9mm leading

[marineshooter]

hi guys, i just got a s&w sigma 9. loaded 100 rounds of m.b. 115 gr lrn with 4.2 grains of titegroup. all rounds functioned as expected. last 1/2" of barrel leaded real bad. it took about 40 mins of hard work to remove. i use titegroup and lead rounds in my 380- 357- 45, with no leading to speak of. could this be a bit close to the max i can push these bullets. hodgdon's web site gave 3.9 to 4.3 as the charge. i am using lee's auto disc .37 hole, if i go down to the .34 it is right around 3.8-3.9. would this be too low of a charge???? at 4.2 gr my brass is 6-8 feet away, would a lower charge not throw it as far?? any ideas are a great help

 

[Quoheleth]

You should be OK. Make a dozen or so and try it and see.

Q

 

[Walkalong]

Interesting. Haven't had that in a pistol barrel.

Leading towards the end of a long barrel is usually lube related, but this is a pistol barrel, making me wonder if they were pushed too hard, but 4.2 Grs of Titegroup should have been OK.

Sure won't hurt to try 3.8/3.9 Grs.

 

[LiveLife]

Interesting. Haven't had that in a pistol barrel.

+1. Any leading I have seen were near the chamber end.

 

[depoloni]

Would agree with the sagely advice already posted. You should cycle just fine at 3.8-9 grains. One suggestion I might add, if you know how, would be to slug that barrel and see if it's just not constricted near the muzzle. Seems weird to me too to lead that way in a pistol but, on occasion, the bores aren't uniform down their length. Would wonder if a slug tapped in from the muzzle didn't suddenly move more easily a short way down the barrel.

 

[1SOW]

Marine- I agree with Quoheleth.

FWIW I use the Autodiscs too, and run into the same problem with 'jumps between disc holes. With chrono tests, I'd find a 'sweet spot' for the load that didn't have a 3.9 gr disk hole. I found two fixes.

1. Buy the ($10?) micrometer adjustable charge bar and be able to make .01 grain changes. Works best with ball powders. I use Vit n320 powder and it wasn't real consistent for me. It was just acceptable.

2. Some may say this isn't a good idea, BUT If the #32 hole drops 3.8grs and you want 3.9grs:

Find a drill bit just slightly bigger than the #32 disc hole- A 1/32" bigger or less would be okay.
Turn the disc UPSIDE DOWN and using a drill press align the drill with the disc hole. Drill into the BOTTOM of the disc hole a small amount.

This enlarges the hole AT THE BOTTOM ONLY slightly and it tapers where the drill bit tip tapers. With some very fine sandpaper and a dowel lightly sand the enlarged portion to smooth it.

Drilling from the bottom leaves no lip or surface for powder to catch on.

Clean the dust off, install it in the press and drop several loads through it then drop another load to weigh it on your scale-looking for 3.9grs. It will be light, so take it back off and drill it a skosh more , sand, clean and retry it. If that gets the scale close then do it again just another skosh at a time until your right at 3.9. BE PATIENT and weigh each change several times checking for consistency.

I then use white paint and a very fine brush and mark the top and side of the disc hole with the number "33".

What you've just done is increase the "Volume" of the #32 hole to become a #33 hole, and this will work with any powder using the #33 hole. With Tightgroup it's 3.9grains.
The volumetric conversion # for each powder is on your disc chart.

Writing it down makes it sound complicated, but its not if you go slowly.

I have two loads done this way and both are dead on and repeatable. For $5 you can buy a replacement disc from LEE to replace the #32 hole (or whatever hole) you just drilled.

Hope this helps.

EDIT: to change drill bit increase in size to max 1/32"

 

[Steve C]

Generally speaking, leading at the muzzle end of the barrel is that your velocity is too high. Leading at the chamber end indicates improper bullet size and seal in the bore resulting in gas blow by. Your load is only .1 gr below the maximum for a 115gr lead bullet in Hodgdon's on line data. Try dropping down to the start load of 3.9grs and see if the leading doesn't go away.

 

[idahoglock36]

I ran into leading with the new Missouri Bullet 115's running a hot load. I dropped the load down .4 or .5 can remember and now I'm as happy as can be. The leading issue went away. I am using WST which has very little load data. Drop the charge down to starting or a couple of .1 over and I think you will be pleased. I can't comment on where your getting the leading as my leading was at the throat and about 1/2 barrel length not the end but it took care of the problem. I've noticed generally the hotter the load the further the brass flies at starting loads my brass generally only falls a foot or two from my feet...max loads the brass flies farther 5-7 feet. Try it and report back. Thanks.

 

[lwknight]

I have never seen leading at the end of the barrel.. I shoot em hot too. If I get leading its at the chamber end or all the way down it.
It must be a lube problem. You could try some tumble lube on top of the existing lube. It couldn't hurt anything to try.

