Upper with Canted A2 FH and Cycling Issue

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[ARCHIVED THREAD] - Upper with Canted A2 FH and Cycling Issue

Posted: 6/23/2019 3:03:29 AM EDT

I bought a free-float upper several months ago, and then got super busy at work and I am just now getting ready to take it to the range. However, I just noticed that the A2 FH is canted to the 11 o'clock position (while looking butt to barrel). Is this something that will make a difference in performance or just an OCD thing?

Edit: Changed title to reflect cycling issue

Posted: 6/23/2019 3:20:36 AM EDT

[#1]

If you're a righty, it could push the barrel a tad bit more down and to the right if looking from stock to muzzle.

Just grab a wrench and back it off a tad to line it up at 12 o'clock.

No big deal.

Posted: 6/23/2019 3:39:49 AM EDT

[#2]

That would be good if you shoot from the left shoulder. I, personally, would not worry about it, unless it was going to be used on a machine gun.

Posted: 6/23/2019 4:04:08 AM EDT

[#3]

It would bother what little OCD I possess, but fortunately it's an easy fix.

If I'm understanding your post, it's actually timed at what most would call 1 o'clock.

Replace the crush washer and index it correctly. Done.

Posted: 6/23/2019 8:07:50 AM EDT

[#4]

According to Coldblue, he designed the A2 flash hider so that it could be set up for right and left handed shooters. Indexing the center slot to the 1:00/11:00 positions would push the rifle better into the shooter's support arm than with the slots centered (think AK slant brake). If you're left-hand, you inadvertently made things better!

Posted: 6/23/2019 9:03:51 AM EDT

[#5]

New crush washer and re torque it down, centered. $1 problem.

Posted: 6/23/2019 9:25:40 AM EDT

[#6]

Quote History

Quoted:

Replace the crush washer and index it correctly. Done.

View Quote

Posted: 6/24/2019 1:35:34 AM EDT

[#7]

Thanks all!

I am going to take it the range on Tuesday and see if there are any other issues that crop up before adjusting the FH. The upper has a warranty that I do not want to void until I am sure it goes bang.

Posted: 6/24/2019 2:04:05 AM EDT

[#8]

You won't even notice. Who made the upper?

Posted: 6/26/2019 12:58:05 AM EDT

[#9]

Update: Took the rifle to the range today and zeroed it. Didn't notice any recoil issues.

However, it had a LOT of feed issues initially - would eject fine but was very spotty about loading the next round. Switched mags/ammo with no noticeable difference. However, after about 40 rounds, it finally settled down and started working great. Is that normal?

Posted: 6/26/2019 1:30:16 AM EDT

[#10]

That is not normal in my experience. I have not had that happen with any of my builds or new rifles.

What magazines and ammo were you using?

Posted: 6/26/2019 3:07:27 AM EDT

[#11]

Quote History

Quoted:
Update: Took the rifle to the range today and zeroed it. Didn't notice any recoil issues.

However, it had a LOT of feed issues initially - would eject fine but was very spotty about loading the next round. Switched mags/ammo with no noticeable difference. However, after about 40 rounds, it finally settled down and started working great. Is that normal?

View Quote

Eh yes and no. The short answer is no, but I've seen it happen more than once where a new BCG in new (usually off brand or bargain basement) upper receiver. There was just a tad too much drag between the carrier and the upper. A shot of ballistol and a magazine later and it was a thing of the past. In both cases of that I've seen we found sloppy castings on the inside. Where the BCG had been rubbing against the aluminum a tiny bit. Both guns are running today just fine after years and alot of rounds.

Posted: 6/26/2019 6:39:56 AM EDT

[#12]

It was probably short stroking. When I get barrels or complete uppers that have a gas port just barely big enough, combined with new parts and a new recoil spring, this happens to me. I just did a build last week that did the same thing. Wouldn't pick up a second round. After a few rounds hand cycling it it started cycling fine.
As long as it runs perfect after about 3 mags then everything is fine.

Posted: 6/26/2019 8:50:51 AM EDT

[#13]

I would not even worry about it since the A2 has minimal compensation or muzzle rise mitigation.

Like others have said if it triggers your OCD that much get a new crush washer vise the barrel not the receiver and reindex it.

Posted: 6/26/2019 10:44:43 AM EDT

[#14]

Thanks!

I am a little peeved that the upper seems to have two separate quality control issues out of the gate - now I am going to be sensitive about every little thing with it. I am going to shoot it a few more times and see if anything else pops up. If so, I will probably RMA it as a potential lemon.

Posted: 6/26/2019 10:50:00 AM EDT

[#15]

Manufacturer?

Posted: 6/26/2019 11:09:41 PM EDT

[#16]

Quote History

Quoted:
Manufacturer?

View Quote

I am hesitant to mention names since I haven't contacted them yet and given them a chance to respond.

Posted: 6/27/2019 10:36:42 AM EDT

[#17]

OP, did you take down and completely clean the whole upper before shooting?
Including a chamber scrub with a proper chamber brush?

If not, I wouldn't worry about the 40 round break in.

Posted: 6/27/2019 10:53:10 AM EDT

[#18]

I watched/listened to a Primary and Secondary podcast on Ar15 qa/qc last night, and apparently it is not uncommon for new rifles to choke at first when they are test firing them at the factory. Gas port burrs, springs being tight and just general settling in.

However it seems that most factory test firing is 10 rounds or less.

Posted: 6/27/2019 11:50:58 AM EDT

[#19]

Quote History

Quoted:
OP, did you take down and completely clean the whole upper before shooting?
Including a chamber scrub with a proper chamber brush?

