9mm vs 5.56 AR Pistol Build - UPDATE: 5.56 - Help me Build One!

[PA1936MN]

Short barrel ars in 5.56 are ungodly loud. If you're going to use it indoors ever the flash can is a must. It's still going to ring your bell though.

You can ring my bell, ring my bell
You can ring my bell, ring my bell
You can ring my bell, ring my bell
You can ring my bell, ring my bell

I'm building a 5.56 pistol and also would love a pistol in like 9mm or 45acp. Why not just get another upper and use the same lower and you can have a two in one.

[arjohnson]

Id prefer a 8-10" 9mm for home defense, 556 in a short barrel loses too much energy and gains too much flash/noise (and I like flash/noise) 9mm sha a sproingy feeling recoil kinda like an AR when comparing to an AK but even more springy.

The spring twang in a 9mm is annoying, but it can be eliminated with a MVB stock or a JP silent capture 9mm buffer.

[Emptymag]

You can ring my bell, ring my bell
You can ring my bell, ring my bell
You can ring my bell, ring my bell
You can ring my bell, ring my bell

I'm building a 5.56 pistol and also would love a pistol in like 9mm or 45acp. Why not just get another upper and use the same lower and you can have a two in one.

You need a caliber-specific mag block for either 9mm or 45ACP.
I don't think they are meant to be easily removed - some directions mention using a wooden mallet to knock it down into place.

And besides that, I had a 22LR upper to "swap out" on my 5.56 lower and I found it annoying to have to switch them - and that only required pulling the two takedown pins.
I just built a dedicated 22 and called it a day.

[Emptymag]

Id prefer a 8-10" 9mm for home defense, 556 in a short barrel loses too much energy and gains too much flash/noise (and I like flash/noise) 9mm sha a sproingy feeling recoil kinda like an AR when comparing to an AK but even more springy.

Yeah, I could get behind an 8" barrel, but at 10" I don't really see the point - it's only a few inches shorter than a carbine.

Short barrel ars in 5.56 are ungodly loud. If you're going to use it indoors ever the flash can is a must. It's still going to ring your bell though.

I would say that "indoor use" would be the intent. (due to it's compactness) Much like any weapon chosen for home defense - fired outdoors for practice and hopefully never fired indoors - ever.

I assume these "flash cans" direct the flash forward as opposed to out the sides in all directions like a standard flash hider?

[NathanB]

Correct. Now I've never employed a flash can indoors to say how it would go but that's the theory behind t. I have a 10.5 sbr and the reaction it gets form people outdoors is not one of pleasantness. Just something to keep in mind.

[USMC3531]

[QUOTE=Emptymag;3327451]Yeah, I could get behind an 8" barrel, but at 10" I don't really see the point


8-10 was just a range to watch for sales. "they" say 10" is about the best for 9mm it doesnt gain much more past the 10" mark but gains alot over a 4-5" pistol barrel.

[phillyd2]

This is what happens when you fall in love despite all logic and reason telling you she is not right for you.

[arjohnson]

You need a caliber-specific mag block for either 9mm or 45ACP.
I don't think they are meant to be easily removed - some directions mention using a wooden mallet to knock it down into place.

And besides that, I had a 22LR upper to "swap out" on my 5.56 lower and I found it annoying to have to switch them - and that only required pulling the two takedown pins.
I just built a dedicated 22 and called it a day.

I have 2 9mm bottom load mag blocks that remove easily. These are ideal if you plan on using your lower for different uppers.

If your going to build a 9mm pistol get a 5-5.5" barrel, anything longer IMO is unnecessary.

[solrac7]

I have Glock pistols and I have 5.56 rifles,I just built a 5.56 AR pistol with 2 different uppers, a 10.5 and an 8 inch barrel - I thought about 9mm in the AR platform -for ease of ammo swapping and magazine compatability -but the 9mm doesn't really gain much from the longer barrel other than the sight radius. If I really wanted a dedicated home defense weapon in a pistol (short rifle with some sort of brace/pseudo-stock -see- www.thordsencustoms.com) I would go with a .300 blackout upper in a short barrel - probably from Palmetto State.
I went with 5.56 primarily due to ammo cost, and this is primarily a range toy for me (lower than 10 inches, the 5.56 loses significant velocity and "terminal effectiveness" )

My 2 cents... but hey - You get to make up your own mind - ain't it great ?

Cb

[Emptymag]

This is what happens when you fall in love despite all logic and reason telling you she is not right for you.

Sometimes I get your cryptic posts - and sometimes I don't.