Heavy vs Light in short barrels?

[entoptics]

Anyone have any hard data on "+P" ammo velocity in short barrels vs "normal" barrels. Ideally, a variety of loads in a controlled test (e.g. polygonal vs polygonal or conventional vs conventional).

I have a G17 and it will fling a 115 FMJ "cheapo" in the neighborhood of 1200 fps, and +P will show up about 75-100 fps faster. My pet 115 JHP load with Unique will nudge up against 1400 fps. I've chronied a billion 115 grain bullets in my glock and 16" barreled SUB2000, both factory and reloads, and have never seen a "heavy" bullet perform as well in terms of energy.

Is this the case with short barrels too? I have a CW9 and was curious if I might actually see an energy gain with a heavier bullet. Perhaps a 124 +P will outperform a 115 +P due to the decreased burn distance?

Obviously this must be highly load dependent, thus I was wondering if there's any hard data out there. Maybe a particularly fast burning powder can chunk a 124 (or god forbid a 147) fast enough to beat out a 115 in ftlbs. I'm quite certain it can't happen in a 4.5" barrel, but a 3.5" barrel is a complete unkown for me right now. I suspect the 115 is optimum regardless of the length, but till I see some data I can't know for sure.

When the weather gets good, and my work schedule falls off, I intend to find out, but till then, maybe you guys can help me.

[jocko]

nothing wrong with 115 grain ammo, but irt seems like there is a nicer variety of defense ammo in the 124 grain stuff than ther 115, unless I am just not seeing what is all out there on the market. ANY defenbseroiund tha tis totally reliable is what one should consider, are some better than others in certain guns???Probably so. Not sure the BG willnoiti8ce if he getshit by a 115 hp or a 124 HP either. Reliability has to be #1. Then just shoot it like u stoleit..

[CJB]

Energy is a function of the "square" of the velocity times weight time one half. A little extra velocity gets you a lot of extra energy. Its always a tradeoff because you can only push things so fast... and at that point bullet weight comes more into play, like with those small 95 and 88 grain ".380" bullets. I think you'd have to make a comparison between your 3 or 3.5 inch barrel and a much longer one to see one weight overtake the other because of acceleration and burn duration. An inch, or half an inch... you'll see more variation between shots, between barrels... than because of that.

[wyntrout]

http://www.ballisticsbytheinch.com/index.html

These guys spent a lot of time and money to research the difference barrel length makes with popular ammo... and they shot real everyday guns for velocity tests as well... very informative!

Wynn

[Bill K]

http://www.ballisticsbytheinch.com/index.html

These guys spent a lot of time and money to research the difference barrel length makes with popular ammo... and they shot real everyday guns for velocity tests as well... very informative!

Wynn

Found the site awhile back; wished they had done a foot pounds column alongside the the velocity columns so that energy could be compared. None the less still very informative.

[wyntrout]

There are energy tables... computed, of course... who can actually measure that stuff!?

In the results they explain that:

http://www.ballisticsbytheinch.com/results.html

Wynn

[Bill K]

There are energy tables... computed, of course... who can actually measure that stuff!?

In the results they explain that:

http://www.ballisticsbytheinch.com/results.html

Wynn

Yep, I understand. I just wish they would have done it for me. I've seen lots of ballistic tables where the velocity and energy info is displayed side by side.

[wyntrout]

There's always the manufacturer's data and other reviews and testing by magazines, etc. You can get an idea or "interpolate"... SWAG about how your particular setup does.

It was nice that they went back and did some updating and included the Kahr P380 along with most of the other popular pistols, as well. I'd like to see that for 9mm, though. They only had CorBon and Federal listed for that.

The 9mm was designed around the 115-124-grain bullet, as was the 230-grain for the .45. I try to stick to those, preferring the 124-gr +P for 9mm and the standard 230-grain for the .45 ACP.

The NATO 9mm is 124-grain and closer to +P. I personally don't want to shoot lighter, faster bullets or push heavier ones like the 147-gr. To each his own, though. I guess you won't find someone who owns a "Smart" Car AND a full-blown Hummer.

Wynn

Wynn

[JimBianchi]

Out of my MK9 the 147 v 147+p HST, the +p was an average of 75fPS faster,

it also had a much bigger fireball and much slower follow-up shots.

