Carbon rings in 6.5mm creedmoor.

[ar10ar15man]

NOT
chemicals are your friend

I have used a split maroon pad several times with excellent results. It takes an abrasive to remove a true carbon ring.

 

[ar10ar15man]

ok...
yes to seafoam or what ever top engine cleaner the outboard division is selling.
i am still using gm TEC. SUBARU has/had one that works.
i use it FIRST every time.
if you want to wear out your arm, go ahead with scrubbing, i perfer to let modern chemistry to work for me.

 

[Cold Trigger Finger]

I'm going to try the atf.
Got lots of atf around.
Got some real fancy Amsoil that I use for power steering fluid.

 

[DCAN]

Maroon. Check out Nathan Foster. He has some very interesting views on things, but I've found truth in them. It will work on a carbon ring. Maroon is a medium grade.

I've read his books and make use of his ideas on a regular basis. They work every time.

 

[JTB]

Ran a little test last night using hardened carbon on top of one of my old race car pistons. I tried most of what I had in my shop (shooters choice, JB, Butches, Kroil, WD40, Remington bore cleaner, gunslick foaming, lacquer thinner, acetone, top end engine cleaner, gasket remover, several other penetrating oils, marvel mystery oil). I applied the cleaner and allowed it to sit for 30 minutes before wiping it from the piston and observing the quantity of carbon left on the shop towel. Anyway, lacquer thinner worked faster and more effectively than anything else tested but evaporates quickly. All the penitrating oils and other liquid bore cleaners were moderately effective. The foaming cleaner was close to the lacquer cleaner in effectiveness and appeared to be more effective the longer it was allowed to act on the carbon. I tried a mixture of Kroil and lacquer thinner that would quickly remove carbon when used with a brush. In the end they all will assist in removing carbon (with the exception of marvel) but the foaming and the lacquer thinner provided the best results. Mixing lacquer thinner with a penitrating oil and running a brush a through few times looks to be a fast acting solution for removing rings. Think I will stay with the foaming cleaner and just let it soak for a while. Easy and effective. I'm sure there are other good formulations this is just what I have on hand.
Recommend trimming case length close to max to help avoid carbon ring formation