There is always a different POI from each barrel. So how big the difference of POI between each barrel should be tolerated to meet the criteria for a quality double?

Two inches at 50 yards.
peter.

Ideally, the right barrel and left barrel will print side by side, right on right, left on left, from just beyond the muzzle to too far to shoot. Like a figure eight on its side.

I don't have a world of experience but I do know that Butch Searcy told me he garuntees two inch groups with open sights at 50yds and two inch groups at 100 yards with a scope equiped rifle.

My rifle, a Thys, shoots better than I can at 50 yards. I can get a 2 or 3" group, but better shots have done well under 2".

JPK

Not much. A double is a hunting rifle, as opposed to a target rifle, but I expect them to shoot. Good accuracy depends on bore condition and correct ammunition as much as regulation. If I can't find a load that will put two pair in 3" at 100 with express sights, I have the rifle re-regulated.
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quote:

Originally posted by JPK:
Ideally, the right barrel and left barrel will print side by side, right on right, left on left, from just beyond the muzzle to too far to shoot. Like a figure eight on its side.

JPK

First, let me thank Saeed for this forum! It was a needed place here on AR!

Ideally, is the word! The Ideal is sometimes hard to find. However JPK is correct, with his description of the ideal grouping for a well regulated, and properly loaded double rifle! The figure "8" turned on it's side is a good description. The properly regulated barrel set will place the CENTER of the right barrel's group slightly on the right of the POA on the sights, with the CENTERof the left group slightly on the left of POA, with the elevation being the same for each barrel group. The right 1/4 of the left group overlapping the left 1/4 of the right group, forming a composite group of both barrels that is about 150% of either barrels individual group. Example: If the two groups are each 2" the composite group should be , IDEALLY, a 3" composite group!

As 400 NITRO EXPRESS says if a double rifle will not shoot inside a 3", to 3 1/2" group with it's express sights @ 100 yds, it is either not loaded properly, or it needs re-regulating.

I'll add FWIW, in my own experience, I have found that my double rifle can shoot beyond my ability.

JPK

First 2 shots from my Merkel 470 were 1 1/2" spread and 1" left at 50 yds offhand. So I quit and said GOOD. Not really, moved the rear sight (ALL iron sighted guns shoot to left for me from factory) and they are spot on and 1 1/2" 1 3/4" at 50 yds. 3" circle at 100yds as I'm really nearsighted and just plain don't SEE that well at 100 yds ( I wear tri-focals) but I figure the rifle is more than accurate enough for me.