Fouling: jacketed vs gas checks vs lead

[Jech]

I'm curious to know if anyone else here has ever thought about whether or not shooting gas checked boolits can create any measurable amount of copper fouling and if so, do you clean your bore more frequently when shooting GC'd boolits because of that copper? A lot of guys who shoot lead exclusively don't even clean their bores since they appear to season over time...

Also, it is a *generally* accepted fact that one should not shoot jacketed bullets without fully purging any and all lead from the bore for fear of "ironing" it into any imperfections in the bore. Vice versa, one should not shoot lead boolits after jacketed bullets without performing an extremely thorough cleaning of the bore to remove all copper fouling as the lead will adhere to it and foul the bore significantly faster than a "virgin" bore.

I wonder if a gas check leaves any fouling in the bore?

[waksupi]

Well, after 7-800 GC rounds through my main rifle, I see no copper in the bore. Or any other fouling, for that matter.

[btroj]

I have never seen copper fouling due to gas checks.

As for the thorough cleaning after shooting jacketed but before shooting cast, I find that shooting cast is a great way to remove the copper fouling. I have found that a light bit of leading seems to help strip the copper out of the bore in some rifles. I am not talking a milsurp with 80 years of built up fouling in a slightly rough bore here. My Marlin 336 MG gets the copper out with about 50 rounds of cast. This was after only 75 to 100 rounds of jacketed but it still shows me that this is not always a big deal.

[stubshaft]

The last time I cleaned my 50 AK barrel was 1200 rounds ago and there is still no sign of copper fouling or leading.

Your post is the first time I heard the OWT about cleaning lead before shooting jacketed bullets. If the bore is rough enough to have lead forced into it's pores it will probably be better off.

[Bret4207]

I think it depends on the gun. I have some rifles that I can shoot cast over jacketed fouling with zero issues and others that can't take any jacketed fouling if I want to shoot cast. As far as GC's go, in many cases my recovered boolits show the GC is acting as a scraper and scraping cast fouling. (That kind of backs up my theory that a GC of significantly less than groove diameter is a waste of money in many cases). GC fouling itself...that's a pretty small band of metal to be causing much fouling, but I imagine there are guns someplace that would show some fouling in some cases.

[44man]

I do not believe in bore "seasoning" at all.
A lot of problems are from the bore itself, some get fouling and some never do even if the same loads are shot from the same make gun.
I have tried to make heads or tails of it forever and what I do just will not work for someone else.
You will not get copper fouling from a gas check and a gas check will not prevent leading if something is wrong.
I will always clean a gun before changing bullets either way. I find that after shooting lead for so long that copper will not foul my bores as much. I also get so little leading, maybe none at all, that shooting jacketed after has no affect, but I still try to clean first.
I would never shoot jacketed with a heavily leaded bore, nor would I shoot lead with a heavily copper fouled bore.
I have a BFR .475 that never needs cleaned and it has shot lead from day one. My friend bought a new one and accuracy started to go south with my boolits and loads. I found a lot of lead in the bore.
The bore is smooth and measures correct, yet it can't be explained.
My friends, that is why we all have different results.

[Jech]

You will not get copper fouling from a gas check and a gas check will not prevent leading if something is wrong.

In my recent development of a load for my Marlin 336ss, I put several rounds downrange that were loaded too hot, several produced 2280fps, one round from the next step up was 2377fps. Needless to say, the rest were pulled when I got home.

What was interesting to me about the series of warm loads was that there was absolutely no visible fouling of any kind. The boolits were poured from waterquenched range lead and sized to .310" and shot through a mic'd .3090" bore. Not having a BHN tester, I tried the fingernail test and was unsuccessful at scratching them. Shouldn't these have still leaded fairly badly given the extreme speed?

[XWrench3]

i do not know, i clean ALL of my guns shortly after shooting them EVERY TIME. so i really do not worry about what i shoot next. i just go out and have fun. life is to short to have to worry about what i shot last time i was out.

