On saturday I had obtained a 215 yd zero using a rifle rest with my 260 Rem. Groups were about 1/2 MOA. This morning I was checking something and ended up throwing on the shortest Harris bipod at 100 yds. Instead of hitting approx 2.1" high @ 100 my tiny group was hitting dead center; 2.1" low! Is this common? Can changing back and forth from a bipod to a rifle rest and maybe someother form of rest such as a backpack, jacket/hat covered brush, branch, etc really make that much of a difference?

Alan

What was your bipod resting on? They are supposed to recoil rather badly if rested on a hard surface like a bench or a concrete pad. I am not surprised at the POI change.
Peter

I put a square of carpet under the harris legs when shooting off the bench.

Von Gruff.

I use a portable folding platic picnic table as a portable bench. Only had a thin blanket to keep stuff from rolling around covering the table. I guess bounce might be the culprit?

Alan

Is your bipod sitting on the same spot as your rest is supporting? Move that point and you change the harmonics in the barrel.

It might be a difference of 6-8".

Alan

Went back out yesterday am and tested something. Switching back and forth between a front BR and my Stoney Point Hunt n' Hike shooting sticks, their is no POI change. Throw in the Harris bipods and the POI does change.

Alan

From my experience, it is dependent on the rifle. I have heavy tactical type rifles that shoot the same zero off of Harris bipod as they do off of a rest. Seems like the lighter sporter type rifles I have used them on have changed POI more. It is always low in my experience. I assume it is the extra weight out near the end of the stock?????????

If I am going to use one when I hunt with it, I zero the rifle with it. End of problem. But I rarely every use a bipod hunting. I prefer a good sling like the tactical intervention with a detachable cuff. Get slung in properly and you are rock solid with out the extra weight hanging on the rifle and messing up the way it handles and balances. I killed a coyote with that set up on a 260 Rem at a lasered 471 yards while I was sitting on the ground leaning against the tree slung in. The crosshairs layed rock solid on him.

Just my experience with bipods. Hope this helps some.

PaPa 260

I have a theory of my own when it comes to changing POI's depending on the front rest.

My experience shows that it is not the front rest in itself, which influences POI but the surface of it, meaning how much resistance is offerd to the stock when the rifle recoils.

I came to notice it when shooting a rifle with rubber inlays on the forend. It shot high off leather bags with some condsiderable amount of vertical stringing compared to shooting it off a bipod or free-hand.

This was obviously due to the fact that the rubber parts of the stock where sticking to the leather surface of the bag.

I now use a double folded silk scarf between bags and forend. This lets the gun ride the bags in an equal manner from shot to shot. As a result vertical stringing and changes of POI are a thing of the past.

i once tested my harris bipod on two 6.5 x 55 rifles after a hunt for same info but at 260 yds, (as far as I can shoot hear. Both rifles sighted in 2" high at 100 yds. remington 700 classic 10.5" low, tikka t3 4.5" low. Soooooo!

There are a number of variables in how a rifle will react to having a swivel-mounted bipod hung on its front end.

First of all, the sling swivel was designed to connect a carrying strap to the stock, not to attach a rest. So that fact needs to be taken into account when using the sling attachment for some other purpose than a carrying sling.

If a rifle's barrel is floated (not touching the stock forward of the receiver ring) and attaching a bipod and resting the rifle's weight on the bipod does not cause the barrel to contact the stock, then the change in zero may be negligible.

On the other hand, if the rifle's barrel is floated, but utilizing the bipod causes the fore end to move relative to the barrel and move enough that it contacts the barrel either when static or when fired, then you can expect a more radical change in point of impact.

Fully bedded barrels, or barrels bedded with up-pressure near the fore end like a conventional Remington 700, will almost always exhibit a significant zero shift when a bipod is utilized. The reasons for that should be obvious to all but shooting neophytes, so I won't go into an explanation.

Simply attaching the weight of a bipod may (likely will) change the point of impact even if the rifle is fired offhand without the bipod resting on anything. Again, the weight of the bipod changes the relationship between the stock and the barrel, therefore the point of impact is almost certain to change.

I have a Remington 700 30/06 that has a Harris bi-pod that I use for shooting mostly at 800 yards. A couple of months ago I checked the zero at 100 yards off a bench and sandbags and much to my surprise the elevation was the same but the group landed 8 inches left. I didn't check at 100 yards with the bi-pod but should have.

During recoil with that rifle the bi-pod always leaves the ground and seems to want to rotate somewhat to the right so that must be the windage difference. Confusing but that is the facts.

Regards, Keith

Barrels and forends bend if they are put under pressure. You can demonstate this with just a benchrest. Many shooters will shoot with one hand on the pistol grip and one under the butt stock. When shooting like this many will try to hold the rifle down with their cheek. This pressure is bends the stock and if the forend touches the barrel, it also bends the barrel causing a lot of vertical dispersion.
If you shoot with the same rest put your off hand between the rest and the fore end. Your hand will easily be able to detect variations in the force your put on the stock with your face.