AR Pistol vs AR SBR - Which Is The Best Choice?

[ShootDontTalk]

Abraham....take a look at this:

http://www.mechtechsys.com/index.php

Lots of very real advantages.

[The Annoyed Man]

This much about them is fact. The BATFE has ruled that these add-on Sig stocks are legal. But, just don't shoulder it and you're fine.

SBR AR-15's are finicky at best. The gas system is always a concern. Some ammo won't operate the gas system properly, so there is that concern.

The other issue is ammunition itself. 5.56 was designed for a 20" barrel. Half that barrel length does terrible things to the performance of the round. 1:8 or 1:7 twist is a must and then you still will need to run heavier bullet weights to get adequate performance on target. Fortunately there are some better heavy bullet rounds out now.

If you're building an SBR or pistol, I would go 6.8 SPC instead of 5.56 (sorry, opinion). This much is fact. The 6.8 was designed specifically to handle short barrels without losing so much performance. A lot of people like the 300 BLK. Based on the popularity of the round, it must be acceptable as well. Either one would make a fine SBR or pistol.

EDIT: One real negative to these is muzzle blast. There are few things on earth as loud as a 10" barreled AR-15 shooting hot 5.56mm ammo.

My son works at a class III dealer. According to their contact at BATF: If you shoulder an AR pistol with one of those thingamajiggy braces, you have converted the firearm to an SBR by that action, and you can't convert it back. At that point, you have to get a tax stamp for it. The problem with some of those braces - I'm thinking of the Sig brace in particular - look tempting to shoulder. Conversely, you can build an SBR with a real minimalist stock, and shoot it either way - as a pistol or a rifle.

In addition to gas system issues, SBRs can get stupid dirty inside the receiver and BCG from incomplete powder burn. I've addressed both of those issues with a carbine-length Anderson Arms gas-piston conversion kit, on a 10.5" barrel.

I'm building mine primarily as a home defense/CQB/PDW weapon. The barrel I've selected is a 1:8 twist, and uses polygonal rifling, which will give a slight boost in velocity. That is why I'm not worried about bullet fragmentation distances, or terminal ballistics of 5.56 beyond 100 yards max. At most distances I'd want to use the SBR, I'll be inside those capabilities. I have a DMR for longer ranges, and a SCAR 17 if I need more punch if I need them. However, I am considering building a secondary upper for it in 6.8 SPC, but it won't be an SBR.

Muzzle blast won't be an issue as the SBR is suppressed.

[Eric Lamberson]

The AR pistol is a rifle with a short barrel; however, the law in this case works in our benefit by categorizing this AR configuration as a pistol. The buffer tube on the AR pistol is an integral part of the weapon and necessary for function; therefore, it is not a stock. An AK pistol, the Kel-Tec PLR16, piston AR pistols, and similar designs do not have this feature and as a result it is difficult or impossible to get more than two points of contact when firing.

The main plus for the AR pistol is that it is light and compact yet provides the power and range of a rifle. Since it is not an NFA controlled item, you can take it anywhere a pistol is legal without additional ATF permissions. It breaks down into a package that fits easily into a daypack or small duffle so you could carry one if you wished. Forget the arm brace unless you truly need one. The brace is not necessary to shoot the pistol accurately, adds weight, and is tempting to shoulder and therefore a shiny object for unwelcome government attention.

It is very easy to get a good cheek weld with the buffer tube and thus create three points of contact (rubber cover not necessary, but is does add some cushion). You can then manipulate and fire the pistol like you would a rifle. If you have a red dot sight, the buffer tube cheek weld positions your eye behind the sight just as a stock would on a rifle.

The 5.56 round from a short barrel is unpleasant to say the least. However, the 300 Blackout with a pistol length gas system is much milder and the cartridge is very versatile. There are a number of commercial loadings; however, reloaders can make their own brass and it is easy to reload. It will handle bullet weights from supersonic 110gr up to subsonic 220gr and everything in between. There is a lot of load data available and many loads use pistol powder (e.g. WW 296). Loads with pistol powder certainly reduce the amount of unburned powder flashing into the air and I’ve not noted them to be any dirtier than any other direct impingement system.

For years I turned up my nose when I saw one of these—then I shot one.

[Abraham]

Thank you all for your fine suggestions.

I'll definitely be researching all the 9mm carbines.

[AJSully421]

I have a 10.7 and a 12.5" SBR. Both are insanely brutal to shoot without a suppressor. Velocity is terrible, and even shooting at raccoons I can tell there is a decrease in bullet performance, even within 80 yards. I shot four coons this weekend with my 16" and it felt like I had some sort of a death ray compared to the ones I shot last month with the 10.5".

Mine all run 100% because I planned them out properly with the gas port size and did the correct buffer to include the suppressor.

