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Folks,
I'm looking for your opinions here. I've put together a dozen or so 5.56 ARs. I've never had ANY issues before. I am disappointed in my 6.5G.
I built my first 6.5G last February/March. Here's the parts list:
- Alexander Arms 18" fluted barrel and bolt
- Adams Arms piston kit, micro adjustable gas block
- Anderson Arms upper and lower
- Hyperfire trigger (243G)
- Various Magpul furniture
- Vortex Optics Viper PSTII, 3-15x44 ffp
- LaRue Tranquillo 7.62 muzzle brake/adapter
I had many failures. Every few rounds would fail to extract or occasionally fail to feed. The extraction failures were rarely the bolt cycling, but the brass staying in the chamber. Usually it was a jammed bolt, still attached to the brass. (Obviously, if it cycled, the next round would jam into the rear of the stuck brass. This is a failure to extract, not a failure to feed.) The feed failures were either stovepipes or rounds only halfway stripped out of the magazine, with the ogive jammed into the M4 feed ramps. The MAIN problem was stuck brass.
The extractor (Alexander Arms bolt) was in good shape. The brass was not deformed. Mortaring the rifle, or using my cleaning rods, was needed to get the stuck brass out. This indicated a bad chamber.
I took a 5.56 chamber brush (brass and steel), wrapped it in cotton patches and applied liberal amounts of polishing compound. I attached the brush to a length of cleaning rod, put it in a drill and went to town. After 30 minutes and then cleaning up the mess, that is now the best looking chamber I've ever had.
The benefit is that I no longer had stuck brass. So, I can reliably ascertain that my Alexander Arms barrel had a rough chamber when it was delivered.
Then I had cycling issues. Sometimes the bolt would overrun the next round, sometimes the bolt would not feed the next round but only strip it partially. Sometimes the ogive would jam against the feed ramp (where it transitions from the upper to the barrel extension).
In order to work the cycling issues, I went through MANY iterations of gas and buffer weight. I started with Carbine and then went through H, H1 and H2. I also started going through magazines (in case the springs or lips were the issue). It was not the magazines.
I -think- I've finally gotten all the cycling issues sorted. I'm using minimal gas, a carbine weight buffer, and a tubbs flat buffer spring.
Next, I decided to work on the pitiful accuracy. It was shooting about 3" groups at 100 yards.
Now, remember, this has been taking a LONG time because of the reliability issues. In order to get to the point where it could shoot 5 rounds in row took me until early this summer. By the end of the summer, I'd shot about 250-300 rounds and it had not tightened up at all.
Last week I decided to rebuild and retorque everything. My first thought is to look at the builder (me).
I clamped the upper in my vice (wheeler upper vice block) and unscrewed the muzzle device (LaRue Tranquillo). I applied about 30 lb ft of torque...and the BARREL ROTATED. The barrel nut was still fully tightened (I use the 3x tighten/loosen with lube before final tighten to 80+ lb ft while timing the barrel nut.)
Well, that was disconcerting. I've never had a barrel come out of its extension before. I contacted Alexander Arms and their rep stated that he wished I'd contacted them sooner (rough chamber and maybe the accuracy???). However, he did reply that the barrel should be torqued to 120 lb ft into the extension and to use green loctite. After cleaning the barrel and extension threads with brake cleaner, I tightened them together as best I could. I did not want to use the chamber lugs to torque against, so I could not achieve the full 120 lb ft. (The extension was slipping in the vice and I did not want to tighten too much against it (using padding) nor did I want to rely on the alignment pin at that torque.)
24 hours later, I took it out again. I fired 20 rounds of Hornady 123gr Black. The groups are about 2.5 inches at 100 yards.
My questions:
1. Is this type of grouping expected?
2. How do you tighten a barrel onto the extension to 120 lb ft of torque? (E.g., what tools do you use and what part of the extension do you apply the torque to?)
3. Should I send the barrel back to Alexander Arms? (Their rep was quite willing to have me send the barrel back and have them tighten it up.)
4. If I do send it back, are my accuracy expectations too high? (I'd like ~1.5" and would love <1".)
5. Or, do I just give up on this barrel and go with an Odin Works?
Thanks,
Ken
I'm looking for your opinions here. I've put together a dozen or so 5.56 ARs. I've never had ANY issues before. I am disappointed in my 6.5G.