 

[germ]

I'm certainly no expert. I've read in more than one place, if it's leading at the breach end it's most likely an undersized or too hard of a bullet. If it's leading at the muzzle, the lube is running out too soon.

My 5" XD9 leads the whole length, tumble or conventional lube, .356 or .357. Gonna try .358 next. 50% range / 50% ww + 2% tin (yeah I know that's not 100%). I'm currently using a middle of the road charge of WSF.

 

[marineshooter]

thank you all for the great advice. i am going to drop down to the .34 hole and see how they shoot. i will post what i find!!

 

[plateshooter]

"It must be a lube problem. You could try some tumble lube on top of the existing lube. It couldn't hurt anything to try. "

This is what I do and it works great for me. I buy my lead bullets from the guy at the Medina Gun Show. I tumble them in Lee Liquid Alox and have never had a leading problem since. BTW we are neighbors, do you shoot at the Marksman range?

 

[243winxb]

Match the bullet hardness (BHN) to the pressure (PSI) Your running out of lube or its not working. Tumble lube them in some Xlox.

Cast bullet leading

A clue to what is causing the leading is where the leading first begins to appear. If it appears near the chamber, chances are that bullet diameter or hardness are the cause.

A diameter too small and/or too hard an alloy will allow high pressure gas to leak past the bullet, which erodes the bullet and leaves leading near the chamber.

If the leading first appears on the leading edge of the rifling (if you imagine the bullet being pushed through the barrel, you will note that one edge of the rifling does most of the work of imparting a spin to the bullet. This is the edge you see when you look through the barrel from the breech end) the bullet might be too soft, and/or the velocity too high.

If the leading appears in the second half of the barrel, the bullet is running out of lube. You should see a star shaped pattern of lube accumulate on the muzzle. This is an indication that there is a little excess lube.

http://www.leeprecision.com/cgi/faq/index.cgi

 

[scrat]

my 9mm i shoot using lee liquid alox. i have never had any problem at all. With thousands of rounds. So i will totally recomend it. very simple. take a two litter bottle cut it in half to make a big bowl. put in the bullets. pour some allox and shake really good. then pour the bullets on a piece of wax paper then let dry for 24 hours or more. then your ready to go no more leading the liquid alox is about $5.00 for a bottle that will last a long time.

 

[marineshooter]

leading

hi guys, i just got back from a quick to the range. i dropped down to the .34 hole with my lee disc. it giving me 3.8- 3.9 grs. i loaded up 1oo rds to see if they would lead up as bad as 4.2 grs. very little leading to speak of. cleaned right out. brass did not fly that far from my feet. i got some lee liquid alox will this also cut down on the smoke. i know that titegroup and lead does smoke. i was just wondering if this would smoke more or less. i also got lewis lead removal tool from missouri bullet. what a cool tool. way to go brad, i ordered that and some 158 gr swcs on monday got them thrusday . what a company thanks again brad

 

[navyretired 1]

A good gas-check mold that drops the right diameter and you can cast and size your own go fast with no leading.

 

[1SOW]

I did find this about 'leading'.

hope it helps

Re: Anyone shooting Lee 125gr .357 cast bullets in their CZ75?
« Reply #2 on: Today at 07:15:04 PM » Quote

--------------------------------------------------------------------------------

,

You absolutely must slug your barrel first. Cast bullets should be sized .001" over your actual bore diameter. To do anything else is guess work. Also the BHN hardness is practically as important as the proper size bullet diameter. 9mm is typically in the 18 BHN range.

If the barrel leads at the front of bore, the bullet OD is to large. If the bullet leads at the muzzle end, the lube is inadequate. If it leads the entire bore, your BHN and or powder combo is not compatible.

You can succuessfully shoot hard cast bullets in a 9, but you must have the right combo. Don't ask how I know all this (made lots of mistakes in the past).

 

[ArchAngelCD]

I'm guessing m.b. bullets are Missouri Bullets. (are you using Missouri Bullets?) Their 9mm bullets have a BHN of 18 so I'm very surprised you get heavy leading at the velocities you were probably generating with that original charge. I would have thought it was possible you were not pushing them hard enough but you said the leading went away when you lowered the charge. I'm a little confused...

 

[marineshooter]

arch, i am using missouri bullets 115 gr rn, and yes the bh is 18. in my post the 9 sigma was new. i shoot 50 rds of blaizer brass. 115 fmj then i shoot my reloads. using titegroup with 4.2 grs, shoot good but leaded the last 1/2 inch of the barrel. i dropped the charge to 3.8-3.9 and got no leading to speak of. will the lee alox cut down on the smoke or not??

 

[Walkalong]

BHN 18 should take everything the 9MM has, assuming a good fit to the grooves. It may very well be undersized for your barrel.

The alox will not make much, if any, difference in the smoke.