING-FINAL_FINISH.html

You may find these more suitable for your needs than hand lapping, which if done to excess can not only alter the bore profile to disadvantage but also actually increase a bore's tendency to foul.

Brownell's & Midway (maybe even more suppliers) sell fire lapping kits of graded abrasives you can use to coat your own choice of bullet too. It's possible these same products could be used for hand lapping too, if you choose to go that route.

I'm curious: did you use any kind of break in routine when you first started shooting this barrel? Some say it's worth it, others say just shoot the thing. In 6.5-284, barrel life's going to be short enough without having to waste any of it trying to eliminate problems....

 

[JDY]

I did the one shot / clean process and 5 shots / clean with no luck. I will be sending the barrel back.
THANKS
JDY

 

[JDY]

Glad I returned the barrel to Shilen.

I received a call from Shilen yesterday. The barrel I sent back was out spec. The nice lady ask me to send my action to Shilen and they would chamber and install a new barrel.
Any barrel maker is subject to send out a bad barrel. I think that Shilen is doing what is the right thing to do. This is the reason Shilen has been around for a long time.

JDY
PS
A satisfied customer