New rifle eject issues

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Re: New rifle eject issues

Postby Texas Sheepdawg » Sun Jan 14, 2018 8:59 pm

One thing I’ve noticed on all my new builds is the standard milspec buffer springs these days are total crap and very raspy. I replaced all the buffer springs in all of my ARs with JP polished flattened springs, making sure to have carbine size springs and carbine buffers on my carbine length gas systems and rifle length springs and rifle spring buffers on my mid length and rifle length gas systems. This has improved my actions on my rifles immensely. I’ve also been running my bolts wetter using
either Teflon spray lube or “Duralube”. And I’ve gone back through every rifle to be sure the hammer face is stoned&honed to a mirror finish to reduce drag on the BCG. Also, I’ve double checked the bumpers on the back of the buffers themselves to see if the stock screw is kissing the buffers. If they are, I dremel off the excess. (My AR 450 Bushmaster had this issue with an excessively long screw causing the buffer to stop just shy of lock-up on the last round. These little nit-picky tuneups seem to have helped eliminate the questions of whether it’s a receiver issue or not. Now I can focus more on the loads themselves.
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Re: New rifle eject issues

Postby Rklenke » Sun Jan 14, 2018 9:17 pm

I've had my eye on the strike industries flat wire spring for some time now, probably about time I pull the trigger on that one. It seems I have to get my scope rings lapped as well, I can't keep the scope from shifting aft due to the recoil.
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Re: New rifle eject issues

Postby Hoot » Mon Jan 15, 2018 9:59 am

Rklenke wrote:I've had my eye on the strike industries flat wire spring for some time now, probably about time I pull the trigger on that one. It seems I have to get my scope rings lapped as well, I can't keep the scope from shifting aft due to the recoil.


Assuming you have a torque wrench and have torqued the ring screws to the manufacturer's specification for their model, the scope should not move. I use Burris Signature Zee rings with the plastic inserts, torqued according to Burris' specs and the scopes on my two 450b uppers haven't budged. The heavier the scope, the more likely it will drift forward and I'm using heavy scopes on both uppers.

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Re: New rifle eject issues

Postby Rklenke » Mon Jan 15, 2018 10:18 am

I don't have a torque wrench that would do inch pounds, only a heavy one with a 1/2" drive. I torqued them down pretty hard by hand, I just didn't want to strip the head out or stretch the threads. The mount is a Burris PEPR, so it's not low quality. Something else that might help more would be a compensator :shock: My shoulder would appreciate that too
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Re: New rifle eject issues

Postby Hoot » Mon Jan 15, 2018 10:47 am

Rklenke wrote:I don't have a torque wrench that would do inch pounds, only a heavy one with a 1/2" drive. I torqued them down pretty hard by hand, I just didn't want to strip the head out or stretch the threads. The mount is a Burris PEPR, so it's not low quality. Something else that might help more would be a compensator :shock: My shoulder would appreciate that too


I left out rifle weight as a big mitigator in scope drift. It sounds like you have the screws torqued down pretty tight already. The specs on your PEPR are the same 20 in/lb as my Sig Zee's. A muzzle brake such as Ross' 3 or 4 gill units will help, especially with shorter, lighter rigs, assuming the muzzle is threaded. If your barrel is not threaded, you can send it to Ross and he'll thread it and match up a brake to it. He also includes a knurled thread protector with your order if you ask for one at little or no charge. Here's my Bartz barrel that he threaded and matched up a brake to:

Image

Another trick I have used is to wet the inside of the rings with liquid Rosin flux used for soldering. I solder a lot for a living and hobby, so I have a bottle of Kester liquid flux in the shop. There's no water in it, so no need to worry about corrosion. The clamping force will squeeze all but a thin layer out and once the alcohol carrier evaporates, they resulting friction really helps stabilize stubborn scope/caliber combinations. It's not LocTite, so no worry about getting the scope back out. Any residue left on the rings and scope wipe away easily with Alcohol or Acetone without harming the finish on the scope or rings. I use a cotton swab to apply a thin layer before truing the scope. You have a little working time once applied but don't dawdle. Perhaps you know someone with some liquid Rosin flux? Not to insult you, but no liquid Acid Flux for obvious reasons. ;)

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Re: New rifle eject issues

Postby Rklenke » Mon Jan 15, 2018 11:18 am

No insult taken, I had never heard of that before. It may be worth a try after I get a brake. I'm going back and forth in the Ross brake and the GLFA 3 port. Once again, thanks for all the help.
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Re: New rifle eject issues

Postby Al in Mi » Mon Jan 15, 2018 11:50 am

Rklenke wrote:No insult taken, I had never heard of that before. It may be worth a try after I get a brake. I'm going back and forth in the Ross brake and the GLFA 3 port. Once again, thanks for all the help.


I can vouch for Ross's brake
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Re: New rifle eject issues

Postby Texas Sheepdawg » Mon Jan 15, 2018 6:14 pm

Rklenke wrote:No insult taken, I had never heard of that before. It may be worth a try after I get a brake. I'm going back and forth in the Ross brake and the GLFA 3 port. Once again, thanks for all the help.


I have several Ross Shuler Brakes. They are very effective.
1A2D8B91-5837-4F46-81AE-D87DAAC5DB60.jpeg
Ross brakes
1A2D8B91-5837-4F46-81AE-D87DAAC5DB60.jpeg (828.24 KiB) Viewed 11240 times
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Re: New rifle eject issues

Postby Rklenke » Mon Jan 15, 2018 6:23 pm

+1 I've already started the conversation with Ross for a brake... Which reminds me I need to go take a measurement for him.

Also, I tried loads at 30 grains, 31 and 31.5 and still had failure to extract with the lighter loads. I even used some once fired Hornady brass in case it was the brass itself. No luck. I'm now talking to the manufacturer to see if there are any other issues like this. 230 grain FMJs show up tomorrow, so I'll finally have something else to test against.
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Re: New rifle eject issues

Postby Jim in Houston » Mon Jan 15, 2018 6:49 pm

Rklenke wrote:No insult taken, I had never heard of that before. It may be worth a try after I get a brake. I'm going back and forth in the Ross brake and the GLFA 3 port. Once again, thanks for all the help.


I've just mounted two scopes, one Leupold and one Vortex. Instructions for both recommended using some blue Loctite on the threads of the screws on the rings and on the cross bolts on the rail. You can break the bond on blue Loctite, whereas red is permanent.

I did not use it, but if the scope tends to loosen up, I will. I use a F.A.T. wrench to torque all of the screws on my firearms. https://www.amazon.com/Wheeler-Firearms-Accurizing-Torque-Wrench/dp/B0012AXR4S

BTW, all of the scope installation instructions include positioning the scope cross bolts forward against the land on the picatinny rail. That way, when the shock of recoil hits, the scope is already hard up against the forward end of the rail slot and will not be able to jerk forward and loosen up.

If the scope is slipping in the rings, check that you have an approximately equal space between the halves of the rings on both sides, when you have finished torqueing the screws. I have (in the past) also used some electrical tape around the scope barrel under the rings to get a little more grip. It makes it much harder to get the scope off, if you need to, since the rings tend to stick to the tape.
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