Rifle Scopes Dope?

[IdahoMike]

Went to the range for the first time in about a month. My zero is at 100 yards and my 400 yard dope was +8 MOA. Today at 100 I had to come up 2 MOA. So I thought to myself, self what could be the reason for this. I had heard that muzzle velocity will slow in lower temps because of density? Then I +8 MOA to shoot at 400 and was way freakin' high. I had to -3 MOA (net + elevation = 5 MOA) to be on target. I didn't have a chronograph but I fiddled with the muzzle velocity number in my ballistics calculator of which my muzzle velocity was 2525 fps., to get my 100 yard dope to match my 400 yard dope it says my muzzle velocity is sitting around 2985 fps.

any ideas other than I fucked the dog when I was loading and loaded exactly 50 rounds of my last batch hotter than usually?

 

[BCP]

Re: Dope?

Have you thoroughly tested your scope? That would be the first thing I would check.

Could be something you're doing as well, 2+5 is close to the original 8 you had figured.

 

[i_rep]

Re: Dope?

When did you "zero" What was the temp then, what was the temp today? Were you shooting at the same range? Same elevation?

 

[Captain Moroni]

Re: Dope?

Mike, next time your in town we'll take my scope calibration board to the range. Its got 45" marked out you hold the center of your reticle and have someone dial 45 MOA and see what you actually get.

 

[IdahoMike]

Re: Dope?

I havent tested it but its in the works, same range, elevation, 15-20 degree temp change. Captain M. that would be cool, bring the chrono. too.

I didn't even think about it being my scope, der... I should chuck the damn thing in the river and get a better one. Thanks for the insight fellas.

Mike

 

[vman]

Re: Dope?

Variations like that are more likely to be scope than the loaded ammo itself especially at short ranges like 100 yards...

Check the scope isnt loose in the rings.

 

[sobrbiker883]

Re: Dope?

20* temp change isn't going to show up as a 2moa difference on paper at 100yds.

With what you are describing, the scope is significantly suspect...