Lack of accuracy AR 16"

[kamikaze1a]

This is what the nut looks like...cutting out a section would be difficult though probably not impossible. Hopefully, I won't need to once the new nut arrives.

[cas]

You're not alone in breaking the pins on the YHM wrench.

[kamikaze1a]

WHEW! New nut and tool just arrived...and found the formula for torque (with an offset extension). Assemble tonight, sight-in tomorrow, match on Sunday...assuming no issues with install. Talk about cutting it close!

Thanks everyone for your input! And good shooting!

[kamikaze1a]

Thanks everyone. Install went pretty smoothly. I had to torque to 50lbs to get the gas tube to index though. but it's tight for sure now. I sure hope that along with the cleaned crown tightens up my groupings...

[kamikaze1a]

A short and fast trip (after work) to the range on Sat afternoon. I had only 90 mins before the range closed so my goal was get it sighted in again. Those Picatinny mounts are great. Only a minute off after r-n-r of optics and barrel.

Overall, with my limited and down to the buzzer bench time on Saturday, I believe I saw an improvement. Still not minute of angle but but still and improvement. After all, I WAS shooting with a carbon encrusted crown and questionable barrel nut torque previously. Will work on fine tuning the loads and "shoot for" those minute of angle groups...

Thanks for everyones input!!!

Edited July 12, 2010 by kamikaze1a

[Spaceghost]

I know you have taken the flash hider off to clean the crown but did you shoot it without a flash hider. And, is it a standard A2 flash hider or some comp/break. I had a gun with a name brand comp that was shooting 2"+ at 100, I was sure it was the barrel/build. In the process of finding the problem, shot it with no comp and it was sub 1 MOA.

[kamikaze1a]

I'm not sure who the manufacturer is but it's not a standard flash hider and it has slots/ports only on one half. It can be indexed with the ports up and the exit hole is just over bore diameter. You know, it was suggested previously but I did not try. Maybe I should give that a shot. Nothing to lose... Thanks for the suggestion!

[kamikaze1a]

Got some bench time yesterday. I tested with and without flash hider and I was pleased with the results. My groups tightened up quite a bit with the hider removed.

I think I had err'ed when I had called the attachment a flash hider because I now think this is more a comp. My AR came with this KKF (Karl's Kustom) comp/hider and I've never been able to find a listing of it online. I did learn that Karl of KKF passed some time back and he was said to be a fine smith. The muzzle rise when firing without the comp was noticeably greater but on my barrel, accuracy suffered. This comp/hider has ports/slots only on one half of the body and the exit hole is not much more than the bore diameter. The ports are cut to direct the gas upwards and outwards so looks to be for muzzle rise rather than recoil.

The groups I got at 100yd w/o the comp were just over a minute and the 50yd were one ragged hole. And the groups at 200yd w/o the comp were pretty much what I USED to get at 100yds with the comp. I'm still not getting sub-minute groups but taking into consideration that I am using 1X3 optics, I would say I am very pleased. I have another mount coming so intend to try my 2X7 and 3X9 soon. I'm pretty sure that will tighten up the groups even further. Also have a DPMS A-2 hider with slots only on half of the body but with full sized exit hole so I don't think it will really have much of a comp effect. Anyone have experience with this hider?

So, I regret not trying without hider earlier as suggested by a couple of posters but better late than never! Thanks everyone!!!

[kamikaze1a]

Here's my old comp/hider. Searched for it online but can't seem to find any info. It's a KKF but all I find is faux suppressors... It's an interesting design, small exit hole to redirect gas to the ports on side and top. Anyone see this comp/hider before? Maybe a collectible?

Edited July 22, 2010 by kamikaze1a

[kamikaze1a]

A2 hider arrived on Saturday along with crush washer and peel washers. It was a pain getting it to index right even using the peel washers. I had read that each layer was .001 but that's not what I found. It seems that each washer was only three layers thick and each layer being about .020 thick. I ended up cutting washers out of soda cans and using a peel washer minus one layer and five soda can washers. Hand tight for testing...

At the range, with the slots indexed perfectly, shot a few rounds at 100yds. What the... grouped decent but off the top of the paper. Over 3 inches high. 200yds, about five inches high? 50yds, just under two inches high... No change in ammo...only the hider installed and hand tight.

Off with the hider and back to normal POI. Sooooo, all I can think of is that the no ports on the bottom of the hider is pushing the bullets flight up. Funny thing was that it was even higher at 200 than 100. IF I had sighted in with the hider and never tried a bare barrel, I would never know how much the hider was affecting the bullets flight. Ordered A1 hider with slots 360° and a thread protector. I'm kind inclined to just run the thread protector. Man this barrel is sensitive.

On another note, I've been testing various crimps using a LFC and after a couple of sessions, it looks like, OUT OF THIS BARREL, crimping gives me better grouping. No crimp the most inconsistent, mild crimp better, heavy crimp best group. Will be testing if that holds true with various COAL too...

