AR/Stoner barrels, how accurate?

[Arizona_Mike]

I fired my 300 BLK 10.5" AR/Stoner barrel upper for the first time today. Match grade supersonics seemed to deliver about 1.25 moa or a hair bigger at 100 yd and subsonics about 1.5 moa or less at 50. 100yd zero on the supersonics puts the subsonics 6" low at 50. Should I go for 200 yd zero for supers? With the 50/200 EOTech dot zeroed at 100, I could hit the 300yd gong using the 500yd dot.

Honestly I was hoping for better. I have been thinking about a 6.5 Grendel 16" medium taper for 300-600yd hunting but want sub-MOA.

I'm going to re-seat/shim my barrel nut or swap nuts (it came in at 30 but not 35 and I needed to take it to about 90 to the next notch. I'll also return with a finer reticle (was using a 1 MOA hologram), but so far I am on the fence about getting another AR/Stoner barrel.

Mike

 

[cfullgraf]

Although folks and gun scribes have said they have gotten sub-MOA groups with there 300 BLK rifles, that has not been my experience on a regular basis.

My 100 yard groups with a 16" Noveski and an 18" Wilson barrel average just over 1" even with a 20x scope installed. Sometimes, i will get a sub MOA group but I think it is more of a fluke.

I am sure I have not hit the magic powder/bullet combination yet or I am doing something else wrong.

But it sure is not easy to get the sub MOA groups as with my 204 Ruger or 223 Remington ARs.

So, it may be the round not the barrel. Or it could just be me. Just one data point to consider.

 

[greyling22]

I'm pretty sure walkalong here has a 300blk stoner barrel on his ar that is giving him good groups. You might try reaching out to him to see what he is using.

 

[hentown]

The torque on the barrel nut is irrelevant to accuracy. Something else is wrong.

 

[Walkalong]

My AR Stoner 300 BLK will shoot the 110 Gr V-Max and the 123 Gr (.310) Z-Max under 1 MOA consistently. It will shoot the 125 Gr SST under an inch occasionally. Same for the 155 Gr A Max. It shoots the Speer 130 Gr Hot Core into patterns. I have some more bullets to test one of these days.

My barrel loves the 123 Gr .310 7.62X39 bullet. Go figure. Make sure your neck can handle the larger bullet if you try them. I did a chamber cast of my chamber to make absolutely sure. You can also check with a fired case and see if a new bullet has clearance in the neck, but you have to shoot one to thy this.

Consistent < 1MOA groups will likely take some work.

 

[Arizona_Mike]

Hentown , kind of amusing talking about what's "wrong" with 1.25 moa
It might just be a 1.25 MOA barrel . . .
Or it could be the fact that I was using a 1 MOA dot. I'm going to return with a finer reticle.

Mike

 

[wally]

Actual dispersion = SQRT( (gun/ammo dispersion)^2 + (aiming uncertainty)^2)

So 1 moa gun/ammo with 1 moa aiming ambiguity would be ~1.41 moa results.

I'm of the opinion that groups with less than ten shots are poor estimators.

Things like "ransom rests" attempt to make the aiming uncertainty be zero by mechanical means.

 

[dvdcrr]

1 moa dot is sufficient to shoot a one moa group. Its about sight picture and indexing that dot on the target. 10 shot groups are fine if you are interested in measuring the shooter in addition to the weapon. Ive been hunting since I could cock a red ryder. I have yet to encounter any hunting situation where the ten shot group performance of my gun was consequential. You dont eat prairie dogs, and their hide aint worth anything. If my gun isnt good enough to hunt with I'll know it before the end of a ten shot group.

 

[Ramone]

My best guess is that AR stoner barrels are made by ER Shaw (based largely on the fact that Shaw seems to offer the same options as Midway sells).

While I haven't a .300BLK, my .223Rem barrel has been a good performer.- 5R rifling (1:8), Wylde Chamber, Medium contour.

http://www.midwayusa.com/product/79...8-fluted-stainless-steel?cm_vc=ProductFinding

With handloads (developed for the rifle) it'll make consistent .75 MOA groups- .5 when I am on my game.

