a scope sightin problem

[wildcat westerner]

I have a unique long range rifle. In .338 win. mag., the barrel is 34 1/2" long with muzzlebrake, a is full 1 1/2" in diameter. The barrel is encased in a nine inch barrel bedding block and the free floating action is a Stolle tactical action with a fully functioning magazine. The Stolle integral scope base is a 20 minute one piece base.

The problem is that with larger objective scopes,(50mm and 56mm etc.) when mounted properly you cannot adjust the scope low enough to sight the rifle in at 200 yards. We have just placed a scope on the base with a small 40mm objective and that might just work. BUT, this rifle was built for longer ranges and a larger scope with a larger objective allowing more lighting would surely be indicated for this rifle.

I simply cannot figure out the correct answer for this rifle. the 20 minute scope base and even higher, would seem appropriate for such a long range rig meant for prone shooting. Higher rings would provide clearance for the objective bell of a larger scope, but the rifle would need to be sighted in, perhaps, at 4-500 yards minimum. It's embarrassing not to be able to figure out this answer and I would appreciate some constructive answers to this vexxing problem.

Thanks, in advance.

 

[436]

You might start with a standard scope base, check with Mounting Solution Plus... https://www.mountsplus.com/ you're looking for the same height without as much cant forward. Just thinking out loud... Cheers

 

[lancetkenyon]

There is no reason using higher rings to clear the barrel would cause the need for a 400-500 yard zero with a 20MOA base. The difference in clearance between a 40mm objective and 56mm objective is only 8mm, or .315". Get that much higher rings and you should clear.

 

[wildcat westerner]

Hello Lance,
I agree totally BUT in using both a 30mm and 34 mm scope we could not get them adjusted down far enough to get a 200 yard zero. It was frustrating since I have a lot of loads with cheap bullets ready to go to find out exactly which powder will work best with this very long heavy, fluted barrel.
I called Kelbly and told them about my problem. They simply are going to exchange my 20minute base with a level one. They were surprised to hear of the problem, but this will allow me to use the larger 30 and 34 mm scopes for this prone rifle. I realize I may be giving up some range in going back to an absolutely staright scope base, but I do want a practical zero that is not in the next county.

 

[WeiserBucks]

What scope? Is the zero stop holding you back?

 

[bdlesh]

If this is a long range 500 yards and up....what's the problem? If it zeros at 200, why would it matter if you can't go lower? What am I missing?

 

[Mcranch]

Ok, concerning rifle action 20 moa cant. I have a rifle LA action with an 20 cant. I am using Vortex precision 34mm rings. Placing the scope and level. When bore sighting the scope to the bore I used 11.5 minutes reticle elevation. On another scope and rifle with 10 Moa cant it went the opposite clockwise I would say gaining minutes ? back to initial configuration I'm thinking that by going counter clockwise on a 20 Moa cant it should have gone clockwise to be gaining minutes. I'm trying to wrap my head around the cant on the action as well as understanding the concept. I have several rifles but have only flat rails. Maybe I should have -laced this into another page but following along I though about interjecting.

 

[lancetkenyon]

What scope? Is the zero stop holding you back?

This. Are you sure you do not need to loosen up your zero stop to allow adjustment?

Every time I hear someone say "I can't zero at 100 (or 200)", it has been a zero stop problem. Probably 50 times I have seen it.

Unless something is majorly wrong with the rail, or rings, or mounting holes.

What scope is it you are attempting to use?

 

[wildcat westerner]

Zero stops, not being engaged are not the problem. My NightForce 5x25 has worked well on other rifles for years. The new Arken 34 mm does not have the zero stops engaged yet, either.
I simply could not adjust the scopes so the aiming point was at the level of the 200 yard aiming point. The flat scope base will solve this problem and I can then go about ballistics workup and also do a direct comparison of these two different scopes. I have a 800 yard range, so it will prove interesting finding out what these heavy slugs are truly capable of, and how far beyond 800 this particular rifle is capable of shooting accurately.
I retired to the Rockies having won, long ago, a match with 307 other shooters and have also set long range worlds' records. The first year at 6,500 feet I realized I knew practically nothing about long range shooting in the wind. That's why when the opportunity to get this unique barrel came along, I snapped it up.

 

[WeiserBucks]

You've set long range world records without shooting in the wind?

 

[Mcranch]

This. Are you sure you do not need to loosen up your zero stop to allow adjustment?

Every time I hear someone say "I can't zero at 100 (or 200)", it has been a zero stop problem. Probably 50 times I have seen it.

Unless something is majorly wrong with the rail, or rings, or mounting holes.

What scope is it you are attempting to use?

This. Are you sure you do not need to loosen up your zero stop to allow adjustment?

Every time I hear someone say "I can't zero at 100 (or 200)", it has been a zero stop problem. Probably 50 times I have seen it.

Unless something is majorly wrong with the rail, or rings, or mounting holes.

What scope is it you are attempting to use?

Kahles 5x25-56. Impact action.

 

[lancetkenyon]

If they can zero this optic for 100 yards, there is no reason you shouldn't be able to zero yours.

 

[Mcranch]

I had no problem with my Swaro x5i. I just feel that a cant should give one minutes going clockwise instead of counterclockwise. Instructions state bore sight and which I have done. Will try going back to initial position and work from there removing turret cap. . Or count the clicks forward and back see where it's at?

 

[wildcat westerner]

Weiser, both were set in really good conditions. The previous match was shot when the sun broke out from the clouds and nearly everybody had two groups at their 600 yad target. The next match there was a long line of clouds hiding the sun, so that the light was constant and so was the very low, consistent wind.