Home defense round suggestions for 7.5" barrel with 1:8 twist?

[gundam83]

What do you guys suggest for a 7.5" barrel with 1:8 twist? Fragmentation is important, and I want to limit any overpenetration.

[Xpertz1]

I hate to be the one to say it, but, a shotgun or a good old 1911 in 45ACP is a much better weapon for this purpose.
Your AR is firing a round that travels somewhere between 2700 and 3200 feet per second. It IS going to go thru walls and maybe even people.

Buckshot or a frangible 45 round are a lot safer in the home.
Now , if your going to pick them off at 50 or 100 yards out the bedroom window, then the AR is the tool.

You may not get that velocity out of a 7.5 barrel, but its still going to be too much for in home use.
Hornady Ballistic tips would be the best , but not my choice of weapon.

[GPalmer]

I can dig up the links but in most respects it's a tradeoff between say 12 gauge buck and 5.56. The 12 gauge won't penetrate as many walls but it will still penetrate quite a few, as I remember somewhere around 8 sheets of sheetrock and even after penetrating a wall, it will penetrate the same amount of ballistic gel. The 5.56 really isn't a bad round for the purpose.

The OP specified fragmentation not expansion. I think the only round you MIGHT get fragmentation out of would be the Hornady TAP 5.56 with the T2 bullet. The stuff I have is marked 5.56 X 45 75gr BTHP/WC T2. There are several variants they sell that are close to that, i.e. a .223 loading of the same bullet weight and Personal Defense loading. These both have lesser performance so accept no substitutes. The 5.56 with T2 bullet will expand out to 40-45 yards with my 10.5" barrel. I've never studied the ballistics of the 7.5" barrels in 5.56 though so I'm not sure what kind of speeds you'd get or what range you'd get.

If I were the OP, I'd run those numbers and see what you get. If that distance isn't suitable for your purposes consider the expanding rounds since you should be able to get more range out of them.

[bkb0000]

I hate to be the one to say it, but, a shotgun or a good old 1911 in 45ACP is a much better weapon for this purpose.
Your AR is firing a round that travels somewhere between 2700 and 3200 feet per second. It IS going to go thru walls and maybe even people.

Buckshot or a frangible 45 round are a lot safer in the home.
Now , if your going to pick them off at 50 or 100 yards out the bedroom window, then the AR is the tool.

You may not get that velocity out of a 7.5 barrel, but its still going to be too much for in home use.
Hornady Ballistic tips would be the best , but not my choice of weapon.

ugh.. probably 90% of members here use 5.56 for home defense. it's actually, comparatively speaking, a really good load for home defense.

i suggest you spend some time in the terminal ballistics thread.. buckshot penetrates as much, if not more, depending on the 556 load we're comparing, than 556. and i can't think of any specific comparison between 556 and 45 off the top of my head, but 45 is by far the best barrier penetrator of all the popular handgun loads.

[ryan]

I hate to be the one to say it, but, a shotgun or a good old 1911 in 45ACP is a much better weapon for this purpose.
Your AR is firing a round that travels somewhere between 2700 and 3200 feet per second. It IS going to go thru walls and maybe even people.

Buckshot or a frangible 45 round are a lot safer in the home.
Now , if your going to pick them off at 50 or 100 yards out the bedroom window, then the AR is the tool.

You may not get that velocity out of a 7.5 barrel, but its still going to be too much for in home use.
Hornady Ballistic tips would be the best , but not my choice of weapon.

Please read thru the terminal ballistics section and get educated

[C4IGrant]

I hate to be the one to say it, but, a shotgun or a good old 1911 in 45ACP is a much better weapon for this purpose.
Your AR is firing a round that travels somewhere between 2700 and 3200 feet per second. It IS going to go thru walls and maybe even people.

Buckshot or a frangible 45 round are a lot safer in the home.
Now , if your going to pick them off at 50 or 100 yards out the bedroom window, then the AR is the tool.

You may not get that velocity out of a 7.5 barrel, but its still going to be too much for in home use.
Hornady Ballistic tips would be the best , but not my choice of weapon.

Please educate yourself more before posting (as the majority of what you are saying is INCORRECT).

Nothing pentrates MORE that a SG buck or slug or a handgun bullet (9mm/40/45).

The only round that fragments is the .223/5.56. This means that the odds of killing someone in the next room is far less.


C4

[Sam1002057]

55gr TAP FPD or anything with the 40gr or 55gr V-Max will fragment down to 1700 fps... confirmed by Hornady and my own informal testing.

Your MV with a 7.5" gun should be around 2350 +/- 25 fps with 55gr loadings.

It won't give you the full recommended 12" of penetration, but will start to come apart after going through wallboard, so if the fragmentation is the most important aspect, this is a good way to go.

You could shoot some of the heavier loadings... ie 62 gr JSP and 75 gr OTM's and get more penetration, but they might not fragment or deform... you are limited by the velocity you can get out of your setup. 75gr Hornady OTM bullet out of a 7.5" gun would come out around 2150 FPS... about 100 FPS slower than the fragmentation threshold.

We can argue the benefits of different loadings all day long, but remember it all comes down to your shot placement. Anything that is worth shooting once is worth shooting again.

All that being said... a 7.5" gun is less than ideal for home defense... too limited by the velocity you can get, as well as having to deal with the extreme amounts of concussion and flash of shooting a 7.5" gun in a confined space... if you're 100% set on using this setup for HD, make sure you keep some electronic ear muffs or plugs next to the gun.

Hope this helps.

-Sam

[bkb0000]

or stick a KX3 on that biiiaaaatch.

totally off-topic, but sort of related, so i'll stick it in here anyway- how well do seven-fives run suppressed? it probably doesnt make much difference with the piston, but i imagine it'd be really hard to balance a seven five DI gun between unsuppressed and suppressed... but a mildly suppressed sevenfive, probably even dedicated suppressed, that ran reliably, would probably be a straight up CQB killer. something like an AAC Ranger.. wouldn't exactly be ear-safe, but you could do some serious blasting in an un-ear-protected situation with a hell of a lot less hearing damage than an un-suppressed 10-12 SBR.

the length of an 11.5, give or take, but without the ear-drum shattering report.

[markm]

All that being said... a 7.5" gun is less than ideal for home defense...

It's horrible for home defense.... or anything else for that matter.

[Sam1002057]

or stick a KX3 on that biiiaaaatch.

The KX3 and the PWS CQB Comp. are impressive and help alot... it is still loud as hell though, and you still get some concussion bumping you around in hallways.

7.5's run fine suppressed and it takes the bark out of shooting it...its a good idea... however now you run into potential legal issues... and I know its a whole other debate in and of itself.

I mean, in my opinion it shouldn't matter if I shoot a guy with my 10.5" Noveske Upper on my M16 or run him over with a car.... justifiable is justifiable no matter what tool I use...

But all it takes is one over zealous DA or civil atty to frame you as the bad guy... cause we all know from years of movies and TV that only snipers, spys and assassins use suppressors.

-Sam