Action/scope mount recommendations

[Zatchmo]

So I've decided I want to shoot reliably from 1000-2000, and stretch to 2500. I've settled on 300 NM for caliber. My short action is an impact so that was my natural initial choice for the long action as well. Now come the issues.

The Impact 787 has a 2 piece integral base and only 20 MOA built in. Estimating using BallisticsARC, I need 30 mils to hit 2500 yards with a 230@3000 fps. Even using a ZCO, I need 50-60 MOA in the base/mount, or use a prism. I can't imagine it's a good idea to span a one piece mount across a 2 piece rail, so that kind of makes that action a no-go. Several of the long actions seem to be the same. I can't imagine I'm the only one with this issue. How are you all solving it?

Note that I do not currently own that action, I just like my short so I logically went that way for long. If the answer is to buy something else, I'm all ears. Availability of prefits is super nice for trying random stuff, but not a hard requirement with my proximity to Mile High Shooting.

I currently am in possession of the chassis and barrel. I'm locked into a "standard" 700 footprint and that's about it.

 

[A5scott]

As far as actions, the CIP length long actions are good. You can do something like the Lone Peak 338 that uses Rem 700 long action footprint or a BAT CT if you just want a shell holder, but then you'd need a different chassis or stock than what you currently have.

I went with a Defiance Deviant with the 20 MOA rail and I'm happy but there are lots to chose from. Mile High probably has Zermatt (Bighorn) TL3 long actions. the Lone Peak 338 is worth a good look, and whatever else BAT makes if they have a Rem 700 LA .

I use Spuhr and ERA-TAC mounts to get the most out of the adjustment range.

Make sure your chassis has shims or whatever to adapt your mag well for CIP length (3.850") mags if you go with a CIP length action. The Lone Peak can use even longer mags.

If you go ZCO optic, you'll want 18 to 20 MRAD cant so you can get a 100 yard zero and use the full 35 MRAD adjustment in the turret. You can also set it up for a 700 or 800 yard zero to keep you away from the edges of the glass when dialing 30 to 35 MRAD.

Sounds like a great build in the making.

Scott

 

[GIXXER2000]

Accuracy International or DTA. I run an AXMC with a 30 moa rail and have no issues getting a 100 yard zero and use a Charlie Tarac passed 2000 yards. If you go AI or DTA you can change cartridge at will no gunsmith wait time. This just give you more options.

 

[Steel head]

Easy peasy
ARC scope mount with 30 moa

Gives you 50 moa which will give you probably 26-28 mils with a 100 zero and hold the rest n the reticle.

Or get a prism, adjustable mount or Charlie tarac.

 

[Zatchmo]

Easy peasy
ARC scope mount with 30 moa

Gives you 50 moa which will give you probably 26-28 mils with a 100 zero and hold the rest n the reticle.

Or get a prism, adjustable mount or Charlie tarac.

Interrupted rail on the 787r makes mounts with cant a no-go.

 

[Steel head]

Why not just get the 737 then?
Otherwise the prisms are probably the best option.

 

[Tchitcherine]

+1 ARC mount or rings. Very impressed with M-Brace quality, fit and ease of set up. And of course they have 36mm needed for ZCO. Also, Mausingfield can be had with 0.588" bolt face, 45 MOA rail (slightly less than your requirement), CIP length mags no problem.

 

[Steel head]

+1 ARC mount or rings. Very impressed with M-Brace quality, fit and ease of set up. And of course they have 36mm needed for ZCO. Also, Mausingfield can be had with 0.588" bolt face, 45 MOA rail (slightly less than your requirement), CIP length mags no problem.

I get 26.5 mils with the 45 rail on my ARC action and the ZCO almost certainly has more vertical capability than my scope.

Could easily hold 3-4 mils, in fact I often hold everything out to 32-33 mils as my Charlie tarac is set to 35 mils so with 32-33 mils I just hold down a bit with it on.

 

[Zatchmo]

Straight jacket seems to have the longest list of "prefits" available and that list is pretty extensive. I was narrowed in a couple because of the short action prefit game.

It seems like there isn't a magic mount solution I wasn't aware of to span a split rail and work, so prisms are the only option for split rails. The list of actions that aren't split is decently long. Seems like the lone peak and the terminus cover the need pretty well. I've handled a terminus before and liked it. I'll see if I can find a lone peak around.

Next question is tenon size, and this may belong over in the gunsmith section, but we'll try here first. Seems like all the custom long actions are 1 1/16" or 1 1/8". Is the extra 1/16" necessary? And if so, do you need to go up to a 1.350 barrel diameter? I can order one and have it in a year, but I have a 1.250 in my hands today and would like to use it.

 

[Steel head]

Straight jacket seems to have the longest list of "prefits" available and that list is pretty extensive. I was narrowed in a couple because of the short action prefit game.

It seems like there isn't a magic mount solution I wasn't aware of to span a split rail and work, so prisms are the only option for split rails. The list of actions that aren't split is decently long. Seems like the lone peak and the terminus cover the need pretty well. I've handled a terminus before and liked it. I'll see if I can find a lone peak around.

Next question is tenon size, and this may belong over in the gunsmith section, but we'll try here first. Seems like all the custom long actions are 1 1/16" or 1 1/8". Is the extra 1/16" necessary? And if so, do you need to go up to a 1.350 barrel diameter? I can order one and have it in a year, but I have a 1.250 in my hands today and would like to use it.

If I was really wanting to push pressure I’d want as big of diameter tenon as possible.
Tons of successful Norma’s and lapua’s running with 1-1/16 and 1-1/8 tenon though.

 

[kthomas]

If the Impact/Lone Peak doesn't quite fit your fancy, then give the Mausingfield a look as another poster suggested. It's no slouch of an action.

 

[Shoots 700's]

I built a 300 N and went with something I didn't have, a Mausingfield.

 

[Zatchmo]

Just for closure here, I settled on the Terminus. I kinda wanted to try a 3 lug anyway.

And for the historical records, Impact 787r is available with a full top rail, you just have to ask for it. At the time of writing this it's a no cost option.