Info on ARPerformance 16" LW middy

[RWH24]

I sent an email to ARP asking what size of port they drill on their 16" 5.56 Lightweight barrel, 4150 CMV, Wylde chamber.
In their FAQ section the question was asked if steel cased ammo can be used in an ARP chamber, Answer is

Can I use steel case ammo in ARP rifles?
Yes, the mid gas system allows more time for the cases to shrink back down aiding extraction. The Nitro treatment makes the chambers 70 Rockwell and very slick also aiding extraction, Our Nitro carburized barrels were made to handle steel cased ammo.
The question was asked what buffer did they recommend with their barrel. Answer to both questions are as follows:

.082”
The standard carbine buffer should work fine.
If the ammo you choose to shoot ejects forward of 3 O’clock you can change to an H2 buffer.

Apparently someone complained about accuracy from sustained firing with this barrel. Answer from them:

These are lightweight combat type barrels not target barrels. Common accuracy with decent ammo is 3/4-1.5" at 100yds, 55gr FMJ can be worse.

http://www.ar15performance.com/inc/sdetail/11562/14041

[lethal dose]

Exactly what point are you trying to make?

[RWH24]

Not a point but an FYI. Seems lots of discussion has come up on what the port size does your barrel have and what buffer weight should I use.
I asked the manufacture what size they drill their ports and what they have seen work buffer wise.
Just a matter of reference.

[C4IGrant]

Not a point but an FYI. Seems lots of discussion has come up on what the port size does your barrel have and what buffer weight should I use.
I asked the manufacture what size they drill their ports and what they have seen work buffer wise.
Just a matter of reference.

That gas ports seems on the large side to me. You could get away with an H2 buffer for sure.


C4

[RWH24]

Thank You Grant. From what I had found here, The .082" gas port seemed to be a little larger, needing a heavier buffer, spring or both to keep from battering it'self to death.

[SomeOtherGuy]

Midlength gas setup so .082" is not as huge as it would be on a carbine setup.

I've been using one of their 16" midlength uppers (slightly heavier SOCOM barrel weight, but still a 5.56 16" midlength) for a little over a year now. It's been used with several lowers, being setup with (1) H buffer and GI spring, (2) H buffer and Springco blue spring, and (3) VLTOR A5 system with standard A5 buffer. The BCG was lubed with Froglube paste prior to any use. In the first 10 rounds from new, using H buffer and GI spring, I had 3 failures to extract. Since that time I have had no failures of any kind, in temperatures from 80's to 20's, much of it competition use (fairly rapid fire for 1-3 minutes at a time). ITS/ARP mentions that their bolts fit very tight when new, and that plus ordinary break-in is what I attribute the 3 initial FTEs to. Felt recoil and speed of operation seem normal for a 16" midlength, neither harsh nor sluggish.

I think a standard H buffer will work fine. The carbine weight or H2 probably also fine.

[RWH24]

Thank You, good to know.

[Iraqgunz]

I am fairly certain that with something like M193/M855 or similar that it will run with an H2 and probably an H3.

As Grant stated, .082 is a little on the large side.

[Clint]

.082" is quite strong for a 5.56

Something seems off.

.082" is the defacto standard for 6.8x43 16" middy barrels

It might be worth a double check 5.56 vs 6.8

[dkindig]

.082" is quite strong for a 5.56

Something seems off.

.082" is the defacto standard for 6.8x43 16" middy barrels

It might be worth a double check 5.56 vs 6.8

I was going to say something about this earlier and I wish I had.

There has been an ongoing discussion on 68forums about port sizes and Clint's data matches that. I'm running an older ARP 18" 6.8 middy barrel and the port on that is .086. Harrison normally runs a .082 port on those barrels but mine was made around the time that he was trying to make them run reliably with Remington UMC SAAMI ammo so he wanted more gas for the weaker rounds.

The only flaw I can think of with that theory is that (and I'm not sure about this) with the increased dwell time of an 18" barrrel over a 16" barrel, you would think that the port would be slightly larger for a 16" barrel. I could be over-thinking the whole thing though...

[Clint]

All things being equal, a longer barrel uses a smaller port.


I was going to say something about this earlier and I wish I had.

There has been an ongoing discussion on 68forums about port sizes and Clint's data matches that. I'm running an older ARP 18" 6.8 middy barrel and the port on that is .086. Harrison normally runs a .082 port on those barrels but mine was made around the time that he was trying to make them run reliably with Remington UMC SAAMI ammo so he wanted more gas for the weaker rounds.