[geargnasher]

In my recent development of a load for my Marlin 336ss, I put several rounds downrange that were loaded too hot, several produced 2280fps, one round from the next step up was 2377fps. Needless to say, the rest were pulled when I got home.

What was interesting to me about the series of warm loads was that there was absolutely no visible fouling of any kind. The boolits were poured from waterquenched range lead and sized to .310" and shot through a mic'd .3090" bore. Not having a BHN tester, I tried the fingernail test and was unsuccessful at scratching them. Shouldn't these have still leaded fairly badly given the extreme speed?

I don't know who's "Rules" you're going by buy my advice is to throw them out and let your individual GUN tell you what IT'S rules are. If it shoots straight, doesn't foul, and is at a safe operating pressure then it doesn't matter if it's 2400 fps. If it's showing overpressure signs, then yes, back down some, but there is no correct rule that says your boolits will lead at anything over "x" velocity. It's all about how they are loaded and launched. I worked up a series of loads for my .30-'06 several years ago that were holding an honest, 100% and repeatable two MOA at nearly 2700 fps using water-quenched wheel weights.

Gear

[44man]

In my recent development of a load for my Marlin 336ss, I put several rounds downrange that were loaded too hot, several produced 2280fps, one round from the next step up was 2377fps. Needless to say, the rest were pulled when I got home.

What was interesting to me about the series of warm loads was that there was absolutely no visible fouling of any kind. The boolits were poured from waterquenched range lead and sized to .310" and shot through a mic'd .3090" bore. Not having a BHN tester, I tried the fingernail test and was unsuccessful at scratching them. Shouldn't these have still leaded fairly badly given the extreme speed?
Why should they lead the bore?
You need to worry more about pressure and safety first.

[btroj]

Yep, leading or lack of leading have nothing to do with whether or not a load is above or below max pressure. You have gotten no leading while at or over max pressure because you had good bullet fit, appropriate hardness, a gas check, and good lube. Pressure is a factor, but not the only one. Also remember that a 30 cal bullet may get a certain velocity in a 30-30 and be over pressure for the lever action in was shot in while it can reach the same pressure and velocity in a 308 and the same pressure is no big deal.
The gun and cartridge determine max pressure, not the bullet.

[Jech]

I don't know who's "Rules" you're going by buy my advice is to throw them out and let your individual GUN tell you what IT'S rules are. If it shoots straight, doesn't foul, and is at a safe operating pressure then it doesn't matter if it's 2400 fps. If it's showing overpressure signs, then yes, back down some...

I see what you're saying. A cratered and slightly flattened primer, abhorrent accuracy and unusually high velocity reading all indicated that I was pushing the envelope way too hard. I'm sure that the same charge/projectile chambered in 30-30ai would be perfectly appropriate.


Yep, leading or lack of leading have nothing to do with whether or not a load is above or below max pressure. You have gotten no leading while at or over max pressure because you had good bullet fit, appropriate hardness, a gas check, and good lube. Pressure is a factor, but not the only one. Also remember that a 30 cal bullet may get a certain velocity in a 30-30 and be over pressure for the lever action in was shot in while it can reach the same pressure and velocity in a 308 and the same pressure is no big deal.
The gun and cartridge determine max pressure, not the bullet.

You're absolutely right, I hadn't factored in that the bullet could very well be used in other cartridges like 308win, 30-06 etc that run much hotter. Thank you for setting me straight!

==========

It sounds like the bottom line here is this: when shooting/swapping between plain-based lead, gas-checked lead or jacketed bullets, if the rifle still shoots accurately and the bore appears to only be fouling minimally if at all, don't worry about it.

[Von Gruff]

I like to run some ER through more for the powder than anything else. Two wet patches and a dry one is all it takes after 2-300 cast that might run from 50/50 at 1500 up to lino at 2400.

Von Gruff.

[GabbyM]

I’ve never noticed copper fouling from a gas checked cast bullet. Some shooters think they are seeing copper fouling removed from a barrel when the green color on there patch is actually copper from the brass brush or jag.
I have shot gas checked rifle and revolver bullets down bores I thought were cleaned up from (other bullets) only to find the rifling looked more sharp after shooting.

