Reduced loads in Double Rifle: Accuracy

[Ray B]

The regulation aspect of reduced loads (all loads) in DRs has been discussed a lot- What I am asking is if the DR barrels are accurate within the limits of a reduced load- nothing to do with how the right barrel shoots relative to the left barrel. Put another way- Could a cast bullet load be developed, lighter than normal, less pressure and velocity than normal but the rifle is sighted to the point of impact for that barrel? As an example, A DR chambered for 458 Win Mag will place 500 grain full velocity load bullets from each barrel within a small distance at 50 yards- Will that same gun shooting a 400 grain bullet, reduced powder charge with 1500 fps MV place five bullets so loaded in a small area at 50 yards when fired from the same barrel?

 

[uplander01]

That’s a valid question and the barrel might put the bullets in a small group somewhere on the target but I would wager the group won’t match up with your point of aim with your sight. Sight regulation on a double is for specific velocity, specific weight, specific point of impact. If you were willing to have sight work done you could probably sort it….but why turn a double into a single shot?

 

[Ray B]

Just as Townsend Whelen loaded full-power and reduced loads for his rifle to be carried on his wilderness sojourns, having full loads for which the rifle is regulated and having reduced loads with separate sight settings can add utility to a rifle. Most DRs are now set to have optical sights in place and the better sights have multiple settings so it could be arranged for one setting to match the regulated barrel and another for the reduced load in one barrel. i realize that some would be confused by having two sight settings, but most with familiarity could adapt to the challenge.

 

[Rare Breed]

That’s a valid question and the barrel might put the bullets in a small group somewhere on the target but I would wager the group won’t match up with your point of aim with your sight. Sight regulation on a double is for specific velocity, specific weight, specific point of impact. If you were willing to have sight work done you could probably sort it….but why turn a double into a single shot?

My point exactly. A DR is all about regulation. I just do not understand the value in trying to shoot reduced loads in a DR given you will not get regulation so the bullets could be widely apart. In effect you are tying to turn a DR into a single rifle. Just do not understand why...I can guarantee you will not get regulation from doing this which is what is critical about any DR.

 

[MacJenkins]

The regulation aspect of reduced loads (all loads) in DRs has been discussed a lot- What I am asking is if the DR barrels are accurate within the limits of a reduced load- nothing to do with how the right barrel shoots relative to the left barrel. Put another way- Could a cast bullet load be developed, lighter than normal, less pressure and velocity than normal but the rifle is sighted to the point of impact for that barrel? As an example, A DR chambered for 458 Win Mag will place 500 grain full velocity load bullets from each barrel within a small distance at 50 yards- Will that same gun shooting a 400 grain bullet, reduced powder charge with 1500 fps MV place five bullets so loaded in a small area at 50 yards when fired from the same barrel?

I would doubt it. Where I would start with using the same charge that regulates your 500 grain with the 400 grain bullet. Or try even a 350 grain.

I've done this with 4 doubles now and had good results, it got me in the ballpark quickly. Adjust a little form there.

 

[Mountaineer]

I have gotten very good regulation from bullets ranging from 480 to 300 grains in my 458.

 

[zephyr]

Are you familiar with the 75% rule??? loading a bullet that is 75% the weight of the bullet that the rifle is regulated for over the same powder charge should shoot to same POA POI ...
for example your 450NE is regulate for a 480gr bullet over so many grains of H4350 75% of 480 is 360 a 350gr bullet over the same powder charge will have less recoil .... I also shoot lots of Trail Boss or 5744 will shoot a 405gr cast bullet at 1800 fps shoots a little low but my 200yard leaf will put it close enough