Short version: Is a stout 45-70 load too much for a $100 Nikon Prostaff 4x32 scope to handle?
Long version: I recently put a scope on my Marlin GBL Guide Gun because I can't see iron sights at dawn/dusk and with my eyesight I can't use them to any great effect past about 35 yards anyway even in broad daylight. SO I slapped on a Nikon Prostaff 4x32 (~$100) and sighted it in at 50 yards with Bitteroot Valley's 405-grain JSP. All told I have put maybe 60 rounds of this ammo down the pipe with the rifle in this configuration with no problem.
Today I began shooting my first batch of 45-70 reloads - 47.4 grains of IMR 3031 pushing a 405-grain LRN bullet from MO Bullets. I expected some shift considering this round is not jacketed and it is a starting-level charge, but I wasn't even on the paper at 50 yards (shooting seated, rifle on sandbags). I started shooting for the corners and finally found my POI - looked like it had shifted about a foot down and a foot right at 50 yards
This is definitely not distance I expected it to be off. Nor is it the direction, either...a lighter-level charge should make the POI for a given weight of bullet go up, not down (at least, at 50 yards). I know the 45-70 is a brick, but it doesn't behave like a dang .22LR for pete's sake!
Anyway I started trying to dial it but I kept losing the POI. I thought the scope had shot loose but I tried to wiggle it and could not. I checked the screws that hold the scope in the rings and the screws that hold the rings to the base and they were all tight (Leupold Rifleman aluminum rings). The POI still wandered crazily. After about 15 rounds of this I gave up, thinking maybe I had shot the scope out. I even took the scope off and checked the 4 screws that hold the base to the receiver - they were tight as well (they are loc-tite'd). It is a Leupold Rifleman aluminum 1-piece base.
So tonight I put on another Prostaff - a 3-9x40 that I used to have on my .308. I've probably put 500+ rounds of .308 down the pipe using that scope and it was a $150 scope so hopefully it will stand up to the 45-70 - if that's my problem. I plan to go back to the range tomorrow (provided it is not raining too hard) so I will update when I get back.
Until then...what do you guys think? I find it hard to believe I killed that Nikon but I guess stranger things have happened. I mean, I know it is not the cream of the scope crop but I think Nikon is a pretty respected mid-range brand and they don't make cheap crap.
-cls
Long version: I recently put a scope on my Marlin GBL Guide Gun because I can't see iron sights at dawn/dusk and with my eyesight I can't use them to any great effect past about 35 yards anyway even in broad daylight. SO I slapped on a Nikon Prostaff 4x32 (~$100) and sighted it in at 50 yards with Bitteroot Valley's 405-grain JSP. All told I have put maybe 60 rounds of this ammo down the pipe with the rifle in this configuration with no problem.
Today I began shooting my first batch of 45-70 reloads - 47.4 grains of IMR 3031 pushing a 405-grain LRN bullet from MO Bullets. I expected some shift considering this round is not jacketed and it is a starting-level charge, but I wasn't even on the paper at 50 yards (shooting seated, rifle on sandbags). I started shooting for the corners and finally found my POI - looked like it had shifted about a foot down and a foot right at 50 yards
This is definitely not distance I expected it to be off. Nor is it the direction, either...a lighter-level charge should make the POI for a given weight of bullet go up, not down (at least, at 50 yards). I know the 45-70 is a brick, but it doesn't behave like a dang .22LR for pete's sake!Anyway I started trying to dial it but I kept losing the POI. I thought the scope had shot loose but I tried to wiggle it and could not. I checked the screws that hold the scope in the rings and the screws that hold the rings to the base and they were all tight (Leupold Rifleman aluminum rings). The POI still wandered crazily. After about 15 rounds of this I gave up, thinking maybe I had shot the scope out. I even took the scope off and checked the 4 screws that hold the base to the receiver - they were tight as well (they are loc-tite'd). It is a Leupold Rifleman aluminum 1-piece base.
So tonight I put on another Prostaff - a 3-9x40 that I used to have on my .308. I've probably put 500+ rounds of .308 down the pipe using that scope and it was a $150 scope so hopefully it will stand up to the 45-70 - if that's my problem. I plan to go back to the range tomorrow (provided it is not raining too hard) so I will update when I get back.
Until then...what do you guys think? I find it hard to believe I killed that Nikon but I guess stranger things have happened. I mean, I know it is not the cream of the scope crop but I think Nikon is a pretty respected mid-range brand and they don't make cheap crap.
-cls