Originally Posted by
Meatpuppet
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.