Crossing (but not much)

[norfolk shooter]

Hello all I think I may have hit gold with a load for my double. It is crossing over by about half an inch at 25 yrds I'm just wondering if i was to move back to 50 yards would that be corrected?? I'm going to load up some ammo 1 grain +- of the 87.5 of rs70 that got me good results.
Many thanks chaps

 

[BRICKBURN]

I'm interested to see what the double shooters say.
I can not imagine that it would improve with distance.

 

[norfolk shooter]

I think the -1grain will do the trick. But saying that Im just trying to apply basic geometry and feel the slight crossover should go with moving back (I hope).

 

[BRICKBURN]

I can barely handle loading for one barrel.

 

[Red Leg]

Cross-over doesn't get better as range increases - they just keep progressively separating.

 

[norfolk shooter]

Cross-over doesn't get better as range increases - they just keep progressively separating.

Will that apply if the right barrel is hitting left and vice versa?

 

[norfolk shooter]

Thinking about it your right about it getting worse with distance. Im hoping that the slight decrease in powder will do the trick.

 

[Red Leg]

No two barrels ever shoot perfectly parallel. However it is possible to regulate them close enough so that the separation doesn't matter over the ranges at which it is used. Assuming your cross-over separation measurement is accurate, and allowing at least one minute of angle for each barrel, you should have a one - two-inch composite L/RxL/R 4-shot group at 50 meters and something like three - five inches at 100 meters. That would be fine, even if they are crossing. Unfortunately, distance seems to accentuate other gremlins that aren't apparent at 25 meters. The barrels aren't actually shooting the load 1 MOA, there is a vertical dispersion issue as well, etc. etc.

I use 70 meters as my proof of load distance on most doubles. (An exception is my Blaser S2 which is a 250 meter rifle in .375 guise, and a 300 meter rifle with the 30-06 barrels in place - obviously shooting with a scope). A three - four inch composite group at seventy meters using open sights means that you have an extremely useful firearm capable of doing anything a traditional double should be asked to do.

 

[CAustin]

Norfolk didn’t you say it was shooting well with factory loads?

 

[norfolk shooter]

No two barrels ever shoot perfectly parallel. However it is possible to regulate them close enough so that the separation doesn't matter over the ranges at which it is used. Assuming your cross-over separation measurement is accurate, and allowing at least one minute of angle for each barrel, you should have a one - two-inch composite L/RxL/R 4-shot group at 50 meters and something like three - five inches at 100 meters. That would be fine, even if they are crossing. Unfortunately, distance seems to accentuate other gremlins that aren't apparent at 25 meters. The barrels aren't actually shooting the load 1 MOA, there is a vertical dispersion issue as well, etc. etc.

I use 70 meters as my proof of load distance on most doubles. (An exception is my Blaser S2 which is a 250 meter rifle in .375 guise, and a 300 meter rifle with the 30-06 barrels in place - obviously shooting with a scope). A three - four inch composite group at seventy meters using open sights means that you have an extremely useful firearm capable of doing anything a traditional double should be asked to do.

In that case I guess I should just leave the 87.5 grain load alone and test it at 50 meters. I have since starting this post loaded up some more ammo + and - 1 grain of the 87.5. If I can get it to shoot right I would prefer that

 

[norfolk shooter]

Norfolk didn’t you say it was shooting well with factory loads?

Nope it was hopeless. The hornady ammo is shit and not very consistent. One shot to the other would vary by 100-150 fps!!!