9mm Major at sub-insane pressures? QuickLoad says yes, but I'd lik

[BrotherJack]

So, I'm an old rifle guy just getting into the pistol world. I've been using QuickLoad for years on my rifles, and have generally found it so accurate that the only real use I have for load manuals anymore is to make sure QuickLoad didn't just tell me I could use 10 grains more powder than I should (and bizarrely, the one time a manual ever told me that, I did some research, and the manual was wrong, quickload was right). QuickLoad is also usually on the money within 50FPS of estimated velocity for any given load in most rounds (including my 9mm). So, anyway - thats' my backstory and why and how much I love quickload. All that said, I've heard rumors it isn't always as accurate re: striaght walled pistol cases?

Anyway, moving along, 9mm major looked interesting to me, so I sat down with QL and started crunching numbers. If QuickLoad is right, it's possible to make 9mm Major in any old 5inch barreled gun with a vaguely gennerous throat, well within the realm of +P pressures (and without even hitting +P pressures, if you can seat the bullet in question out to a full 1.69). You should be able to do it in a 4.4 inch barrel (like my 226Sig), but it'd be up nearer the edge of +P (but still inside spec).

However, I'm scratching my head a little bit. The load that QL thinks is the most power factor for the least pressure doesn't seem even vaguely like what I see folks posting for their 9mm Major load data (and the 9mm Major load data I'm seeing is kind of scary looking stuff, some of it nearing up on 50,000PSI (rifle territory) says QuickLoad).

Anyway - I'm digressing. Back on track - load data, according to quickload for the lowest pressure vs highest power factor, looks like you want a short 147 bullet (such as a Montana Gold's 147 which I used for my calcs at 0.636 in), seated at around 1.140 (which I see fairly commonly used for this bullet in other folks load data), with about 5.5 grains of Power Pistol. Should get you around 1150FPS fairly easily, and at only around 36,000 PSI, thinks QuickLoad. If you can seat full spec length at 1.169 and still feed, you could do it around 34,000PSI (not even +P). Even if it turns out you need an extra 0.1 grain to get your gun over the top, you'd still be under 38,500PSI according to QL.

So - that's a bunch of rambling after I did some theoretical lab stuff. You guys with some real world experience, school me. Am I missing something? Am I on to something? Discussion, please and thanks.

[kneelingatlas]

Power Pistol is too fast and doesn't produce enough gas. 9 Major isn't just about making 165pf with a .355 projectile, it's about getting as much gas volume to work the comp as possible without blowing up the pistol.

Most 9 Major shooters load upwards of 175pf because it shoots flatter in their pistols.

Edited July 23, 2013 by kneelingatlas

[superdude]

Looking at your charge weights and velocities I think you might be right about your predicted velocity. Alliant/Speer and Hornady manuals stop at 5.0 or 5.1 for their max for PP and a 147. If they tend to list their max loads as near max pressure, then the only thing I would question is QL's pressure estimate. But I'm guessing here. QL might be right. I've not used PP in 9mm with 147s so I can't offer you any real data.

Folks have found that, generally, all else being equal, you can make major with heavy bullets at less pressure than with light bullets.

[gng4life]

I did use quite a bit of PP with MG 147 bullets one year (due to 124 out of stock for a while) and I was running somewhere around the 7.0+ range. I chrono'ed at 172 at Area 6 that year. While I will admit it's not the most ideal load for 9Major, it wasn't bad and shot okay.

However...if you are trying to make Major with a 124, I would be very cautious with PP. In fact, I would go to a different powder.

[Hi-Power Jack]

Power Pistol is too fast and doesn't produce enough gas. 9 Major isn't just about making 165pf with a .355 projectile, it's about getting as much gas volume to work the comp as possible without blowing up the pistol.

+1. The 147 grain bullet wouldn't work the comp as well.

[BSeevers]

Yes these are high pressure loads.

The PF used to be 175 with about half the choice of powders today

I used to see lot's of Super face and always laughed at articles that said these loads could/must be in the 50,000 cups range. Well duh but we was racing.

That's like telling a drag racer If you advance your timing you will go faster. Of course it does and I will do it til I detonate a piston

Things in the 165 PF and powder choice world is way safer now but I know 9mm is less safe than 38 Super. Less doesn't mean unsafe

[BrotherJack]

I'm a little confused as to why PP would be too fast. It's a fairly slow powder, 9mm wise, right at 100% case fill, and only about 90% burnt when the bullet hits the end of the barrel. I also am well acquainted with the muzzle blast from Power Pistol, which is substantially more than pretty much anything else I've tried in the 9 (which I presume to be gas/unburnt powder blow-out, which would be good for the comp?). Or is it because the 147 grain bullet provides more recoil, negating the comp somewhat?

Side note, I went back and did some math, and with a short 123/124/125 grain bullet, you could accomplish similar PF, still in SAAMI spec with a long seating depth and 7.2GR of Power Pistol.

I'm really honestly not trying to argue - I'm just ignorant and want to learn!

[superdude]

The principles for recoil reduction with a gun with a compensator and one without are polar opposites.

For a gun without a compensator, the ideal combination is a fast powder and a heavy bullet.

With a compensator the ideal combination is a slow powder and a light bullet.

Here's why:

Bullet weight.

The heavier bullets work great when you're shooting without a compensator. When loaded to the same power factor with the same gunpowder heavier bullets recoil less than light bullets. (http://38super.net/Pages/Recoil.html#Anchor-47857)

Gunpowder burn rate/charge weight/gas volume.

Fast powders require less charge weight to reach a given velocity than a slow powder. Less powder weight means less recoil for the same velocity. The weight of the gunpowder factors into the force of the recoil by way of the conservation of mass. (http://en.wikipedia.org/wiki/Recoil#Including_the_ejected_gas)

Thus, for a gun without a compensator the ideal combination for low recoil is a fast powder and a heavy bullet.

