9mm mold size for Hi Power

[biscot]

Hi,
I'm getting ready to start casting - still educating myself.
I want to cast 9mm boolits, but I have a question about mold sizes.
My Hi Power barrel slugs out at .357 (I need to do it again with a micrometer - just used a caliper and I don't quite trust the measurement). All the 9mm molds I see in Midway's catalog are .355 or .356.
I presume I'd want to size them at .357 or more, if my barrel is .357, but they seem to have discontinued the .358 molds - I was specifically looking for the Lyman 358242, but now all they have is the 356242.
So, do they come out of the mold a little large, or are they actually .356. The only .358 molds I see are for 38 special.
Thanks for any advice.

[theperfessor]

I use the Lee 358-125 RF sized to .358 in my Hi Power. I also use an out of production Lyman 358480(?) that casts a 133 gr SWC. Either bullet over 6.8 to 7.0 gr of old Blue Dot. Both are conventional lube types, I have never tried any tumble lube types, seems like there is a lot of trouble with TL bullets in 9 mm for a lot of people.

[biscot]

Thanks perfessor. I've been doing some forum searching and it seems the Lee 358-125 RF is popular. I just wasn't sure if a mold for 38 special would work for a 9mm, but I guess a boolit is a boolit!
I plan to use a lube-sizer, rather than tumble-lube.

[BarryinIN]

A couple of things-

You won't really know what diameter a mould will cast until you cast with it. Seriously. Manufacturing tolerances, your alloy, casting temp, etc, has an effect. Most of my moulds cast a little larger than their manufacturer states, although some are smaller. You never know until you have some bullets from your mould to measure.

Some moulds advertised for 38 Spl might be OK for 9mm. And vice versa. Some guys use the Lee 125 grain FP mould (for 38 cal) in 9mm. I use a couple of older Lyman 358 moulds. So don't rule out all 38 cal moulds.

If your barrel slugs at .357, I would start at .358. But .357 might turn out to be the best, or maybe something like .3585 will be it. Like bullet diameters from the mould, you really don't know until you try some things.
FWIW, my HiPowers slug around .357 (.3565-.358) and I size to .358 or .3585.

And just so you know, I found crimp to have a big effect in 9mm. It's true with some other calibers, but seemed really important in the 9mm. The lighter the better worked for me. Just enough to take the flare out. A hair too much crimp did more damage than .001 bullet diameter change.

EDIT: I guess the Perfesser posted while I was typing. See, I told you some like the Lee 125 FP!

[biscot]

Great info, BarryinIN.
Thanks. Lots to learn here.

[theperfessor]

The current Lee 358-125-RF molds cast a bullet that doesn't look much like the illustration that they're still using. It has a longer nose and no bevel base (mine at least, a 6 cav about two years old). My Hi Power has a generous(?) throat that allows a .358 bullet to be seated out far enough that I can adjust OAL for best feeding, usually don't have to worry much about chambering.

The current Lee bullet looks to me like a 125 gr RN/ball bullet that has been flattened out in a die with a little nose swelling as a result. It would be interesting to HP some of these down to 110 grs or so.

If the biscot will pm me I will send him 50 of these to try.

[biscot]

Perfessor,
Thanks for your generous offer!

pm sent

[moptop]

Biscot, I also cast for a BHP and had a very bad leading problems when trying to use a .356" size bullet. I tried Lee's 124grn .RN 356" tumble lube bullet at first but it didn't make me happy!! Sooo, I did a little research in my Dad's old loading manuals and found in the Lyman books that they listed a 158grn sized at .358 for 9mm. Since I already I have a RN tumble lube that I use of .38 spl I tried it and it works great! Very accurate and no Leading. It's kinda touchy in seating to the bullet in the case. If you seat it too far in it bulges the case and it will not chamber correctly. Other than that it's a nice load. It cycles in my BHP without any problems.

You might aso try "beagling" the mold you have. I did the 124 gr TL mold to bump it a couple of thousanths then sized them at .358" and they work well too. Even at .358" I have no case bulging problems with this one at all. The folks here were kind enough to steer me to some good articles on it which helped a bunch. I'm strongly considering lapping it out permanently so I won't have to deal with the gooey adheisive and the tape falling off when the mold gets up to temp.

I hope this helps!

[MtGun44]

356-124TC works great for me and mine casts at .358. Strongly recommend for 9mm.

Bill

[biscot]

You might aso try "beagling" the mold you have. I did the 124 gr TL mold to bump it a couple of thousanths then sized them at .358" and they work well too. Even at .358" I have no case bulging problems with this one at all. The folks here were kind enough to steer me to some good articles on it which helped a bunch. I'm strongly considering lapping it out permanently so I won't have to deal with the gooey adheisive and the tape falling off when the mold gets up to temp.


So, if I have a mold that throws at .356, I can enlarge it a bit. Sounds like a good option - can you steer me to some of the articles you are referring to, or help me understand how I could do this?

So far I'm thinking of trying these dies
358-125-RF
356-124-TC
356-124-2R

[MtGun44]

Use the search function and study "Beagling", a process of shimming the mold slightly open with thin aluminum tape to increase the diameter. Named after our member Beagle that invented the concept.

