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Mark 4 problem?

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Category: Scopes
Forum Name: Tactical Scopes
Forum Description: Police and military tools of the trade
URL: http://www.opticstalk.com/forum_posts.asp?TID=6924
Printed Date: March/29/2024 at 03:24
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Topic: Mark 4 problem?
Posted By: snpr9696
Subject: Mark 4 problem?
Date Posted: June/10/2007 at 21:31
Hello all, Ive posted on a couple other threads as well so sorry if this is repeatative. I completed my build an 18' WOA barreld SPR Bushmaster w/ LaRue 13.2 Freefloat Handrail and Vltor flash hider. I mounted a Leupold Mark 4 MR/T M3 3x9 scope using the LaRue SPR 1.5 mount on the receiver. After a quick boresighting i went to the range and shot a nice 1inch group at 100yrds. Problem though is it was approx 8-10 inches high. I attempted to dial down for the correction but my Mark 4 has no more available move ment for the correction.

What do I do?

Shiming is not an option due to my using a throw lever mount. Everything is properly tourqued to spec 40lbs on the barrel and 15in lbs on the rings. The rings have ample room and do not touch the obj bell. The flash hider is tightened a little more then hand tight w/ loc-tite. And if it help even the Iron sights are way off, like 3 ft High. Im confused.

Do all Mark 4's that use a BDC method have the reticle/erector tube start at the bottom with no room for inital set up. I though most scope give you ample MOA adjustments up or down and start somewhere in the middle.



Replies:
Posted By: Urimaginaryfrnd
Date Posted: June/12/2007 at 15:58
Sounds like you need professional help - might try GAPrecision in Kansas City. I'm thinking if if the iron sights are 3ft high and the scope is maxed out of adjustment and still 8 to 10 in high, it is the way the barrel is fitted to the upper reciever. I have two Rock River Arms guns and a Colt that are dead on at 100 yds and shoot a very tight group - so the other choice might be to trade into a Rock River upper complete or trade the whole gun for an RRA gun and put the Mark 4 on that probably with a vortex flash suppressor. Who built the upper you have now maby you should take it back to them and ask them why.

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"Always do the right thing, just because it is the right thing to do".
Bobby Paul Doherty
Texas Ranger


Posted By: Rancid Coolaid
Date Posted: June/12/2007 at 16:42

You don't have a Mk4 problem, you have a Bushmaster problem.   Is your mount bent?  Are you shooting with both eyes closed?

 

That the scope and irons go very high is unusual - since the scope is mounted to received and independant of barrel and the sites are mounted on received and barrel.

 

My recommendation, like U. said above: swap the Bushmaster for a Rock River.  Or find the guy that did the work and make him fix it.



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Freedom is something you take.
Respect is something you earn.
Equality is something you whine about not being given.


Posted By: sandsock
Date Posted: June/12/2007 at 18:44
Barrel alignment or bent barrel....even with all the adjustment possible you've got a flat shooting round and a scope a few inches off the bore line.....if everything was mechanically zeroed it wouldn't be terribly far off the POI.



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