9mm leading

[weasel 21]

I shoot 10 different 9mm handguns and cast bullets for them. They are cast from WW and sized to .356. I am getting leading in all the guns . I have not slugged any guns but have noted in all my research that .356 is the generally accepted diameter for cast. Any help is appreciated

[jdgabbard]

Slug your guns. Could need as large as .358 diameter. Also it could be the lube you are using. Too many variables. Give us some more info.

[Firebricker]

Sounds like a lube problem the chances of all ten pistols having off size bore are slim.
jdgabbards right need more info.

[HeavyMetal]

First post the load or loads you are using.

Second are you casting or buying cast?

Third have you confimed boolit diameter? I'm a big fan of trust but verifiy.

Then we can make suggestions.

[weasel 21]

I have checked the bullet diameter w/ a micrometer. lube is nra formula. Load is 4 gr bullseye over a 124 gr bullet

[anachronism]

You need to slug your barrel to determine the correct sizing diameter. 10 guns? You need to slug all of them. There will never be any guarantee that every barrel will be cut to identical dimensions, even if all the guns came from the same manufacturer & had sequential serial numbers. Every one needs to be slugged, each slug needs to be kept separate from the others, & measured. .358 is a lot more common for 9mms than you might think.

[MtGun44]

.356 will very likely be undersized for almost all 9mms.

Try .358 and you will likely solve the problem.

Bill

[MT Gianni]

Where is the leading in the bbl? At the rear usually indicates lube failure, front is more often stripping due to too fast a speed for the twist. What is the alloy?

[HeavyMetal]

O.K.

Here's my thoughts on this problem.

First your using the NRA Lube? Never used it suspect it's an alox mix like Javalina lube.

Second your using 4.0 grains Bullseye as your load? This is almost a full grain under the start load in most manuals for 124 / 125 grain boolits.

Here's what I would do in your place: I'd bump up the load to the minimum start load, 4.9 grains Bullseye, or try another powder. Do not load lighter than the start load! If the boolits your using/casting are on the order of 11BHN or harder you are not getting them to "slug" up to fill the bore!

Second thing: I'd change lube. I've never been a fan of alox lubes, liquid or solid! If you have an old Iron to use as a heater get some Lar's carnuba red and see if these two changes ends your leading issue.

Now it is possible your trying to make a 38 wadcutter "equivalent" load for the 9mm. If this is the case I will suggest an alloy change instead of the previous suggestions.

A softer alloy , about 7 on the BHN scale, will upset easier and seal the bore with the 4.0 grain Bullseye load your using. I would also suggest sizing .357 with the softer alloy. In this case alox should not be a problem except for smoke.

Let us know how this works out.

[weasel 21]

I used my Speer manual # 12 as a reference-.356 , 125 cast,3.5-3.9 gr bullseye. I have been using bullseye for years without a problem.

[243winxb]

Add 2% Tin to your wheel weights. While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore. I have read that this process can take up to 24 hours as the alloy oxidizes. If your going to size a cast bullet, wait 1 day. Don't Water Drop.

[Leftoverdj]

I don't care what the books say. .356 is the jacketed bullet diameter. Cast bullets need to be bigger.

[HeavyMetal]

Think I spotted your problem!

As I mentioned in my previous post some manuals treat lead boolits in a very off hand way.

The Speer manuals are leaders in this "mistake". Every Speer Manual I have shows loads for Swaged lead boolits! They state this in the Begining of the pistol loads section.

In my number 8 manual page 329: Any lead bullet, no matter how well lubricated, is liable to lead the barrel when shot at high velocity.

In my number 10 manual, again page 329,: The 158 gr. semi-wadcutter and round nose lead bullets are the traditional general purpose 38 caliber bullets. They are stil in general usebut are being replaced by jacketed bullets for high velocity loads.

I can't find my number 12 manual but I'm sure if I could I'd find some more of this "lead drivel" in it as well.

Speer, as well as other manufacturers, are in business to sell bullets! Telling you how to be successful casting lead boolits doesn't help them keep the doors open.

Now as I mentioned in my earlier post swaged lead bullets, as made by Speer, are dead soft lead with a powdered dry lube. These are great until you hit about 700 FPS and then will lead like all get out!