Guy with more time than me have test this same ammo in ballistics gel, with and with out denim, and found the standard 147 HST to penetrate 12 to 13 inches and consistently open up to a full expansion and not shed it;s jacket.

In most cases, anymore penetration than that and you could be looking at pass-through rounds, adding a dangerous element to anyone behind the bad guy and the loss of energy transfer to the person shot.

But basically, any premium SD round by one of the major manufacture will be an excellent choice for a SD round.

My MK9 (and K9) both have cycled and fire Ranger 127+p+, HST 147/147+p, Gold Dot 124/124+p and the Wally World 147 JHP ammo without fail. (Originally I carried Double Tap 147+p ammo in my MK9, it ran perfect for about 500rds. They raised the price significantly, so I did some ballistics research went elsewhere for SD ammo.)

After 100 to 200 rounds of your chosen SD ammo, using all you mags, what ever works perfectly and is readily available for training purposes, is what I would pick.

I would not want to get shot by any of them....

[entoptics]

Thanks for the info guys. Especially the link to the barrel tests.

Judging by that website, my gut instinct was correct and there isn't really a "crossover" point for barrel length where heavy bullets will jump up above light ones in terms of muzzle energy, particularly when comparing a "short" barrel to a "shorter" barrel.

Obviously when shooting a 16" carbine one should pay attention to how fast a light bullet is traveling, as bullets can start to fail when you grossly exceed their recommended or designed velocities. Not sure what speed that is for a 9mm but I wouldn't be surprised if the average 9mm bullet won't perform well at 1700+ fps. I've considered running 124 gr bullets through my KT SUB2K when I'm carrying it as a backpacking gun for that reason.

I think I'll probably stick with 115+P rounds for "serious" stuff in my CW9. I've had excellent results with Magtech Guardian golds in my Glock. I'll try those in the Kahr and I have some Cor-bons to try too.

I really hate the fact that "Self Defense" ammo is so darn expensive (even the magtechs are 3X the price of FMJ), but I wholeheartedly agree with the above comments that mention putting several magazines full through a gun to ensure it feeds and functions well with something you might have to rely on.

[DKD]

The guys here are basically all correct. I have read alot and over 35 years of reloading and testing loads yields alot of information. But the long and short of it is if you want to push heavier bullets especially in +P configuration, they really need the additional barrel length to burn the slower burning powder to achieve the higher velocities. (They also tend to produce greater mizzle flash)
In the barrels under 4 inches, and especially 2.5"-3" range the slightly lighter weight bullets perform better in our pocket carry guns. Velocites need to be kept up to ensure proper deformation of the hollow points. heavy bullets do tend to penetrate better, sibce they have more momentum which is a factor of the bullets mass. The muzzle energy as noted in a previous quote was stated as 1/2M*V squared or half the mass times the velocity squared.
In the end function of the weapon is paramount. I tend to lean toward the 124 grainers by Gold Dot as my prefered 9MM load.

[TucsonMTB]

I think I'll probably stick with 115+P rounds for "serious" stuff in my CW9. I've had excellent results with Magtech Guardian golds in my Glock. I'll try those in the Kahr and I have some Cor-bons to try too.

I really hate the fact that "Self Defense" ammo is so darn expensive (even the magtechs are 3X the price of FMJ), but I wholeheartedly agree with the above comments that mention putting several magazines full through a gun to ensure it feeds and functions well with something you might have to rely on.

At $189.50 (plus about $20 shipping) for 500 rounds (10 boxes) this should be a cost effective self defense round. Here's a link to the supplier, SGAmmo.com.

[ltxi]

Prefer 124 gr in standard pressure in lightweight nines. I shoot it better. I like Gold Dots for contemporary bullet design but confess to still carrying HydraShok in my PM9 and, in 230, in my LW 1911. Older design but it's worked well for me in the past, I feel comfortable with it, and I still have quite a lot on the shelf.

[rwblue01]

How does this effect terminal performance?

I came to the conclusion that I like 9mm 147gr bullets in my regular guns. I did lots of gel testing to be happy with my selection. I really don't want to do this again with my PM9.

[joshh]

+1 for the 147gr in my pm9. a win rep & a gun guru recommended them to me and after doing some homemade tests i agreed that the winchester pdx or rangerT's were the rounds that worked best for me.