 

[Walkalong]

I bought that same .223 AR Stoner barrel and my first group out was about .75. Didn't measure it. I got it on paper at 50 yards with no wind and put three cutting each other with that load before going to 100 yards. I bumped the charge up .5 and it went to heck, so back down I go.

.5 when I am on my game.

I certainly know that feeling.

 

[hentown]

Hentown , kind of amusing talking about what's "wrong" with 1.25 moa
It might just be a 1.25 MOA barrel . . .
Or it could be the fact that I was using a 1 MOA dot. I'm going to return with a finer reticle.

Mike

JHC, Mike!!!! How could you POSSIBLY expect sub-m.o.a. groups, shooting a red dot? That just defies my ability to fathom! Get a scope. Get a Geissele or similar trigger. Shoot some more.

I haven't bothered to measure the groups I've shot through my .300 Blackout, 16" barrel. However , first three shots downrange @ 100 yds were all touching.

Shot an upper I built for a cousin, using a 16" YHM barrel, and got good groups, also.

I'm using 168gr. match bullets and 1680 powder, clocking at over 1900 fps.

 

[Arizona_Mike]

It wasn't a red dot, it was an EOTech holographic and a 3x magnifier, but reticles are still finer. Got lots of scopes. Most are 1" since I bought them last century. Been waiting a while for a 1" version of the Burris PEPR I ordered a while back to arrive.

The trigger on the lower at the time and still on the lower is a Geissele High Speed DMR set up the way Geissele recommends (3lb first stage, 1.25lb second). I was getting 2.25lb on the first stage at first but a hundred or so trigger pulls later it is 3lb.

Hopefully the mount arrives this week and the range will not be closed by the rain we are expecting this weekend.

Mike

 

[Arizona_Mike]

It did rain like crazy the next weekend. I just returned with a fine dot conventional scope and did a little worse. It was windy/gusty 30-40 mph so I'm taking vert max * sqrrt(2) for the obviously L-R streaky ones.

100 yd:
5 shot group: 0.7 moa (2.3 with 1 flyer)
5 shot group: 1.6 moa (2.8 with 1 flyer)
5 shot grouo: 2.2 moa (3.0 with 1 flyer)
4 shot group: 1.0 moa (2.1 with 1 flyer)
4 shot group: 1.9 moa

200 yd:
5 shot group: 0.7 moa (1.9 with 1 flyer)

Averages: 1.35 moa excluding all flyers. 2.33 moa including all flyers. 1.42 moa excluding two flyers that I fealt I pulled from the bench due to sight picture. I am usually a 1 moa shooter withhandloads or bull barrel bolt guns.

This was a lightweight taper 300BLK 10.5" barrel. Assuming it is a ~1.5 or just under MOA lightweight barrel what can I expect from a 16" medium-heavy 6.5 grendle from the same manufacturer. Will it meet my goal for hunting or will I be disapointed?

Mike

 

[benzy2]

How well can you shoot? That isn't an insult. Going based on the Barnes 110gr factory load at 2350 (which I doubt your 10.5" barrel is getting), wind drift is .16" per 1 mph of wind change (0.2" if you only reach 2000 fps). If your setup is a .75 MOA setup, that means a wind change of 3 mph missed on just a single shot opens you up to a 1.25 MOA group. Add in a little bit of aiming error due to the Eotech (assuming there was a little) and the setup may be closer to a 1/2 MOA rifle in a wind tunnel on a machine rest.

Windage for the subsonic ammo is a hair better but if you are right up against the sound barrier it would change it from a 3 mph wind to a 4mph wind change to push you off 1/2 MOA.

