RangerTrace Posted August 16, 2018 Share Posted August 16, 2018 My LANTAC Raven, Vortex Razor 1-6 with Larue QD mount was zeroed about 3 months ago at an indoor range at 100 yards with American Eagle 75 grain ammo. I have shot a few 3gun matches since then and hit steel out past 500. It has not been dropped or treated roughly since it was zeroed. Today, I wanted to see where POI would be for some Hornady Steel 75 grain LE Training ammo. I use a post it note, in the center of IPSC target at 100 yards. The first round of Hornady missed the whole IPSC target. I then fired 3 rounds of AA 75 grain. Group was 3" high and 1" to the left. I made my adjustments and the next rounds were off the target. That was with 2 clicks down, 1 click right. Now I'm thinking the scope is broken. Scope mount is tight and all of the rings were tightened with a dental grade torque wrench. It's rock solid. I tried a few more shots and moved to a 50 yard range. First shot was about 18" high. I made my adjustments and worked it down until I was shooting a 1" group at 50 with the AA. I then shot some close range, high speed stuff. Tossed the rifle on a barrel and purposely hit the butt of the rifle on the ground a few times. I then went back to the 100 and was able to get a 1" group.. Windage ended up at the same point I started. Elevation was about 15 clicks off. How the heck does that happen?? I honestly thought (think) the scope was broken. But it maintained the 1" group even after I reset the turrets to "0". FWIW, the Hornady ammo is about 18 FPS slower than the AA and shoots about 1" to the left of the AA. Link to comment Share on other sites More sharing options...
TonytheTiger Posted August 16, 2018 Share Posted August 16, 2018 I've heard plenty about erratic zero issues with both QD mounts as well as vertically split rings, and you've got both. But your issue sounds so extreme that the scope does sound like the problem. Got a spare scope to test the rifle/mount with? Link to comment Share on other sites More sharing options...
RangerTrace Posted August 17, 2018 Author Share Posted August 17, 2018 Not really. My spare is a strike eagle on my back pack gun......... Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted August 17, 2018 Share Posted August 17, 2018 I presume you've tightened down all the screws ? Link to comment Share on other sites More sharing options...
TonytheTiger Posted August 17, 2018 Share Posted August 17, 2018 That's gonna be the easiest way to troubleshoot. Beats sending parts back and forth to the manufacturer unnecessarily. Link to comment Share on other sites More sharing options...
RangerTrace Posted August 17, 2018 Author Share Posted August 17, 2018 2 hours ago, Hi-Power Jack said: I presume you've tightened down all the screws ? Yes they are all torqued to spec. When I pulled the top end off today for cleaning....it felt rock solid. Link to comment Share on other sites More sharing options...
RangerTrace Posted August 17, 2018 Author Share Posted August 17, 2018 2 hours ago, TonytheTiger said: That's gonna be the easiest way to troubleshoot. Beats sending parts back and forth to the manufacturer unnecessarily. We have beat these Larue mounts to bits at work and they just work, over and over again. Our test for the .308s is to zero the rifle, remove the sight, throw it down range about 15 meters, retrieve it, mount it, and shoot it again. They always shoot into the same hole. Link to comment Share on other sites More sharing options...
TonytheTiger Posted August 17, 2018 Share Posted August 17, 2018 Thats great the LaRue mounts are working for you, but you should still throw the Strike Eagle on the rifle and see if it works better than the Razor. Link to comment Share on other sites More sharing options...
gerritm Posted August 17, 2018 Share Posted August 17, 2018 Stupid question, but did you check the comp. Maybe hitting a baffle? Loose? gerritm Link to comment Share on other sites More sharing options...
RangerTrace Posted August 17, 2018 Author Share Posted August 17, 2018 24 minutes ago, gerritm said: Stupid question, but did you check the comp. Maybe hitting a baffle? Loose? gerritm It's pinned/welded and the holes are perfectly round. Link to comment Share on other sites More sharing options...
Chills1994 Posted August 17, 2018 Share Posted August 17, 2018 11 hours ago, TonytheTiger said: That's gonna be the easiest way to troubleshoot. Beats sending parts back and forth to the manufacturer unnecessarily. Or heck!... Even BUIS at 50 yards.... then if your eyes are still good enough, try the BUIS at 100 yards....see if the gun and just the gun can print groups. Then move the Vortex Razor to a different mount. Link to comment Share on other sites More sharing options...
