Reloading for a compensated 9mm

[Choid]

So my wife, in her great generosity, bought me a compensated 9mm pistol for my birthday. Only shot it a little, but what I read is that the more muzzle pressure, as opposed to chamber pressure, you have, the flatter the comp makes it shoot because of physics or something. Anyway, I was wondering if anybody had load data for comped pistols with 124 grain bullets. As far as powders that may be suitable, I have gobs of 3n37, n340, AA7, CFE Pistol. I have some faster pistol powders, but generally those create low amounts of muzzle to chamber pressure, which is why they are enjoyable to shoot.

 

[IronicTwitch]

AA7 and CFE Pistol are good slower pistol powders that create lots of gas to work a compensator. Depending on your gun (is it designed as a USPSA Open gun?), suggest looking for load data for 9major.

 

[Deleted member 115591]

Depends on what kind of compensated pistol your wife got you.

I have a single port comp 2011 that I run regular ammo through... but just loaded it a little bit hotter.

My other 3 port comp 2011, I use Winchester Auto Comp using 9major load.

I think AA7 and CFE Pistol are your best bet, but might need to run them pretty hot to work the compensator.

 

[Choid]

Depends on what kind of compensated pistol your wife got you.

I have a single port comp 2011 that I run regular ammo through... but just loaded it a little bit hotter.

My other 3 port comp 2011, I use Winchester Auto Comp using 9major load.

I think AA7 and CFE Pistol are your best bet, but might need to run them pretty hot to work the compensator.

It's the Staccato XC, so single port, and not particularly extreme. It definitely runs regular 9mm loads fine, but you can feel it actually shooting flatter with hotter ammo. I'll experiment with those powders.

 

[Cascade Hemi]

AA7, WAC, and HS6 should be at the top of your list. At the end of the day you're just loading +P+ ammo.

 

[davsco]

yes hs-6 is pretty popular for 9mm open guns.

 

[Choid]

AA7, WAC, and HS6 should be at the top of your list. At the end of the day you're just loading +P+ ammo.

So, correct me if I am wrong, but if I don't need to make power factor, isn't the best goal to maximize muzzle pressure while keeping chamber pressure relatively low? What I mean is that a comp shouldn't react to chamber pressure, so why maximize it?

 

[Cascade Hemi]

Gas volume is as important as pressure.

 

[Choid]

Gas volume is as important as pressure.

Gotcha, that is why I was trying to focus on muzzle rather than chamber pressure. Is there a better proxy for gas volume? I mean actual grains in the load is pretty good too, I guess.

 

[Cascade Hemi]

Gotcha, that is why I was trying to focus on muzzle rather than chamber pressure. Is there a better proxy for gas volume? I mean actual grains in the load is pretty good too, I guess.

I don't have a good answer other than to say velocity and actual feel is the most common metric.

 

[Choid]

Thank you!

 

[Gustav7]

Just recently talked to local USPSA(Master) guy who runs 9mm open. He said he always runs 115's with HS-6 at around 1400-1500fps.

He essentially said the more powder he can safely get into the case, the better his comp runs (within reason obviously).

 

[EMorr]

You guys are correct that gas volume and muzzle, not chamber pressure effects the effectiveness of a compensator.

However trying to pick a powder and charge to optimize the effectiveness of a comp is probably not the route I would take. The muzzle pressure will drop off exponentially once the bullet leaves the muzzle and I know of no cheap or easy way to model this information. Quickload can give you the numbers on the gas after effect of an un-comped gun, but it can't tell you how it will interact with a comp. (At least not that I am aware of.)

If it were me and I was looking for a way to reduce muzzle rise and target reacquisition time I'd be researching what was the most effective comp on the market.

To sum it up more powder, gas and pressure may make a comp work slightly more efficiently but there is also a change that those same factors will speed the projectile up and further increase the recoil of the gun and you find yourself in a self canceling solution. JMHO YMMV.

 

[davsco]

sounds like you don't need or want to make 'major' power factor. in my 9mm sti steelmaster (with an actual compensator) i run 7.7g of 3n38 with 115 zero hp's at 1.156. i use this for steel matches where there are no major power factor requirements.

 

[whatsupdoc]

"Winchester AUTOCOMP is a ball powder designed for competition race guns. A perfect burn speed to feed the compensators with a higher volume of gas, it is a great choice for 38 Super, 9mm, 45 ACP and 40 S&W. With AUTOCOMP, competitors get off faster shots with minimal muzzle flash."

 

[Cascade Hemi]

It's not magic, you want to stuff as much slow burning powder in a case without the pistol exploding in your hand. The byproduct is velocity. If you were loading specifically for USPSA you'd need to care about velocity for rules compliance but you're not. Howevet, velocity and gas volume are tied together.

 

[TSpork]

It's the Staccato XC, so single port, and not particularly extreme. It definitely runs regular 9mm loads fine, but you can feel it actually shooting flatter with hotter ammo. I'll experiment with those powders.

Your wife bought you an XC for your birthday? Jesus you’re a lucky guy

 

[Choid]

Your wife bought you an XC for your birthday? Jesus you’re a lucky guy

She's pretty great.

 

[davsco]

when you invite me out to colo in october to guide me on an elk hunt, i'll bring some 3n38 out with me. hahaha

 

[Choid]

when you invite me out to colo in october to guide me on an elk hunt, i'll bring some 3n38 out with me. hahaha

Montana, and any time!

Thanks a lot guys. As mentioned, I don't need PF, so I guess my best path is to try some slower powders and shoot by feel until I reach a point that feels bestest. It's a really cool gun. In all my years of shooting and collecting 1911s I've shied away from comps, which seems to have been kind of dumb.

 

[vwpilot]

AA7 will produce more gas than CFE Pistol (which is basically the same as Autocomp).

I've used both WAC and AA7 in my open gun and with both running about 1370-1400 fps with a 124gr bullet, the AA7 works the comp better. Those velocities took 7 grains of WAC and 9.6 of AA7 in my gun.

I'd start with the AA7 and start around 7-7.5 grains if you're using a 124 bullet. Then work up a few tenths at a time and see what feels good. Yo shouldnt need to get to the 9 grain point without using an open gun, but on the high end of a normal load should work well for you.