But with a compensator, that whole thing gets turned around, and heavier bullets in this case tend to produce more recoil, specifically muzzle rise. The reason is that compensators take advantage of gas to reduce muzzle rise. More gas is better. Since you need less gunpowder to make major with a heavier bullet, you have less gas to aid the compensator's function of redirecting the gas to reduce muzzle climb. Thus, for a compensated gun, the most effective load is a light bullet (because it requires more velocity and therefore more gunpowder for the same power factor) with a gunpowder that produces a lot of gas. Slow powders usually require more weight to produce the same velocity. More gunpowder weight (for the same velocity) = more gas. So in this case slow is good.

Previous posts stating that PP is too fast is likely a reference to how effectively it will run a compensator. It doesn't require as much charge weight (think gas volume) to reach a given velocity as other, slower, gunpowders. A slower powder, one that requires a larger charge weight, would help the compensator work more effectively because you wants lots of gas.

Did that help or just cause more confusion?

Your combination would certainly work, and with a compensated gun you would have less muzzle rise than you would without a compensator, but using a lighter bullet with a slower powder would offer you even less muzzle rise.

[gng4life]

Side note, I went back and did some math, and with a short 123/124/125 grain bullet, you could accomplish similar PF, still in SAAMI spec with a long seating depth and 7.2GR of Power Pistol. I

I can almost promise you that a 124 with 7.2 of PP will not make Major. I will go back and check my load data, I could be wrong.

[Yardbird]

7.2gr + 124 = 162pf in my Glock. It took 7.7gr to make 166pf. 8.2gr was 179pf with no pressure signs.

[kneelingatlas]

7.2gr + 124 = 162pf in my Glock. It took 7.7gr to make 166pf. 8.2gr was 179pf with no pressure signs.

How well does it work the comp?

[Yardbird]

It was comparable to AutoComp for me.

[BrotherJack]

Yardbird - was that 5 inch barrel? (which is what I'm feeding quickload for my calcs).

Superdude, does not cause more confusion - other than me being confused as to how a powder that only makes about 90% burn before end of barrel is "too fast", which lots of folks are doing HS-6, which is very near burn rate?

Great/informative discussion so far guys, much appreciated, now -- more of the same.

[Yardbird]

Yup, 5" barrel.

[BrotherJack]

Also - for clarification - superdude - I do see your point, that needing 7+ grains of powder with a light bullet is better than 5+ grains of powder with a heavy one, compensator wise.

[BrotherJack]

Yardbird - and what was bullet OAL and cartridge OAL?

[Yardbird]

Bullet = .588

COAL = 1.158

[BrotherJack]

Yardbird - yow, that's enough to somewhat shake my faith in QuickLoad for 9mm loadings. If QL is right, that 8.2 gr load would be 65,000PSI, which I refuse to believe would not have shown pressure signs (and would be more like 192PF). Oddly, QL usually shows about 20/30 FPS low for me on my 9mm loads (ie: it'll say 1190, and my chrony will say 1210 or similar).

Though, on the other side of it, I agree - I have never figured out how to get enough Power Pistol into a 9mm to get scary looking brass/primers. It's one of the reasons I like it so much. It also makes awesome reduced pressure loads for brass-that-lasts-forever.

[superdude]

Yardbird - was that 5 inch barrel? (which is what I'm feeding quickload for my calcs).

Superdude, does not cause more confusion - other than me being confused as to how a powder that only makes about 90% burn before end of barrel is "too fast", which lots of folks are doing HS-6, which is very near burn rate?

Great/informative discussion so far guys, much appreciated, now -- more of the same.

I'm not familiar with how QL works or how important the % burn before end of barrel is for determining efficient use in a compensator. But empirical evidence shows that the simple parameter of charge weight is a very good predictor of compensator function. You can see how PP compares with other gunpowders in a standard and compensated pistol in the link below.

http://38super.net/Pages/Gunpowder%20and%20Recoil.html

[BrotherJack]

Superdude - awesome link, great info! Thanks. I'm not sure how well the QL info would translate to comp use either, other than when it says your burn is not complete, and pressure is still high at the muzzle - my redneck intuition thought that'd be great for a compensator.

Reading over that link, the diff between PP and the two slower powders they tested is close enough in a comp'd gun to make me think I might still try it (heck, I'm a total newb at competition anyway - if I don't come in dead last, I'll be shocked anyway, LOL).

[kneelingatlas]

I say less theorizing, more shooting!

[BrotherJack]

Aw, come on now - you know thinking about shooting is almost as much fun as shooting.

[kneelingatlas]

Aw, come on now - you know thinking about shooting is almost as much fun as shooting.

It's true; with two boys under four and another in the oven, I do way more thinking than shooting!

[bajadudes]

I'm not familiar with how QL works or how important the % burn before end of barrel is for determining efficient use in a compensator. But empirical evidence shows that the simple parameter of charge weight is a very good predictor of compensator function. You can see how PP compares with other gunpowders in a standard and compensated pistol in the link below.

http://38super.net/Pages/Gunpowder%20and%20Recoil.html

Thank you, this was a very informative read and confirms much of what I have intuitavely learned over the years.

[superdude]

I'm not familiar with how QL works or how important the % burn before end of barrel is for determining efficient use in a compensator. But empirical evidence shows that the simple parameter of charge weight is a very good predictor of compensator function. You can see how PP compares with other gunpowders in a standard and compensated pistol in the link below.

http://38super.net/Pages/Gunpowder%20and%20Recoil.html

Thank you, this was a very informative read and confirms much of what I have intuitavely learned over the years.

You're welcome. Glad you found it useful.