Steve133 Posted August 17, 2018 Share Posted August 17, 2018 I had something similar happen to me - the rifle would consistently group well, but POI would shift by 10 MOA or so depending on the position I was shooting from. Spent months figuring out what I was doing wrong, and trying to correct whatever issue there was in my technique... and it turned out to be an issue with the rifle. Barrel nut wasn't torqued down enough. Not saying that's your issue, but it's probably worth doing a few trials to try to isolate all the variables. Try the Razor in the LaRue mount on your backup gun. Try the Strike Eagle in whatever mount it's in on your main competition gun. Swap the mounts, then try each mount/scope combination on each rifle. Just try every possible combination of rifle, optic, and mount until you've isolated the source of the issue. Link to comment Share on other sites More sharing options...
Stuey Posted August 17, 2018 Share Posted August 17, 2018 I would recommend putting the scope on a different rifle and see if you have the same issue. Or switch scopes and see if it is doing the same. Also are shooting off a rest?Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
mgrs Posted August 17, 2018 Share Posted August 17, 2018 I think something with the rifle is likely, but it's worth eliminating the optic system variable. A note on the LaRue mounts- I've not seen the split rings be much of a problem in practice, but their mounts will come out of adjustment and slide on the receiver until the recoil lugs stop them. Even if it feels tight, it may be moving. Probably not enough to have a significant effect on precision for this type of rifle, but if you check the bottom of one that has been in use for a while you may find that the mounting surfaces and recoil lugs are worn white from sliding on the receiver during recoil. Check the bottom of any heavily used LT mount and you will probably find this. The levers have to be almost painfully tight to prevent this wear in the long term. Of course, this marks your receiver if that is a concern. Link to comment Share on other sites More sharing options...
Steve RA Posted August 17, 2018 Share Posted August 17, 2018 If you put them against the recoil lug when originally mounting it should do away with that problem. The levers should still be tight, of course. Link to comment Share on other sites More sharing options...
RangerTrace Posted August 19, 2018 Author Share Posted August 19, 2018 Some of you may now Jack Yost, a salty old shooter in the DFW area. He offered to help diagnose my rifle issues and we met up today at CCC after my IDPA match. We were able to quickly get holes touching at 50. I suck, so I never got a real group at 200. We then moved across the street where I was hitting steel out to 500. I don't think anything is broken. I can't explain why it did, what it did. We did switch out lowers so I could try his two stage trigger. While I love my LANTAC/Rise Armament for fast splits, the two stage seems to make longer shots a bit easier. Link to comment Share on other sites More sharing options...
poortrader Posted August 20, 2018 Share Posted August 20, 2018 What was the indoor temperature? I’m sure it’s hotter outside now than indoors. Plus, different brand ammo will have different POI. You zeroed AA 75 indoor and got different POI with Hornady LE 75. I shoot 75gr steel match. Years ago when ammo was scarce I was running out and someone gave me some steel match practice ammo. Let’s just say the reshoot god crushed me because the the POI was totally off. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Boudreaux78 Posted August 21, 2018 Share Posted August 21, 2018 I haven’t heard of 18 inches off target before, but I do know that different ammo will shoot differently through the same gun. We did some ammo testing a few years back for department stuff. All 55 grain at 100 yards. Same rifle. Some of the stuff shot a nine inch pattern and other stuff was a nice tight group but in a different location than what the rifle was zeroed at. Lastly, if you barrel has been used for a long time, there is a possibility that it could be moving with the heat of the rounds and throwing off your accuracy. I shoot a specific match grade Hornady 75 grain at 200 yards and use whatever will hit paper at fifty for my hoser ammo. By by the way, try zeroing your rifle at 50 and the 200, it should be the same hold at both locations and you will be hitting higher at 100. Link to comment Share on other sites More sharing options...
RangerTrace Posted August 21, 2018 Author Share Posted August 21, 2018 On 8/19/2018 at 9:31 PM, poortrader said: What was the indoor temperature? I’m sure it’s hotter outside now than indoors. Plus, different brand ammo will have different POI. You zeroed AA 75 indoor and got different POI with Hornady LE 75. I shoot 75gr steel match. Years ago when ammo was scarce I was running out and someone gave me some steel match practice ammo. Let’s just say the reshoot god crushed me because the the POI was totally off. Sent from my iPhone using Tapatalk This is interesting. I've heard different things from different people about the Steel Match vs. Steel Training ammo. Dallas PD has had great success with it for training. I can get it for 15.50 a box from Bud's. I wish is was the same load as the match. Link to comment Share on other sites More sharing options...
poortrader Posted August 21, 2018 Share Posted August 21, 2018 I shoot 75gr steel match out to 700 for DMR matches without any issues. I actually hit the target. I’m paying less than $20 per 50. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
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