The only flaw I can think of with that theory is that (and I'm not sure about this) with the increased dwell time of an 18" barrrel over a 16" barrel, you would think that the port would be slightly larger for a 16" barrel. I could be over-thinking the whole thing though...

[1slow01Z71]

My socom profile ARPerformance barrel runs great. Shoots sub moa with pmc 54gr junk ammo. Ive been very happy with it and an H2 buffer.

[RWH24]

I was specific on asking about a 5.56, but could have been quoted the port size for a 6.8.
Never even thought about that.
Great catch.

[constructor]

If you port barrels to run with true m193 and everyone uses cheap ammo how many call backs do you get and how many shipping charges do you eat?
The OP asked about shooting steel case Tula, it takes a .082 just like it does to run American Eagle and Remington UMC.
As a manufacturer I think it's better to port the barrels to run what works with a wider range of ammo and what most shoot not just the upper end and everything else short strokes.
How many times have you been to the range and hear someone say "this POS wont cycle"...and most are using the cheapest ammo they can find at Wally World. That same crowd wouldn't notice the m193 cases landing forward of 3 O'clock.
The high speed low drag crowd runs H2 buffers and heavy springs anyway. m193 drops right around 3-3:30 setup that way.
OP, what I told you is how we port the barrels. If you use cheap steel case they will run fine, if you use m193then you may need a H2 buffer to slow things down. As far as the accuracy thing, I'm just truthful. Some guys will buy a $200 lightweight barrel and then say "this thing wont shoot 3/4" with the cheapest ammo made, what's wrong with this thing".
Shoot 69 or 77gr SMKs with 24gr Re15 off a bench with a good trigger and scope and shooting skills and they'll shoot under an inch.
I have no idea how they will shoot with Tula off the tailgate of a truck using a $28 red dot from Walmart.

[lethal dose]

From the horse's mouth. Overall, good info, here.
If you port barrels to run with true m193 and everyone uses cheap ammo how many call backs do you get and how many shipping charges do you eat?
The OP asked about shooting steel case Tula, it takes a .082 just like it does to run American Eagle and Remington UMC.
As a manufacturer I think it's better to port the barrels to run what works with a wider range of ammo and what most shoot not just the upper end and everything else short strokes.
How many times have you been to the range and hear someone say "this POS wont cycle"...and most are using the cheapest ammo they can find at Wally World. That same crowd wouldn't notice the m193 cases landing forward of 3 O'clock.
The high speed low drag crowd runs H2 buffers and heavy springs anyway. m193 drops right around 3-3:30 setup that way.
OP, what I told you is how we port the barrels. If you use cheap steel core they will run fine, if you use m193then you may need a H2 buffer to slow things down. As far as the accuracy thing, I'm just truthful. Some guys will buy a $200 lightweight barrel and then say "this thing wont shoot 3/4" with the cheapest ammo made, what wrong with this thing".
Shoot 69 or 77gr SMKs with 24gr Re15 off a bench with a good trigger and scope and shooting skills and they'll shoot under an inch.
I have no idea how they will shoot with Tula off the tailgate of a truck using a $28 redot from Wamart.

[TheBelly]

Shoot 69 or 77gr SMKs with 24gr Re15 off a bench with a good trigger and scope and shooting skills and they'll shoot under an inch.
I have no idea how they will shoot with Tula off the tailgate of a truck using a $28 red dot from Walmart.

I owned an ARPerformance upper in 6.8SPC (a mid-length SOCOM barrel), and with factory ammo (Barret 6.8), the thing was a tack driver: sub-MOA as long as I did my part, and sometimes even when I didn't do my part.

When I buy from Harrison, I buy with confidence and without hesitation.

[RWH24]

He answered my question and confirmed it before the masses.
Most of my ammo is brass cased M193 and Amer Eagle A223, but I do have a good bit of Tula and Silver Bear left over when this upper wore a Spike's Tactical 5.56 chamber CL barrel. I purchased this barrel after reading and others personal experience with ARP products. Not being a precision shooter with my AR, I would not expect TULA to shoot like match ammo.
Come on Fall so I can enjoy shooting more.
RDS is a Aimpoint H-1 2MOA on a Seekins fixed mount.

http://pic20.picturetrail.com/VOL1321/4777050/24318160/407108401.jpg

http://pic20.picturetrail.com/VOL1321/4777050/24388554/407189373.jpg

[TheBelly]

in any case, that's a good lookin stick!

