moose-hunter Posted December 15, 2014 Report Share Posted December 15, 2014 Using a Mega MaTen receiver set, I'm finding out the rail height differences have their drawbacks... I'm using a Precision Reflex carbon fiber tube and flip up front sight / gas block... The curve ball is the "height" of the front sight itself... The combination of the "regular" DPMS forearm and taller (Armalite/DPMS "high") front sight led to this condition... There's rougly .125" of interference, thus the sight can not lay flat when folded down. Leaving it alone is way more than enough to drive me nuts! That said, my options seem to be... (A) I clearance the forearm (carbon fiber) just enough to accept the sight hood in it's down position... OR ( B) I fire up the mill and remove enough material from the sight hood to clear the tube... Basically transforming the shape into a more of a "HK" style rather than a full hood. I've tried every different combo of assembly and spacing of the G.B. I can think of and it appears... Something needs to get cut. My impasse... Which way do I go? Either mod is very do-able... Which way would you go? Or am I over looking a way to create the needed room? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 15, 2014 Report Share Posted December 15, 2014 Call PRI, and email these pics to them after that. They'll come up with a solution for you. <thumbsup> Quote Link to comment Share on other sites More sharing options...
crimsonfalcon07 Posted December 15, 2014 Report Share Posted December 15, 2014 It doesn't necessarily need to be a full removal. What if you take off .125" of the back of the sight hood to let it lie flush against the forearm, but otherwise leave it be? You'll still have full hood, and with a little paint or cerakote, will look 100% custom-fit. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted December 15, 2014 Report Share Posted December 15, 2014 Crimson took the words right out of my mouth. I think the small relief would look perfect, and very "one of a kind". Mated parts always look best. Quote Link to comment Share on other sites More sharing options...
DNP Posted December 15, 2014 Report Share Posted December 15, 2014 Not having access to a means of drawing on the photo here from my phone...instead of a square cut, you could slope it towards the front and no one would ever know. It wouldn't look like a relief notch at that point. Just one straight line if you get what I mean. Quote Link to comment Share on other sites More sharing options...
Tripledeuce Posted December 15, 2014 Report Share Posted December 15, 2014 In the gunsmithing business, the old axiom is. Work on the cheapest part. in case you need to replace it. Respectfully Terry Quote Link to comment Share on other sites More sharing options...
blue109 Posted December 15, 2014 Report Share Posted December 15, 2014 I could trade you my 14" tube and lowpro for your 12" tube and front sight ;) Quote Link to comment Share on other sites More sharing options...
survivalshop Posted December 15, 2014 Report Share Posted December 15, 2014 You said you had a Mill , Contour the back of the sight to the Hand guard radius . Quote Link to comment Share on other sites More sharing options...
sketch Posted December 16, 2014 Report Share Posted December 16, 2014 SS has a good idea! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 16, 2014 Report Share Posted December 16, 2014 In the gunsmithing business, the old axiom is. Work on the cheapest part. in case you need to replace it. Respectfully Terry I will endorse this - to an extent. I know what the PRI carbon fiber rail price is. I know what the PRI front sight cost is. I've done two builds with those parts. If you cut up the front sight, you will be working on the cheaper part. However, even if the front sight were the more expensive part, I wouldn't fuk with the carbon fiber rail. Don't fuk with the structural integrity of carbon fiber parts. Don't fuk with the structural integrity of carbon fiber parts should be the new axiom of gunsmithing. You can't undo that, no matter what. Quote Link to comment Share on other sites More sharing options...
shibiwan Posted December 16, 2014 Report Share Posted December 16, 2014 (edited) Don't fuk with the structural integrity of carbon fiber parts should be the new axiom of gunsmithing. You can't undo that, no matter what. Take it from someone who works/has worked on carbon fiber on a regular basis -- you can't fück up the integrity on that carbon fiber tube if you notch it. It'll take a lot to fück the integrity up on that thing. Besides, carbon fiber is easy to repair, IF you know how. :)) If it's "real" carbon fiber, you can grind it off to form a notch very easily, but given what you have, I'd notch the front sight. Tom would just take a hammer to it and beat it into submission. Edited December 16, 2014 by shibiwan Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 16, 2014 Report Share Posted December 16, 2014 (edited) That tube is real carbon fiber. I've beat people to death with that thing, out here in the real world. Don't mess with that tube. <thumbsup> It's not car fairings, and $hit. <dontknow> :banana: Edited December 16, 2014 by 98Z5V Quote Link to comment Share on other sites More sharing options...