They are fun range toys and to show friends. The 12.5 would be ok for stalking some hogs or something... Other than that, stick with 16" and spend your money on more ammo.

[Eric Lamberson]

300 AAC Blackout 150gr bullet at an average of 1750 fps' from a 10.5 inch barrel. Seems reasonable.

[xb12s]

Abraham,

I'm late to the party, but you might also take a look at the Kel-Tec Sub 2000 (Sub2K) 9mm carbine also. Offered in a few different magazine flavors compatible perhaps with pistols you may already own. I have a Sub 2K in .40 (Glock variety) and am very happy with it. I'd like another one in 9mm if I could find one. Supply on these dipped a lot during the big shortage. I'm not sure if they've stocked back up to the point where they are easier to find at reasonable prices. Used to be about $300 to $400.

[goose]

Abraham,

I'm late to the party, but you might also take a look at the Kel-Tec Sub 2000 (Sub2K) 9mm carbine also. Offered in a few different magazine flavors compatible perhaps with pistols you may already own. I have a Sub 2K in .40 (Glock variety) and am very happy with it. I'd like another one in 9mm if I could find one. Supply on these dipped a lot during the big shortage. I'm not sure if they've stocked back up to the point where they are easier to find at reasonable prices. Used to be about $300 to $400.

I really like my sub2k (also a Glock variety). If you want to get geeky and accessorize, look at the Red Lion forend. Very versatile for folding up the rifle with a red dot or similar.

[LSUTiger]

The 5.56 AR Pistol is in essence an 5.56 AR SBR without the stock.

The Pro's of an AR Pistol:
-Most Compact, concealable AR Configuration. Easily fits in a tennis racquet case or other non gun case for concealment. Stocks add at least an inch or two even when fully collapsed.
-"Rifle" performance in a pistol", although the shorter you go the more velocity you lose, thus diminished performance. 10.5", 11.5". 12.5" seems to be the SBR/Pistol sweet spot in length/performance trade off.
-"Rifle" fire power.
-Can use pistol buffer tube for cheek weld. You cannot imagine how much this helps. Comparable to being able to shoulder a stock. Enough so I've considered not going the SBR route.
-*****No NFA paperwork/hassle required.*****

The Con's of an AR Pistol:
-Diminished performance as you shorten barrel.
-No stock to shoulder.
-Technically it's a pistol so you would need a CHL to carry just like a normal CC gun. Or to OC. For OC there are no AR shoulder or belt holsters that I'm aware of. Unless a sling counts as a shoulder holster.



The Pro's of an AR SBR:
-Can add a stock to shoulder, offers more control/stability than pistol buffer tube cheek weld alone.
-"Rifle" performance in a compact package. Although the shorter you go the more velocity you lose, thus diminished performance. 10.5", 11.5". 12.5" seems to be the SBR sweet spot in length/performance trade off.
-No CHL needed to OC a rifle or CC a rifle.


The Con's of an AR SBR:
-Diminished performance as you shorten barrel.
-NFA paperwork/hassle required.

Don't knock either until you try them (rifle caliber pistol or SBR)

Although I am do not see the advantage to pistol caliber carbines. In that case a pistol caliber pistol is better IMHO, compactness and concealment vs not much in the way of improved performance.

[Mike S]

The main plus for the AR pistol is that it is light and compact yet provides the power and range of a rifle..

Not quite sure about this one. There is a big loss of velocity & stability between a 14 1/2" M4 & a 10 1/2" version (or 16" civilian model). So much so that you'll see your rounds hitting the dirt when attempting to reach out to 'rifle ranges' with the 10 1/2" version. Others have already posted ways to make it more reliable, but in the end temper expectations when shooting a rifle round through a really short barrel.

[Iunnrais]

My buddy has one of those Beretta carbines. Extremely fun little range toy. Probably decent little gun for home defense as well.

I do rather like the pistol caliber carbine concept, though my ideal combination is a little larger. I've a S&W 629 paired up with a Marlin 1894 carbine. The 629 drops out a 240gr xtp at 1352fps. The 1894 fires that same load at 1708 fps. Nice thing about the carbine is that at 150yds, that bullet will slow down enough to match the muzzle velocity of the revolver. And out to 185 yards with enough energy retained to comfortably drop a deer and not have to really worry about bullet drop. It will run into drop issues long before it runs out of gas (That XTP is rated down to 900 fps). Call it .45 acp type performance out to ~400 yards, but way too much drop out there to even think about taking any real shots. Might be fun to try at a range with large steel targets.

I'm not sure that I'd go with an AR pistol unless you just really want one. The carbines do a real good job in the same role especially if you can match them with a pistol that you already own.

[LSUTiger]

Yes, the NFA and Hughes amendment are ridiculous, arbitrary, only hinder the law abiding citizen and do nothing to stop crime, are contrary to the 2A and should be abolished along with I dare say the ATF itself.