Edited July 26, 2010 by kamikaze1a

[kamikaze1a]

New A-1 f/s arrived. Installed it and set off to the range. I found that it did not "deflect" my bullets and POI was the same as with no f/s.

Also, more no crimp, moderate crimp and heavy crimp trials seems to again indicate that out of my barrel, crimping appears to improve grouping. Also, my barrel seems to like ammo loaded long. At 2.23-2.22, groups started to really open up. Did not try any shorter but know some load as short as 2.20. My barrel seems to like 2.25-2.23...not sure what col best yet but had some great 10 shot groups that were just over a minute.

Edited August 4, 2010 by kamikaze1a

[jsneff]

That "A2" comp looks like a Branson. I have several, they make an A2 length and a longer model for permanent attachment to 14.5" barrels. I have both lengths, they reduce muzzle climb better than a flash hider and are quieter than a more effective muzzle brake. I am pretty sure that KKF was Kurt's Kustom Firearms. I had him flute a shorty HBar for me years ago. He sold these comps or ones like them. Glad to hear your barrel is shooting better. It is not beyond possibility to get a used barrel that looks good but is shot out. As for the barrel nut torque. Sometimes it is not possible to get it to align to the perfect torque. I always try several times and if lacking the needed give, I back it off and retighten the nut to the previous tube notch.

[cas]

Fwiw... you need to use a knife on the peel washers. Those larger sections were made up of very fine layers. Getting them apart layer at a time can be tricky.

[Jadeslade]

Hand tight is too loose.

[larry weeks]

After the carbon on the muzzle I'd go for a good cleaning if you haven't. Had great luck wetting the bore with Sweets, letting it sit a bit then pushing a patch soaked with hydrogen peroxide through. Foams like crazy and seems to have gotten my barrel cleaner than ever. Had 1000 rounds through without cleaning and after two repetitions the patches actually came out white. For the carbon build up, try Brownells EZ Soak. Great carbon cutter. Also, check your gas tube alignment. Put one finger on the tube as you slide the carrier forward, over it. The tube shouldn't move to one side or the other.

[kamikaze1a]

Scraped the carbon off carefully with a knife. It was pretty hard stuff... But will look into that EZ Soak for future cleaning.

As for the accuracy, a couple of members suggested firing without comp/hider but I did not try that out initially. I should have because group tightened up drastically once I removed it and shot it bare. Bought an A2 hider but it caused my grouping to elevate about 3". I then ordered an A1 hider that has slots positioned 360°. Now it groups like it did with a bare barrel. Also bought a thread protector that I may switch to later... It went from a 3-4 minute grouping to just a bit over one min. I think it could be better if not for the 1-3X optics I am using but just received my 1-5X so will know soon.

[Steve RA]

Get a JP brake if you want a good one.

[kamikaze1a]

Get a JP brake if you want a good one.

Yeh, I read a lot of reviews and lots of good ones around. Probably stick with this one though. I find the blast harsh when I shoot next to someone with a comp so don't want to harsh out the guy next to me...just want it to shoot straight. Thanks!

[warpspeed]

Glad to hear that things are moving in a positive direction. I think that solving mechanical mysteries like this are what makes shooting so enjoyable to me. I like the competition but the building and testing are just as much fun.

BTW, what is the load you are shooting ?

[kamikaze1a]

For now, 26 BLC2 with 55gr Hornady FMJBT LC. Been trying H335 too but it seems they are about equally consistent but H335 uses slightly smaller charge. Either groups well but not quite subminute with my 1-3X optics. Most at our club range have 3-9 or higher but personally, I sure like the 1X option.

[kamikaze1a]

Mounted a new 1-5X Weaver and though the 1X is not quite as good as on the 1-3X, the 5X sure is nicer at distance. Did some 200yd groups and the higher magnification squeezed the groups down some. At 100yds, not that much difference but beyond that, I like it... Too bad more of the 1->3X optics don't have duplex reticles.

[2alpha]

I have had a little experience with AR barrels, you are having way too much trouble getting your AR to shoot well.

I won't mention any brands but if you can get access to a good magnifying, lighted, borescope have a good look at your barrel especially where the gas port was drilled. There are barrels that have problems in that area and will never deliver the accuracy an AR is capable of. I'm lucky to have access to a borescope that hooks into a computer so you can see everything on the monitor.

[kamikaze1a]

I have had a little experience with AR barrels, you are having way too much trouble getting your AR to shoot well.

I won't mention any brands but if you can get access to a good magnifying, lighted, borescope have a good look at your barrel especially where the gas port was drilled. There are barrels that have problems in that area and will never deliver the accuracy an AR is capable of. I'm lucky to have access to a borescope that hooks into a computer so you can see everything on the monitor.

Good suggestion...don't have one but will ask around at our range. I actually got it to group pretty well once I removed the comp/hider. I got a bird cage hider mounted now and it groups consistently provided I do my part. Not sub-minuted but not using a high magnification optics either. I sometimes am tempted to mount a higher power scope just to see what she will do...