shibiwan Posted December 16, 2014 Report Share Posted December 16, 2014 Structural stuff, actually..... aerospace structural stuff.... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 16, 2014 Report Share Posted December 16, 2014 (edited) I didn't really beat people to death with it - but I wouldn't hesitate to. <lmao> OP, did you call PRI yet? Edited December 16, 2014 by 98Z5V Quote Link to comment Share on other sites More sharing options...
blue109 Posted December 16, 2014 Report Share Posted December 16, 2014 tom just realized he made an opsec slip...and tried to backpedal. cannot confirm not deny..... Quote Link to comment Share on other sites More sharing options...
moose-hunter Posted December 16, 2014 Author Report Share Posted December 16, 2014 (edited) Thanks for all the suggestions! I have contacted PRI and am currently awaiting their response. Also... The barrel has been sent out and will be back in a couple weeks so I still have time to formulate a course of action. I have an idea of where I'd like to take this but it's tough to explain... I'll hit the Paint program and see if I can make a couple scrbbles for you folks... Hang tight, it may take a while as I've never been accused of being an artist... Edited December 16, 2014 by moose-hunter Quote Link to comment Share on other sites More sharing options...
moose-hunter Posted December 16, 2014 Author Report Share Posted December 16, 2014 Okay... Don't laugh! I know it's not the latest release of AutoCAD or SolidWorks... Let's see if I can explain my possible plan... Very basically, the height dim in red ("A") is the amount I need to remove in order for the sight to lay flat with just a bit overlapping the PRI tube. Without the barrel, I don't have exact numbers but it would amount to removing +/- .095". Less than half of the "flat" you see on the top of the sight hood. The raidus at the end of the pass, nearest the hinge, doesn't really matter and will end up being what ever the radius of the tooling is. Or it would end up at 90*... Depending on the direction of the cut. With this also being the gas block, I can mount and fit this and the gas tube, then cut the sight to suit. Finishing the cut will be either with a flat, non-reflective black paint. I found some that is VERY close to the original color, OR... My buddy, who runs a metal coating business, said he'd give it a go and match it as best he could. Either way, as long as it's close, and uniform from top to bottom, it will only be noticable when when the irons are deployed. Which hopefully will only be to dial them in. If they're need after that, I'll have more to worrie about than finishing since the $2K+ piece of glass on top of the rifle has just gone FUBAR... I hope I explained that correctly... Your thoughts? Quote Link to comment Share on other sites More sharing options...
blue109 Posted December 17, 2014 Report Share Posted December 17, 2014 looks good....but seriously, I would have bumped the tube with a dremmel sanding drum and been done with it :) Quote Link to comment Share on other sites More sharing options...
392heminut Posted December 17, 2014 Report Share Posted December 17, 2014 looks good....but seriously, I would have bumped the tube with a dremmel sanding drum and been done with it :) Same way I would have handled it. Quote Link to comment Share on other sites More sharing options...
moose-hunter Posted December 17, 2014 Author Report Share Posted December 17, 2014 I'll make the final call when the barrel gets back... All options are still on the table and the dremel is standing... Quote Link to comment Share on other sites More sharing options...
Rsquared Posted December 19, 2014 Report Share Posted December 19, 2014 You're on the right path Moose. Measure twice, and cut once. There's a reason that it's an "old saying". Quote Link to comment Share on other sites More sharing options...
moose-hunter Posted December 19, 2014 Author Report Share Posted December 19, 2014 Hold the presses! Drop that Dremel! Power down the mill!! There are wheels in motion... I'll report back when a definite resolution has been arrived at. (Something tells me it's the answer I was looking for! <thumbsup> ) Quote Link to comment Share on other sites More sharing options...
Tripledeuce Posted December 19, 2014 Report Share Posted December 19, 2014 Why is it that everyone who has a dremel tool thinks they are a gunsmith????? Terry ( no respect) Although a dremel IS the ight tool ,at times. Quote Link to comment Share on other sites More sharing options...
blue109 Posted December 19, 2014 Report Share Posted December 19, 2014 I've seen work done by gunsmiths that would have been better off getting dremeled in the garage. Quote Link to comment Share on other sites More sharing options...
Tripledeuce Posted December 19, 2014 Report Share Posted December 19, 2014 Blue,,,,, That is oh so true!!!!! Did you know that their are NO(!!!!!) rules, regulations, or laws on who can call themselvs a :gunsmith"???? OK.............. time for me to get off my soapbox!LOL!! Respectfully Terry Quote Link to comment Share on other sites More sharing options...
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