AR Failure To Feed Problem

[Mecanik]

I had a couple free minutes today and took the hand guard off. One of the set screws on the gas block has started to work it's way loose. So, the gas block was a little loose and in the inside looks like this...
View attachment 737437

I have a new gas block and gas tube on order. Hopefully, it'll be here in a couple days. Yes, I'll make sure I use some loctite.

I used a gas block identical to that one on my last build. I haven't had any problems with mine yet but I've only put a couple of hundred rounds through it so far. It's steel like that one and it lined up fine. I used two set screws with dimples and a longer screw for a sling on the barrel though. But I didn't use any loctite on mine. Maybe I will get it out and apply some on it after seeing that.......

Here's a picture of mine...

 

[Quirt Evans]

If you load your own ammo it's a little easier to "tune" the gas system.
All powders have the same amount of energy per unit weight,, for their same type.
Single base powders that are fast can be compared to other single base powders that are slower,, the same for double base powders.
To push the bullet out the barrel at a certain velocity requires an x amount of pressure.
By playing around with different powders and charge weights we can alter the ejection pattern, while still keeping within a reasonable velocity range.
Sometimes being willing to lose a little velocity can get a gun "in the groove", so to speak.
Most targets don't know the difference between a couple hundred fps.

 

[rjmt]

Yep, that was the ammo I was talking about and the exact barrel I had. It was marked SPR Mk 12 I didn't really understand the significance of all of it at the time and should have kept the barrel but sadly sold it and moved on to other things. I ordered the barrel from Midway on sale for some ridiculously low price and thought nothing of it. It was a stainless barrel with 1-8 twist.

I personally use the IMI 69 gn Razor Core
these match my old match ammo hand loads in the '90s
that way all my sighting charts out to 600 yrds are still valid

and I also prefer the mid length gas system, even for piston drive ARs

I read this week that Colt has released a carbine with a mid length gas system

 

[Tony617]

What brand of gas block was it? I did not see the brand?

Never mind I reread this thread and the guy does not remember...

 

[rjmt]

years ago when I put an M4 upper on my old Colt large hole HBAR, I went with a JP adjustable gas block under a free float tube
Black Hole Weapons P3 20" barrel
tuned specifically for IMI 69 gn Razor Core
but I do prefer Tubbs flat wire buffer springs with the original Colt buffer weight
recoils like a Ruger 10/22

 

[Soren]

My wife came home today with this... a POF USA Dictator Gas Block. I don't even want to know what she payed for it. I'm anxious to give it a try though. I was wrong before about the gas system in this rifle. It is carbine length, not mid-length.

 

[Mecanik]

After following this thread to it's eventual end I have an itch to build another upper....I don't need another one but it's fun none the less.

 

[rjmt]

After following this thread to it's eventual end I have an itch to build another upper....I don't need another one but it's fun none the less.

man, don't do that to me
I still have a stripped upper in the gun safe

 

[rjmt]

My wife came home today with this... a POF USA Dictator Gas Block. I don't even want to know what she payed for it. I'm anxious to give it a try though. I was wrong before about the gas system in this rifle. It is carbine length, not mid-length.

View attachment 737863

I thought is might be a carbine length
you shouldn't get flame cut in your gas block with a mid length gas system

 

[titsonritz]

I read this week that Colt has released a carbine with a mid length gas system

The CCU has been out for a while now and features a Centurion Arms CMR MLok handguard.

 

[titsonritz]

I used a gas block identical to that one on my last build. I haven't had any problems with mine yet but I've only put a couple of hundred rounds through it so far. It's steel like that one and it lined up fine. I used two set screws with dimples and a longer screw for a sling on the barrel though. But I didn't use any loctite on mine. Maybe I will get it out and apply some on it after seeing that.......

Here's a picture of mine...

View attachment 737573

You are begging for issue there putting a sling on a non-pinned gas block. IMO LPGB should be protected under the handguard.

 

[nk02442]

I would bet most commercial AR's have considerably larger gas ports than they should. Manufacturer's do this on purpose to increase reliability with cheaper ammo because "Johnny Civilian" doesn't always use NATO pressure 5.56. This creates problems. The buffer weight is not a fix for this.

You are correct. Most run of the mill commercial manufactures cannot or will not put in the R&D to ensure a reliable running system. The solution is to overgas everything to make up for poor machining and quality. It will also help ensure Wolf/Tula will cycle.

Your quality Manufactures like KAC, BCM, COLT, LMT (with KAC by far leading the pack) will have dialed in gas systems that will run dirty.

All AR's with the exception is KAC are overgassed to a degree, and this can be fixed by running a Bootleg Carrier. AGB always fail and there has yet to be one invented than can stand up to the test of time and round counts.

