Problems dealing with Alexander Arms....

[tango29]

Problems with Alexander Arms

I ordered a 24 inch barrel, railed gas block, and a hard use bolt. Order was put in at thanksgiving 2012. Received order May 23, 2013. Six months for an order is ridiculous.
Built new Grendel with AA components, Started having short stroking issues and emailed AA to ask if the could tell me the diameter of the gas port on the barrel. Gave them a lis of AA components installed an used AA ammo. AA person got defensive and tried to divert blame from AA for the problem. All I had asked was the diameter of the gas port
And if they had any ideas. I can get better support or customer service from monkeys.

[LRRPF52]

What is the total list of your build components?

I'm mainly interested in the core frame of the rifle, gas block, reciprocating parts (M16 carrier versus AR15 carrier), buffer weight and type, recoil spring, extension tube length.

Some people have had issues installing the wrong buttplate screw with PRS stocks, carrier keys that aren't fully sealed to the carrier, mis-aligned gas tubes, BCG not lubricated, aluminum gas blocks, gas blocks not properly installed (port not fully aligned with the block), etc.

[tango29]

Grendel Build specs

]What is the total list of your build components

6.5 Grendel Build

Mega Arms GTR-H Ambi Billet Lower. 237
Megsa Arms GTR-H Billet Upper. 147
AA 24 in Buttoned Rifled barel. 360
AA Railed gas block 85
Giessele Nationa Match trigger DMR. 240
LPK Stag. 70
Magpul PRS stock. 225
Brownells rifle length buffer tube 39
Heavy Buffer. 125
Adams Arms Gas piston Kit. 399
Magpul Miad Grip. 39
US Optics SR-8 1-8 scope. 1995
Matech 600 yd rear sight. 65
Troy front sight. 100
Bad Ambi safety. 45
Misc Orr parts 200
Young Mfg BCG. 200
AA 6.5 Hard Use Bolt. 85
Wolf buffer spring. 25





I'm mainly interested in the core frame of the rifle, gas block, reciprocating parts (M16 carrier versus AR15 carrier), buffer weight and type, recoil spring, extension tube length.

Some people have had issues installing the wrong buttplate screw with PRS stocks, carrier keys that aren't fully sealed to the carrier, mis-aligned gas tubes, BCG not lubricated, aluminum gas blocks, gas blocks not properly installed (port not fully aligned with the block), etc.[/QUOTE]

[montana]

Did you check to see if the gas block port hole was lined up correctly with your barrel port hole? I have an 18" AA barrel that was over gassed and the Adam Arms gas piston being self regulating solved the problem. Do you have the Adam Arms bolt carrier ?

[denimdeerslayer]

Measure where the hole is on your gas block and make sure it is in line with the hole in the barrel.

[LRRPF52]

Which operating system are you using? The Direct Impingement one, or the Adams Arms? I personally would never put an op-rod system on a 24" gun. Your list shows that you have both the AA railed gas block and the Young's MFG Bolt Carrier, as well as the Adams Arms Gas Piston Kit.

[tango29]

Problem with Grenel Ejecting

I am using the Adams Arms GP with the Adams Bolt carrier and the Alexander hard use bolt. I listed the Alexaander GB because I bought it with the barrel, but I have not tried it. I checked the alignment of the holes in the piston,GB, and barrel and everything looks good. I tried three diferent buffer springs/ I tried the Anti Tilt Heavy
buffer and wolf springs from Heavy Buffers. I tried a buffet and buffer spring from brownels and I still am not ejecting or the bolt locking after the last round.
I emailed Alexander arms to see what the gas port diameter was and all they wanted to do was divert blame from their products being the problem. I just emailed to see if they had run into this problem before. Any Ideas on how to fix it guys. And I was was using Alexander Arms factory ammo.
I may just go back to DI if I cant get it to work the the Gas Piston.
I have done the following.
1. Aligned the holes in the barrel. gas block. and piston
2. tried 3 differnt buffer springs
3. tried 2 differen buffers
4. lubed everything in the grendel
5. cleaned the barrel.

any other suggestions

Which operating system are you using? The Direct Impingement one, or the Adams Arms? I personally would never put an op-rod system on a 24" gun. Your list shows that you have both the AA railed gas block and the Young's MFG Bolt Carrier, as well as the Adams Arms Gas Piston Kit.

[BjornF16]

I believe the Adams Arms piston kit that AA uses is different from a .223/5.56 kit…

Where did you get the Adams Arms piston kit from? Is it for .223?

[tango29]

I purchased it from Western sport. It is for the 6.5 grendel.

[LRRPF52]

Did you take the gas rings off the bolt?

I personally would use the DI system. There are usually a lot more issues caused with the op-rod systems over the DI system, unless someone with a lot of experience engineers the whole weapon to run around the op-rod it was never designed for. They make sense for some SBR applications where submersion is frequent maybe, but it says a lot to me when some of the primary people who developed the op-rod systems for the recent trend in placing them in AR's don't use them personally in their own training courses with AR15's. (There have been 3 different times in history where someone has tried an op-rod system, first in 1968, then in the 1980's, then starting in 2004 with the HK M4, which I helped source parts for.)

If the gas rings are still on the bolt, that could cause sluggish operation, but I would refer to the installation instructions of Adams Arms if you are committed to installing that operating system.

