10mm Ammo History and Specifcations

[Intercooler]

No charge weight for the 170's to match it up. Do you know if anything exists?

[4949shooter]

Did we do a gel test on the 170 yet?

[Intercooler]

   Raggedyman got a huge package I sent him the other day with these, Black Max, Critical Duty, etc... in there. Enough to really keep him smashing things  He seemed really excited to get the Norma and Critical Duty tested first.

[4949shooter]

Awesome....thanks!

[gandog56]

Hmm, if a 357 SIG is just a 40 cal S&W necked down to 9mm, I wonder what you could do with a necked down 10mm?


357 Super SIG?

[The_Shadow]

Gandog56 writes,

Hmm, if a 357 SIG is just a 40 cal S&W necked down to 9mm, I wonder what you could do with a necked down 10mm?


357 Super SIG?

9X25Dillon is what its called.  Learn more here: http://10mm-firearms.com/wildcats/welcome-mr-randy-shelley-designer-of-the-9x25dillon-cartridge/

[Osageid]

Another fun round to shoot.  I have the conversion barrel for my glock20 SF

[Mike_Fontenot]

Gandog56 writes,

Hmm, if a 357 SIG is just a 40 cal S&W necked down to 9mm, I wonder what you could do with a necked down 10mm?


357 Super SIG?

9X25Dillon is what its called.

I would suspect a necked-down 10mm (to a 9mm bullet diameter) would have close to true .357mag ballistics, like .357sig was intended to be, but fell short of that.  Is that about what you get with a 9x25Dillon (in terms of energy, i.e., around 700 ft-lbs)?

[The_Shadow]

Here are a few correlations of the 9x25Dillon cartridge...

90gr Speer Gold Dot Hollow Point 2100 fps/6" bbl - 881 Ft / Lbs


115 gr Speer Gold Dot Hollow Point 1800 fps/6" bbl - 827  Ft / Lbs


125 gr Speer Gold Dot Hollow Point 1700 fps/6" bbl - 802  Ft / Lbs

[Mike_Fontenot]

Midway shows a 9x25 147gr DoubleTap at 733 ft-lbs ... that's a bit more than .357mag, but not by much.  I'm surprised that most of the 9x25 loadings use such light bullets.

[The_Shadow]

I suppose its because the 10mm delivers better heavy bullet performance than the 9x25Dillon.

[Mike_Fontenot]

I suppose its because the 10mm delivers better heavy bullet performance that the 9x25Dillon.

I was really thinking of .357mag vs 9x25 ... the most common light .357mag bullet is the 125gr, and the most common heavy .357mag bullet is the 158gr, with .357mag 180gr bullets occasionally being used.  It appears that the range of bullets used for the 9x25 are noticeably lighter.

What has always seemed strange to me is that the top .357mag energies are about the same as the top 10mm energies.  The max pressure is slightly higher (about 7% higher) for 10mm (37500 psi) than for .357mag (35000 psi).  And the cross-sectional area of the 10mm bullet is about 26% greater than for the .357mag (.16 sq-in vs .127 sq-in).  For the idealistic and un-realistic case where the pressure stays at max pressure for the whole bullet travel down the barrel, the energy is just the max pressure times cross-sectional area (which gives the force on the bullet), times the total length of the bullet's travel down the barrel (expressed in feet).  That would give about 2000 ft-lb for the 10mm, versus about 1487 ft-lb for the .357mag.  Of course, the actual pressure is usually fairly peaked, and the pressure falls rapidly after the peak is reached, so the energies are substantially less.  But the fact that the top commercial loadings in the two cartridges have about the same energies seems to imply that in the .357mag loadings, the pressure is kept nearer the max pressure for more of the bullet travel ... why would that be the case?  Maybe some of the experienced reloaders on this forum can shed some light on that question.

[The_Shadow]

There were a few guys that claimed to have loaded 180 grain bullets in the 9x25Dillon cases, but didn't divulge their load data.

The 180 gr 357 bullets I cast are a bit too long to use in the 9x25 cases.  The balance of what sticks outside vs. what's inside plays a part in pressures.  But these 180s in my 357 Magnum are loaded to 1325 fps from the 6" S&W Mod19, however with other powders I could drive it harder...

[gandog56]

Midway shows a 9x25 147gr DoubleTap at 733 ft-lbs ... that's a bit more than .357mag, but not by much.  I'm surprised that most of the 9x25 loadings use such light bullets.

It's kind of hard since 99.9% of 9mm loads don't seem to go above 147 grain bullets. Wouldn't be much of a market for heavier 9mm bullets.

[Captain O]

A warm load for the 170 grain JHP in the 10mm would be 13 grains of the original Accurate Arms #7. Such a load will generate 1324 fps in a Colt's Delta Elite, and 1374 fps (713 fpe) from my 7" barreled, long slide, Hunting Model IAI Javalina.

The load was from John Taffin's column, "Taffins Tests" in the American Handgunner, June 1991.