I have loaded up four light loads in 308, all with IMR 3031 using Hornady 150 grain SP bullets. The loads were all shot from a Winchster Model 70 built in 1973 at 100 yards. I sighted in the scope using regular load Fusion bullets, 150 grain. I did this just to make sure the gun fired accurately as it was a new purchase in Feb. What I found was that the light loads all shot right of the point of aim by at least three inches. The dispersion was not too bad, working down from 2.5 inches to about 1.5 inches, however, all the loads shot consistently right.

I know many on the forum have experience with light loads. I would be interested in knowing if my out come using the light loads is similar to others, Is there a pattern of light loads shooting to the right, left, high or low? I would also appreciate knowing what the MOA that others have found with light loads. Can one expect a MOA of sub 1" or is 1.5 inches the best that can be expected due to the lower velocity.

Lastly is it something in the handloads that I am doing or not doing that could have cause the gun to shoot that far right.

Thanks for the help.

Brad S
Hebrews 10:39

Welcome to the sometimes fustrating world of reduced loads...as you found out, getting them to shoot where you want them to can be a lot of work.

Might be several things...some you just can't do anything about other than trying differnt loads.

Lets assume the scope is level and not cnated and that the nut behind the butt plate was tight that day.

Could be barrel vibrations. Barrels do vibrate, and it's not a stright up-and-down pattern.

Barrel time plays a part...recoil is less with reduced loads, but the bullet spends more time in the barrel. If your shooting style and stock shape lets the gun pivot a bit to the right (for a right handed shooter), might be part of the effect.
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Usually I try for loads that shoot to the same windage...usually they shoot low, but if I can find one that lands where the thick part of a duplex reticle starts, am pleased.


So don't give up.

MIGHT want to test fire a few groups from your left shoulder (if you are a righty) and see if the POI changes. Not thaqt you'd use the rifle that way, but if the POI does change, then we'll know it's gun-related rather than load releated.
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Accuracy:

To tell the truth, other than cast bullet loads, haven't tried for max. accuracy with jacketed reduced loads. Usually have a specific use for those kind of loads, and once a load fills that expected use, will stop refining it.

No reason it can't be as accurate as full charged ammo...does have air space issues inside the case, a longer barrel time to make your hold more important, and tend to be more wind sensitive...but should be able to match full charged accuracy.

For BradS

I have two loads for a Ruger in 280 Rem that shoot left /right of each other. Neither load in this case are reduced loads. I use the same bullet with both loads and the velocities are very close to each other. The only difference is that one is Reloader 19 powder and the other is IMR/DuPont or whatever they call themselves now. How does this relate to your original post , you may be wondering? Only that in the world of handloading ammo there are no absolutes .

agree with ribbonstone,start simply,If you are right handed that would be a simple explaination.
If you change from powder to powder your impact point is likely to change.Another thing,2 diferent rifles even from the same maker in the same chambering will not always like the same load.
Knowing this,what you are experiencing doesn't surprise me.I don't mess with reduced loads for jacketed bullets but maybe some of what I know can help.
I had a Rem 700 Sendero in 300 Win Mag.I was trying to squeeze all I could out of it.After developing many loads for it and shooting all the way out to 1000yds,I sent it off to be cryo treated.An unusual result came from it.Upon rebedding it in the stock and taking it to the range with 6 or seven of my loads for longe range I was shocked to learn that loads that had formerly impacted in different places from point of aim had now moved.......to point of aim. A fellow 1000yd bechrest shooter had firelapped his barrel and acheived the same results.I can't say this will work on your rifle, and personally I still cringe at the concept of firelapping although ive done so to a pistol or 2,but it is something you could try.In my experience in benchrest the premium barrels are not near as fickle when developing loads.hope this helps.

Thanks for the help so far. This was my first run at light loads. The purpose of the light loads was simply to give my son some shooting time without the full kick. My loads were 150 grn Hornady SP with IMR 3031. The loads ranged from 28.9, 29.4, 29.9 and 30.4.

In working with light loads, my first thought is that they may fire slightly below the full loads. I was surprised to find that they were all at the same level. At first I thought the drift had something to do with the spin of the bullet being impacted by the slower velocity. I estimated the velocity at 1900 to 2100 fps. THis is much less than the 2700 fps that I was estimating the full load was.

The holes on the target were sharp with out any evidence of tumble. I will try again this weekend if the weather cooperates.

Any other comments would be greatly appreciated. Thanks for the help.

Brad S
Hebrews 10:39

[ tend to be more wind sensitive...but should be able to match full charged accuracy.[/QUOTE]



Ribbonstone-
Just realized, there was a very slight breeze left to right while we were shooting. Like my prior post, I will try again with this load to see if the breeze may have been part of the issue. Will keep you informed.

Thats the fun of the sport, there as so many variables in shooting, it just gives you more excuses to go shoot :)

Brad S
Hebrews 10:39

When working up loads in my 300 WBY I found a 1 foot left to right impact diiference in going from the Speer start load to 1 gr shy of the max load..

Never figured out for sure what caused this, but did notice it..

Good luck

Nate