I like the simple builds that can deliver.

[03scgt]

I was thinking about using one of their 6.8 barrels on a new build.I know they have a pretty good rep with that crowd

[jmnielsen]

I was thinking about using one of their 6.8 barrels on a new build.I know they have a pretty good rep with that crowd

Just sighted in my rifle with 16" scout barrel and five shot groups were right at 1" with factory SSA 110gr accubonds. Haven't had the change to roll some of my own loads but when I do I'm positive the group will shrink up. For the price, Harrison's barrels can not be beat.

[AKDoug]

1.457" 10 round group at 200 yards with my ARP 6.8 Scout barrel and handloads. They are the real deal.

[dukduk]

maybe its a reverse guarantee, most barrel makers will make a subMOA or MOA promises wil match ammo(pending you know what you're doing behind the gun, i sure don't).

maybe ARP knows that alot of ppl will build a tacktikooool gun and then fail when trying to shoot groups with bulk wolf at 100. if you know what you're doing with the right ammo, then results will be better than advertised and that =:happy:customers

[constructor]

maybe its a reverse guarantee, most barrel makers will make a subMOA or MOA promises wil match ammo(pending you know what you're doing behind the gun, i sure don't).

maybe ARP knows that alot of ppl will build a tacktikooool gun and then fail when trying to shoot groups with bulk wolf at 100. if you know what you're doing with the right ammo, then results will be better than advertised and that =:happy:customers

A lot of it comes down to what different people call match grade barrels. I started out making full blown custom rifles from lapped true match grade barrels like Krieger, Hart, Pac Nor and others that could have been used in benchrest matches.
There are some big names out there that sell what they call "match grade" barrels but they are just plain old production grade stainless. Those companies know with their big name and people thinking all stainless barrels are match grade they can sell those plain stainless barrels for more money and the shooter will never know the difference, after all they're shooting a XXX brand and all their friends are impressed.
Others think that any barrel that will shoot a few groups under 1" it is perfectly fine to call them match grade. If you go to arfcom they will say 3" groups is normal. Normal for what, standing in the middle of a field shooting beer cans with surplus ammo or shooting match grade ammo off a bench?
I know what a true match grade barrel is. I am not going to call our barrels match grade even if they will shoot 1/2" groups with the right ammo and a good trigger puller. You're right I don't make promises for the reason you stated. Minimizing returns and theft is part of running a business.
I had 2 cops from Chattanooga return 2 real Pac Nor match grade barrels because they could not get them to shoot. I tested them with factory ammo and shot 3/4"groups with the first 5 shots. After the whole deal was over I found out they had 1 scope mount on the receiver and 1 on the handguard. Hmm, I wonder why they wouldn't shoot for them.
There are a bunch of big companies out there selling barrels. I couldn't break in to the market selling what everyone else does. I have to try to produce better products and then prove it to continue making sales.

[Biggy]

I don't doubt the statement below, but could this barrel http://ar15performance.com/inc/sdetail/11562/4307 be special ordered with the standard 1/2-28 muzzle threads ? Would this barrels accuracy really be much different ?

NOTICE*** THIS BARREL HAS 5/8-24 threads to keep the bore at the muzzle from swelling like most barrels threaded 1/2-28. The tighter bore at the crown gives better accuracy.

[constructor]

I don't doubt the statement below, but could this barrel http://ar15performance.com/inc/sdetail/11562/4307 be special ordered with the standard 1/2-28 muzzle threads ? Would this barrels accuracy really be much different ?

NOTICE*** THIS BARREL HAS 5/8-24 threads to keep the bore at the muzzle from swelling like most barrels threaded 1/2-28. The tighter bore at the crown gives better accuracy.
No, they all come threaded the same and have already been stress relieved and Melonite treated. Any machine work done after stress relief will effect the accuracy, especially at the muzzle.
Shooting 69 or 77gr SMKs the difference would not be much but shooting shorter bodied bullets like 55gr boat tails would be more noticeable. Some bullets aren't quite .224", they will not be as accurate as full .224 dia bullets in any barrel. Bullets that are small diameter and have short .224 diameter areas will in general not be as accurate.