What happens if soft lead and many layers of PC are used? answer inside

[nueces5]

Hmm. I reread your original post and last one. This is an interesting issue to resolve.

Your powdercoat, what brand is it? Other people have done all the legwork on powdercoating boolits and I just jumped on the bandwagon with Smoke 4320's PC (forum vendor) and never looked back. Someone with more knowledge may be able to explain what works and what does not work with powder brands.

What barrel manufacturer are you using if the .358 sized bullet will not chamber? What is your final overall length? I had to purchase a Manson Throat Reamer (not chamber reamer) for my CZ barrels to allow the porky, round ojive of the heavy 147gr and up 9mm bullet profile to reliably chamber at my desired OAL (Glocks and 2011 were not a problem). You should not have that problem with the MP 135 profile unless you are loading very long or have too many coats of PC.

What is your final crimp DIA? I have heard that severly over crimping can cause chambering issues and keyhole issues. After sizing the case with a U-die, I typically run .379 taper crimp with PC boolits and have no issues with setback or chambering. I'm loading on a progressive press and I do also use a Lee FCD at the last station (I can hear the howler monkey cries of rage!). The FCD did not affect my accuracy, but dropped my chambering issues to zero with all varieties of coated boolits.

For my 9mm uses (Action Pistol and Suppressed) absolute best accuracy was not my goal, but 100% reliability is. Like it or not, the Lee FCD works for me and my guns. Also, it resolved a chambering issue with 165gr loads into a suppressed PTR 9K (MP5 Clone), which supposedly have "tight" chambers and extremely short Throat.

Again, this is super interesting and I am looking forward to what the fix will be.

although I did a lot of tests on a glock, now I'm shooting ipsc with a tanfoglio stock2
This year I've started shooting a lot more than before, so I'm looking for a way to reduce the cost, since I also have some friends who want to take advantage and shoot the boolits that come out of my molds.
Unfortunately, in Argentina, costs have skyrocketed with inflation, and many shooters have started making their own boolits. So the linotype is scarce.
This is the main reason.
I have a linotype for myself, but not to be generous with 3 more friends.
They are on the hunt for linotype too, but usually only get pure lead.
I have an expander made by lathesmith, which doesn't swage my boolits, they generally stay at a diameter of .3565 which I have measured after disassembling them. As I said before, my barrel is 356
With this configuration, I have no problems with feeding or keyholes.
I used to use the LFC before, but have gotten better results using just the seat and crimp set that comes in the dillon die set.
In IPSC I have to have a minimum factor of 124,000, that is, a boolit of 124 at 1,000 fps.
The pc I use is polyester resin, this==>
https://www.sinteplastindustria.com....42e60ebcbaf988
I tried other colors and brands, but this was always the best.

[nueces5]

for multiple PC coats, cook at lower temp till PC flows well. Last coat cook as normal. You want all layers to catalyze at the same time into one layer. Once you get to a thou or so thickness, you just add abrasion resistance, scuff off more before getting to lead. When I was doing ESPC I did some pretty heavy coats and found no difference.
I'm guessing the keyhole is from PC not holding the lands well.

The manufacturer recommends 200 ° C for 20 minutes, my oven reaches 175, so I cook between 40 minutes and an hour
So far I have had no curing issues. I also wait 15 days before loading those boolits.
I can't tell if the problem is the pc or the underlying soft lead, for now increase the lead to 10 bhn to see if that fixes the problem.

[nueces5]

When doing any experiment only change one thing at a time then move on. I talked recently with someone on here who said he doesn't pay much attention to BHN for target boolits when powdercoating. Cast's whatever and coats then sizes. I spent today casting ingots to clear up my melter and am going to give this a try with different BHN including straight PC using some of Smokes powdercoat I got a few weeks ago. Probably try 38sp WC first.

It's good that we try several shooters

[Hanzy4200]

Interested to see results. I have been curious on this topic. I would expect that even with heavy PC, you will get less than great performance at higher velocities. In my mind, I would expect the bullet to deform and not grip the rifling strongly enough once you breached a certain speed.

[Super Sneaky Steve]

Thick PC means it's only plastic engaging the rifling. Not good. I shoot a lot of pure lead and it does just fine with one coat.

If you go hypersonic you'll want a gas check to maintain accuracy. Never had one tumble.

[pjh421]

These comments have been some of the most useful I’ve read here: https://castboolits.gunloads.com/sho...s-in-a-new-9mm

Thanks Bill! A buddy has a Ruger Security Six (.357 Magnum revolver) that will not chamber a .358” boolit. Had to get Chris to make me a .357” sizer die for the Star and all was good. I start with a very thin coat of Hy-Tek and bake at 385* for 20 minutes. They go in front of a carpet drying fan until they’re cool. Then they get a second coat that is slightly more dense and a second bake. This is all that’s necessary. I don’t use PC so I probably should have kept my mouth shut but think about how your paint goes on. There’s no way that after four coats your boolit is concentric and balanced. Thinner is better, especially if you’re using a gas check. Your boolit base will not deform. The keyholing has got to be, as others have mentioned already, from an undersized boolit as well as being an unbalanced boolit. Read the comments by MtnGun44 and you will be well on your way. It’d be nice to know how you’re doing on this project even if the thread is kind of old. Paul

[fredj338]

A few bores may need 0.358” but i do fine with 0.357” & even my stock glocks will run 0.356”. I do 0.357” fo insurance across several diff guns. I use one coat, baked for 15min. I water drop out of the oven, about 12bhn.
I didnt see your load data, but a buddy of mine shoots my bullets over tg & gets afew that keyhole. Another pchis own & also got keyholes with tg.

[MT Gianni]

I assume that in Argentina they reuse wheel weights until they fall off. Are your friends able to buy old pewter as a source of tin? I would be interested in seeing if you could harden with just tin, say 1 in 16 or 1 in 20 and get good results with PCing.

[pjh421]

Fred, I’m gonna try a few hundred at .357” and see how it goes. I always enjoy your comments. I just bought a G40 and a LW barrel for cast with a 4 port compensator. Should be fun. I cast a few hundred Lee 175 TCs for it last night.
Gianni, he could maybe use some magnum shot too if that’s available.

Paul