9mm 8-Cavity MP Mold

[o416]

Hello Everyone :)

New member here, and this is my first post, so please be gentle as I am a super newbie to casting. I know there are a lot of casting elders here so I thought I would ask before being sorry.

I purchased this mold from MP:
https://www.mp-molds.com/product/mp-356-130-2r-8-cav-bevel-base-no-lube-groove/

If it drops bullets at ~.359" and is powder coated, which adds ~.002" in thickness, that would make it ~.361" in diameter. Can I run it through a Lee .357" sizer on my APP? That is a reduction of ~0.005" which could ruin the powder coat no?

Anybody using this mold and powder coating with success?

Thanks :)

[Super Sneaky Steve]

Welcome! The extra PC thickness isn't a problem. Give them a squirt of lube and run them through.

[o416]

Thanks for the info :) I will try the lube idea.

Anybody else here using this mold? If so, do you have any pictures you can post?

[Wheelguns 1961]

I don’t use that exact mold, but an mp 359-125 no lube groove hollow point mold. It comes in at about 135 grains with a large hp pin.

[StuBach]

As long as your mold is clean and smooth it won’t scrape the PC. Sizing swags down the lead rather than shaving it so as long as there should be no issue with PC.

That being said I used to have some Lyman 45/450/4500 sizers that had burs in the lube holes that had to be polished out otherwise they scraped PC.

I have a MP 359-93 that I PC than size down to .355 and never have any issues. Other alternative is size first, PC, size again.

[44Blam]

If your PC comes off in the sizer you might have an issue with your PC batch. You should be able to take a PC'd boolit and smash it flat with a hammer and the powder coat should stay on.

[tomme boy]

I had that mold. Had to get rid of it as you had to seat the bullet extremely deep to get it to not engage the rifling. You will have to reduce your load a lot to keep it from going too high of pressure.

This one has a reduced nose diameter that lets you seat to the drive band to the end of the case. This shoots really good. https://www.mp-molds.com/product/359-135-flat-round-nose-bevel-base-8-cavity-aluminum-no-lube-groove-mold/

The problem is most all 9mm guns now made have no throat. That is why you need a reduced nose diameter.

[FLINTNFIRE]

Why not use one closer to desired size like this one in .356 or .357 https://www.mp-molds.com/product/357-359-125-flat-round-nose-flat-base-8-cavity-aluminum-no-lube-groove-mold/ I have a couple 357 hollow point molds from mihec , I powder coat and I am having no issues with mine and I am able to cast coat and load without sizing .

[o416]

I seat my bullets at 1.12" in order to work with all of my 9mm pistols; the CZs tend to be very picky.

This mold has, more or less, the same profile as the copper plated 124gr round nose that I use here:
https://www.campro.ca/en/products/bullets/9mm/9mm-124-rn-fcp

I don't expect any pressure issues but I will reduce the load a little given that my mold will drop 130gr bullets as opposed to the 124gr I normally use.

Do you rememeber what you had to seat them at? Which pistols were they for? Which powder were you using?



I had that mold. Had to get rid of it as you had to seat the bullet extremely deep to get it to not engage the rifling. You will have to reduce your load a lot to keep it from going too high of pressure.

This one has a reduced nose diameter that lets you seat to the drive band to the end of the case. This shoots really good. https://www.mp-molds.com/product/359-135-flat-round-nose-bevel-base-8-cavity-aluminum-no-lube-groove-mold/

The problem is most all 9mm guns now made have no throat. That is why you need a reduced nose diameter.

[mdi]

If you are concerned and wanna try something, size to .357" and remeasure after PCing. I have sized before PC and after PC and it seems to differ with powder and methods of coating...

[fredj338]

You wont know the as cast size until you cast some. Alloy & temp affect final size, you may end up well over or under 0.359". PC should stick, but if you have to size a lot, that may or may not hold true.

[tomme boy]

1.085" is were they had to be seated for my ar9 pistol, g19, g26, sig365

[o416]

1.085" is were they had to be seated for my ar9 pistol, g19, g26, sig365

That is pretty low. Which powder did you use? What kind of velocity were you getting?