Bill

[9.3X62AL]

Biscot--

I have the Lee 124-TC and 125-2R moulds, and both cast a slight bit over .358" in 92/6/2 alloy for me. In my 2 SIG and 1 Ruger 9mm, .357" does the trick nicely.

One dimension to watch will be the expander spud diameter in your expander die. Many of these spuds are sized at .352" to service the jacketed .355" bullets that get used in 9mm applications. An expander that small will reduce diameters on cast boolits of .357"-.358" when seating--so a brief pass with a 38 Special expander spud may be required to set the case mouths properly.

[theperfessor]

Pm received. I'll try to get them out this week, no charge except please print your results on this site so we can all learn some more.

Same to other party who pmed me - send address and I'll send you some also.

[biscot]

Thanks, perfessor, will do. Much appreciated.

[biscot]

Found it, thanks.


Use the search function and study "Beagling", a process of shimming the mold slightly open with thin aluminum tape to increase the diameter. Named after our member Beagle that invented the concept.

Bill

[biscot]

Good tip, thanks!


Biscot--

One dimension to watch will be the expander spud diameter in your expander die. Many of these spuds are sized at .352" to service the jacketed .355" bullets that get used in 9mm applications. An expander that small will reduce diameters on cast boolits of .357"-.358" when seating--so a brief pass with a 38 Special expander spud may be required to set the case mouths properly.

[beagle]

I'm feeding two of those monsters and they seem to handle the .358s really well and I'd try that if I already had one.

I've also used a .3575 (custom) and one of my old Lymans that sizes .3565 (measured). The HPs are not picky at all from my experience./beagle

[biscot]

Good to know beagle. Thanks.

[Larry Gibson]

356-124TC works great for me and mine casts at .358. Strongly recommend for 9mm.

Bill

+1 on that mould, especially in 6 cavity. I've been loading for numerous 9mm handguns and several subguns over the years and have used 358242, 356402 and Lee's 356-120-TC. I use the Lee now exclusively. I size them at .358 and lube with Javelina or Lars 50/50 lube and have never had an accuracy or leading problem in any 9mm. Feed and function when loaded over 4 gr of Bullseye is excellent as is accuracy.

Larry Gibson

[biscot]

So, buying a mould like the Lee 356-120-TC, are you just taking the lottery that the boolits can be sized at .358, or do they all come a bit oversized? I'm assuming a boolit can only be sized smaller that it's cast, not larger.

[casterofboolits]

My HiPower would tumble at five feet and lead like a bear with .356 sized boolits. Sized at .357 it would do one holers at fifteen yards. The boolit I was using is the H&G #275 09-125-SWCBB from a six cavity H&G mould. Did not try sizing .358 as the 357 worked so well. I loaded this boolit over 6.5 grains of BlueDot.

I have read that some HP's bores go as high as .360 depending on when and where it was manufactured.

[NuJudge]

A mold will cast different diameters, based upon which alloy you use, and perhaps a bit on what temperature you cast at. There are threads on this.

Also, be aware that your barrel may require a cast bullet bigger than what will chamber in your pistol. Try a few before you load a lot.

CDD

[docmagnum357]

I have been having problems with my cz75b. I think iI will follow some of thius same advice....

[biscot]

What sorts of problems with the CZ75B? I've been thinking of getting one (the CZ75B SA). I need a backup pistol, and I've been told they're typically easy with cast boolits, and good shooters as well.

[ChuckS1]

I have both a T-series Hi Power and a pre-B CZ-75 that I shoot 358242s, sized at .357. My most accurate load is 3.7 grains of Bullseye with the 358242.

[fecmech]

I also have the 6 cav Lee 120 TC and it casts at .358. It is a very good boolit in the 9MM with lighter loads using Bullseye powder or at 1100-1200 fps using Hogdon Longshot or Blue dot. It is very versatile, giving good accuracy with any number of powders and feed reliability is excellent. IMO it's the best 9MM bullet design of all, which also includes the Lyman 356402 and RCBS 124 CN.

[Crash_Corrigan]

My Browning with .356 dia boolits fails to function after 20 or so rounds fired. It allows gas to blow back into the action and gunks it up something awful.

Tried .357 and it was better. Tried .358 and that was the ticket...no blow by..accurate and functions well and stays clean through hundreds of shots. Nothing wrong with Lee molds but you may have to beagle them up some. Cast a few and see what they come out at. Alloy and temps can change the diameter a lot.

Even .360 boolits work in my Browning.

[MtGun44]

MOST (not all) Lee molds cast a couple thousandths larger than the first three digits of
the designation. The designation seems to be the "intended final theoretical size" or
some concept a bit like that. I think if Lee called the 356-120 TC a 358 -120TC too many
people would not buy it for 9mm, thinking that they need a .356 diameter cast like they
use a .356 diameter j-bullet.

And you are correct, you can size down but not up. As stated previously, individual mold
tolerances, alloy composition, molding temp and , I think your hat size, all figure into what
final diameter you get out of a particular mold. ;-)

Another great boolit for 9mms is the 105 gr SWC from Lee. This mold was my first ever
mold and produced top accuracy and perfect feeding in my HP (my first pistol ever for me
to reload for) for many years when I was fairly clueless about this whole boolit casting
hobby, back in the mid 1970s.

Bill