9mm diameter question

[Apple Man]

I am after a 9mm mold. After just getting a MP brass mold I am sold on this company.

The one I desire is the MP 8 cavity 135 gr. flat base but it is out of stock in .357 diameter (will be sized to ..356) . It is available in .358


So I have two questions:
1. Is .002" too much to size down for 9mm use.
2. Would this be also useable in 38 special which I normally size to .358. The sizer wouldn't do anything but would lube the bullet.

A final thing, any idea how long it is before MP replenishes their inventory?

[P Flados]

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".

[Outpost75]

Important to cast chamber and origin of rifling and to also slug barrel. All three of my Beretta 9mm pistols are .357-.358 groove, but chambers run tight so that it is absolutely necessary to select brass and plunk test rounds.

[Apple Man]

Important to cast chamber and origin of rifling and to also slug barrel. All three of my Beretta 9mm pistols are .357-.358 groove, but chambers run tight so that it is absolutely necessary to select brass and plunk test rounds.

I understand the importance of slugging barrels. But loading 9mm is new to me and these will be used in a Rock Island Pro Ultra Match, Browning Hi Power, a Hi power knock off and a Glock 17. ( my cast boolits have worked just fine in Glocks in 40 S&W and 45ACP with no barrel leading or kaboom yet.) Slugging all of these barrels seems like a lot of effort.

[Apple Man]

BTW, I have loaded 38 special and 357 mags for decades and size to .358.

Would you get a .357 sizer for the 9mm?:coffee:

[ddeck22]

I understand the importance of slugging barrels. But loading 9mm is new to me and these will be used in a Rock Island Pro Ultra Match, Browning Hi Power, a Hi power knock off and a Glock 17. ( my cast boolits have worked just fine in Glocks in 40 S&W and 45ACP with no barrel leading or kaboom yet.) Slugging all of these barrels seems like a lot of effort.

Outpost75 is indicating that since 9mm is a tapered case, if you size to .358, the thickness of the case wall is very important. If you choose thickwalled brass, it will not chamber. So, if you do need to go to .358, make sure to find a brand of brass and use it. I know for me, I only use Blazer for 9mm since I also size to .358.

45ACP is a breeze compared to 9mm for cast. (IMHO)

There is a long thread on this site about loading 9mm and things to watch for...but I can't find it at the moment.

[Apple Man]

Outpost75 is indicating that since 9mm is a tapered case, if you size to .358, the thickness of the case wall is very important. If you choose thickwalled brass, it will not chamber. So, if you do need to go to .358, make sure to find a brand of brass and use it. I know for me, I only use Blazer for 9mm since I also size to .358.

45ACP is a breeze compared to 9mm for cast. (IMHO)

There is a long thread on this site about loading 9mm and things to watch for...but I can't find it at the moment.

Thanks, that is the type of thing I need to know. Was not aware it was tapered.

[Dusty Bannister]

This is probably the sticky that is being suggested.

https://castboolits.gunloads.com/showthread.php?121607-Setting-up-for-boolits-in-a-new-9mm

[ioon44]

You need to slug your barrel to see what da is best for your bullets to sized to.

I have a Walther PPQ SF which slugs at .357" so I size to .359" and adjust the OAL to pass the plunk test and make sure your loading dies are not swagging the bullet to be undersize after loading.

[LAH]

I simply size the bullet as large as I can & still chamber, thus the plunk test. My S&W MPs will chamber nothing larger than .357 while the CZ75 has no problem with .358.

[Half Dog]

I size my bullets 0.358” That caused a chambering issue but I sent the barrel to a member and he opened the chamber to accept the rounds.

[JonB_in_Glencoe]

I understand the importance of slugging barrels. But loading 9mm is new to me and these will be used in a Rock Island Pro Ultra Match, Browning Hi Power, a Hi power knock off and a Glock 17. ( my cast boolits have worked just fine in Glocks in 40 S&W and 45ACP with no barrel leading or kaboom yet.) Slugging all of these barrels seems like a lot of effort.


BTW, I have loaded 38 special and 357 mags for decades and size to .358.
Would you get a .357 sizer for the 9mm?:coffee:
My experience/opinion addresses both of these comments.
I size all my 9mm boolits with a .357 lubesize die. I've had several 9mm guns over the years and .357 always works...EXCEPT...
Many years ago, I borrowed my buddy's 1980s vintage Browning Hi Power (9mm). It had a tight chamber and wouldn't accept my handloaded ammo with .357 sized boolits. But worked fine with .356 size.
I don't start investigating (slugging and such) until I have a issue...But I do make dummy rounds for plunk test anytime a new gun or new boolit mold is used.

[Apple Man]

Wow, this has been enlightening. Sure glad the mold I was going to order was not in stock as it most likely would have been too small.

I had no idea the 9mm was a "problem child" as far as getting to work with cast bullets.

I just found this article regarding shape of boolits from most of the mold makers. It turns out many have copied the dimensions of jacketed boolits and that does not translate into a workable design for cast.

https://castbulletassoc.org/blog/article/2017/7/92/loading-cast-bullets-in-the-9mm-luger

[Apple Man]

So in reality, the dimensions of conventional 38 special boolits and sizers, (.358) aren't too far from what is needed?

Looks like the barrel of one of the guns could be slugged with a 38 boolit which I have LOTS 325647

[243winxb]

Bullet as cast diameter changes with the alloy used. More antimony, larger, lighter bullets. For 9mm, i size to .356" + https://www.thehighroad.org/index.php?media/albums/taurus-g3c-9mm-luger.317/page-2

This bullet can be used in 9mm & 38,357 when sized correctly.
https://www.thehighroad.org/index.php?media/9mm-lee-356-120-tc-size-to-356.3597/full

[Kenstone]

I am after a 9mm mold. After just getting a MP brass mold I am sold on this company.

