I'm basically looking for experiences and/or advice. Any up or downsides to either would be great, and pictures too!!

10.5/11.5:

Uses standard carbine gas tube
Uses standard carbine handguards
Higher velocity

7.5

Smaller package
nonstandard gas tube
nonstandard handguard (usually free float)

i like the looks for the 7.5" on the pistol.

Let's face it, the AR pistol is more of a novelty and a "fun gun" than a real weapon.  Sure, it fires bullets, but if going into battle, it would be the last of my rifles that I would consider taking.

From the "fun gun" standpoint, one of the big reasons to have the pistol is the compact size.  Why put a long barrel on what should be a compact weapon - at least that's my take.  I've currently got the CAR buffer tube on mine, and now that it runs good, I'll be switching to the M1S buffer setup that I have sitting, will get it to work and use that since it's a good bit shorter.  I have the 7.5" barrel, flattop upper, no sights, lightweight gas block, carbon fiber free float tube and a laser.

Quoted: Why put a long barrel on what should be a compact weapon - at least that's my take.

I can give you a reason why someone would want to put a 10.3" or 11.5" bbl on an AR pistol. Some of us live in states where we can't own SBRs so a long bbl AR pistol is the NBT (next best thing).

A 10.5" barrel will be a lot more accurate than the 7" barrels

Plus it uses standard grips and rail systems, and a standard gas system

.223 is a rifle round, you might as well use a longer barrel than 7" if you want the benefits out of the 223

Quoted: Let's face it, the AR pistol is more of a novelty and a "fun gun" than a real weapon.  Sure, it fires bullets, but if going into battle, it would be the last of my rifles that I would consider taking. From the "fun gun" standpoint, one of the big reasons to have the pistol is the compact size.  Why put a long barrel on what should be a compact weapon - at least that's my take.  I've currently got the CAR buffer tube on mine, and now that it runs good, I'll be switching to the M1S buffer setup that I have sitting, will get it to work and use that since it's a good bit shorter.  I have the 7.5" barrel, flattop upper, no sights, lightweight gas block, carbon fiber free float tube and a laser. www.speedcraving.com/ebay/pistol-w-laser.jpg

you said now that you have it running fine, what kind of issues did you run into? currious so i can have a heads up when i start my build

Quoted: A 10.5" barrel will be a lot more accurate than the 7" barrels

could you please explain how?

i'm curious as to how much more accurate the 10.5 would be also.  If it is alot then why is everyone going from 20" to 14.5".

Quoted: i'm curious as to how much more accurate the 10.5 would be also.  If it is alot then why is everyone going from 20" to 14.5".

its not, just the velocity goes up.

Quoted: Quoted: i'm curious as to how much more accurate the 10.5 would be also.  If it is alot then why is everyone going from 20" to 14.5". its not, just the velocity goes up.

the longer bbl would help accuracy some too. like all those super long barrels they sell for varmint rigs and such.



forget what they call that, stabilize?

how many pistols shoot 1k m?

I have a 7" barreled AR pistol and I have built my new pistol with a 10.5 barrel.

There is no comparison, the 10.5 will outshoot the 7" everytime.

I am selling my 7" now...I can't hit anything with it anyway

Quoted: Quoted: Why put a long barrel on what should be a compact weapon - at least that's my take. I can give you a reason why someone would want to put a 10.3" or 11.5" bbl on an AR pistol. Some of us live in states where we can't own SBRs so a long bbl AR pistol is the NBT (next best thing).

Gotcha.  I have an SBR, so never really considered the pistol for anything but a fun gun.  I gotta try to remember that some of you guys don't live in FA (Free America).  Sorry.  :)

Quoted: you said now that you have it running fine, what kind of issues did you run into? currious so i can have a heads up when i start my build

Well, it ran fine when I got it.  Swapped the stock M1S steel gas block for a lightweight one, and changed over to a carbon fiber Hiperform free float tube.  When my guy had it apart, he didn't get the gas hole lined up exactly right, and it wouldn't cycle the last time out for me.  Now it does again.  

Quoted: I have a 7" barreled AR pistol and I have built my new pistol with a 10.5 barrel. There is no comparison, the 10.5 will outshoot the 7" everytime. I am selling my 7" now...I can't hit anything with it anyway

I know that within 300 yds with a regular length bbl AR (14.5-20"), the bbl length doesn't affect accuracy by any measurable mount so I would like to see more details about the differences between your two pistols such as ammo, sighting system, distance, etc.

