DBChaffin Posted September 2, 2003 Share Posted September 2, 2003 Ok, Patches and I have both built AR's, using mostly DPMS parts including flat top uppers and carry handle rear sights. However, we both have JP adjustable gas blocks on them. He built his first and put a DPMS removeable front sight on it. In order to sight it in with the rear sight all the way down, the front sight has to be sticking up so high that you can see daylight under the platform that the detent engages. Knowing this, I order an M&A and a DPMS front sight from Brownells for mine. The differences are amazing. What the heck is the spec on these supposed to be? So I go to sight it in, but having measured, I lower the M&A as low as I will accept (platform sunken in on sight). It shoots 8" low at 50 yards. I swap to the DPMS and am 4.5" high at 50 with the platform just coming above the surface. What do we do? Mill down M&A's? I think I have calculated up what I need taken off of and where, but what does everyone else do? The DPMS front sight can't be used as far as I see it. Changing the rear sight won't work (it's down all the way) and a taller post would sit too high out of the protective "ears". Sure, we could crank the rear sight up and use the M&A, but we lose the ability to crank up for distance. Who is out of spec? JP's gas block? Anyone have this problem or have any ideas? By the way, I called JP and although he was really nice on the phone, he told me he sells DPMS removable sights for his block. So unless our DPMS carry handle's are too high someone else is having this problem. Thanks in advance. Link to comment Share on other sites More sharing options...
ErikW Posted September 2, 2003 Share Posted September 2, 2003 The easy solution is to get a front sight mount/riser from Accuracy Speaks (or a dozen other vendors, none of which supports practical shooting and is run by a USPSA Area Director) and stick on a globe front sight from OK Weber. Then you'll have way more sight radius, a better sight picture, and unbelievable adjustability. But if you're married to the idea and look of clamping something to your gas block... Link to comment Share on other sites More sharing options...
RodneyLtd Posted September 3, 2003 Share Posted September 3, 2003 If you have not purchased your front sight yet, JP makes a very nice adjustable height front sight that will correct this problem. I have a DPMS rear with the JP adjustable height front and really like the combination. I did not have any problems setting my 200 yard elevation zero with the front sight. Link to comment Share on other sites More sharing options...
DBChaffin Posted September 3, 2003 Author Share Posted September 3, 2003 Erik, actually I wanted a setup just like you described, but I have a post ban Clark Gator upper with a Miculek comp already attached. Although I can't find it, Clark tells me there is a blind pin under the bottom of the comp. It's frustrating to know I can't change gas block, handguard, etc, because of the comp. Anyway, I'm pretty sure that knocks out the Accuracy Speaks riser, doesn't it? Yendor, I have looked at the JP Adjustable and may end up with it. It is $125 plus $20 for Shaver inserts though I do believe... Removeable front sights are $30 or so and a national match front post is $11. But I haven't found one that works without some work. I guess that just surprises me. I figured there was a spec somewhere and they were all made to it. Link to comment Share on other sites More sharing options...
ErikW Posted September 3, 2003 Share Posted September 3, 2003 Oh well then you can't slip on an Accuracy Speaks or Lipski or Schuster. Maybe call up OK Weber and ask if there's any two-piece base out there. You want a spec? HA! Carry handles rear sights and front sight housings are known to be different among different manufacturers. Mixing them sounds like a nightmare. Bushmaster has an A2 front sight post for Colts and it's .040" taller than standard A2 posts. If that's not the ticket, they have a detachable front flip sight for $73. Man, it sucks to be you. Link to comment Share on other sites More sharing options...
Larry White Posted September 3, 2003 Share Posted September 3, 2003 Just went thru this. Measured every front sight I could get my hands on. Finally took a Dpms detachable, bored the sight pin well .200 deeper, cut .200 off the flat between the ears and .200 off the top of the ears. Works now but what a pain, sucks. Another reason for a USPSA limited w/optics div. Larry Link to comment Share on other sites More sharing options...
DBChaffin Posted September 3, 2003 Author Share Posted September 3, 2003 Carry handles rear sights and front sight housings are known to be different among different manufacturers. Mixing them sounds like a nightmare. That's why we started with DPMS front and rear. Maybe it's the JP Gas block that threw that off? I have seen the Bushmaster taller post, but it is .04 taller, and I need more like .1 taller for the DPMS sight. It's a wide post, AND I don't want the post sitting up that high in the protective ears of the sight. lkytx, it's interesting that you you cut down the DPMS detachable. It is too short for us. We will have to cut down an M&A (or something else taller). What rear sight are you running out of curiousity? Thanks for the replies. I really appreciate it. Link to comment Share on other sites More sharing options...
Larry White Posted September 3, 2003 Share Posted September 3, 2003 DB, I misspoke, the rear was a DPMS detachable, the gas block and sight were from Brownnels. Larry Link to comment Share on other sites More sharing options...
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