aharley1

Here's the deal. Shot my Remington 7400 for the first time in about 10-15 years. Remington 165 gr. I got a 3 in group about 9" to the right at 9x on the scope. Zeroed it in and was getting 2-2 1/2" groups at 100 yds. Went back a week later with Nitrex 165 gr and shot a tight group but about 9 in to the LEFT! I noticed the zoom was at 4x. It's a Deerfield scope that's about 15 years old. I tweaked the scope to the right some and got back on the paper with Remington ammo. New scope time??

spaniel

Your post is not clear but it sounds like you zeroed, switched ammo, and didn't shoot the the same POI...doesn't sound so surprising to me.

Also, if you switch back and forth between ammo the first few rounds after you switch are not reliable.

aharley1

There are two problems I'm having. First is I can't get the same brand ammo twice in a row (everybody's out here) and second is the gun kicks like a mule so it's hard to shoot too many shots at once.
I shot a fair group with Remington ammo at 9x, but it was off 9" to the right. Zeroed it & did well. When I went back, the scope was at 4x and I had Nitrex ammo (I know - two variables). I put it back to 9x and was still about 6" off to the left with the Nitrex. I'd like some consistency. I wouldn't think ammo would throw it off that far??

skeeter 7MM

I too am confused. I don't buy factory ammo but Nitrex used to be Speers not Rem?? I agree when assessing you need to base on 1 load. If it was the same load, was a rest/bench used? Scopes that go bad rarily group tight, JME!

Posting at the same time!!

So how did it group with the nitrex (besides being left)?
What is the rest situation?

Can't buiy 2 boxes of the same ammo...any ammo? Or trying to match up to what you have?

aharley1

I was using a good bench rest. Nitrex and Federal were bought out by someone else. I'll get some more Remington when I can find it and try again. I was just wondering if the scope was changing when I went from 4x to 9x.

aharley1

I'll try to get a few boxes of Remington this afternoon. Have to drvie a ways to get it. The Nitrex group was larger than the Remington and to the left, but then again I was shooting 4x instead of the 9x. When I went to 9x, it moved some to the right but not much....but I only shot about 9 rounds of the Nitrex.

skeeter 7MM

It's possible that mag is throwing it off, however I would sight in at one power then test your theory. I have seen where guys groups change @ lower mag because they can't see the target area as well..just an FYI or thought. Not saying its you.

Are you allowing for any cooling time between shots or groups? Auto's can be fired off pretty quickly and it can lead to heat up issues.

If the groups are constistent or repatable it sounds like your optics are fine.

Another trick you try to test repeatability , is slide in a nitrex as #3 shot and see if it drifts as per the norm.

aharley1

Thanks. I'll try that. One problem was, I ran out of Remington ammo after four shots. The other was recoil management.

JagMagMan

Using different ammo can be the problem, as could a bad scope! Out of the problems you mentioned, the one that causes the largest groups could be the recoil! Flinching causes awful groups, you might try some of the reduced recoil loads, stick with the same ammo and go from there!

aharley1

Yep the recoil is bad, BUT the group moved to the left. The group size changed but didn't change all that much (4 shots per group).