There are a lot of factors that can make a 1/2 MOA setup shoot closer to 2 MOA. Brass, bullet selection, and barrel quality would be the first three that come to mind. Mixed headstamp non-annealed brass seems like it alone could cause problems. Bullets designed for hunting rather than target bullets is another potential. Then we have the fact that the AR Stoner brand barrels are the cheapest option on sale today. I'm not sure where the idea that the cheapest barrel possible is a good route towards sub-MOA accuracy. Not to mention the optic, bench technique, wind reading, consistency of the ammo (be it factory or handloads).

Personally, for the distances that 300blk is useful, a 1.5 MOA rifle is well within acceptable to my standards. When considering that it would be used with an Eotech (magnifier or not), I wouldn't be unhappy with such results. Not long ago it was a chore to find a load that quality factory hunting rifles would send into 1.25-1.5 MOA consistently. Now we turn our noses at the idea. The 6.5 has quite a benefit over the .300blk when it comes to wind drift.

 

[Arizona_Mike]

Good questions. I realize I have answered them here but not all in one place. I am a <1 moa shooter with my Douglas barreled .257 Roberts AI. My last 200yd group with my Mossberg MVP Predator 3-weeks ago was 0.3 moa using 69 gr PPU match. That is me on my game.

My update yesterday was using a 6-24x fine reticle sight on 24x. Ammo with that and the first outing with the EOTech was PNW Match 155gr Nosler Custom Competition BTHP

I am at a place in life where I am not price conscious. Stoner barrels may be cheep but they are also available. Been in the market for an AR barrel lately??? I told Uncle Sam I was going to use 10.5" (was going to us a Ranier Match or Ultramatch.) After waiting 8 mo for one to become available I went with a Stoner (constantly in stock at Browells was too tempting) and then got an in-stock notification from Rainier 2 months after that. For my SDM-R build, I am waiting for the Rainier Ultramatch .223 Wylde (no choice).

I am happy with the accuracy of my 300 BLK. I am trying to decide if I want a Stoner barrel for my 6.5 Recce-like build. It is not about price for me or even out of stock issues this time. 16" 6.5 barrels are rare, threaded 6.5 barrels are uncommon, I don't know anyone but Stoner who sells a 16" threaded medium-heavy 6.5 Grendel barrel. I've been looking and emailing/calling. The few Grendel experts who dominate the market (who are 600-1,000 yd oriented) feel that the extra 14% muzzle energy from going from 16" to 24" is important. It may be for them, but compared to other cartridges it is not a huge gain/in. Like I said, I am looking for 300-600 yd hunting and happen to live in a state that allows hunting with a sound suppressor so I don't want the barrel too long.

I am starting to think that I may want to scrap the Grendel build entirely and go with a 260 Rem upper for my 7.62 AR or a bolt action 6.5x55. I won't need special mags for the 7.62 and 6.5x55 has a lot of ammo availability and can be loaded to modern pressures (I have had the dies since the 1990s).

Mike

 

[Agent1209]

300 blk

I have the exact same barrel, I wanted the rainier arms but the AR stoner was the only pistol length barrel I could find in stock. I am waiting on my rail and gas tube so I have not shot mind yet but I will be happy with 1.25". That's acceptable for 100 yards.

 

[jon_in_wv]

Any brand of barrel doesn't guarantee a particular amount of accuracy regardless of load. I've had several rifles that couldn't shoot 1 MOA until I tailored a load that it liked. Look on line to see what load is popular with reloaders. Then find out the proper OAL that works best with YOUR barrel. Then you may have to adjust the load up or down a few grains in powder to find the sweet spot for your weapon. Real accuracy takes some real work. You may want to just shoot for a while more to become more familiar with the weapon. People are always looking for hardware problems to software solutions.

 

[Arizona_Mike]

I just saved myself a fortune and dropped all plans for a Grendel build and a .260 build on a 7.62 AR platform.

In picked up a pawned Savage 110 with Accutrigger yesterday cheap (270 barrel hardly shot if anyone wants it) and will use the 6.5x55 for my 300-600 yd hunting rig. I already have dies (since 1994-my late wife loved to hunt with her '96 Swede). The sloppy-feed Savage seems to have more than generous enough opening for European 0.480" case head brass.

Mike