Question about M40a5 zeroing?

[USMC_CPL]

I'm new to Precision shooting, so please excuse my ignorance. I have a 100% correct M40a5 built by GAP topped with Civilian S&B PMII 3-12x50 with correct reticle & turrets. To date I've only boresighted, set zero stops, and dialed in best I could while doing first 20rd barrel break-in on short 100yd range I have behind the house. With elevation dialed all the way down, the closest range I figure I can "zero" for would be 300 or 400yds since at 100yds I was having to hold between 2- 2.5mil low. My question is, is this normal for elevation range adjustment for M40a5 to be for 300yds to 1000yds for example? Do Marine Snipers have to used hold offs for ranges inside 300yds, or is there something wrong with my setup? I understand Marine Snipers taking shots inside 300yds should be uncommon and being a newbie I just assumed a quality scope with a lot of elevation adjustment would have the range for 100-1000, but I also realize it's mounted on a 30moa rail. Hoping it's normal and someone could set my mind at ease. BTW used Remington 175gr Match for break in, but will be shooting 175gr FGMM from here on out.

 

[oldrifleman]

What mount/rings are you using.

 

[USMC_CPL]

USMC Badger 30moa and USMC Badger 34mm rings. Everything is 100% authentic. Action machined for rail and installed @ GAP. Rings and Scope installed myself per Badger instructions/ torque specs. Only thing I didn't do was lap the rings.

 

[roostercogburn98]

To date I've only boresighted, set zero stops,

You set the zero stop after you boresighted? That should be done after you zero at preferred range. IF you did set the zero stop after boresighting, that would explain no adjustments left to zero at 100.

 

[USMC_CPL]

Thanks, I'll look into that aspect again. However, I used .308 Shell style laser boresight at 100yds, rather than 10-25 or whatever they typically recommend. If I remember right, I dialed the elevation as close as I could to lining up the crosshairs with the dot from laser on the 100yd target, so I believe I ran out of adjustment before setting 0 stops, but I could definitely be wrong as I did it all last Spring.

 

[Rio Precision Gunworks]

Loosen the turret screws so the knob isn't engaging the turret.....slip the knob to 3 mil or so above zero, then tighten the screws back down.

Then you should have enough elevation left to dial down to get your zero. Then do the same thing and slip the knob to zero.

 

[oldrifleman]

Laser boresighters are OK to get near the target but are in no way accurate enough to set a zero stop.

 

[spife7980]

According to my brief googling you should have 23 mils of elevation travel in the scope, do you have that much dialing up? If not then you have the zero stop wrong as has been pointed out, lower where that’s stopping and you’ll get access back to the full travel

 

[JINm40a1]

Sorry OP,off the topic a bit....how long have you waited your M40A5 from GAP for? I have an order put in with with them of the same rifle since Feb 2023 and it is still in the process of making.

 

[USMC_CPL]

Damn! Want to say it was about 8mo. Idk your situation, but I had all the parts already except for M40 (M24?) Trigger that I sent them for the build. Luckily they came across an authentic trigger in process, which I can't believe is a Remington trigger it feels so good, so I didn't have to use the Timney. Anyways, I had already waited for and received barrel from Gary Schneider. Therefore, they just needed to call to confirm everything, finish barrel and machine and true action/bolt, assemble and test fire. I was lucky enough to have sprung for the S&B from Jason @ Euro Optic right before they were discontinued.

 

[USMC_CPL]

As for my zero, I loosened set screws, dialed up 3mil, tightened and was able to dial down the 2.5mil... as you all probably know. I think what my problem was, is that I dialed down as close to laser boresight and POI at 100yds as I could from where turrets were set from factory and reset the zero stops there, thinking there was no more adjustment to scope due to the 30moa rail. I'm sure it sounds stupid to many of y'all, but as I said I'm new to the whole thing. Grew up shooting, joined the Marines (never went to Sniper School obviously lol), but always wanted an M40. Never thought I'd be able to afford one, so I bought an SPS Tactical with hope of one day being able to convert it. Piece by piece I made it happen and sure I could've had a nice 300winmag for the money, but I like the historical significance. The 300winmag will be down the road at some point maybe.