Question Regarding Sight Adjustment and Heavy Bullet

[randyb]

So, I'm still chipping away at this revolver game.
Last weekend I went out to the ranch and set up my targets for a little shooting before I froze out.

I am shooting a Toklat with 45 Colt loads and an Ultra Dot 30 mounted up top.

I usually do a little dry fire practice at 15 and 25 yards, then some offhand shots, then get out the sticks and shoot from field positions.

My normal practice load is fairly tame:  260gr cast from Matt's Bullets with 8gr W231 under it.  At 15 and 25 yards this load groups very well and is pretty much right on point of aim in the center of a paper plate.

I also shoot a 305gr cast from Matt's with 22gr H110 under it.  When shooting from a sitting position off my sticks this load is just a tad high, maybe an inch at 25 yards.
Same set-up but stretched out to 50 yards and my groups are still pretty good, probably around 4" with an occasional flyer...but they are about 5-6" high.
Learning from the folks here I understand that heavier bullets will typically hit a bit higher due to the recoil impulse.  

My question:  How should I adjust my sight?  Where should I be at 50 yards in regards to my zero?  Then, knowing every gun and load is different, what should I expect at longer ranges like 75 and 100 yards?

I appreciate your input and guidance.

Thanks!

[bradshaw]

Dec 5, 2017 10:59:22 GMT -5 randyb said:

So, I'm still chipping away at this revolver game.
Last weekend I went out to the ranch and set up my targets for a little shooting before I froze out.

I am shooting a Toklat with 45 Colt loads and an Ultra Dot 30 mounted up top.

I usually do a little dry fire practice at 15 and 25 yards, then some offhand shots, then get out the sticks and shoot from field positions.

My normal practice load is fairly tame:  260gr cast from Matt's Bullets with 8gr W231 under it.  At 15 and 25 yards this load groups very well and is pretty much right on point of aim in the center of a paper plate.

I also shoot a 305gr cast from Matt's with 22gr H110 under it.  When shooting from a sitting position off my sticks this load is just a tad high, maybe an inch at 25 yards.
Same set-up but stretched out to 50 yards and my groups are still pretty good, probably around 4" with an occasional flyer...but they are about 5-6" high.
Learning from the folks here I understand that heavier bullets will typically hit a bit higher due to the recoil impulse.  

My question:  How should I adjust my sight?  Where should I be at 50 yards in regards to my zero?  Then, knowing every gun and load is different, what should I expect at longer ranges like 75 and 100 yards?

I appreciate your input and guidance.

Thanks!

*****

Two reasons the heavy bullet prints higher:
1) Recoil actually begins while the bullet is in the gun (movement is minuscule).
2) The heavy bullet takes more time to accelerate, thus producing longer BARREL TIME. Barrel time translates to gun movement before bullet departs muzzle. With the bore axis above your hand, a slow, heavy bullet raises the muzzle a fraction of a degree more than a faster, light bullet.

The same heavy bullet pushed faster exits sooner. Velocity lowers Point of Impact. Whereas, high Extreme Spread may have no effect on accuracy of a light bullet----until out yonder----high extreme spread causes vertical stringing with a heavy bullet. Thus, a low ES is favorable to accuracy with heavy-for-caliber bullets.

You cannot be a sharpshooter fighting recoil. Go for the ride. Any grasp of the gun which is not steadily repeatable is fighting the gun.

Decide which load you will live with, then visit the other. Bring pencil & pad, and screwdriver, or don’t even shoot. Record sight dope----one load at a time----25, 50, 75, 100 yards, etc. Count clicks and record. ZERO revolver for one range. Make a drawing of your sight picture. Memorize hold. Record sight adjustment for both loads. Restore “live with" ZERO After all that, learn to Kentucky your “visitor” load.
David Bradshaw

[Yetiman]

Heavier bullets tend to shoot higher because the bullet is in the barrel longer causing recoil last longer and push you off the point of aim more than a lighter bullet does (as you describe in your post).

That theory assumes you are using a similar level (stout or light) powder charge for each.

8 grains of 231 and 22 grains or H110 are quite different loads.

As to where you should set your point of aim, that is a personal choice.

For me, in 44 mag with my SBH Hunter and my Super Redhawk, I shoot some similar loads. My plinker load is a 240 grain SWC over 8.2 grains of W231, and my hotter load (and my hunting load) is a 240 grain XTP over 24 grains of W296.

I tend to set my zero for the 240 XTP at 50 yards. The POI is not too far off at 25 and 100 yards to require a lot of thought, and even my light load is close enough to deal with at 25 yards where I usually use it.

On my Super Redhawk I am using an Ultradot 30 which has a very easy to adjust vertical adjustment that has very repeatable settings. I have the zero set for my 240 xtp load at 50 yards and know that a couple of clicks will have me right on at 100 yds.