The jig you guy's are refering to is for a .750 gas block, not for the .625 block i believe he will be using on the lw dd barrel
I had one made at work to do the .625 lp gb
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The jig you guy's are refering to is for a .750 gas block, not for the .625 block i believe he will be using on the lw dd barrel
I had one made at work to do the .625 lp gb
Good catch, MtC ! ! You guys had me a little worried with the GB dim...
Anyway, I've decided to put any milling on hold until tomorrow. I'm still a little groggy from the flu and don't want to scrap any parts. The set screws appear to be .450" on center so it should be a straight forward operation. As we all know, setup is 90% of the work!
Somewhat related to this topic (uppers), I need to purchase some moly grease for the barrel nut. Everyone on M4C recommends Aeroshell 33MS but is there any downside to using one of the automotive brands? I came across Coastal Premium Moly EP Grease at AutoZone and was wondering if this would be an acceptable alternative? I can hold out for the good stuff if necessary.
Thanks again for all the quick responses to my questions!
-- ale
On the last rifle I put together instead of dimpling the barrel, I staked the set screws on the gas block so they can't back out. Still holding strong after 500 rounds.
While doing a search for "pinned low profile gas block" I ran across this image:
http://i447.photobucket.com/albums/q...nedLPGB015.jpg
Has anyone else tried this? It seems to me that two set screws (with dimples) on the bottom plus a horizontal cross pin along the top would make for a bullet-proof setup, but what do I know. lol
-- ale
Yes,
This is what everyone has been referring to by pinning it.
The only difference is the pin is usually on the bottom rather than the top.
Like this
http://bisonarmory.com/product_image...nd-dimple2.jpg
Thanks, Clint. I'm new to the upper building world so I'm sorry if my questions make it appear like I'm in grade school. lol...
OTOH, I may have just found a way to re-purpose the roll pin from my factory trigger guard I recently replaced :)
It's not a question of backing out. The purpose of the dimple is so your set screw has something to fit and press into and not just onto, reducing, if not eliminating, the chances of it rotating, granted the set screw doesn't back out. In which case, one could could then opt stake the set screws.
Jax: Im not sure about the availability of a .625 jig but after seeing CoryCop's method, I'm now finding my dimple jig useless. I honestly never thought of that before.
ETA: Ale, I wouldn't use a roll pin. You need either a straight pin (not sure what spec), or a 2/0 taper pin, for which you need a #31 bit and a 2/0 reamer.
On an SBR build, a couple of years ago, I used a BCM barrel (comes with setscrew dimple), then ordered a DD Lite 9 rail, a VLTOR low profile gas block, and gunsmithing services from Ranier. I sent them the barrel, they secured the set screw and pinned the gas block. They even thought to slip the barrel nut on before they pinned it. It was pretty cheap, as I recall...$25.
http://www.rainierarms.com/?page=sho...roduct_id=1655