The one I desire is the MP 8 cavity 135 gr. flat base but it is out of stock in .357 diameter (will be sized to ..356) . It is available in .358


So I have two questions:
1. Is .002" too much to size down for 9mm use.
2. Would this be also useable in 38 special which I normally size to .358. The sizer wouldn't do anything but would lube the bullet.

A final thing, any idea how long it is before MP replenishes their inventory?

Good question.
I shoot/load both 9mm and 38/357.
I don't cast but buy coated bullets, all at 0.358" diameter and use Lee push thru sizing dies when needed.
The plunk test will quickly identify a tight chambered 9mm barrel and thick-walled cases that will require further bullet sizing.
Using the same head-stamped cases/same wall thickness will make loading go quick without plunking every round.
The plunk test saves a lot of measuring case wall thickness, barrel slugging, is simple to do.

Stocking just one diameter bullet of different weights and shapes that I can size to suit has greatly reduced my on-hand inventory.

I also use a 38 S&W expander when loading 9mm, so the bullets don't get swaged down by the case while seating.
Some may question my methods, but the target is the ultimate answer for me.
jmo,
.

[Taterhead]

Outpost75 is indicating that since 9mm is a tapered case, if you size to .358, the thickness of the case wall is very important. If you choose thickwalled brass, it will not chamber. So, if you do need to go to .358, make sure to find a brand of brass and use it. I know for me, I only use Blazer for 9mm since I also size to .358.

45ACP is a breeze compared to 9mm for cast. (IMHO)

There is a long thread on this site about loading 9mm and things to watch for...but I can't find it at the moment.

I can second this. I size 9mm bullets to .357". To ensure that these chamber in all the 9mm guns I load for, I sort for FC, Speer, and Blazer headstamps. They are thin. RP and CBC are on the other end of the spectrum in 9mm.

[JonB_in_Glencoe]

Wow, this has been enlightening. Sure glad the mold I was going to order was not in stock as it most likely would have been too small.
I had no idea the 9mm was a "problem child" as far as getting to work with cast bullets.

>>>SNIP
If you happen to have been thinking of Lee's 356-120-TC like the one in 243winxb's photo, which is a favorite one of mine for 9mm, you'll learn that not only some 9mm guns are a problem child, but also some Lee molds are problem child. My first 356-120-TC mold was a two cavity and the mold would drop boolits that measure .358 and my guns really liked it. So I ordered a 6 cavity mold of same design, and it dropped boolits that measured small (.355") I was not happy, nor were my guns. A year later, I ordered another Lee 356-120-TC 6 cavity mold, and it drops boolits that measure .360" and I like it alot.

I hope this info gives you a little perspective.

[Apple Man]

If you happen to have been thinking of Lee's 356-120-TC like the one in 243winxb's photo, which is a favorite one of mine for 9mm, you'll learn that not only some 9mm guns are a problem child, but also some Lee molds are problem child. My first 356-120-TC mold was a two cavity and the mold would drop boolits that measure .358 and my guns really liked it. So I ordered a 6 cavity mold of same design, and it dropped boolits that measured small (.355") I was not happy, nor were my guns. A year later, I ordered another Lee 356-120-TC 6 cavity mold, and it drops boolits that measure .360" and I like it alot.

I hope this info gives you a little perspective.

After getting one brass mold from MP, it is pretty hard to look at Lee again although they work and are cheap.

Future molds for me will be from MP.

[243winxb]

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

"What alloy is used to regulate the molds?

[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.
:castmine:

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.
:castmine:

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.

[Apple Man]

Just got back from the range, the MP 9mm boolits shoot GREAT and function in two different pistols well.

[jakharath]

Awesome!

[trapper9260]

Good to hear. The way it is with 9mm cast , you use the ones for 38/357 you be ok. Just size them to what the gun you use it for. With it stated that different 9mm bore is different. I have that also. One will take .358 then some others will take .357 . It depends on what will work for what you use it in.

[ioon44]

Just got back from the range, the MP 9mm boolits shoot GREAT and function in two different pistols well.

Did you use the .358" bullets?

[Apple Man]

Did you use the .358" bullets?

No the .357 sizer came last Friday.

Using moderate crimp pressure @ .378, Here is a calculator to find crimp pressure from Dillion:



https://www.dillonprecision.com/crimp-calculator.html

[Apple Man]

Did you use the .358" bullets?

I happened to have the .358 sizer in an old Lyman 45, I did one boolit and loaded with all dies set up for the .357 which works fine. The .358 boolit would not go in the case gauge.

[Rickf1985]

The case gauge is NOT your gun. You need to do a Plunk test to actually find if it fits that particular gun.

[Apple Man]

The case gauge is NOT your gun. You need to do a Plunk test to actually find if it fits that particular gun.

Well I have a number of 9mms. I want ammo that shoots in ALL of them. The .357 boolits that fit well in the case gauge shoot well in all the guns. I just can't see loading ammo that might now work in everything.

[Kenstone]

I have determined which of my 10 different 9mm barrels is the "tightest and use it for my plunk test.
I don't own any gauges and don't see the need for any.
jmo,
.

[jsizemore]

I have determined which of my 10 different 9mm barrels is the "tightest and use it for my plunk test.
I don't own any gauges and don't see the need for any.
jmo,
.

You got that right!