Add a Can to the system and its starts getting froggy. With Most quality built guns, an H2/H3 buffer along with the Bootleg is going to make an AW so sweet shooting carbine or rifle. Simple, reliable, cheap.

 

[nk02442]

You are begging for issue there putting a sling on a non-pinned gas block. IMO LPGB should be protected under the handguard.

ALL GB's need to be pinned. Can't tell you how many dimpled, set screwed, loctighted, rockset , clamped ect GB's I have seen fail over the years.

Pin them people. They will not fail.

 

[CLee0507]

ALL GB's need to be pinned. Can't tell you how many dimpled, set screwed, loctighted, rockset , clamped ect GB's I have seen fail over the years.

Pin them people. They will not fail.

While I agree 100%, non-pinned LPGB's under rail seem to be fine as long as installed properly (dimpled, knurled, threadlocker etc).... ie....BCM

 

[rjmt]

You are correct. Most run of the mill commercial manufactures cannot or will not put in the R&D to ensure a reliable running system. The solution is to overgas everything to make up for poor machining and quality. It will also help ensure Wolf/Tula will cycle.

Your quality Manufactures like KAC, BCM, COLT, LMT (with KAC by far leading the pack) will have dialed in gas systems that will run dirty.

All AR's with the exception is KAC are overgassed to a degree, and this can be fixed by running a Bootleg Carrier. AGB always fail and there has yet to be one invented than can stand up to the test of time and round counts.

Add a Can to the system and its starts getting froggy. With Most quality built guns, an H2/H3 buffer along with the Bootleg is going to make an AW so sweet shooting carbine or rifle. Simple, reliable, cheap.

I'll let you know when my JP AGB on my Colt HBAR target rifle fails
or I'll leave a note for my son to let you know long after I'm gone

 

[nk02442]

I'll let you know when my JP AGB on my Colt HBAR target rifle fails
or I'll leave a note for my son to let you know long after I'm gone

Both are game guns.

 

[rjmt]

Both are game guns.

and there is the difference
with a slow fire target rifle, with a rifle length gas system, in a P3 style barrel, I'm not getting much wear or unburned gas into my gas block
since I shoot ONLY one type of ammo, 69 gn Razor Core, readjustment and dirty ammo is never an issue
and the JP has a 4 screw clamp base
your application and experience and mine are different

 

[titsonritz]

ALL GB's need to be pinned. Can't tell you how many dimpled, set screwed, loctighted, rockset , clamped ect GB's I have seen fail over the years.

Pin them people. They will not fail.

While I agree 100%, non-pinned LPGB's under rail seem to be fine as long as installed properly (dimpled, knurled, threadlocker etc).... ie....BCM

I have seen plenty of incorrectly installed ones fail and pinning makes them bomb proof for sure but when done properly they aren't going anywhere with a dimpled barrel, knurled set screws, Red 271 Loctite with everything degreased prior to install.

In addition to BCM, SIONICS and SOLGW uses that method. Between those three there are a lot rifles in the hands of LEO and hard use guys without any issues. I have and know several others that have had a hell of time removing BCM gas blocks, some to the point of destroying the block.

 

[CLee0507]

I have seen plenty of incorrectly installed ones fail and pinning makes them bomb proof for sure but when done properly they aren't going anywhere with a dimpled barrel, knurled set screws, Red 271 Loctite with everything degreased prior to install.

In addition to BCM, SIONICS and SOLGW uses that method. Between those three there are a lot rifles in the hands of LEO and hard use guys without any issues. I have and know several others that have had a hell of time removing BCM gas blocks, some to the point of destroying the block.

Yes, those BCM gas blocks are a pain to remove. Their FSB's are as well.... (big hammer) LOL.... I prefer a gas block to be pinned and wish more companies offered it like BA and Noveske. Thinking back, I remember BCM's had pinned MK12 uppers, but again, it was because they were exposed in front of a 12" rail.

 

[titsonritz]

Yes, those BCM gas blocks are a pain to remove. Their FSB's are as well.... (big hammer) LOL.... I prefer a gas block to be pinned and wish more companies offered it like BA and Noveske. Thinking back, I remember BCM's had pinned MK12 uppers, but again, it was because they were exposed in front of a 12" rail.

I think the FSB's are easier. It's more about technique than hammer size, I use Brownells 1" Nylon/Brass Hammer with great success (pro tip: those hockey puck things are worthless).

Centurion Arms offers barrels w/o a gas block or with a pinned gas block. I also prefer a pinned gas block, hell most of my ARs have a standard FSB but I'm not in the least bit concerned about my unpinned ones as I know who put them together and how it was done. Still, pinning is cheap insurance.