Quoted: Quoted: I have a 7" barreled AR pistol and I have built my new pistol with a 10.5 barrel. There is no comparison, the 10.5 will outshoot the 7" everytime. I am selling my 7" now...I can't hit anything with it anyway I know that within 300 yds with a regular length bbl AR (14.5-20"), the bbl length doesn't affect accuracy by any measurable mount so I would like to see more details about the differences between your two pistols such as ammo, sighting system, distance, etc.

I would also be fascinated to know

I don't know what to say, but the Professional Ordnance Pistol I have is very, very inaccurate.

It won't put out decent groups at 50 yards....were talking 3 or 4 inches.
The LMT 10.5 Upper I have on my new pistol is just a lot more accurate.

It could be the way I am shooting it...or it could be the twist rates of the barrells...I know the LMT is 1X7, not sure what the Pro Ord Pistol is.



I would still recommend at least a 10" barrel for a AR pistol.....IMHO.

AFAIK, the reason varmint rigs have such long barrels is for the extra velocity, NOT because they are any more mechanically accurate.  

I've read several long(ish) threads on ARFCOM about long vs. short barrel accuracy.  The consensus that I remember is that shorter barrels are not any less (mechanically) accurate than longish barrels.  If anything many longer barrels can be LESS mechanically accurate because of barrel whip and the associated harmonics (i.e. shorter barrels are stiffer barrels).  Granted, those discussions mostly centered on something like 16" vs. 20" or 24".  Perhaps there are some different factors involved with super-short barrels.

A longer barrel does mean a greater sight radius with irons.  That does help with practical accuracy.  Also, one person's experience with one particular gun is hardly the last word on the accuracy of 7.5" ARs.

To answer the original question; I like the 7.5" barrels because AR pistols are mostly just toys (for me).  I don't care if I loose a few hundred FPS or an inch of practical accuracy.  Short barrel AR pistols look great and I imagine they handle better than longer versions (I've never shot a 10.5" AR pistol).  On the other hand, the 10.5 inchers might be more reliable in some cases (cause of the longer gas system).

Quoted: I don't know what to say, but the Professional Ordnance Pistol I have is very, very inaccurate. It won't put out decent groups at 50 yards....were talking 3 or 4 inches. The LMT 10.5 Upper I have on my new pistol is just a lot more accurate.

That explains things a bit more. The LMT upper is without a doubt higher quality than the Professional Ordnance.

It could be the way I am shooting it...or it could be the twist rates of the barrells...I know the LMT is 1X7, not sure what the Pro Ord Pistol is.

I don't know what the twist rate of the PO is either but I'd be surprised if it wasn't 1/9 though there is a possiblity it could be 1/12. What weight ammo are you using?

I would still recommend at least a 10" barrel for a AR pistol.....IMHO.

Ok but what are you basing that opinion on? If it's on your experience with a single pistol whose manufacturerer is no longer in business and whose accuracy is definitely FUBAR than your opinion is very biased. If you're going to give an opinion you need to state why you have that opinion or your opinion is of very low value. Nothing personal of course.

I have both 7.5" & 11.5" AR Pistols.  The 11.5 has an A2 upper & the 7.5 is a flattop w/ a dot scope.  I find the 11.5 makes a very nice NBT (as was stated above) & the 7.5 is a much more manageable pistol.  The 11.5 is at the top of my home defense guns if I wanted to investigate a noise around the house.  The 7.5 is at the top of my list of fun guns.  It depends on what you want it for.  11.5 is as short as I'd go for a social AR, but 7.5 is lots of fun as a noisy paper punch.

I shudder at the thought of firing a 11.5" AR indoors without a suppressor.  Ouch!

Quoted: I shudder at the thought of firing a 11.5" AR indoors without a suppressor.  Ouch!

I shudder at having to fire anything indoors, but the 11.5 is really compact.  I can maneuver through the house & never have to dip/raise the muzzle due to corners & doors.  It is barely long enough to be effective at indoor distances so I guess I'm willing to live with the muzzle blast for the advantages it gives me.  Supressors are not an option here & a SBR is out until I can raise the funds & setup a corp to own it.  Now the 7.5 is a different matter.  It hurt to shoot at a 100 yard indoor range.  I don't even want to imagine what it would be like in a normal sized room.

7.5in = under 2ft
10.5in = over 2ft
i was gonna go with a 10.5 but then i checked the messurement and a pistol over 2 ft is reachin

You truely want my opinion!? (GASP)


Neither... have a custom one built at 8.5" or 9" (w/ flash hider on).  Use the 7.5" gas block location on a light weight barrel, the 7.5" handguards and make the barrel 8.5-9" long.  A few inches may not sound like much, but....