If not, I wouldn't worry about the 40 round break in.

View Quote

I did clean it beforehand, but admittedly did not use a chamber brush.

Posted: 6/27/2019 1:20:34 PM EDT

[#20]

Quote History

Quoted:
If you're a righty, it could push the barrel a tad bit more down and to the right if looking from stock to muzzle.

Just grab a wrench and back it off a tad to line it up at 12 o'clock.

No big deal.

View Quote

THIS... AND put a new Crush Washer behind it and properly time her to true 12 with a 3/4 inch wrench inside of an upper vice and bench vice... Or you could get a better flash hider and use this as the excuse as to why... I love my Smith-Enterprises "Vortex" flash hiders... On a budget, a YHM "Phantom" is a solid choice as well...

Posted: 6/27/2019 2:51:52 PM EDT

[#21]

Quote History

Quoted:
I watched/listened to a Primary and Secondary podcast on Ar15 qa/qc last night, and apparently it is not uncommon for new rifles to choke at first when they are test firing them at the factory. Gas port burrs, springs being tight and just general settling in.

However it seems that most factory test firing is 10 rounds or less.

View Quote

I've not had an AR not run properly.......yet. Guess I've been lucky.

Eta: well.....there was that ONE TIME where I forgot to install a gas tube on a build.

Posted: 6/27/2019 4:05:16 PM EDT

[#22]

Yea that will do it. Haha I have never had one fail to run either. Though my sample size is around a dozen guns counting ones I have helped others with.

Jordan Bowles (of Carnikcon fame and worked at CMMG) said that a new gun may need one or two shots to get things going. Idk what percentage of guns that actually is.

They started talking about it around 1:55:00. It is a pretty interesting podcast if you are into that kind of thing. It is called Gun Nerds for a reason. It is 4 hours long, but makes good background noise.

P&S ModCast 130 - Gun Nerds 12: AR Manufacturing QA/QC & You

https://www.youtube.com/watch?v=p9uApV0IfbU

Posted: 7/5/2019 7:37:09 PM EDT

[#23]

Took it back to the range today and it ran great until I switched to Tula at the end. It would then cycle fine but would not lock back when the mag was empty. I then ran one-round mags of Winchester and it locked back every time.

Posted: 7/5/2019 7:58:51 PM EDT

[#24]

I asked the same question as Op, link below...for future reference.

A canted FH can effect the bullet, but only in a long range precision set up. I didn't notice anything inside of 200 yards.

https://www.ar15.com/forums/ar-15/Is-the-timing-of-A2-FH-important-/118-733045/

Posted: 7/6/2019 12:09:49 AM EDT

[#25]

Quote History

Quoted:
Took it back to the range today and it ran great until I switched to Tula at the end. It would then cycle fine but would not lock back when the mag was empty. I then ran one-round mags of Winchester and it locked back every time.

View Quote

Good to hear you got it working. Chances are good it will run steel cased later on as it gets smoothed out.
Stick to Winchester for the first couple hundred rounds and it will probably run the steel cased after that break in.

Posted: 7/6/2019 8:32:14 AM EDT

[#26]

Quote History

Quoted:
Took it back to the range today and it ran great until I switched to Tula at the end. It would then cycle fine but would not lock back when the mag was empty. I then ran one-round mags of Winchester and it locked back every time.

View Quote

Tula is providing a bit less gas due to having a lighter load. The simplest way to up your carrier strength would be to lower the buffer or spring weight. If you have more than one AR, you could try swapping carriers to see if that fixes it.

Posted: 7/6/2019 10:55:01 AM EDT

[#27]

If you're gonna shoot Tula, or any steel case for that matter, get yourself a chamber brush. It's good to clean out that carbon once in a while after shooting steel.

You should really have one anyways.

But, if I fire steel case through any rifle that I would use for personal defense, I go straight home a brush the chamber and pull a bore snake through before I consider it good to go for defensive duties.

Posted: 7/6/2019 11:38:14 AM EDT

[#28]

Quote History

Quoted:
If you're gonna shoot Tula, or any steel case for that matter, get yourself a chamber brush. It's good to clean out that carbon once in a while after shooting steel.

You should really have one anyways.

But, if I fire steel case through any rifle that I would use for personal defense, I go straight home a brush the chamber and pull a bore snake through before I consider it good to go for defensive duties.

View Quote

Thanks! I bought a chamber brush and I do a full clean after any range trip.

I have another rifle that is my my go-to and has run reliably on all sorts of ammo for years. I will see if swapping the bolt/buffer/spring helps this one run better without impacting the other.

Posted: 7/6/2019 12:17:57 PM EDT

[#29]

Quote History

Quoted:

Thanks! I bought a chamber brush and I do a full clean after any range trip.

I have another rifle that is my my go-to and has run reliably on all sorts of ammo for years. I will see if swapping the bolt/buffer/spring helps this one run better without impacting the other.

View Quote

You should really only need to swap the carrier and leave the bolts alone to see any change in cycle. If you can check headspace, it wouldn't hurt anything though. The fitment of the bolts tail into the carrier does effect gas leakage and cycle pressure also but the bolt tails should technically be the same diameter and fit the same in both carriers. I would personally swap just the carriers first and if nothing changes, then try swapping bolts.

Posted: 7/6/2019 12:38:44 PM EDT

[#30]

Got it!

[ARCHIVED THREAD] - Upper with Canted A2 FH and Cycling Issue

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