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Joe Chicago
November 11, 2012, 10:01 PM
A month ago I took my rifle (Weatherby Vanguard S2 in .308 with Redfield Revolution 2-7 scope) to the range to confirm zero and see which brand of ammo it liked best. At the end of the session it was right on target and shooting tight groups with several different brands and weights of ammo. It liked CoreLokt 180 grain ammo best and shot sub MOA groups with it. As always, upon returning home I thoroughly cleaned the rifle.

Today I went to the range to practice for deer season, and to my surprise my rifle was shooting around six inches to the right of the bullseye at 100 yards. There was a good wind, but it was blowing to my six, not across the range. I check my scope mount screws and action screws, but they were fine. The rifle consistently shot six inches right multiple times with a couple different types of ammo. I adjusted my zero, got back on target and shot good groups.

Any thoughts on what caused this? I have never had trouble with this scope before and it did not see any hard treatment between trips to the range. I am worried that after flying to PA for deer season it will be off again, and I probably will not get a chance to check my zero before hunting.

Thanks in advance for your advice.

DnPRK
November 11, 2012, 10:18 PM
Does the stock forend touch the barrel?
Did you take it out of the stock to clean it?

arizona98tj
November 11, 2012, 11:03 PM
Lots of rifles will shoot to a different POI after they are cleaned. Some number of shots later, they will settle back in to where they were. However, 6" @ 100yds is excessive and I've not seen one do it that badly.

mrbatchelor
November 12, 2012, 12:59 AM
Lots of rifles will shoot to a different POI after they are cleaned. Some number of shots later, they will settle back in to where they were. However, 6" @ 100yds is excessive and I've not seen one do it that badly.

One of my Mosin Nagants is just like that. As it copper fouls it pulls to one side, then settles down to shoot great groups for several hundred rounds. Then after a few weeks of no Cu solvent it begins to get erratic.

Soak it with Hoppe's for several days in a row until it's truly clean as a whistle and it's back off to the side.

Interestingly it's about 6 inches just like the OP.

Ok, yeah, it's a Mosin Nagant, not a high price hunting or target rifle. So I can overlook it on this one. I'd be ticked off if I spent a lot of money on a nice rifle and it did that.

Art Eatman
November 12, 2012, 09:37 AM
I would suspect some sort of change in either forearm pressure on the barrel (humidity changes affecting a wood stock) or else from a change in the bedding if the rifle had been disassembled for cleaning.

sc928porsche
November 12, 2012, 11:45 AM
It is also possible that you may have knocked it around without noticing it I always make it a habit of checking my zero after arriving to be sure that the rifle is dead on before going out hunting.

jmr40
November 12, 2012, 11:48 AM
I'm with Art. Wood will often do this, but rarely 6". But I'm betting this is not a wood stock. Having the action screws tightened properly, and in the right sequence can have an effect and would be my guess. The front action screw should be tightened 1st, and be the tightest. The rear screw is next and it should be slightly less tight. If there is a middle screw it should just be snug enough that it will not come out. Torque specs can be found for specific rifles.

BTW, once a rifle is zeroed I don't touch the barrel for cleaning unless it gets wet and wouldn't think about removing the action from the stock until after hunting season. Even after cleaning I wouldn't trust the zero to be the same until I had put 10-12 rounds through the rifle. Most rifles are a little less accurate for the 1st few rounds after cleaning anyway. Accuracy won't decline until around 200-300 rounds with most guns anyway before they need cleaning.

warbirdlover
November 13, 2012, 12:30 PM
If the barrel isn't free floated I would try that after hunting season. And maybe glass bedding and pillar bedding the action?

It almost has to be side pressure from the stock IMHO assuming the scope adjusting ring (sticking?) is not a problem.

hooligan1
November 13, 2012, 03:14 PM
That Revolution is prone to stuck erectors, ie,( tamping on the side to make it actually adjust) and the reason I say this is maybe after your first range outing the scope may have "popped" itself to the last adjustment that was made?
And my sons Redfield Revolution has done this, so we verify the last group after adjusting windage by tapping on the turret with a pocketknife, (easily) and this "set's" the erector to it's final setting.
What Art said about the stock could also be something to look at, but unless it got wet it probably wouldn't bind it that hard.

Joe Chicago
November 14, 2012, 12:40 PM
The rifle has a synthetic stock and the barrel is not free floated.

Metal god
November 15, 2012, 03:01 PM
tight groups with several different brands and weights of ammo. It liked CoreLokt 180 grain ammo best

Did you use one of these at the same wieght ?

If you removed the barrel and action from a non-free floating stock . You most certainly could have changed presure points on the barrel.

If the screws were torqued to a different specs then the last time . That could cause problems .

Any of these things can cause your rifle to lose zero . Put them all together and it can get out of control fast .

This is nothing that was not said earlier . Im just not sure if you answered and or commented on the questions/statements :)