Like I said, DI is the way to go, especially on a 24" barrel in my opinion.

[montana]

The Adam Arms Piston kit work's with both 5.56 and 6.5 Grendel. The problem I have had with AA barrels is too big of a gas port not too small. Have you removed the BCG from the upper and removed the gas piston return spring from the gas rod and check to see the piston slides back and forth without any resistance?. If the gas block is not straight it will bind the gas piston in the upper receiver. Did you put the stainless steel bushing in the upper receiver gas tube hole correctly? If you manually pull the charging Handel back with an unloaded magazine does the bolt carrier catch work and hold the bolt carrier back? Does your hand guard rub on the gas piston ? If you are trying to get the most accuracy LRRP52 is correct in changing to a DI gas system. That said your AA gas piston should work and I would try to find the problem to make sure it is a problem with your gas piston and not something else with your rifle.

[montana]

Do you feel any rubbing or resistance between your Bolt carrier group and buffer tube? If you think you do take your buffer and recoil spring out and look for metal shaving's or scratch marks inside your buffer tube. This could also be the problem. I have seen poor quality buffer tubes create short stroking.

[tango29]

I took the gas rings off the bolt. followed the Adam ARMS video wile installing the GP system. I will go back to the begining and lube everything and go step by step very slowly and make sure everything is lined up correctly.

Did you take the gas rings off the bolt?

I personally would use the DI system. There are usually a lot more issues caused with the op-rod systems over the DI system, unless someone with a lot of experience engineers the whole weapon to run around the op-rod it was never designed for. They make sense for some SBR applications where submersion is frequent maybe, but it says a lot to me when some of the primary people who developed the op-rod systems for the recent trend in placing them in AR's don't use them personally in their own training courses with AR15's. (There have been 3 different times in history where someone has tried an op-rod system, first in 1968, then in the 1980's, then starting in 2004 with the HK M4, which I helped source parts for.)

If the gas rings are still on the bolt, that could cause sluggish operation, but I would refer to the installation instructions of Adams Arms if you are committed to installing that operating system.

Like I said, DI is the way to go, especially on a 24" barrel in my opinion.

[tango29]

I want to get this GP running to see what the difference is and see if it worth the expense on any future builds. I have a cut rifled barrel from satern that is comming soon and that one I am going to make DI and see what the perfromance is between gain/loss is between the two.

Did you take the gas rings off the bolt?

I personally would use the DI system. There are usually a lot more issues caused with the op-rod systems over the DI system, unless someone with a lot of experience engineers the whole weapon to run around the op-rod it was never designed for. They make sense for some SBR applications where submersion is frequent maybe, but it says a lot to me when some of the primary people who developed the op-rod systems for the recent trend in placing them in AR's don't use them personally in their own training courses with AR15's. (There have been 3 different times in history where someone has tried an op-rod system, first in 1968, then in the 1980's, then starting in 2004 with the HK M4, which I helped source parts for.)

If the gas rings are still on the bolt, that could cause sluggish operation, but I would refer to the installation instructions of Adams Arms if you are committed to installing that operating system.

Like I said, DI is the way to go, especially on a 24" barrel in my opinion.

[BjornF16]

Not sure if this will help you any…but it is from older thread started by Bill Alexander as he was investigating Adams Arms piston setup in Grendel:

I posted this quick review over at M4carbine but now the Grendel site is here this is more appropriate

During the past few months I have been slowly examining the effects of using a piston type operating mechanism on the accuracy of 20" DMR type build. The baseline rifle for the study is our existing GDMR which houses a 20" Satern barrel with rifle length operating system in a monolythic upper, in which the railed handguard forms an integral part of the whole receiver. The gas system uses a conventional gas tube with a non adjustable gas block and a port size of 0.093" which is nicely balanced for most loads. The barrel profile is medium heavy at 0.980" dia under the handguards with 8 off 3/16" flutes. Typical fleet data from building and testing these rifles during production shows the accuracy to be around 0.5 inches at 100 yards for a 10 round group, testiment to the Satern barrel.

The corresponding piston operated rifle came into being due to the duty cycle of one of the customers. Extensive use of suppression accelerates fouling and heat transfer so a piston design was requested. The rifle shares a common chassis and gas system length, although the barrel fluting is heavier to help with weight. Gas port diameter increases to 0.106" to balance the Adams Arms gas piston used in this build with most ammunition.

The testing was started with the preconception that the gas piston would open the group sizes. It was therefore surprising to see that accuracy was identical to that seen in the direct impingment units. Recoil although subjective felt somewhat smoother and more straight line. Responding to the possibility that the shift in accuracy was being masked by the barrel quality, an identical unit was made using a Begara button rifled blank. Again the rifle shot exceptionally well and it was clear that the piston mechanism, although it imposes off axis loadings has little effect on the accuracy of this rifle layout. To verify accuracy was examined out to 600 yards.

It is hypothesised that for the 6.5 grendel, the piston type design, when restrained within a suitably ridgid reciever has no negative effects on the accuracy of the host weapon. Timing is still set by the port position and unlock timing is adjusted by the same.

This is a very rough summary of work to date and more comprehensive testing is required. Additionally it is proposed to build a series of shorter barrel weapons to se how these respond.

Questions, suggestions and observations please.

Bill Alexander

If you are going to disassemble and start over might as well measure the gas port yourself...