Is a 9mm upper worth the money?

[Axeman]

According to these charts, if I use a typical 55gr .223 in my 10.5" barrel I'm getting around 825 ft/lbs of energy at the muzzle.

If I went with a 7.5" 9mmP in the hottest loading I can find (Cor-Bon 115gr +P) I'll be getting around 550 ft/lbs.

A 10.5" barrel is at approx. 575 ft/lbs. A 147gr apparently gains almost nothing after a 5" barrel, so there's no point in putting those through anything bigger than my M9, unless it's just to put a can on it.

I just don't see the merit in dumping $500+ in a 9mm upper with these lousy ballistics.
I'd rather spend the money on a can, so that's what I'm gonna do!
FINALLY!
Now I just gotta finish the paperwork for the NFA Trust...and wait...

 

[Leshaire]

I don't follow your logic here. Is the only thing in question muzzle energy? Go buy a 458 socom or 300 win mag upper then. Do you want a cheaper to shoot AR, cross gun mag compatibility, home defense with much less wall penetration or a shorter barrel without going deaf? Then go 9mm. Do you want muzzle velocity, muzzle energy, longer range, and more standard AR parts? Then go 223/556.

 

[Laufen]

I don't follow your logic here. Is the only thing in question muzzle energy? Go buy a 458 socom or 300 win mag upper then. Do you want a cheaper to shoot AR, cross gun mag compatibility, home defense with much less wall penetration or a shorter barrel without going deaf? Then go 9mm. Do you want muzzle velocity, muzzle energy, longer range, and more standard AR parts? Then go 223/556.

The added benefit for me is being able to make hits further away by using a stock...and yeah, being able to slap a Geissele trigger into it is nice too.

The problem with these charts is that they don't take into account what the minimum necessary is, just the maximum you can hope to get.

 

[Leshaire]

The added benefit for me is being able to make hits further away by using a stock...and yeah, being able to slap a Geissele trigger into it is nice too.

The problem with these charts is that they don't take into account what the minimum necessary is, just the maximum you can hope to get.

Agreed. Why would someone need the maximum amount of muzzle energy possible anyway? I don't see the appeal.

 

[Laufen]

Agreed. Why would someone need the maximum amount of muzzle energy possible anyway? I don't see the appeal.

Maybe you do, but the fact is, it's just one facet to performance. For hunting or HD I'll take lower ME, and a potential for more penetration of the bonded 147gr bullets. Mass x Velocity is one way to measure performance but it's not always the best way.

 

[NWS]

9mm SBR AR with a can is one of my favorite guns.

 

[cmshoot]

Not a fan myself, unless it’s select-fire.

 

[BangBang]

You forgot the most important question....

Which one is cheaper to shoot?

 

[BangBang]

Well actually, the most important question is....

@The Mechanic (Greg Vess) what’s your opinion on AR’s in 9mm?

 

[The Mechanic]

There is nothing wrong with them although I have never seen the allure to drop to a lower power cartridge. Except for target I guess but hey I'm not the one to judge someone for what they want. If they see that they need one then they should go for it. I have AR's in other calibers so it's basically the same thing.

 

[The Mechanic]

You forgot the most important question....

Which one is cheaper to shoot?

It is a hell of alot cheaper.

 

[dial1911]

Pros:
Cheaper to shoot, by a good bit.
Can be used in pistol caliber carbine (PCC) matches.
I already had a 9mm can, so that was a plus.
Cardboard/clay pigeons do not care how much muzzle energy the bullet has... And most people don't want to get shot with any amount of muzzle energy, regardless of the number.

Cons:
Don't know... long barrel plus can equals super long carbine. Although the stock is a huge plus.
Which reminds me... I've got to get a dang lower filed with the alphabet folks. I'm going to fix the stock vs. brace vs. long/short barrel problem.

 

[The Mechanic]

It worked for the MP5 and Uzi.

 

[Axeman]

I don't follow your logic here. Is the only thing in question muzzle energy? Go buy a 458 socom or 300 win mag upper then. Do you want a cheaper to shoot AR, cross gun mag compatibility, home defense with much less wall penetration or a shorter barrel without going deaf? Then go 9mm. Do you want muzzle velocity, muzzle energy, longer range, and more standard AR parts? Then go 223/556.

Well that’s a great question.
My initial reason for considering a 9mmP upper was because the 10.5” 5.56 upper I have on my pistol project is just a bit too long to fit in a normal backpack, even though I’ve got a folder on it. So I was thinking about doing the 9mm to replace it as my EDC bag gun. Just in case something horrible happened and I needed more firepower than one of the normal pistols I keep with me. That’s why I was worried about energy, for defensive purposes. Going to something a lot larger defeats the purpose of it being a backpack gun.

 

[Axeman]

Maybe you do, but the fact is, it's just one facet to performance. For hunting or HD I'll take lower ME, and a potential for more penetration of the bonded 147gr bullets. Mass x Velocity is one way to measure performance but it's not always the best way.

I disagree here. You need as much energy as possible to make the bullet expand, which will cause the bullet to stop inside it’s intended target - rather than over penetrating and dumping that energy past the target - possibly into an innocent, but certainly not where it will do the intended job.
In pistol calibers, heavier slower bullets just don’t perform as well with one exception; 230gr Hydra Shok in .45ACP.

 

[BangBang]

There is nothing wrong with them although I have never seen the allure to drop to a lower power cartridge. Except for target I guess but hey I'm not the one to judge someone for what they want. If they see that they need one then they should go for it. I have AR's in other calibers so it's basically the same thing.

I’ve got AR’s in .22lr, 5.56 and .308 (you helped me build the .308)

My AR22 sees more range time than the other two combined because it’s WAY cheaper to shoot.

I’ve seriously only put MAYBE 40 rounds through that Mega .308 since you and I completed that build because it’s AT LEAST 50 cents everytime I pull the trigger.

I can’t even enjoy it because I’m thinking about the money the whole time! LOL!

 

[dial1911]

Just one other thought.... it's going to be hard to claim self defense if you shoot somebody at 40 yards... unless they were already shooting at you first.

 

[Jake]

In pistol calibers, heavier slower bullets just don’t perform as well with one exception; 230gr Hydra Shok in .45ACP.

Hydra Shok's suck. HST is where it's at, in all calibers.

 

[Jake]

In pistol calibers, heavier slower bullets just don’t perform as well with one exception; 230gr Hydra Shok in .45ACP.

Man, those 230gr Hydra Shok's work really well!

 

[cmshoot]

With the increase in active shooters, the possibility of engaging nogoodniks at longer distances is likewise increasing.

I don’t shoot matches, so I’m not a fan of PCC’s. For one thing, for anti-personnel use I want to be able to punch through body armor.

I already have cans to fit every caliber I own, except for my .338 Lapua, and that is next. If I want to run a can on a long gun, I slap my Silencerco Omega on my 10.5” SIG 556xi in 7.62x39mm.

A buddy of mine, who happens to be a dang fine operator and sponsored competitor, once said, “They only call it ‘over penetration’ when they ain’t trying to shoot through shit.....otherwise it’s just fine!”

If I have the choice between over- and under-penetration, I’ll choose the former and watch my backstop.