I understand this will give the best test of pure mechanical accuracy. But for a hunting rifle, do any of you zero with the fore-end supported by your hand on the bag, or anything else that will reduce the possibility of upward or lateral movement?

Or, do you use different techniques for different guns? I read some writer who suggested that for pump-action rifles and slug shotguns, the fore-end should be gripped with the hand, and I've found this to be helpful with my 870. Similarly, Dave Scovill says he tests lever-action rifles with the front bag under the receiver to reduce vibrations through the barrel bands and magazine tube.

John

I now generaly zero by resting on the wing mirror and door of my car and holding onto the fore end. I generaly check zero in this fashion on a rabbit at 150 - the perfect confidence booster that also keeps the farmer happy (but not at 6am!)

You are absolutely right. Many, if not most, people do sight their rifle in under conditions that will result in a different POI than they will experience in the field.

The phenomenon you are referring to is generally called "barrel time". That is, the time the bullet is in the barrel, while it is recoiling. Recoil begins the instant the powder and bullet begin to move.

The greater the recoil, the greater the effect of barrel time on POI. For instance the change in POI of a .243 with an 85 grain bullet between "free recoiling" (no hand on the forestock or barrel) and shooting with a supporting hand on the forestock, is quite small. Try the same thing with a .300 Mag and you'll see a substantial difference (a couple inches at 100 yards). Stock design also makes a difference. For example, Weatherby stocks cause greater muzzle lift than straight stocks, and as a result will have a greater impact on vertical movement of POI.

I usually do load testing and sighting in using the "free recoiling" technique, as it is the most accurate (removes more human variables). Then I practice from different shooting positions to note the change in POI. All shooting positions will vary. For instance, off hand shooting will result in more muzzle lift than shooting from a sitting position (at least for most people -- everyone is different) because your shoulder will have less give when sitting down and leaning in.

In the field, I try to use a rest if possible. From that rest I will try to shoot "free recoil" whenever possible. That's when I know I am most deadly. If that is not possible, however, I use whatever technique is most fitting of the situation, but I have a good idea how that will effect POI (it will always be lower) from my practice at the range.

Regards, Canuck

[This message has been edited by Canuck (edited 10-09-2001).]

Using real guns I've not had nearly so much trouble. One benefit of a free floated barrel is that sling tension should have little impact.

I never leave the range without practicing some off hand shooting, say 10 shots at least.

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

Most of the time I hunt western states, and shoot off a fanny pack that acts much like the sandbag I use at the range. I shoot prone when I can, sitting if need be. POI has not been a problem.

Tom

I have never busted a knuckle on a trigger guard nor broken the skin of my forehead from a scope bite...knock wood I think you can mimic the dynamics of the offhand grip even when shooting from the bags, and have minimal POI shift between the two techniques.

That 0.147" 3-shot group at 100 yards with the GS Custom FN (380 grain) and 105 grains of H 4831 (2509 fps) was shot from the bags and a death grip with both hands, on the Ruger 416 Rigby. The same load and rifle drilled a cape buffalo heart dead center at 75 yards off shooting sticks, with both hands gripping the rifle tightly, forearm tip only lightly supported by the crotch of the sticks. Works for me.

------------------
Good huntin', shootin', and spear chuckin',
RAB

The problem is that hunting situations call for all different shooting positions and POI is going to change a little with each change in position. But in most instances not enough to worry about.

I recommend sighting in off the bench to eliminate as much pilot error as possible and then trying various positions to see what effect, if any, they have on POI.

------------------
To be old and wise.....first you have to be young and stupid!

quote:

---

Originally posted by R. A. Berry:
I always grip the rifle with both hands even when shooting off the bench. The bags merely eliminate the wobble of the offhand shot.

---

IMHO this is the best way to eliminated POI shift. I think a lot of people do this without thinking of it. At the range I don't see too many shooter that let their rifle free recoil from the bench. Almost all of them have their non-trigger hand on the forestock, barrel or even the top of the scope when sighting in. By controlling muzzle jump in this manner, they are unwittingly mimicing off-hand or field position shooting and will see little change in POI.

The best example I can think of that demonstrates the effect of barrel time, is the addition of a bipod to a sighted in rifle. By adding weight to the fore-end of the rifle, muzzle jump is reduced and POI generally shifts downward.

FWIW, Canuck

------------------
Good huntin', shootin', and spear chuckin',
RAB