Crossing (but not much)

norfolk shooter

AH legend
Joined
Dec 22, 2012
Messages
2,049
Reaction score
3,260
Location
Norfolk, UK
Media
19
Articles
1
Hunting reports
Africa
1
Member of
BASC
Hunted
UK, Norfolk, Cambridgeshire, Dumfries and Galloway, Isle of Arran (Scotland). RSA, North West, Kalahari, Limpopo
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
 
I'm interested to see what the double shooters say.
I can not imagine that it would improve with distance.
 
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).
 
I can barely handle loading for one barrel. :A Bang Head:
 
Cross-over doesn't get better as range increases - they just keep progressively separating.
 
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?
 
Thinking about it your right about it getting worse with distance. Im hoping that the slight decrease in powder will do the trick.
 
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.
 
Norfolk didn’t you say it was shooting well with factory loads?
 
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 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!!!
 

Forum statistics

Threads
53,626
Messages
1,131,413
Members
92,685
Latest member
YvonnePaws
 

 

 

Latest profile posts

Impact shots from the last hunt

Early morning Impala hunt, previous link was wrong video

Headshot on jackal this morning

Mature Eland Bull taken in Tanzania, at 100 yards, with 375 H&H, 300gr, Federal Premium Expanding bullet.

20231012_145809~2.jpg
 
Top