9mm Profile for P38

[Taterhead]

I'm working with a cool old P38. First attempts at cast boolit loads are no good. At an COL that kerplunks ok, it is too short to feed. Inconsistent failures to feed. Factory ball ammo at traditional COL feeds and cycles fine.

Bullet profile was a Lee 356-125-2R. Freebore is almost nil. This gun likes a longer COL to feel properly from the mag (tip-in angle). Factory ball ammo runs fine.

Here's what I think, and I'd love some advice or thought. I believe a longer/thinner profile like a truncated cone might be the ticket to help with tip-in.

Looking at the Lee 356-120-TC.

or maybe the Lyman 356402

What say you?

[marlin39a]

I run the Noe 358-124 TC GC in my P-38, and Luger. They like them hot. Both those boolits should work.

[Walks]

I grew up shooting the LYMAN #356402 cast of LINOTYPE, sized .356DIA. Many 1,000's were shot in WW2 P-38's & various LUGERS. Even a BIG RED 9 Broomhandle. Plus S&W Model 39's & Hi-Power's. Always at MAX LOADS.

JUST MAKE SURE YOU HAVE GOOD MAGAZINES !!!!

[Dusty Bannister]

How did you determine the cartridge OAL? Did you use the cast and lubed bullet, or are you powder coating which will increase the nose diameter and require you seat deeper into the case?

What is the powder and charge weight? If you are under powered, the slide is not moving back as far and might be altering the cycle time and thus try to return to battery before the nose of the bullet is in the correct position. Specifically, what is the "failure to feed"? Sticking the nose on the ramp? Not picking up a fresh round? Sticking the nose on the top of the barrel hood?

Along with this, does the case eject to about the same position as the factory rounds? If it falls short, you might consider loading a little faster, if your book data will allow for that. Again, the powder and charge might be informative. What book are you using for your cast bullet data? More information will usually be helpful. Dusty

[rintinglen]

The LEE Conventional 356-120 TC has worked well for me in a 1938 Mauser MFG Luger as well as several other more modern guns. Run them warm, near or at Max loads for best results in the old guns, which is contrary to the usual advice, but when I started working up loads in mine, the recommended start loads were an invite to a jam fest--and I didn't like that music at all. Unique worked best, though nowadays I would likely use Power Pistol which has become a favorite for me in the 9mm, since the bad old days under Obama when old favorites couldn't be had.

[bruce drake]

It was designed for a Truncated Cone bullet profile if I remember the history on that cartridge's development in the Post WWI timeframe. http://cartridgecollectors.org/documents/Introduction-to-9mm-Luger-Cartridges.pdf

I prefer to shoot TC bullets in all my 9mm semi-auto pistols.

[Taterhead]

How did you determine the cartridge OAL? Did you use the cast and lubed bullet, or are you powder coating which will increase the nose diameter and require you seat deeper into the case?

What is the powder and charge weight? If you are under powered, the slide is not moving back as far and might be altering the cycle time and thus try to return to battery before the nose of the bullet is in the correct position. Specifically, what is the "failure to feed"? Sticking the nose on the ramp? Not picking up a fresh round? Sticking the nose on the top of the barrel hood?

Along with this, does the case eject to about the same position as the factory rounds? If it falls short, you might consider loading a little faster, if your book data will allow for that. Again, the powder and charge might be informative. What book are you using for your cast bullet data? More information will usually be helpful. Dusty

Good questions. Yes. Should have included more data.

PC bullets. Sneaked down on COL until a consistent kerplunk.

Cases eject similarly to factory ball. Did not chrony the factory ball ammo. Charges of Hercules Unique from mid to high 4s runs 1050ish to 1100ish. I think I have enough recoil impulse.

Same loads cycle a Norinco 213 (an interesting pistol) flawlessly. Different gun geometry though.

Nose-up jam into the hood of the barrel.

[Taterhead]

I appreciate the input guys. Thank you very much.

A 6 cav Lee TC mold is en route. I'll let you know how it goes.

[gwpercle]

My 1944 cyq Walther P38 , although lacking the finely finished surfaces of earlier manufactured P38's actually will feed, fire and eject everything. I did replace the recoil springs and magazine spring with new Wolff's springs. The following boolits have all worked: all boolts sized .357 and no tumble lube designs , TL design did not work in mine.

