Heavy Lead Fouling

[AJ80]

I was shooting my M&P 15-22 today at a plastic coke bottle. Shooting 100 rounds off fairly quickly, reloading, doing it again.
After about 250 hundred rounds I noticed my accuracy was, well, nonexistent. I couldn't believe how far off my rounds were hitting.

Anyway, I decided it was time to use the bore snake. I tried, but the metal weight end of the snake would stop about half way and go no further.
I looked though the barrel and saw two huge chunks of lead on either side about half way down.

No wonder my accuracy was so off, my bullets somehow had to squeeze between those chunks of lead, and by the time they left the barrel, I'm sure they were quite deformed.

I didn't have a cleaning rod with me at the range, so I took it in and let the range owner use his to brush it out. At first he had a hard time getting the brush to go through, but he eventually got all the lead out. I went back out to shoot more and could finally hit what I was aiming at again.

I made sure to give my rifle a REALLY good cleaning when I got home.

I was using a 333 box of Winchester(which happened to have 334 rounds in it).
I don't know if it was the ammo that caused it or not, but I've shot thousands of rounds of Federal through it with no problem.
Maybe I was shooting too fast and got my barrel so hot that it was melting the lead on the way out? Is that even possible?

I'm glad my barrel is nice and clean now with no apparent damage.

Has anyone else experienced such excessive leading?

[couzin]

I'll go out on a limb here and guess you were firing LRN rounds. You should be shooting a jacketed round - the lead rounds will foul the ports (and the barrel if the gun gets hot enough from rapid fire).

[WildBill]

I just did a google for the M&P 15-22 and it shoots .22LR, so FMJ is not an option. It sounds like you should go back to shooting Federal. Or slow down.

[MoJo]

.22 rimfire ammo is the dirtiest ammunition made especially the stuff loaded for the bulk boxes.

Now as for the chunks of lead you are speaking of - - - the bullets should have been pushing it out ahead of them each time you were firing. Inspect your bore carefully and make sure there are no obstructions and then run a DRY patch through the bore slowly feeling for "catchy" places. Inspect the patch after you remove it for any flakes or chunks of metal. If all is OK proceed to clean as usual paying special attention to the bore. If you do find a "catchy" place have it looked at by a competent gunsmith and a trip back to S&W may be in order.

I have never heard of leading accumulating like you have described it's usually streaks inside the bore.

[AJ80]

.22 rimfire ammo is the dirtiest ammunition made especially the stuff loaded for the bulk boxes.

Now as for the chunks of lead you are speaking of - - - the bullets should have been pushing it out ahead of them each time you were firing. Inspect your bore carefully and make sure there are no obstructions and then run a DRY patch through the bore slowly feeling for "catchy" places. Inspect the patch after you remove it for any flakes or chunks of metal. If all is OK proceed to clean as usual paying special attention to the bore. If you do find a "catchy" place have it looked at by a competent gunsmith and a trip back to S&W may be in order.

I have never heard of leading accumulating like you have described it's usually streaks inside the bore.

I just tried a dry patch, although I haven't fired it since cleaning it yesterday. I didn't feel any "catchy" places, but in one spot the patch sounded slightly different, like the little threads that make up the patch were running over a small burr or something. When I look down the barrel toward the light, all I see is a nice shiny bore and rifling, nothing out of the ordinary.

I may try Winchester 333 again to see if that reproduces the error, and if so I may send it to S&W with the leading intact so they will know what is happening.

The range owner said he has never seen that happen before as well.

[jimlongley]

There is no way you could, easily, see the sort of thing that could cause that just peering down the bore at a light source. It might appear as a "grey" spot in the shiny, and may just look like a reflection of something further down the bore. Bore scopes are expensive, so I am not recommending you buy one, but check to see if you can borrow one, or if your local gunsmith will scope the bore for you. If you have a tool chatter or rough spot, it may be able to smooth it out.

Or you can just try smoothing it out anyway. I don't have time or space to describe lapping a bore, the instructions are readily available on the 'net and it is relatively easy to do.

[AJ80]

Thanks for the input.
If it becomes a regular problem, I'll either check with a gunsmith or let S&W handle it.

The melting point of lead is 621 degrees F.
Is it possible for a barrel to get that hot with just a few hundred rounds?
If so, I was thinking that maybe those chunks of lead were streaks as described above, but just ran down as a liquid and hardened in that spot in the barrel as I was walking to where I had my bore snake. So maybe it's not as bad as I was originally thinking.

Either way, if it just happens with one type of ammo that I only bought because they were out of what I regularly buy, then it's probably a non-issue. It's accurate enough for my purposes and I have fun with it.

[jimlongley]

I have set a Garand and a BAR on fire and have seen machinegun barrels glow red and warp, and had a Kydex holster deform and stick to my 1911, so I guess if you really worked it it you could heat up a .22 barrel enough to at least soften, if not melt, lead, but in all the years I have been shooting I have never personally seen a .22 get that kind of hot.

[ahogo]

Heavy lead is good for geese.

[WildBill]

Heavy lead is good for geese.

Only if it comes out of the barrel.

[chartreuse]

Heavy lead is good for geese.

Only if it comes out of the barrel.

I'm glad to see that I wasn't the only one who found the spelling mistake to be the most important point in the thread.

[AJ80]

Heavy lead is good for geese.

Only if it comes out of the barrel.

I'm glad to see that I wasn't the only one who found the spelling mistake to be the most important point in the thread.

Oh, there was a point to this thread?

[jimlongley]

Heavy lead is good for geese.

Only if it comes out of the barrel.

I'm glad to see that I wasn't the only one who found the spelling mistake to be the most important point in the thread.

Can you find the mispelled word in hear?

[kragluver]

I cast and shoot cast bullets in both rifle and pistol (obviously not for 22LR though). Your problem is most likely caused by a rough spot in the bore and/or the Win 333 bullets run slightly on the small side.
While pure lead does melt around 600 deg, the lead used in cast bullets is alloyed and typically melts around 700-800 deg. The bullets cannot get hot enough to melt during the very short time they spend in the barrel. Leading is typically caused bt 1: undersized bullets (usually the culprit) or 2: lube failure (not typical). Try mic'ing the diameter of the Win bullet vs the Federal.

Finally, 22LR bullets are not jacketed - some are plated but none that I'm aware of have a true jacket like larger calibers.

Like all firearms 22s will show a preference for one type of ammo over another. Shoot what works best in your particular rifle. I have had good luck with Rem and Federal bulk ammo in my 22 semi-autos. Not so much with Winchester though.

[GOP]

I find the lead rounds don't function well in all my 22's so I only use Federal plated. They don't foul as much either.