Was the seat depth the only reason?

[tomme boy]

Power Pistol, SW Auto Pistol. Never ran it over chrono. Seating depth was the main factor. They shot well but did not want to risk shooting them in the pistols other than the AR9. The AR 9 is a blow back so was not concerned with any type of set back. In a locked breech it could blow up the gun if they were set back too far. Or do unnecessary wear from shooting high psi loads. The blow backs can handle that without worry but not the other guns.

[ebb]

I am new to this also and would beg for patience. In my mind I was thinking that I would size and then coat. Is that not right???

[o416]

I am new to this also and would beg for patience. In my mind I was thinking that I would size and then coat. Is that not right???

From what I have heard, you can do either. It depends on what diameter you are looking for in the end. It would make more sense to size after coating.

[o416]

Power Pistol, SW Auto Pistol. Never ran it over chrono. Seating depth was the main factor. They shot well but did not want to risk shooting them in the pistols other than the AR9. The AR 9 is a blow back so was not concerned with any type of set back. In a locked breech it could blow up the gun if they were set back too far. Or do unnecessary wear from shooting high psi loads. The blow backs can handle that without worry but not the other guns.

Now I am worried that I picked up a bad mold for my pistols :( I use Titegroup and I have seen people seat their bullets really deep without issue.

Anybody else have experience with the mold I am using? I really don't want to buy another one because I like the no groove round nose bullets.

[mdi]

I am new to this also and would beg for patience. In my mind I was thinking that I would size and then coat. Is that not right???Although I do both, more often I'll size prior to coating. One thing about sizing before PCing, I seem to get better results with very clean bullets and there is occasionally a need for sizing lube and or residual lube in the dies, so I have to clean the bullets after sizing but before PCing. No big deal. Largely depends on the as cast diameter...

http://castboolits.gunloads.com/forumdisplay.php?184-Coatings-and-Alternatives

[Flailguy]

I use this exact mold and size to .358" no issues.
My 9mm's are throated so I can load all the way out to max length. my brother on the other hand runs the same boolits at 1.1" with 4.2gr of unique.

[o416]

Do you have pictures of your cast/coated bullets using this mold? Do you size after PC, before or both?

Do the bullets cast at .359 normally?

Thx! :)

[Handloader109]

size to what you need, pc and resize if necessary. I size my boolits down to 358 for my 9mm.

[wv109323]

I think you will be alright but you made the same mistake I made. The size of the bore will determine what size your bullets need to be. The unpredictable is 9mm's are from .355 to .359.
In my pistol it required a .358 bullet to properly engage the rifling with a lead bullet. It required this diameter to stabilize the bullet for accuracy. The problem was there was no leade in the barrel and the .358 bullet hit the rifling,. The bullet would shave a little lead and that lead accumulated at the front of the chamber ans soon you would have a round that would not fully chamber. I had the barrel throated and the problem went away. This was with uncoated boolits. You may be ok with coated bullets.
My pistol would do ok with .355 jacketed bullets before any work.

[Flailguy]

Do you have pictures of your cast/coated bullets using this mold? Do you size after PC, before or both?

Do the bullets cast at .359 normally?

Thx! :)

Don't have any pictures will try to take some later today. the as cast diameter is .359"
I size them right after pc, and I mean RIGHT after. its significantly easier that way. Still doable later, it just uses a little more elbow grease.

[Flailguy]

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[Flailguy]

No matter what I do they are upside down or sideways...

[Burnt Fingers]

I use this mold.

https://www.mp-molds.com/product/357-359-125-flat-round-nose-flat-base-8-cavity-aluminum-no-lube-groove-mold/

and this mold

https://www.mp-molds.com/product/mp-359-125-hp-pb-4-cav/

for 9mm. I either PC or use Hi-Tek. They all get sized to .357 and work just fine in every 9mm I've tried.

I will note I use a Star with the NOE bushing system.