Lee 105 gr. SWC
Lee 120 gr. TC
Lee 125 2R RN
NOE 124 gr. TC GC

The 105 gr. Lee SWC shoots to the fixed sights POA with a moderate load of 4.7 grs. Unique, very accurate load.
The trouble I had was with new guns...tight chambers, little or no throats...the old P38 only needed a load with enough powder to reliably cycle the action...boolit profile and seating depth was not a problem at all.
Gary

[robert12345]

The best, and my most favorite 9mm bullet of all time is the RCBS, 125 grain 9mm gas check bullet.
.
Sadly;
it's painfully slow to cast,
and,
it's a pain to size, and apply the gas check...

But,
once loaded, they are plenty accurate enough, and they feed through any 9mm magazine, slick as a whistle.

I shot a ton of those, ( 4.2 grains of bullseye ), through my old Beretta 92, until I just got tired of casting, sizing, gas checking, etc...
.
One day at a gravel pit, I set the sights of that 9mm, on a aluminum can and shot 1, ....the can tilted a little, I then shot 4 more, but, the can did not fall down.

Thinking to self, "I am pretty hot with this gun, how did I miss all 5 ?"

Turns out I didn't miss at all, ... fact is, I hit all five, but the energy transfer was so low, with those pointy 9mm bullets, that they passed right through the thin aluminum, the can simply did not fall down.

5 neat little round holes, in that pop can, .......through and through, ....the can just sat there as if it didn't not even feel it.
.
.
My favorite 9mm bullet is now an LBT 125 pb;
it's fast to cast,
no gas check,
has a big flat nose,
will knock down anything I shoot at,

and,

it feeds great in my model 19 Glock.

[sixpointfive]

What was the oal with 105?
My 1944 cyq Walther P38 , although lacking the finely finished surfaces of earlier manufactured P38's actually will feed, fire and eject everything. I did replace the recoil springs and magazine spring with new Wolff's springs. The following boolits have all worked: all boolts sized .357 and no tumble lube designs , TL design did not work in mine.

Lee 105 gr. SWC
Lee 120 gr. TC
Lee 125 2R RN
NOE 124 gr. TC GC

The 105 gr. Lee SWC shoots to the fixed sights POA with a moderate load of 4.7 grs. Unique, very accurate load.
The trouble I had was with new guns...tight chambers, little or no throats...the old P38 only needed a load with enough powder to reliably cycle the action...boolit profile and seating depth was not a problem at all.
Gary

[sixpointfive]

What was oal for 105 sac?

[gwpercle]

What was the oal with 105?

I have used a OAL of 1.065 " and a OAL of 1.070" with the short Lee 105 gr. SWC boolet , both OAL's work just fine in my old P38 . I seat the boolit so the mouth is between the top driving band and the crimp groove with the taper crimp die . Holds just fine . I have no idea why the P38 groups it so well .
Gary

[Conditor22]

Slug that P38.

Mine slugged out at 0.3582 and the throat was too small to fit a correct sized boolit :( I'll have to get it throated)

[sixpointfive]

Thank you. I’m going to run 4.7 gr unique.
I have used a OAL of 1.065 " and a OAL of 1.070" with the short Lee 105 gr. SWC boolet , both OAL's work just fine in my old P38 . I seat the boolit so the mouth is between the top driving band and the crimp groove with the taper crimp die . Holds just fine . I have no idea why the P38 groups it so well .
Gary

[sixpointfive]

247122

[Walks]

If take the bbl/slide assembly off a P38 and stick a loaded mag into it you will see that the bullet has a almost straight line feed path.
Copied into the Beretta 92 and Desert Eagle.
The Truncated Cone was designed for the P-08 Luger. In WW1 the Brits complained that this was a violation of the 1899 Hague Convention as it caused Grievous Wounds. It forced the Germans to adopt a 124gr RN FMC.

I've cast the Lyman#356402 for many years. Cast of Linotype it feeds it EVERYTHING. Just seat it to the edge of the bearing surface where it starts to angle into meet the small meplat. Works with every pistol I've tried it in.

