Severe leading from powder coated bullets

[sbeatty1983]

I'm getting a lot of leading in my m&p 9mm from my powder coated bullets. I am only getting leading in this gun. Same load and bullets give me no leading in other guns. I slugged my bore and best I could tell. My groove diameter is .357. My bullets are sized .356 after coating. Would sizing .357 and then coating to give me close to .358 reduce my leading?

[AlaskanGuy]

Yes, in a word.... Size must be larger then bore... If not, you get leading....

[gefiltephish]

For cast, I generally go as large as I can making sure it'll chamber AND unchamber without a fight. Especially for 9mm, since I and so many others have much trouble with it leading. I'd suggest powder coat as cast and then size to at least .358.

9mm brass is all over the map in terms of wall thickness, where the wall taper begins, hardness, springback etc. I now separate by headstamp and expand according to that brass's needs. Make sure you're sizing large enough and deep enough so as to not be swaging the bullet when seating. Also make sure you're belling the mouth just enough to prevent scraping the coating off during seating.

Another factor can be barrel condition. The bore's in my Smith revolvers and Sig P238, P938 are all mirror smooth with no bore leading. The bore in my LC9 looks like it was chopped out with an ax - and 40-50 firelaps later it looks exactly the same. Think it leads?

That said, my only experience with powder coating thus far is 4 test bullets that dropped at .359+ and I sized 'em to .358 with the Star after coating. Haven't loaded 'em up yet though, so...

[bangerjim]

It's your size. The boolit is wobbling down the barrel and is probably having some of the coating scraped off at 9mm velocities, exposing the lead.

I have no leading in 38, 40, 45. My S&W 9 is being a PITA. I cannot load my cast loads because they stick in the barrel. Yet FMJ's shoot 100%....working on a solution. But I cannot report on my 9 leading, if any.

You are one of the 1st that has had any problems and I do believe it is your sizing.

Let us know what your results are!

Thanks for posting.

banger

[sbeatty1983]

It's got to be either the sizing or my bore, because the same loads shot perfect in my kimber 9mm with no leading. I'm gonna coat some bullets as cast and shoot them. They should be about .358 since my mold drops at .357. I really like the gun and have been planning on getting a threaded barrel anyway for a suppressor. If I can't get this barrel to shoot maybe ill luck out and get an aftermarket barrel with a smaller bore

[kryogen]

easy, bullet is smaller than bore = leading and not accurate
try .358, if it does not chamber, try .357

[gefiltephish]

I'm assuming your casting. If so, what mold? If your bullets are dropping small, beagle the mold. Simple and cheap to do. A search here will turn up a description.

[popper]

My XDs 9 & PX4 40 leaded when oversized. Large chamber & small bore. I size 357, works in all 3 XDs 9s. M&Ps evidently have a sharp edge at the bore which saves coating & lead. There is a way to break that edge but I haven't needed to. The XDm 40 doesn't lead when PCd, except when I shave one when loading.

[sbeatty1983]

Mold is a Lee 6cav 120 TC Im not happy with it, the sprue plate doesnt sit tightly against the mold and I have to remove the fillout where it over spills on most bullets and it casts a bit under sized. I also have a lee 6 cav 200gr .452 that makes perfect boolits. guess my 9mm mold was made on a friday or a monday.

[dverna]

sbeatty,

There is a lot of stuff of Lee-menting a mold to fix issues with some of their molds.

There is a reason that Lee molds are half the price. Most work reasonably well, but some are not so good. It is one reason I do not recommend Lee molds as the first mold for a new caster unless they understand the mold may need to be tweaked. Most beginners have a tough enough time without getting into mold-smithing.

BTW, you can lap the mold to get it to drop a larger bullet if that is only thing wrong with it. Take it slow as aluminum is soft. Start with one cavity only - that way if you bugger it up you have learned a lesson and have not destroyed the mold.

Don Verna