I built my first 6.5G last February/March. Here's the parts list:
- Alexander Arms 18" fluted barrel and bolt
- Adams Arms piston kit, micro adjustable gas block
- Anderson Arms upper and lower
- Hyperfire trigger (243G)
- Various Magpul furniture
- Vortex Optics Viper PSTII, 3-15x44 ffp
- LaRue Tranquillo 7.62 muzzle brake/adapter
I had many failures. Every few rounds would fail to extract or occasionally fail to feed. The extraction failures were rarely the bolt cycling, but the brass staying in the chamber. Usually it was a jammed bolt, still attached to the brass. (Obviously, if it cycled, the next round would jam into the rear of the stuck brass. This is a failure to extract, not a failure to feed.) The feed failures were either stovepipes or rounds only halfway stripped out of the magazine, with the ogive jammed into the M4 feed ramps. The MAIN problem was stuck brass.
The extractor (Alexander Arms bolt) was in good shape. The brass was not deformed. Mortaring the rifle, or using my cleaning rods, was needed to get the stuck brass out. This indicated a bad chamber.
I took a 5.56 chamber brush (brass and steel), wrapped it in cotton patches and applied liberal amounts of polishing compound. I attached the brush to a length of cleaning rod, put it in a drill and went to town. After 30 minutes and then cleaning up the mess, that is now the best looking chamber I've ever had.
The benefit is that I no longer had stuck brass. So, I can reliably ascertain that my Alexander Arms barrel had a rough chamber when it was delivered.
Then I had cycling issues. Sometimes the bolt would overrun the next round, sometimes the bolt would not feed the next round but only strip it partially. Sometimes the ogive would jam against the feed ramp (where it transitions from the upper to the barrel extension).
In order to work the cycling issues, I went through MANY iterations of gas and buffer weight. I started with Carbine and then went through H, H1 and H2. I also started going through magazines (in case the springs or lips were the issue). It was not the magazines.
I -think- I've finally gotten all the cycling issues sorted. I'm using minimal gas, a carbine weight buffer, and a tubbs flat buffer spring.
Next, I decided to work on the pitiful accuracy. It was shooting about 3" groups at 100 yards.
Now, remember, this has been taking a LONG time because of the reliability issues. In order to get to the point where it could shoot 5 rounds in row took me until early this summer. By the end of the summer, I'd shot about 250-300 rounds and it had not tightened up at all.
Last week I decided to rebuild and retorque everything. My first thought is to look at the builder (me).
I clamped the upper in my vice (wheeler upper vice block) and unscrewed the muzzle device (LaRue Tranquillo). I applied about 30 lb ft of torque...and the BARREL ROTATED. The barrel nut was still fully tightened (I use the 3x tighten/loosen with lube before final tighten to 80+ lb ft while timing the barrel nut.)
Well, that was disconcerting. I've never had a barrel come out of its extension before. I contacted Alexander Arms and their rep stated that he wished I'd contacted them sooner (rough chamber and maybe the accuracy???). However, he did reply that the barrel should be torqued to 120 lb ft into the extension and to use green loctite. After cleaning the barrel and extension threads with brake cleaner, I tightened them together as best I could. I did not want to use the chamber lugs to torque against, so I could not achieve the full 120 lb ft. (The extension was slipping in the vice and I did not want to tighten too much against it (using padding) nor did I want to rely on the alignment pin at that torque.)
24 hours later, I took it out again. I fired 20 rounds of Hornady 123gr Black. The groups are about 2.5 inches at 100 yards.
My questions:
1. Is this type of grouping expected?
2. How do you tighten a barrel onto the extension to 120 lb ft of torque? (E.g., what tools do you use and what part of the extension do you apply the torque to?)
3. Should I send the barrel back to Alexander Arms? (Their rep was quite willing to have me send the barrel back and have them tighten it up.)
4. If I do send it back, are my accuracy expectations too high? (I'd like ~1.5" and would love <1".)
5. Or, do I just give up on this barrel and go with an Odin Works?
Thanks,
Ken
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