A boolit cast of any reasonable wheel weight alloy is going to be much harder and require a bit more pressure to "slug up" and fill the bore.

The 4.0 Grain Bullseye load your using is not the real problem and you can continue to use it. The problem is the alloy is to hard and will not expand, "slug up", to fill the bore when fired.

Now, when you fire this load, the hot gas's from the powder charge are sliding past the boolit, and melting it as they do so, creating the leading problem your experiencing!

The fact that it's happening in every 9 you own supports this idea!

Again I will suggest two ideas: make the load a little hotter and think better lube or make some dead soft cast lead boolits and continue with this load.

[ciPeterF]

I'd be looking at the lead alloy composition.. I've cast 9's that don't lead at all, and 9's that do. (Same mold, same guns..) In my case (and as memntioned above), tin was the critical item. I've got some commercial lead coming, but haven't had a chance to try it. As to size, I use .356, which is .001 bigger than std jacketed (.355). If the bootlit is a tight fit in the sizer, there will be a teansy bit of springback as well. Slugging the guns is a good idea, I did three, (S&W, Walther, CZ) and .356 is the right answer. Also mentioned before is the issue of stripping on 9mm.. be sure they're right up agains the lands, with only perhaps .001 - .003 jump space.

[Wally]

I shoot moderate loads in my Taurus 99AF...it leads up badly. I use bullets sized to .358" and tried a wide varoety of alloys...still it leads up. Rather than let it bother be I run a Lewis lead remover (LLR) patch down the bore after so many shots--takes just seconds and the lead is gone. As one tends to shoot more rounds with their 9mm, it is a good way to slow down abit to rations one's ammo. Whle it leads up, the lead is removed quite easily with the LLR.

Wally

[243winxb]

Cast bullets go thru a swaging process when entering the barrel grooves, same as a jacketed bullet. This is why bullet diameter is the same or larger then the barrel groove diameter when using cast bullets. Bullets are sized to the correct diameter. They do not need to oburtate (Bump Up). If you study Lees BHN chart and the Obturation link page, you will see that Lee keeps the pressure UNDER the pressure where obturation would happen. Go to Hodgdons site , check the pressures for given cast bullets loads. Compare there BHN to the max. load pressures. You will see that Lee and Hodgdons max pressures are under when a bullets obturation would happen. http://en.wikipedia.org/wiki/Obturate Also check out the Lee hardness tester chart for maximum pressures used for different alloy hardness. Bullet's BHN x 1422 = Pounds per square inch, flat base bullets. You never want hot gas getting past the bullet as it goes down the barrel, lead alloy or jacketed bullets.

[Larry Gibson]

.356 will very likely be undersized for almost all 9mms.

Try .358 and you will likely solve the problem.

Bill

Concur with Bill and will also ask; is your "NRA formula" lube commercial or home made? If it is home made or an off brand make I suggest you try Javelina or one of Lars 50/50 lubes. I have been using Javelina, Tamerack and Lyman's 50/50 since I started casting and have never had leading with 120+ gr bullets in any 9mm since I started using it. Your 4 gr Bullseye load is not "high velocity" as mentioned. It is pretty much a standard US service type load.

I have been loading for 9mm since '70 and learned that .356 is not the correct size for case bullets (anyone want an old used .356 H&I die?). I have been sizing .358 and using 50/50 beeswax/alox lubes with no leading and excellent accuracy.

Larry Gibson

[bobthenailer]

i have 2 -380s , 2- 9mms, and 2 - 38 supers i shoot cast bullets in them allmost all of the time! ww water dropped, about 25 bhn , hard lube and all sized to .357 dia they all shoot better sized to .357 instead of .356 dia , i get very minimal leading if any

[deltaenterprizes]

Imported 9mm barrels have a fast twist rate and shallow rifling and need a lot of bearing surface on the bullet or they strip the rifling, this can be acomplished by using 147 gr bullets.
When I did commercial casting I got numerous complaints in one month on this subject and the info was from Irv Stone of Bar-Sto Barrels.

[flinchnjerk]

Are you using a Lee Factory Crimp die?