Holy carbon build-up!

[Desertbuck]

Just open up my M1 Garand gas cylinder for its spring cleaning. Been shooting PC boolits and at first I was thinking I was seeing leading! Nope it was carbon very hard carbon! I spent the last hour and a half with a dental pick, 20ga copper brush, MMO and a small butane torch, got it as hot as I dare then doused it with MMO. The stuff still keeps coming off most of it is located in the cavity just after the gas port just after the gas plug threads. Almost got it all but my gosh! I'm letting some bore solvent sit on it for the rest of the night to finish it off.
Any of you got any tips on how to prevent that buildup in that particular spot? It's the hardest to clean. And scratching at it with a dental pick kind of makes me cringe.

[sawinredneck]

Two things, you probably already know, clean it right after shooting, find a cleaner burning powder for your loads.
Sorry, not much more help than that.

[country gent]

Carbon build up can be an issue in garands ( not as bad as the M14) and other gas operated semi autos.A reamer of the appropriate size could be dulled on the sides and used as a scarper or a drill bit would work if one can be found of the right size. Some swore by Mercury upper end cleaner for 2 cycle boat motors. I have used oven cleaners easy off works good for softening and removing carbon but be carefull on finishes with it. The old hoppes #9 was a good carbon cutter also. On the M1A I have seen the pistons lower hole plugged completely full of carbon and the larger hole caked to a much smaller dia. These were simply cleaned with a set of drill bits used to scrape cut the carbon out, A letter o drill was the one for the larger hole cant remeber the small holes size. Cutting the carbon out only took a few minutes. Keeping the gas system dry and oil free helps keep the build up from sticking also. With a dry system the carbon should blow out and not stick

[Scharfschuetze]

What powder were you using. I've not ever seen that happen with my Garands with either jacketed or cast projectiles.

[Desertbuck]

What powder were you using. I've not ever seen that happen with my Garands with either jacketed or cast projectiles.

IMR 4895- 42gr of it

[Kraschenbirn]

That kind of carbon fouling with IMR4895 strikes me as 'unusual' to say the least. Back in the day when I could buy pull-down G.I. bullets for $25/1000 and milsurp 4895 in gallon milk jugs for $6/lb I'd put, literally, hundreds of rounds through my Garand without cleaning the gas piston/cylinder and never experienced anything near the kind of carbon build-up you've described. When I did get carbon fouling, it was always just a build-up on the face of the piston and in the gas port, itself ...easily taken care of with a utility knife blade and a wire-gauge drillbit.

Bill

[perotter]

What powder were you using. I've not ever seen that happen with my Garands with either jacketed or cast projectiles.

As per his original post he is using powder coated cast bullets. I'm wondering if the carbon build up is coming from the powder coating and not the gun powder.

[Scharfschuetze]

As per his original post he is using powder coated cast bullets. I'm wondering if the carbon build up is coming from the powder coating and not the gun powder.

Sounds logical as my experience with conventionally lubed cast boolits has never given me any fouling remotely similar to the OPs.

I do use powder coated boolits in the 357, 9mm and the 45 ACP and find them to be cleaner and easier to clean up from than shooting even jacketed bullets.

[Desertbuck]

As per his original post he is using powder coated cast bullets. I'm wondering if the carbon build up is coming from the powder coating and not the gun powder.

This is what I suspect as well. But I'm not positive. I do coat PCed boolits with 45 - 45 - 10 for good measure.
I just took an LED light to what's left of the build-up and I am seeing what looks like leading! Hmmm
Maybe I need to size to.311 instead of .309. In combination of maybe to small boolit and PC the the carbon build up is BAD. Anyhow I'm getting some leading of the gas system so my boolits have to be a bit on the small side BUT the barrel is clean. This was 400+ rounds with out cleaning the gas system.That is a LOT better than with naked gas checked boolits. It just shot so well with PCed booits sized .309 so that is what I used.

[Desertbuck]

I take back what I said earlier 400+ is wrong! I went back and did a quick count of my brass. More like 250 maybe a little bit more with my smaller batches. Shooting a 30/06 makes it seem like you're shooting a lot.

[Scharfschuetze]

I guess that you'll need to fire an equal number of conventionally lubed boolits and check in order to get to the bottom of this "filthy mystery." :)

[Mytmousemalibu]

Maybe a healthy shot of Kroil down the tube would help soften that crud up. Thats the best thing I know to use for stuff like this. Even better if you get it hot with a heat gun, hot enough you don't want to touch it is good but not crazy with the heat.

[Geezer in NH]

Ultrasound cleaner.

[Desertbuck]

Ultrasound cleaner.

That's a good idea! Now I've got a reason to get one. Do you think given enough time it would knock any leading loose?

[Geezer in NH]

As long as it is not soldered on with a flux it should help remove it it will have powder residue and lube in between layers. You will be amazed what stuff will be in the tank when done.

[Hamish]

Sounds like a good reason to mix up a batch of "Ed's Red",,,,,,

I would definitely suspect they need to be .310 to .311.

[reivertom]

I know from shooting black powder that petroleum based products turn into black concrete if you use them for lube or to swab your bore. Could you have had too much oil that made its way into the tube?