Soft primer strikes?

[Blue68f100]

Most all factory ammo is under size, to make sure it fits everything. Not a good gauge at all. Head spacing gauges used for hand loading are good for setting up your brass to fit your chamber. But again not a set of std gauges used to measure head space in a chamber.

 

[gun'sRgood]

Most all factory ammo is under size, to make sure it fits everything. Not a good gauge at all. Head spacing gauges used for hand loading are good for setting up your brass to fit your chamber. But again not a set of std gauges used to measure head space in a chamber.

I'll check with banking, the Darling Wife, and see if a set of gauges are in my future. Thx!

 

[Wolfman0125]

Have you tried a heavier buffer tube spring?

 

[gun'sRgood]

Have you tried a heavier buffer tube spring?

Yes sir. I've put several springs and buffer weights. Both rifle and carbine and in any and all combinations I could think of. The bolt, in most of these variants slams forward so hard, and perhaps it's supposed too, that I began to wonder about bolt bounce. Now with trying three different bolts, BCG's and FP, I think I'm down to an upper or barrel out of spec?

 

[gun'sRgood]

Can't tell by the the photo of the lower. A quick check to see if the hammer pin location is close to spec is see if the hammer face is forward of the front well face. The face of the hammer should be close in alignment with bolt lock catch. Another words the hammer face over hangs the forward face of the well.

PM sent.

Here's what I tried. Took off the barrel, put a cartridge with only a primer into the block of the BCG and locked this into the barrel. Then I taped the FP and the primer went off. There are pics of this as well as three places in the upper that are getting nicked by the BCG. Is milling a thought on one of these areas?
It seem's to me that the blue arrow and the yellow are out of spec?

 

[Blue68f100]

That indicates that the BCG is moving too far forward. The barrel needs to be set back further.

Have you contacted the mfg of the upper with this problem?

Need to dig up the specs for the AR-10 UPPER. Look to see what the Barrel connection length is suppose to be. The Mfg should be able to give you that.

 

[gun'sRgood]

That indicates that the BCG is moving too far forward. The barrel needs to be set back further.

Have you contacted the mfg of the upper with this problem?

Need to dig up the specs for the AR-10 UPPER. Look to see what the Barrel connection length is suppose to be. The Mfg should be able to give you that.

I really wanted to this a long time ago. It seems this company was in business for about two years some 6-8 years ago. Thanks for the brain power but I was thinking that the barrel should be allowed to move forward toward the bolt? If I were to shim the barrel back would that not further the problem of getting the FP to the primer? Sorry for my sophomoric understanding. Thanks.

 

[Blue68f100]

The barrel extension nut shoulders up on the Upper, so it can not go in any further without machining it back. Need to locate a set of drawings/spes on the upper. It will have a measurement for the threaded end to the body face. I have the drawings for AR15 but not the AR 10. Time to put Google to work. Then it will be an easy measurement. The you will know if it's the external thread for the barrel or internal cuts are off.

 

[gun'sRgood]

Dear Blue, would you mind loaning me your brain for a bit? I thought it would be more interesting to keep this thread open to all incase future guys can also utilize your vast experience. I can not thank you enough. Here's my current thinking. If you would tell me if any of this is ill advised. I want to mill the front end. I have a DRO on my mill and believe such would be well within my abilities. Also, where the Blue arrow is, I 'm thinking about enlarging this to the end of the marks left by the BCG. Your thoughts please. In the mean while, I think I'll check on how much a ticket might be to come say howdy! Thanks Blue!

 

[Blue68f100]

I would do some measurements first. If you have another upper you could measure, compare the 2. It's possible the barrel extension nut is out of spec and not the upper. Need to measure every thing first. Then determine which part is out of spec.

If you end up cutting the upper back where the barrel rides, you will also need to make sure the alignment key is deep enough for the pin to recess. Also the face needs to be true on axis.

 

[AK Hunter]

If you are shooting the cheap steel case stuff it could be hard primers. A lot of the steel case is berdan primed & takes a little more to set it off. I have changed all of my AR guns that shoot steel cased to the enhanced firing pins.

 

[gun'sRgood]

I would do some measurements first. If you have another upper you could measure, compare the 2. It's possible the barrel extension nut is out of spec and not the upper. Need to measure every thing first. Then determine which part is out of spec.

If you end up cutting the upper back where the barrel rides, you will also need to make sure the alignment key is deep enough for the pin to recess. Also the face needs to be true on axis.

Thanks! If you wouldn't mind, how would you set this up in the mill? I'm thinking that to set the upper horizontally and make make a pass. It seems that If I set this up vertically I could get wobble? Or some sort of vibration. This because I don't see how to vice the upper to keep the surface to be milled close to the end mill? And, overall, what do you think of the idea?

 

[Blue68f100]

You will also need to make sure you will be able to close the upper to lower. If the BCG is sticking out too far you will have a problem.

I machine that part when setup in my lathe. If I had to do it on a end mill I would clamp the upper in the vice and dial it in on on the rail. Once level you need to locate the center of the axis. Because you will need to cut the slot for the alignment pin afterwards. You could use the barrel extension nut on the barrel to locate the center. Then use a long 1/2" solid carbide end mill to cut the face. If the finish is Hard anodize it will be hard to break through the reason for carbide.

Or use a 90deg plate to mound it vertically. But it's easier doing it horz.

 

[gun'sRgood]

You will also need to make sure you will be able to close the upper to lower. If the BCG is sticking out too far you will have a problem.

I machine that part when setup in my lathe. If I had to do it on a end mill I would clamp the upper in the vice and dial it in on on the rail. Once level you need to locate the center of the axis. Because you will need to cut the slot for the alignment pin afterwards. You could use the barrel extension nut on the barrel to locate the center. Then use a long 1/2" solid carbide end mill to cut the face. If the finish is Hard anodize it will be hard to break through the reason for carbide.

Or use a 90deg plate to mound it vertically. But it's easier doing it horz.

Yep! You da man! Here's something of interest. Through a few searches, I found the new company that used to be the old company who were having these parts made and private labeled for them. They actually remembered the guy who is my buddy, that bought these parts some seven, eight years ago. I'm supposed to be hooked up with the manufacture about the issue. Good ole internet. I'll be following this first. If it goes nowhere, I'll be showing you my machining set up for approval and advice. Thanks Mr.B.!