[Peter Turner]

Power Pistol is an amazing powder. Such high velocity with low chamber pressures. It’s like magic.

I load the RMR hollow point 115 gr JHP (MPR NUKE) at 6.6gr and 1.125″ COAL. They are really powerful, but according to QuickLoad calculations still have a manageable pressure. It seems like Power Pistol burns slower than other powders (like Titegroup) to give a longer push duration from the slowly increasing pressure. Hence the big muzzle flash because all of the powder is not burned as the bullet exits the barrel. These rounds shoot incredible well out of my Staccato P, which seems to like a powerful load to cycle reliably.

I use a lighter load for my other guns. For plinking I use 3.8gr of Titegroup (which seems to have an almost instantaneous pressure peak) with the RMR 124gr FMJ Truncated Cone Flat Point MatchWinner, but at a COAL of 1.075 to get higher velocity out of a lower cost ammo. 1.075″ COAL allows for flawless load in some pistols like a CZ which seem to need a shorter cartridge, based on bullet shape.

As a note of caution based on my experience. Watch your COAL. The beauty of 9mm is your COAL can be varied a lot based on the bullet shape, your load, your gun requirements, and the resultant chamber pressure. But it can significantly change your chamber pressure. Seems like COAL is almost as important to watch as the actual amount of powder. Most other pistol ammo COAL has little wiggle room for a variety of reasons.

[Peter Turner]

Why do you think the underwhelming grouping is related to the powder? How was your grouping before you used TAC? Was everything but the powder the same?

[Peter Turner]

I always use QuickLoad software to validate my loads after doing published research and then backing it up with velocity measurements. Some of those loads at a COAL of 1.110 inch calculate much higher pressures than the +P spec of 38,500psi max. At a “standard” COAL of 1.169 they calculate out at +P max pressure and therefore seem OK for +P loads. I have discovered, sometimes the hard way, that the beauty of 9mm is the ability to seat the bullet at different COAL’s. But that opens you up to distinct variations in chamber pressure. The deeper the bullet seating the higher the chamber pressure (and velocity).

My question is whether a match grade barrel means it is a precision fit chamber or does it mean that the chamber can take much higher pressures than a standard fit chamber? Or maybe both? I prefer to shoot my very powerful 9mm loads out of 1911 or 2011 firearms under the assumption (mine) that that chamber OD sized for a .45ACP cartridge has enough extra steel around the chamber for a very high pressure 9mm cartridge.

Any thoughts, data, or info?

• This reply was modified 2 years, 6 months ago by Peter Turner.

[Peter Turner]

I have successfully loaded N320 with the 147 FN “Heavy Match” RMR bullet for subsonic loads to use with a suppressor. N320 is supposed to burn clean and best of all it is 100% burned according to Quickload calculations. I am trying to reduce the amount of filth that a suppressor inherently drives back into the firearm.
Specifically I charge with 3.5 grain of N320 and seat the bullet to a COAL of 1.110 inch. That bullet is 0.625 inches long so if you use the round nose, just measure it and seat the bullet to that difference plus the 1.110 to get a COAL that yields the same case seating depth, hence about the same pressure. My load yields 902fps muzzle velocity in a Sig P226 with a 4.4 inch barrel, as measured with a Labradar unit . The load cycles well in all my firearms tested with or without the suppressor and includes a Ruger PC 9mm with 16 inch barrel.

[Peter Turner]

For subsonic I wanted a 100% burn and subsonic velocity for a suppressor using the RMR 147gr Flat Nose bullet. I chose VV N320 for that. 3.5gr and COAL at 1.110 inches. In a Sig P226, 4.4 inch barrel the unsuppressed velocity was 902 fps, measured by Labradar. It shoots well. QuickLoad predicts or calculates 100% burn and 951 fps.

VV N330 takes more powder and yields a little higher velocity but still burns 100% according to QuickLoad. 4.1 would be a pretty hot load but still quite doable from the looks of it.

I guess it depends on what you want to do.

[Peter Turner]

What is the twist on that barrel?

[Peter Turner]

I have loaded and shot thousands of rounds of RMR 124 FMJ FN, aka Matchwinner.

3.8gr Titegroup, COAL 1.075. Feeds and shoots in all of my 9mm pistols including the short throat CZ. 1048 fps average muzzle velocity from Sig P226 9mm 4.4″ barrel. Titegroup has a very quick pressure pulse but this load is quite smooth for good all around shooting. 100% powder burn.

Hodgdon Longshot 5.5gr, yields a powerful 1160fps, COAL 1.075″.

For a real punch Power Pistol 6.2 gr, COAL 1.075″ yields 1226fps. The felt recoil pulse is really solid and QuickLoad puts the chamber pressure near max so be careful and have a solid gun for this. COAL lengthened to 1.100″ reduces chamber pressure prediction to a more reasonable but high level, or reduce the powder charge. Only about 85% of powder is burnt in 4.4 inches.

The 3.8gr Titegroup, COAL 1.075 is just a great and safe everyday load IMO.

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