Which Spuhr Mount?

[radford56]

I have an Accuracy International AT rifle on the way with the low 20 MOA action rail (26981). I would like to use a Spuhr mount to mount my scope - which is a Vortex Gen II Razor, 4.5-27x56. I don't currently plan to use night vision on this rifle so I don't need to consider that when choosing the mount.

I'm a little overwhelmed by the choices that are available in the Spuhr lineup (though I'm not sure any are actually in stock anywhere). If anyone has used this set up I'd appreciate any feedback on which Spuhr mount you'd choose and why.

Thanks!

 

[Hemphill072]

While not an identical setup to yours I recently bought an AX308 and mounted a nightforce 7-35x56 with the Spuhr 4002 mount. This is the 38mm (1.5") high mount without any additional inclination(0 MOA). Because of the full length rail on this rifle I needed the 38mm height to allow adequate clearance for the scope caps on the objective bell. You may be able to go with the 34mm (1.18") model as your rifle does not have this rail.

I went with a 0MOA base because it is nearly impossible for me to find a range where I can shoot beyond 1000m. With the elevation I have on the scope with the 20" 308 barrel I have I can dial to over 1,200m which for me is more than enough. It was also the only mount I could find at the time here in Canada which made the choice simple. If you need the additional elevation look at a 4601 or 4602 which are the mounts above but with 20MOA (6 MIL) additional elevation. For me and the purpose for this rifle it really only nets me around 200m additional range, your results will differ.

Hope this helps.

 

[radford56]

While not an identical setup to yours I recently bought an AX308 and mounted a nightforce 7-35x56 with the Spuhr 4002 mount. This is the 38mm (1.5") high mount without any additional inclination(0 MOA). Because of the full length rail on this rifle I needed the 38mm height to allow adequate clearance for the scope caps on the objective bell. You may be able to go with the 34mm (1.18") model as your rifle does not have this rail.

I went with a 0MOA base because it is nearly impossible for me to find a range where I can shoot beyond 1000m. With the elevation I have on the scope with the 20" 308 barrel I have I can dial to over 1,200m which for me is more than enough. It was also the only mount I could find at the time here in Canada which made the choice simple. If you need the additional elevation look at a 4601 or 4602 which are the mounts above but with 20MOA (6 MIL) additional elevation. For me and the purpose for this rifle it really only nets me around 200m additional range, your results will differ.

Hope this helps.

Thanks for the reply - I'm still mulling over the various choices. It helps to get input from other users.

 

[Jarhead6870]

Sphur offers several rings at various cants to help you extend your scope's usuable elevation based on your needs and scope's overall travel. You don't mention the caliber or distances you are shooting but that is going to be your first consideration.

As an example, I have a AXMC in 300 Norma, and although it has a 30 MOA rail, if I use the 0 MOA Sphur 4002 mount, I would be zeroed at 100 yards and it would be fine for most shooting applications out to 2100 yards. However, I shoot beyond that and need more elevation when shooting at extreme distances considering what my calibers AND scope are capable of. This left me with a few options;

1 - If I want to zero at 100 yards and maximize my scope's 28 MIL overall travel (RZR 4.5x27 Gen 2), I need a 50 MOA base to get the most elevation from my scope. To do this I would use the 20 MOA Sphur rings giving me 30 MOA from the rifle and 20 MOA from the rings. With the 300 Norma and my enviromentals I can dial the scope and shoot 2400 yards.

2 - If I want to shoot 2640 yards (1-1/2 miles) I need 34.1 MILS of elevation which is more than I can dial on the RZR when using option 1 which is zeroed at 100 yards. For me, the easiest solution was to use a ERA-TAC adjustable base/ring combo which allows me to change the cant on my scope based on my shooting distance needs. With the base dialed to 50 MOA and the 30 MOA of the rifle (a total of 80 MOA), I need 25 MIL of elevation for the 2640 yard shot making it so I can dial without having to hold over BUT this means I can't shoot anything less than 1300 yards.

Having an adjustable base also means that the ring height must be high enough to handle the changing cant so the scope's objective lens housing will clear the barrel or rail. It works well and is repeatable but, again, it depends on your shooting needs.

 

[radford56]

Sphur offers several rings at various cants to help you extend your scope's usuable elevation based on your needs and scope's overall travel. You don't mention the caliber or distances you are shooting but that is going to be your first consideration.

As an example, I have a AXMC in 300 Norma, and although it has a 30 MOA rail, if I use the 0 MOA Sphur 4002 mount, I would be zeroed at 100 yards and it would be fine for most shooting applications out to 2100 yards. However, I shoot beyond that and need more elevation when shooting at extreme distances considering what my calibers AND scope are capable of. This left me with a few options;

1 - If I want to zero at 100 yards and maximize my scope's 28 MIL overall travel (RZR 4.5x27 Gen 2), I need a 50 MOA base to get the most elevation from my scope. To do this I would use the 20 MOA Sphur rings giving me 30 MOA from the rifle and 20 MOA from the rings. With the 300 Norma and my enviromentals I can dial the scope and shoot 2400 yards.

2 - If I want to shoot 2640 yards (1-1/2 miles) I need 34.1 MILS of elevation which is more than I can dial on the RZR when using option 1 which is zeroed at 100 yards. For me, the easiest solution was to use a ERA-TAC adjustable base/ring combo which allows me to change the cant on my scope based on my shooting distance needs. With the base dialed to 50 MOA and the 30 MOA of the rifle (a total of 80 MOA), I need 25 MIL of elevation for the 2640 yard shot making it so I can dial without having to hold over BUT this means I can't shoot anything less than 1300 yards.

Having an adjustable base also means that the ring height must be high enough to handle the changing cant so the scope's objective lens housing will clear the barrel or rail. It works well and is repeatable but, again, it depends on your shooting needs.

You're right, I should have mentioned my intended use. The rifle is a 6.5 CM and the vast majority of my shooting will be done under 1000 yards to maybe 1200 yards on occasion. Anything longer than that will be the exception versus the norm. From the research I've been doing it looks like the Spuhr 4006 (0 MOA, 1.35" height) might be the best choice for me on this rifle.

 

[Jarhead6870]

For that caliber and the distances you expect to shoot, the 0 MOA is all you need and it keeps the erector fairly close to the middle of its internal travel. You will probably have enough elevation to dial and reach 1500 yards with that configuration.

As long as the objective bell clears the rifle, ring height and scope above the barrel/rail height has become less important with the availability of adjustable cheek risers in stocks and chassis. Just make sure to include the scope height (centerline of action to centerline of the scope) in your ballistic program. As long as the measurement is within a 1/16" or so, you're good to go.