9mm leading, help! [Archive] - Glock Talk


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05-01-2010, 23:31
I experienced some leading with 125gr lead bullets from Dardas. They are measured at .356, hardness at 16. Pistol used was a Sig P226. Here are my loads with Bullseye:

125gr lead .356:

4.0 gr Bullseye
.1150-.1160 OAL
Result: A lot of leading.

4.3 gr Bullseye
.1150-.1160 OAL
Result: still a lot of leading.

4.7 gr Bullseye
.1150-.1160 OAL
Result: some leading.

According to this pattern, should I keep increasing the charge until all leading is gone? Something just doesn't add up. According to most of the load data I've seen, 4.7gr is already over the MAX load suggested.

Could it be the bullet? Too soft?

Please help.

05-02-2010, 01:06
Usually the higher the velocity the worse the leading. How did you clean the barrel of the previous leading? I run my lead bullets pretty mild and get very little leading.

05-02-2010, 01:47
I tested 20 rounds with each load, 10 rounds per magazine, I boresnaked twice every mag.

05-02-2010, 06:11
The bullets are too hard and too small. Don't go over max charges to solve the problem. Try two things. First, load them lighter, say 3.5 BE, it can't hurt. Second, try a different, slower, powder. Bullseye is very good with lead bullets when used for light loads. 4.0 might be a bit high, 3.5 might work well as a light load. Try Unique or another powder near it on the burn rate chart. Generally speaking, Unique and similar powders work better in higher pressure rounds like 9mm.

I just got my 9mm mold, Lee 120TC, and haven't had a chance to use it in 9mm. I did load some light 38spl loads with it and it worked great.

05-02-2010, 09:19
I tested 20 rounds with each load, 10 rounds per magazine, I boresnaked twice every mag.

I doubt the boresnake got all the lead out. try the Chore boy wrapped around a bore rush and it will take out all the lead.

A lot of people swear by by bulleseye powder. I'm not one of them.

I would try a different powder and see what happens.

05-02-2010, 17:01
People told me lots of things about what needed to be done to eliminate leading. From my experiance in 9mm it's all about bullet sizing and being sure your case is not sizing your bullets after you put them in the case and bullet hardness. Nothing had a more dramatic effect then changing the bullet size and then fiddling with bullet hardness after that. My 9mm likes hard (about 16bhn) bullet sized at .356. But I had to use a .357 die to get them at that size. 12 bhn leaded more then 16 bhn by a pretty good amount but sizing made the biggest difference.

05-02-2010, 17:45
I contacted the place where I purchased the bullets from. After a brief chat, they suggest that I should try a bigger diameter bullet, maybe .357 instead of .356.

This makes sense because based on my data, a light load (4.0) was not enough to expand the bullet to fill the bore, letting gas pass through the bullet causing leading. A hotter load (4.7) was enough to cause the bullet to expand more to fill the bore, which reduced in less leading.

Now if my assessment is correct, my bore diameter is too big for a .356. If I switch over to .357, I wouldn't need to load too hot.

Am I correct?

05-02-2010, 18:10
The only way to be sure is to slug it. force a bullet though it and measure the bullet that comes out.

05-02-2010, 19:17
Slugged it twice. Bullets came out at .355 and .355 1/2. Does this mean I need a .357 bullet?

05-02-2010, 20:10
Slugged it twice. Bullets came out at .355 and .355 1/2. Does this mean I need a .357 bullet?
Typically no, 0.001" over groove size seems to work for most. Where is the leading, ahead of the chamber, along the entire bbl or at the end? Too hard a bullet that is undersized (this can happen during seating/crimping too) & operating @ low pressure, can cause early leading. All aling the bore, often meas too soft, only at the end, the lube has failed. The harder the bullet, the more pressure you need to get it to obturate. Then again, some bbls just lead, usually cut rifled bbl., but others can too. Also make sure the bbl is clean of all copper fouling BEFORE shooting lead. It can strip lead in the bbl as well. The 9mm seems particularly tough to get right.:dunno:

05-02-2010, 20:55
Well, considering your getting leading I would try the .357. If your barrel is slugged at .3555 then .356 is really just about the same size. I had a barrel from LW that had too large of a throat. It would lead with anything. Personally. I think store bought lead is harder to deal with. You can't fiddle with bullet sizing, hardness, and lube as easily.