I need help with 9mm load


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target1911
November 12, 2007, 08:48 PM
I will try to keep this as short as I can................

I got me some lead for loading 9mm..I buy thru a friend from a supplier...
The guy sent me 38 125gr TCFP....He said that is what most ppl buy to use in IDPA/IPSC
The other 9mm I have measures .355 and the 38s are .357 (as expected)

I loaded few of the 38s in9mm cases to check them out.
They wont fit in the case gauge....
They wont chamber in my Taurus PT-111....
HOWEVER they WILL chamber in my Kahr..(slide locked and droped in chamber without force)

OAL is 1.118

I was warned by one friend not to shoot them but the manufacture said its ok if they chamber.

I am worried about raised presures due to the added size of the bullet.
Are they ok to use or should I trade them for some 9mm?

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Wildfire
November 13, 2007, 12:29 AM
Most 9 mm Lead rounds should be .356" When hard ball or jacketed rounds are .355" The .38s Will usually be .358" for lead rounds and .357" for hard ball.
Why those ended up at .357" I'm not sure. If they are soft they may not hurt any thing. If they are hard cast they could run the PSI up.
9 mms have some funny quirks when talking PSI issues. The oal or COAL (bullet seating depth is another critical area to watch with 9 mms. Too deep and the PSI goes up fast. The loading manuals warn of this. I guess I would not care for a bullet that was so fat it would not feed right.
The maker should have given you the hardness figures. They also feed best with only a taper crimp. Rolled crimps do not work well, as that round headspaces on the case mouth. Anyway like said 9 mms are fussy with the PSI end of things. When they spike they really spike. Most of the warnings in my books are concerning the use of lead bullets with the 9s. Be careful.
All the loading data I see for any of the 9s with lead rounds are all at .356".
I have no other info on your bullet but it sounds like it may be loaded a little on the short side to me. The 125 gr. lead rounds I see show COL of 1.130"..........

Clark
November 13, 2007, 12:45 AM
The big bullet in a small bore making no pressure increase is counter intuitive.
Likewise the pinched bullet making a huge pressure spike is counter intuitive.
The way I reconcile it is to think in the time domain.
If the peak pressure of powder burn is not concurrent with the increase pressure to swage, the peak pressure does not change.
And if the pinched bullet delays the start of bullet acceleration, the increased pressure makes the powder burn faster which increases pressure which makes the powder burn faster ....

This phenomena of large bullets working in a small bore without
pressure spikes is documented in P.O. Ackley 1966 "Handbook for Shooters
and Reloaders Vol 2" chapter 7
"additional pressure tests":
"..30 cal barrel pressure barrel was fitted to the test gun, but the
neck and throat was enlarged to accept the 8mm bullet, with the bore
remaining the standard 30 caliber. A Remington factory 30-06 cartridge
with the 150 gr bullet had been tested and previously gave 57,300 psi,
for a velocity of 3030 fps. The the bullets were pulled from two more
Remington 150 grain cartridges and were replaced with 8mm 150 grain
bullets. To everyone's surprise, although the velocity was rather
erratic, these loads averaged 2901
fps, with a pressure of 40,700 psi."



What does it all mean?
I shoot .358" bullets in 9mms and 380s all the time.
As long as it drops in the chamber, I have never had an increase in pressure.

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