10MM PRIMER SHOWDOWN: FEDERAL GOLD MEDAL MATCH:VELOCITY AND GEL TEST

[fltbed]

Thank you for posting your results.

If I may weigh in, I have some experience on this topic starting about 30 years ago with the 45 Colt +P.  I had several 45 colts but only one Ruger (Bisley) capable of handling the +P loads.  I wanted to be able to tell at a glance what pressure level my ammo was loaded to, so I came up with the screwy idea of using trimmed down 454 Casull brass for my 45 Colt +P loads.  My brother just gave me several hundred Winchester 454 cases, so I trimmed down some to 45 Colt length and started testing.  In my tests, using the Remington 7 1/2 small rifle match primer, (that freedom arms recommends using in the 454) I was getting almost identical velocities compared to the Federal LPP 45 Colt brass.

When the lead free ammo started showing up over a decade ago, it was only available in 9mm, 40 S&W and 45 acp.  The magazine articles on the ammo back in the day stated they only developed a small pistol primer for some reason, but the compound they were using had a higher brisance but a lower flame temperature and shorter flame duration compared to the standard lead styphnate primers, leading to misfires.  Their solution was "much" larger flash holes and crimped primers.  In my tests back in the day, the 45 acp brass could be reloaded without issue.  (after removing the primer pocket crimp)  The powders I tested showed little to no difference in velocity.
The 9mm and 40 S&W brass was another story.  With the higher chamber pressures, primers blowing out of the cases were all to common.  I started throwing all that NT large flash hole brass in the scrap bucket.
They must be using a different lead free compound now as I haven't seen any of that large flash hole brass in a while.

I'm looking forward to testing the new SPP 10mm brass.  While I can't bring myself to buy any of the ammo to get the brass for testing, I figure it's only a matter of time before I find some at the range.  My testing will be limited to small pistol magnum primers and small rifle primers as I feel they will offer the best chance of duplicating the performance of the standard LPP brass.

Jeff

[Kenk]

That?s really interesting, Thanks Jeff!

[Wyocaddis]

Sorry know this was meant for Mr. Revolverguy. But had to add 2 cents. Mine would have to be a quality 44 mag. revolver. No need to chase brass in the field. I also really like the Ruger 44 Special flattop shoots great with old Skeeter load. I have a 25-5 45 colt Mountain Gun but have never got it to shoot as well as the Flattop.

[Alaska]

Glock 20
KKM Barrel
22 pound NDZ  spring

Never used Small pistol primers when using full race horse loads in 10mm. I use
WLP all the with 220gr Hardcast Coated

[tommac919]

Am I the only one that sees to many small marks on the primers in top pics ??
power spill on to anvil that presses primer in ?

[mr.revolverguy]

No powder spill some brass tighter than others there for I used more hand pressure to seat them fully. I usually prime on press but for this test I wanted to hand prime.