No matter if the bore is clean after shooting or not. You need a anti rust coating to prevent rust. I’ve been using ATF of late. Most of my guns end up with powder fouling which needs cleaned out with solvent on a patch.

I think if you are getting copper fouling from a gas check that wouldn’t be your only issue.
My belief, and it’s only that, is we are lucky to get a good gas seal. Are a ways from getting enough friction to scrub copper. That’s just what’s stuck in my head. If you think about it. If you could scrub copper from a gas check just imagine what you’d do to a full jacketed bullet. I believe the lube we use and the lead prevent the copper gas check from fouling in a good gun and load. Not like I have any data or test to support that but it works so something is making it work.

[Jech]

No matter if the bore is clean after shooting or not. You need a anti rust coating to prevent rust. I’ve been using ATF of late. Most of my guns end up with powder fouling which needs cleaned out with solvent on a patch.

I've been partial to running a patch wetted with Kroil through the bore a few times followed by a quick run of a boresnake. Hasn't let me down yet and appears to be safe on the rest of the gun's parts.

[GabbyM]

I've been partial to running a patch wetted with Kroil through the bore a few times followed by a quick run of a boresnake. Hasn't let me down yet and appears to be safe on the rest of the gun's parts.

KROIL is not a lubricant or protectant. Regardless of what they claim on the can. We had it in gallon cans in a shop I worked in. I had a sprits bottle filled with it. Was coating down milling machine fixtures with KROIL when prepping for storage on an open air rack. Next time I’d get them down after a couple months they’d be brown like a Brown Bess musket. Fixtures were more rusted than the ones which were put away dirty with only the evaporated water based cutting fluid on them.

I do use KROIL in my cleaning regiment for J bullet in rifles. To soak overnight and to swab out the ammonia solvent. Just don’t count on it for a rust preventative because it does not work. It also will not lubricate. DA’s at Caterpillar were issuing it out from the store room as air tool lube. Grinders would run two days before the bearings flew apart.
It’s a great penetrating fluid.

[Jech]

I'm very familiar with what Kroil is and is not for :P ...I don't use it as a rust preventative or lubricant. In my other post, I was detailing the "quick-n-dirty" bore cleaning I do before I leave the range...basic at best! The next day, I'll run a tight patch through to push out any fouling lifted by the penetrating oil (be it lead or copper) then some Shooter Choice MC#7 followed by another dry patch or two.

All my rifles and handguns get some range time at least once every two weeks...if I'm actively developing loads like I am right now with my 30-30, it gets fired probably every 3 days. I'm in a dry climate so I see no need for long-term bore protectant. If that 2 week window gets stretched, I figure all the LLA that gets pushed through it will keep it safe between trips.

Am I off base with my thought process? If so, please speak up so I don't ruin my bores! Them buggers is expensive :(

[303Guy]

I'm a big fan of Rapid-Tap cutting fluid. It does dry but it leaves a film of protective something on bare steel and will even protect bare steel from rust for a few days in sea water. It also happens to be a good penetrant and dirt solvent. That's what my bores get after use. I put a few drops on a ball of cotton wool and push that through the bore. That's it untill I need to use the gun at which time a few dry cotton wool balls get pushed through. Oh, I do sometimes use Hoppes No.9 applied by dipping the brisle brush and running it though just once, in which case a fresh Hoppes cotton wool ball gets pushed through followed by a few dry balls before use. Niether have failed me yet.

[Bret4207]

It sounds like the bottom line here is this: when shooting/swapping between plain-based lead, gas-checked lead or jacketed bullets, if the rifle still shoots accurately and the bore appears to only be fouling minimally if at all, don't worry about it.

Pretty much. It comes down to being observant and listening to what the gun is saying. And something I come to believe more and more is that for every "rule" out there it's almost certain there will be a gun that goes just the opposite of what "should work".

[btroj]

Bret pretty well said it all. Only thing that matter is what your gun likes or doesn't like.