Ok, got that out of the way.

After much thought, in light of ATF 41F, I've finally decided to give in to the temptation and SBR my 5.56 AR pistol before it becomes necessary to provide photos and finger prints. I got my eform 1 in the process before July 13 and now to sit back and wait.

With the proper use of a sling you can can get very good results with an AR pistol, but IMHO it takes a little more training and practice to achieve.

However, for HD applications and the added benefits of using SBR .300 Blackout upper, any diminished performance of the 5.56 is acceptable and the stock should prove much more beneficial under stress. The added versatility of the SBR route offers in the .300 gives you many options. Now I need to get a .300 upper to complement the 5.56.

I know, I know, it's not legal to shoulder a pistol but stuff happens in the heat of battle and it might be effective for some but in my case the extra 2-3 inches needed to be able to simultaneously get a comfortable check rest and be able to shoulder the firearm made all the difference, hence the benefit to SBR. After shooting a few SBR's, I was convinced.

Well,if I wasn't on any government list before, I am now! But now that I am in the NFA club, well should be in 3-4 months, I can hold my head up high when all the other NFA guys show up to the range with their toys.

I plan to build another pistol so I don't have to worry about NFA restrictions. IMHO, owning both SBR and pistol, 5.56 &.300 is the way to go give you the most options. Depending on application, open carry/conceal carry, firearm accessibility and travel you can decide what configuration works best for you.

[bubba84]

Here is my SBR

7.5" barrel in 5.56

Ive shot side by side with a 16" and a 10.5" at varying distances and all three will hit a 4" circle at 100yds.

Ive also never had anyone who told me that the barrel hurts ballistics to stand in front of it to back theyre theory.

[Bitter Clinger]

Yes, the NFA and Hughes amendment are ridiculous, arbitrary, only hinder the law abiding citizen and do nothing to stop crime, are contrary to the 2A and should be abolished along with I dare say the ATF itself.

Ok, got that out of the way.

After much thought, in light of ATF 41F, I've finally decided to give in to the temptation and SBR my 5.56 AR pistol before it becomes necessary to provide photos and finger prints. I got my eform 1 in the process before July 13 and now to sit back and wait.

With the proper use of a sling you can can get very good results with an AR pistol, but IMHO it takes a little more training and practice to achieve.

However, for HD applications and the added benefits of using SBR .300 Blackout upper, any diminished performance of the 5.56 is acceptable and the stock should prove much more beneficial under stress. The added versatility of the SBR route offers in the .300 gives you many options. Now I need to get a .300 upper to complement the 5.56.

I know, I know, it's not legal to shoulder a pistol but stuff happens in the heat of battle and it might be effective for some but in my case the extra 2-3 inches needed to be able to simultaneously get a comfortable check rest and be able to shoulder the firearm made all the difference, hence the benefit to SBR. After shooting a few SBR's, I was convinced.

Well,if I wasn't on any government list before, I am now! But now that I am in the NFA club, well should be in 3-4 months, I can hold my head up high when all the other NFA guys show up to the range with their toys.

I plan to build another pistol so I don't have to worry about NFA restrictions. IMHO, owning both SBR and pistol, 5.56 &.300 is the way to go give you the most options. Depending on application, open carry/conceal carry, firearm accessibility and travel you can decide what configuration works best for you.

Just obtained a 2nd pistol, am SBR'ing the first before the 13 July deadline. Now I need more ammo!!!!

[Bitter Clinger]

This whole discussion got me curious about what the ballistics calcs might say about the 7.5" bbl since I now own 2 and I have shot them out to 100 yds consistently, but how much energy are they carrying?

So, I went to the Hornady site 'cause they have a simple, easy to use on-line calculator and decided - arbitrarily - that a 124 grain 9mm at 25 yds would be my benchmark for energy imparted into the target.

I am going to round the numbers because they are all very rough estimates anyway but at 25 yds a 124 gr 9mm traveling at around 1050 or a little faster (subsonic) imparts around 300 ft-lbs into the target.

I then decided to be conservative and assume that for the 5.56 we would loose 50 fps for every inch of bbl decrease. So for a 16" bbl we can deliver that same approx 300 ft-lbs of energy using a 55 gr bullet at somewhere around 475 yds and the bullet remains in the supersonic range.

For the 7.5" bbl, again using the same 50 fps loss per inch and the same 55 gr bullet we deliver that 300 ft-lbs at around 325 yds and again, remain supersonic.

As I stated , these are very inexact numbers and suitable only to provide a relative comparison. So you just need to decide if the loss in performance is justified given other relative advantages of the very short barrel. For my purposes, the pistol provides an excellent CQB solution, but I am also not a very big guy. Some of you could probably hump a 12 lb, 20" bbl .308 as easily as I can handle the AR pistol