M1 Carbine gas piston

[eb in oregon]

What is that coating called they dip the lead bullets in?
I've seen multiple colors. But just can't remember what you told me it was called.
Do you think that coating and gas checks are the way to go for lead shooters?
What would be the ideal Brinell hardness rating for carbine speeds? Does 18 sound right?

I believe you are thinking of powder coated bullets, which are available in multiple colors. "The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, drum hardware, automobiles, and bicycle frames." The powder is applied electrostatically and then the bullets are baked for a bit. It is my opinion that powder coated bullets are as restricted in velocity as standard lead gas checked bullets. While the coating is easily applied to bullets it still isn't all that hard IMO. But then that's conjecture on my part as I won't be using "PC" coated bullets within this lifetime, I've already enough to last the rest of my life.

[eb in oregon]

As far as the burrs go, please remember that drilling a hole at 90 degrees is a lot less likely to leave a burr than drilling at an angle. The gas port is drilled at an angle.

Actually drilling a hole on an angle isn't subject to leaving a burr any more than a 90 degree hole as the real reason for creating a burr is more related to drill pressure (how hard are you leaning on the drill bit) and the sharpness of the drill bit. Leaning on a dull drill bit is a sure way to leave a nasty burr regardless of the angle. There will always be a small burr or two, but if the drill was sharp and the operator wasn't putting undue pressure on the drill bit they will be minimal and easily removed. Just cleaning with a bronze brush should be enough in most cases.

[DaveHH]

One of the most difficult metal working lessons is using drill bits. The way it is supposed to be done is a slow turning sharp bit with a dab of oil. You can literally watch a ribbon of material cut off the work. Sadly most people take an already dull bit at high speed and push with everything they have, resulting in an even more dull bit and scobbed up work material. Hopefully after many years the light blinks on and drilling holes in steel becomes an easy task.

[jimb16]

During WWII those carbine were being made by whomever they could pull in off the street to do the work. I often drill holes with very tiny bits that require oil and very slow drilling with very little pressure and lots of cooling time due to the ease with which those tiny bits heat up. Drilling a tiny hole (.005 dia) through 1/2 inch of steel takes a fair amount of time if you don't want to snap off a bit or burn it up. Yes, I'm making drippers for lead shot. Slow and ease does the trick.

[USGI]

Smallest bit I've got is .013" I think, and don't use it for drilling holes in steel. Commercial lead shot is getting pretty expensive now, isn't it? Back on Topic: Have any of you guys ever thought about whether the exposed lead on most FMJ carbine ammo contributes much to lead fouling in the the gas system? I've used only about 1 box of Speer carbine bullets and noticed they are made by a different process and are more like a plated lead bullet - require a bit less powder charge, etc. Seemed to work OK, but local stores aren't stocking them any more, so mainly have stocked up on Remington FMJ's, Arsmsor, and X-treme plated lead. Also have a box of Berry's but haven't tried them yet. - Bob

[eb in oregon]

During WWII those carbine were being made by whomever they could pull in off the street to do the work. I often drill holes with very tiny bits that require oil and very slow drilling with very little pressure and lots of cooling time due to the ease with which those tiny bits heat up. Drilling a tiny hole (.005 dia) through 1/2 inch of steel takes a fair amount of time if you don't want to snap off a bit or burn it up. Yes, I'm making drippers for lead shot. Slow and ease does the trick.

I hope that was an error as in over 35 years working with machine tools I've never ever seen (or heard of) a .005 diameter drill. .05 makes more sense. And a flood or air mist coolant works far better than a dab of oil ever few seconds.

---------- Post added at 06:38 AM ---------- Previous post was at 06:29 AM ----------

Back on Topic: Have any of you guys ever thought about whether the exposed lead on most FMJ carbine ammo contributes much to lead fouling in the the gas system?

The exposed tip of lead in a soft point bullet has nothing to do with fouling of the gas cylinder as it never contacts the bore. Only the outside diameter of the bullet touches the bore so that is where any bit of lead would come from as it passes over the gas port. Theoretically lead shouldn't be blown into the gas port as it is on an angle that allows the bullet to ease over it without depositing material in it, but all I can say is I've had it happen. from gas checked bullets made from wheel weights.

[jimb16]

Sorry, one too many zeros. But that isn't quite the smallest that I use. These things a fine wire drills, finer than a tiny needle. I have to special order them. I think they use a laser to sharpen them they are so thin. You have to handle them carefully because light finger pressure can bend them.

I agree with eb about soft points not leading the barrel. As long as the lead doesn't touch the sides of the barrel, there is virtually no way leading can occur. However the jury is still out on lead deposits from gas cutting of plain lead bullets. Too small a diameter on the bullet will cause gas cutting. But properly lubed and properly sized lead bullets should not lead the barrel, unless the lube runs out before the bullet leaves the barrel. The other issue is plain based lead bullets. Does the exposed lead base of the bullet melt and deposit lead as the bullet moves down the barrel? The time needed to transfer enough heat to melt the base of the bullet just isn't there. I just don't see how any melting of the base can occur in that short a time. Some folks will tell you that it happens, but I just don't believe it.

[USGI]

The exposed tip of lead in a soft point bullet

The exposed lead on FMJ is at the back of the bullet. I believe a small amount of it would be vaporized and possibly could enter the gas system. The Speer .30 Carbine FMJ 110g bullets don't have any lead exposed. - Bob

[eb in oregon]

The exposed lead on FMJ is at the back of the bullet. I believe a small amount of it would be vaporized and possibly could enter the gas system. The Speer .30 Carbine FMJ 110g bullets don't have any lead exposed. - Bob

On FMJ it surely is, but there is a roll over at the base of the bullet so the outside diameter of the bullet can't possibly touch the bore. However all standard .30 Carbine bullets (and almost all FMJ bullets) have exposed lead in the back. I've never heard of the problem in any other gas operated firearm firing FMJ bullets. And, I'll mention again that the very bullets I had the issue with were gas checked cast wheel weight bullets. Again, saving a few cents a bullet just isn't that important to me. I shoot lead and lead gas checked bullets in all sorts of firearms, and the only one that had ever an issue was the M1 Carbine.

Edit: I'm reminded that when Ruger was producing the .44 Magnum "Deerfield" Carbine it specifically states in the manual to NOT fire lead bullets but only jacked bullets in the carbine as lead can/will end up in the gas system. I have to find the manual and check but I'm pretty sure it was also mentioned as a warranty issue that Ruger was not responsible for damage or problems if the warning of "proper" ammunition was ignored.