Barrel Droop? - scope elevation maxed out at 100yd

[MAN - GA]

First off I will admit this problem is on a Marlin XS7 which is a kissin cousin to the Savage. I frequent here all the time but just don't post much (always learn alot). I have removed Savage barrels and installed Savage barrels so I am familiar with the process and have the correct tools. I have struggled with accuracy issues on the Marlin since day one and what I initally found was the recoil lug off center causing the action to tilt - once I fixed this by lightly tapping into alignment groupings improved dramatically and I have been happy with the accuracy. The problem that has persisted is getting a scope to zero and not be maxed out on adjustment - presently the scope is a Leupold VX1 and to get POI = POA at 100yd all the vertical adjustment was maxed out and it just barely got close to POA - I have used the mirror method to recenter scope and the amount of movement in the scope to distance in inches POI was low initally at 100yd is very close within 1-2". By my calculation I need around .025 shim to account for the 25" or so low at 100yd. I have a 20moa base and some shim stock to add to get me there, but here is the question. Doing some internet searching I came across the phrase "barrel droop" and it got me to thinking about the recoil lug being off center and tappping to adjust to center I referenced earlier. Does anyone have experience with barrel swaps where inadequate torque on the nut will affect the barrel tilting down in the receiver? I have thought about removing the barrel, cleaning threads well, and reinstalling would this be recommended or just torque the nut to +/- 35ft/lbs.? Or Do I just install the 20moa base and try it first?

[LoneWolf]

Just recently I actually had my first experience with my barrel coming loose. I've done 11 barrel jobs and this is the 4th barrel on my current action. The result of the barrel coming loose first appear as my zero changing to 3" low. I re-zeroed and on day 1 of the South Eastern Region Precision Rifle Club Association of the finale I finished in 9th place for the day. On day 2 I dropped 25 places and couldn't hit the broadside of a barn. Way low and way inconsistent all day. I thought I had a scope issue (Vortex Gen II Razor HD 4.5-27x56). Turns out the barrel had finally come loose enough that it was 1. Drooping and shooting low 2. Loose enough to be in a different position for every shot creating inconsistency. I didn't figure it out till almost a month later when I grab the barrel and it spun on the action.

I would suggest a full reinstall on the barrel and nut. Re-headspace and re-torque. It will guarantee, you know if it's a barrel issue or scope issue. Especially if you moved the recoil lug while the barrel was attached.

[MAN - GA]

seems your experience is confirming my thoughts - barrel doesn't feel loose and since tapping the lug was pretty easy it cannot be too tight and I guess there is enough play in the threads to allow for droop in the barrel

I have tried 4ea scopes and 3ea base/ring sets on this gun all shoot in the same 25-30" low range at 100 so I am confident this is not the issue - I have mounted 2 piece warne bases and they are perfectly flat when I put a straight edge across them and if I level action clamped in vise and then set level on bases there is no change - another interesting aspect is there is no windage adjustments when I mount any of the scopes to stay 2-3" of POA so alignment does not seem to be an issue

[MAN - GA]

pulled barrel off last night - one mild pop on the wrench with the palm of my hand and the nut was spinning free
threads were bone dry I might add
will post outcome as I get thru the issue

[sharpshooter]

Your receiver is warped.

[MAN - GA]

Your receiver is warped.

How did you come to this conclusion - what recommendation would you offer to evaluate this?
I screwed in/out the barrel and it did not feel at all like it was binding

[65Whelen]

I had the opposite results after a barrel swap. Mine shot 20" high. I wonder if we have something similar going on. Would like to get an answer as to what changed my POI so dramatically.
Can anyone explain what's going on?
http://www.savageshooters.com/showthread.php?55371-Unexpected-results

[MAN - GA]

Update....I pulled barrel and did a little filing on receiver where there was a high spot on the side then smoothing recoil lug on a whetstone. Reinstalled and set headspace which took a while because Marlin does not utilize a notch t keep recoil lug in place which is frustrating having it turn during tightening. Went to the range yesterday and first shot is about 24" low but no horizontal movement required. I pulled the scope and base and installed a Weaver 20MOA base and it brought everything up as calculated - only had to pickup about 6" of vertical adjustment in scope and never touched the windage. I will leave as-is and just shoot - cannot complain about the accuracy at all.