9mm diameter question

[Apple Man]

The question to ask mold makers is........

"What alloy is used to regulate the molds?

Absolutely, composition of the alloy = weight and diameter.

[Wheelguns 1961]

Just remember that it is important to use the proper expander when loading over sized bullets.

[oldhenry]

That is my favorite mold. Mine is an 8 cav. & marked "359-130". With COWW they drop @ 135. I bought another one (still in the box) in the event it wears out before I do (I'm 84). The 2nd. one is marked "359-135". I size @ .357 & it works in my Ruger 1911 OM, my son's FN & my son's friend's 3 different guns (not sure of make & models).
I was surprised to discover that my 1911 OM was throated from the factory.
My other 9mm molds are rarely used: why mess with perfection.
I'd buy that .358 dia. one that is available in a heart beat.
Confession: I never measured the dia. of any of these boolits B4 sizing.

Henry

[Outpost75]

With Accurate Molds you can specify alloy and indicate whether you want the 0.002 tolerance positive, negative or centered. I order most molds with nose tolerance negative to enter cylinder thoats or ball seat without sizing and with driving bands centered for autopistols or positive for revolvers.where cylinder throats are larger than barrel.groove diameter.

[243winxb]

Bullet diameters need measuring as cast & after sizing.

As cast can be to small to size.

After sizing, different alloys spring back differently. Hard alloys spring back more.


May not matter for a spray & pray 9mm. Many guns/shooters are not accurate enough to show a difference between good & bad ammo.


Age 79 here. Casting for 60+ years.

[Outpost75]

Bullet diameters need measuring as cast & after sizing.

As cast can be to small to size.

After sizing, different alloys spring back differently. Hard alloys spring back more.


May not matter for a spray & pray 9mm. Many guns/shooters are not accurate enough to show a difference between good & bad ammo.


Age 79 here. Casting for 60+ years.

Agree. The kids today do not measure. We may have met years ago when I was at Ruger and I believe you may have been at New Haven, CT Winchester. Enjoy your posts. Jay Jarvis and Dave Zaidan were a few of my mentors you might have known.
Feel free to PM me.

[Taterhead]

Another consideration on as cast sizing, thkse who coat will introduce additional girth. That's why I habe moved on from molds that drop significantly over sized. With additional girth from PC, it is a lot of work through the sizer, and the bases can take on a little flashing as a result.

[Bigslug]

I measured bore slugs from perhaps half a dozen 9mm's before concluding .357" is where you want your bullets to be. All but one of them were .356" on groove and the outlier was a Springfield 1911 at .355" and super tight in all other respects. If the mold drops to .358 and you size to .357, you'll likely be a happy camper.

Wouldn't be my first choice for revolvers or leverguns due to lack of crimp groove.

[243winxb]

MP molds use wheel weights to regulate their molds. From their email reply.

[max it]

Hi Apple, Although I havent used it lately I have a six banger from MP in hard alum. It's .359 I always ran them thru my Lyman Lubrizer and they were good for 9mm as well as 38/357's.
Nice thing about lead is that it is very forgiving.
Lots of good advise here.
Much obliged, Max

[oldhenry]

I measured bore slugs from perhaps half a dozen 9mm's before concluding .357" is where you want your bullets to be. All but one of them were .356" on groove and the outlier was a Springfield 1911 at .355" and super tight in all other respects. If the mold drops to .358 and you size to .357, you'll likely be a happy camper.

Wouldn't be my first choice for revolvers or leverguns due to lack of crimp groove.

I agree.

[Apple Man]

MP molds use wheel weights to regulate their molds. From their email reply.

Hi Apple, Although I havent used it lately I have a six banger from MP in hard alum. It's .359 I always ran them thru my Lyman Lubrizer and they were good for 9mm as well as 38/357's.
Nice thing about lead is that it is very forgiving.
Lots of good advise here.
Much obliged, Max

Thanks for all the advice guys.

I used the MP brass 4 cavity mold based on the H&G #68 design yesterday and I am happy to report it works as well as it looks. Using 2 cycle oil very sparingly as others have suggested worked excellent. Often the boolits just drop when the mold is opened. I made up a single sample loaded shell and it looks great and should feed way better than the blunter Boolit out of the Lee mold.

So I ordered the .358 mold, 135 grain flat based in 8 cavity for the 9mm, will size to .357. (Would have gotten the .359 but it was out of stock and I am impatient.)
Also ordered 402-165 TC mold in 4 cavity brass and one more pair of handles.

[max it]

A mold sold as 0.358" may cast 0.002" over 0358".

For many 9mm guns, 0.358" is just right as a sized diameter.

Sizing even 0.360" down to 0.356" should be no problem.

Use in a 38 Sp looks to be a "no brainer".

I Have a .359 mold which is 147gn. I have used it for all my 9mm competitions for years. I did run them thru my Lubrisizer to .357 or less.
I hope that helps.
Max

[Apple Man]

I just finished casting a 20# pot of 9mms with the new mold.

The MP molds are amazing. Everything I read from Lee instructions you can throw in the trash on how to use the molds. Anti -sieze and beeswax both just made a mess. I did not smoke the 8 cavity aluminum mold and used 2 cycle chainsaw oils on the alignment pins, sprue cutter and associated areas. The boolits just drop when opened, very little tapping.

[GrizzLeeBear]

Apple Man,

I have the same 358-135-fn mold (bought it from a member here recently). It is my first MP mold. They are really nice molds and dropping 8 at a time makes a pile of boolits quickly. Mine drops .359 and 141 gr. in my alloy. I don't know the actual composition of the alloy but it runs around 12 BHN based on my pencil test. It is also my first go at powder coating. I water dropped them out of the oven and then sized them .358 (the only .35 cal. push thru die I have). I haven't loaded any yet, but they sure are great looking boolits!

[Grayone]

I measured bore slugs from perhaps half a dozen 9mm's before concluding .357" is where you want your bullets to be. All but one of them were .356" on groove and the outlier was a Springfield 1911 at .355" and super tight in all other respects. If the mold drops to .358 and you size to .357, you'll likely be a happy camper.
This is what I have found works in all my 9's also.

[Apple Man]

I measured bore slugs from perhaps half a dozen 9mm's before concluding .357" is where you want your bullets to be. All but one of them were .356" on groove and the outlier was a Springfield 1911 at .355" and super tight in all other respects. If the mold drops to .358 and you size to .357, you'll likely be a happy camper.
This is what I have found works in all my 9's also.

I didn't get the mic out, but the Starret caliper has the boolits a hair of .358 and a .358 sizer just touched the outside of it. The .357 H&I sizer is supposed to be here Saturday.

We slugged the barrel out of a new Rock Island Pro match and it was .356.

[ioon44]

I didn't get the mic out, but the Starret caliper has the boolits a hair of .358 and a .358 sizer just touched the outside of it. The .357 H&I sizer is supposed to be here Saturday.

We slugged the barrel out of a new Rock Island Pro match and it was .356.

Why not try the .358" boolits? I like to stay .002" over the .356" bore.

[Apple Man]

Why not try the .358" boolits? I like to stay .002" over the .356" bore.

That actually isn't a real bad idea. Thanks

[Apple Man]

Well I got the Dillion 550 switched over from 45 ACP to 9mm today. Sized a few of the new 9mm boolits from the MP mold, the loaded shells dropped right in the case gauge.

Went with 3.7 grains of of Bullseye.