Lately I've tried some softer alloys, #2 mixed 50/50 with COWW.

I used Linotype because that's what my Dad used. His thinking was a bullet forced up a feed ramp into a chamber needed all the help it could get.
For Many, Many years Lino was cheap. I had over a ton, until 500lbs was stolen.
Now at $3.00-$4.00 a pound it sure ain't cheap.

It works just fine.

[sixpointfive]

247125
If take the bbl/slide assembly off a P38 and stick a loaded mag into it you will see that the bullet has a almost straight line feed path.
Copied into the Beretta 92 and Desert Eagle.
The Truncated Cone was designed for the P-08 Luger. In WW1 the Brits complained that this was a violation of the 1899 Hague Convention as it caused Grievous Wounds. It forced the Germans to adopt a 124gr RN FMC.

I've cast the Lyman#356402 for many years. Cast of Linotype it feeds it EVERYTHING. Just seat it to the edge of the bearing surface where it starts to angle into meet the small meplat. Works with every pistol I've tried it in.

Lately I've tried some softer alloys, #2 mixed 50/50 with COWW.

I used Linotype because that's what my Dad used. His thinking was a bullet forced up a feed ramp into a chamber needed all the help it could get.
For Many, Many years Lino was cheap. I had over a ton, until 500lbs was stolen.
Now at $3.00-$4.00 a pound it sure ain't cheap.

It works just fine.

[sixpointfive]

Is this correct? Do you think 4.7unique is enough powder?

247142
247125

[sixpointfive]

247143 is this the spot? Will 4.8 unique do the job?

[Taterhead]

Follow-up to the original issue. The Lee 120-TC, seated with the tiniest bit of shoulder above the case mouth, works pretty well.

Sized .358" and powder coated. 4.9 gr Unique makes it run well. Depending on the brass, that means a bit of powder compression.

[sixpointfive]

Here?247155

[Walks]

No not there. Seat to middle of front driving band. Do a plunk test, if it doesn't pass, seat to just a smidge below the leading edge of the front driving band. If it doesn't pass the plunk test ? I don't know what to tell ya.

[sixpointfive]

4.8 gr unique and 105 swc is very accurate in my p38 I just tested today. I did have some failure to feed issues though. Can you look at my seating depth and provide suggestions . Thanks , I’m at 1.070” just in front of the second band. Should I be more forward,?

247353

[gwpercle]

Here?247155

The boolit needs to be deeper into the case ( For my P38 anyways) The top edge of the case mouth should be just below the very top edge of driving the band and above the crimp groove . Right now you are seated below the crimp groove
Move the case mouth/edge up to the next band , effectively seating the boolit deeper into the case . There is plenty of room ...it's a short boolit .
4.7 grains of Unique was the lowest charge that gave reliable functioning and shot to a 6:oclock hold .
I would do a photo if I could but lack skills .

My OAL dimensions may have been off , it's hard for me to read dial caliper lately, blind in one eye , can't see out the other !
seat the boolit deeper OAL be hanged .

4.8 grains Unique should be right on
Gary

[sixpointfive]

The boolit needs to be deeper into the case ( For my P38 anyways) The top edge of the case mouth should be just below the very top edge of driving the band and above the crimp groove . Right now you are seated below the crimp groove
Move the case mouth/edge up to the next band , effectively seating the boolit deeper into the case . There is plenty of room ...it's a short boolit .
4.7 grains of Unique was the lowest charge that gave reliable functioning and shot to a 6:oclock hold .
I would do a photo if I could but lack skills .

My OAL dimensions may have been off , it's hard for me to read dial caliper lately, blind in one eye , can't see out the other !
seat the boolit deeper OAL be hanged .

4.8 grains Unique should be right on
Gary

Deeper?

[gwpercle]

Deeper?

As per photo in post #26 ... That looks just right , do it pass the plunk test ?
( it should ) If so , range time !
This should cure any failures to feed .
Gary

[DocSavage]

I don't load for a P38 but several 9 mm and find seating a round nose or truncated bullet with about 1/16 to 1/32 " of the frant driving band to work well.