Well, you asked.....

Just read that if you have a Carbine/Rifle Buffer tube on your Pistol, -ATF has ruled it a SBR.If I had a Pistol type AR,I would want the rifle type Buffer tube, pay the $200 for a SBR Tax.It would be cool to just pop a stock on the 7 or 10" barreled pistol for added accuracy and shooting fun.Just may build 1 now.Also read that you can use a Rifle Lower reciever as long as it has NEVER been made into a rifle.Did I miss anything?,New to this AR pistol craze.




EDIT: To say,I would want it in a pistol caliber,say 10mm,45acp,9mm.OLY makes the Barrels,plus with their cone feeding system would help the pistol to feed correctly,I believe using a straight Blow back instead of a gas system would help alot...would appreciate input from the more experianced AR pistol owners/builders.Thanks.

Quoted: Just read that if you have a Carbine/Rifle Buffer tube on your Pistol, -ATF has ruled it a SBR.

umm......


i've seen the letter on ARFCOM saying that it's 100% legal as long as you don't put the stock on.

Got linkage?

I built a 11.5" pistol, and I really love it.  I just think I can get more parts for the larger upper and I also think it feels ergonomically good.  I think that if I use anything smaller, it will feel small.  Where as my 11.5" just feels light and compact, but not small.  To each their own!

Quoted: Quoted: Just read that if you have a Carbine/Rifle Buffer tube on your Pistol, -ATF has ruled it a SBR. umm...... i've seen the letter on ARFCOM saying that it's 100% legal as long as you don't put the stock on. Got linkage?

+1

Kaliburz,

Your suggestion is exactly what I have done.  My pistol was an A3 FlatTop with a 7.5" barrel but I installed a LaRue 7.0 four rail FF hand guard which ends at the start of the Phantom flash hider.  You don't see any barrel, just the Phantom sticking out.  I had to use a LaRue Gas Block as it was the only gas block that would fit under their hand guard.  This thing looks so sweet with my SPOT Sight and Troy BUIS that I sent in my paperwork to turn it into an SBR.  The paperwork is Pending, and with any luck will be approved in a couple of weeks.

Pictures will follow when the Tax Stamps comes back and I can add a stock and vert grip.

MadDog

Posted in this Forum by (BIG-Bore).3rd post down.Letter is from ATF Offical.
 



EDIT: I just went back and read the Letter again,it was mentioned that having the Rifle recoil tube is Legal,the Letter does say it is Legal,BUT-If you own a Stock,then you would be concidered as having a SBR. READ THE LETTER SLOWLY and Carefully!!!

Quoted: the longer bbl would help accuracy some too. like all those super long barrels they sell for varmint rigs and such. forget what they call that, stabilize?

I'm calling BS on this...

Barrel length has NOTHING to do with accuracy.
Signt radius does.
Longer barrels have their sights farther out on the barrel and that allows you to potentially shoot more accurately, but it's not the barrel length, it's the sight radius that matters.

Something else to know about accuracy:
Given the same length, the STIFFER barrel is usually more accurate (assuming other characteristics of the two barrels are similar)
Two ways to make a barrel stiffer, make it larger in diameter, or make it shorter.

So, it goes without saying that two barrels of the same diameter, but different lengths, the shorter barrel should be more accurate.

Now, barrel length certainly does play into the ability to hit targets, but it's because a longer barrel makes more velocity and more velocity makes the bullet fly flatter.
The flatter your trajectory, the easier to hit what you aim at when you are not sure of the trajectory.
Again, trajectory has nothing to do with accuracy.
You can also be very accurate with a rainbow shaped trajectory.
Knowing your range is of the utmost importance to do this though.
Just ask the military folks who shoot mortars.

Last, there was a comment about super long barrels for varmints and such.
Note that these barrels are also usually SUPER THICK and that's to make them STIFF.
STIFF AND LONG (Oh baby!) is the ultimate setup for good velocity and accuracy.
There's one downside though (always is) WEIGHT.

Therefore, everyone chooses their own barrel for the things that are important to YOU.
Some want it short, looks cool and makes a huge racket.
Some want them longer, shoots flatter and less noise.
That's why we have options.
To each his own.

If you want something that you just can't find off the shelf, drop me a line, custom stuff is all I do.

Randall Rausch
www.ar15barrels.com