AR Sponsor
Posted: 11/13/2012 2:22:18 PM EDT
|
I need some help! I'm building my first AR and I've ran into a little snag with the gas block. I have this gas block and this barrel. Now I can't get the gas block to go all the way down so I can secure it. I understand that a bit of force is probably required to get the block into place, but I was putting a good amount of force and couldn't get the gas block all the way in place, and can't get it within 2 inches of the gas port. Someone please tell me that I didn't order the wrong gas block. Should I just say "to hell with the barrel coating" and just beat the block into place? But if I ordered the correct gas block, what could be the problem? I haven't contacted the site I got the barrel form yet since I'm not exactly sure what the problem is. Should I start there?
Thanks in advance! and p.s. I realize this is an el cheapo barrel, and could be the problem, but it'd be a lot easier to get a new gas block than a new barrel. |
|
It looks like you got the right gas block for the barrel.
Do you have a micrometer or access to one? Measure the barrel diameter at the gas port to see if it's really .750. If it's larger than that, then the barrel is the problem. Measure it in several orientations to see if the gas block area is round. Also check the inside dimension of the gas block. It should be .752 or thereabouts to just fit on the barrel. Does the gas block stop at the point where the barrel diameter gets larger just ahead of the gas port? |
|
Quoted:
Quoted:
Do you have a micrometer or access to one? I can try and borrow one from my physics professor tomorrow. Quoted:
Does the gas block stop at the point where the barrel diameter gets larger just ahead of the gas port? Yes indeed. I've used a few cheap-bastard barrels and had problems with the gas port not being drilled through, but not the diameter at the gas block seat. It's possible though. One thing you could try is to run some ScotchBrite around the inside of the gas block. It's cheaper to replace than the barrel. I wouldn't recommend beating the block onto the barrel. Is there any chance that the set screws are still sticking through the gas block and preventing it from going on? |
|
I've just installed the identical gas block on a YHM 20" fluted barrel. http://yhm.net/index.php?main_page=product_info&cPath=17_29_58&products_id=395
It was a close fit and all I had to do was twist the block side-to-side slightly as I slipped it on. Fit is perfect. As already suggested, check the barrel diameter and go from there. Good luck. |
|
Quoted:
I've used two of those gas blocks on my rail builds, and each time i used a swipe of oil and worked it on back and forth. Never a problem, so I'm interested to see how this turns out I use this gas block on one of my personal rifles and have never had a problem with it at all. Are you worried about scratching the finish on your barrel if that is what it takes to get the gas block on? It could just be very close. I think If i were you I would first try the old trick of heating the gas block and freezing the barrel and see what happens, if it still seems like it needs to be forced I would wait to hear back from the people that you bought the barrel from. Lots of people here have and use YHM gas blocks, if it was a common problem with the YHM gas block chances are there would be a big thread and some sort of fix to this issue. But i don't believe that is at all the case here. Interested in hearing what comes of this. |
|
I just got the gas block on. Used some CLP and it wrapped the gas block with blue painters tape and used a hammer to lightly tap the block all the way down. It didn't go on super easy, but I didn't have to force the hell out of it either. Thanks for the suggestions guys, I'm still going to use the micrometer on it tomorrow during lab and see what the diameter is.
I'm dropping it off friday afternoon to get it checked over and am heading to the range sunday! |
|
Update:
I borrowed a caliper and micrometer from my physics professor today and measured the barrel at the gas block at exactly 19.0mm. Now that's equal to .748" which doesnt make much sense it's .002 smaller than the .750 gas block and I couldn't get the gas block to slide on easily. I don't want to remove the YHM gas block to measure the inside, so i'm not too concerned about it now since I got it installed, but just thought i'd share my results. If there are any problems with the gas system, i'll take off the gas block and measure it and the gas port, which I should have already done. |
| In order to save a little time and trouble later on test your gas system for blockage before further assembly. Assuming your barrel is mounted and barrel nut is torqued to spec, with your gas block and tube in place block off the muzzle end of the barrel and take a small piece of plastic tubing and affiix it to the end of your tube inside the upper. With an air gun blow into the plastic tubing affixed to the gas tube and you should feel the air freely flowing back into the upper through the barrel. I've done this when installing low profile blocks before completing a build just to make sure it's clear so I don't have to tear it back apart. Hope it helps and good luck! |
|
Quoted:
In order to save a little time and trouble later on test your gas system for blockage before further assembly. Assuming your barrel is mounted and barrel nut is torqued to spec, with your gas block and tube in place block off the muzzle end of the barrel and take a small piece of plastic tubing and affiix it to the end of your tube inside the upper. With an air gun blow into the plastic tubing affixed to the gas tube and you should feel the air freely flowing back into the upper through the barrel. I've done this when installing low profile blocks before completing a build just to make sure it's clear so I don't have to tear it back apart. Hope it helps and good luck! I'll do that as soon as I get my rail and barrel nut tomorrow afternoon. I'm dropping it off either tomorrow or friday to a local AR gunsmith to check everything out. Thanks! |
AR Sponsor