Bench to prone difference POI

[mike a]

so I finally have a good load for my 243. From the bench with bags I'm zeroed at 200. With the Varmit hunter reticle on about 13x I've got the 500 hash printing right on. Then I put on the bipod and went prone. Prints 4" higher at 500. So do I go back to bench with bipod and rezero. Thoughts. Thanx Mike

 

[Lapua40X]

The affect of recoil on the rifle can be expected to differ relative to the support mechanism. To accomodate the differences I try to zero with the support I intend to use routinely in competition. There is a difference between my point of impact when I'm shooting prone in competition with the bipod on a gravel surface compared to when I place a pad between the gravel and the bipod.

 

[FeMan]

It depends on what you are trying to do. Most of my rifles change POI up to 1.5 MOA between bench and prone. It has a lot to do with changes in what the bipod is resting on and how I treat the rear of the rifle (shoulder pressure, cheek weld, etc.). I shoot prone almost exclusively so that is what I use as my true zero and I don't worry too much about the bench.

 

[BoydAllen]

Rifles tend to rotate around their centers of mass, and also the point where their rearward motion is restricted relative to the line of thrust (barrel CL). If you raised the butt so that it was above the bore, rifles would tend to go down when they were fired. You have several things going on here. I suspect that the center of your shoulder contact is higher on the butt in one position than the other, and the weight of the tripod, and its placement have an effect on how the rifle recoils. Bottom line....you should always finalize scope adjustments shooting as you plan to when actually using the rifle.

 

[mike a]

Thanx guys, been working on my bench technique a lot lately. Guess I'll have to get my fat belly dirty more often.

 

[rmist]

Food for thought...When I shoot from the bench and then to the prone my scope isn't anywhere close to where I need the correct eye relief. Maybe it's just me !!

 

[ireload2]

If you plant your rifle on the ground with a bipod on one end and a back at the butt you bend your rifle when you plant your face on the cheek piece.

 

[Shaggy357]

The bench is a good reference, but you want to fine tune in shooting position. Grip, line of sight, recoil, perceived point of impact, etc almost always change. Prone over backpack, sitting over bi-pod, or standing off tri-pod, do a little practice in each position to see impact change. Mark it down so you can do quick adjustments as necessary. I didn't realize how much difference there was until on an antelope hunt in WY several years ago. Got my buck opening morning at 385 yards. Missed several does 150-300 and was sure my scope must have been off. Went to a range and printed dead center. Changing from prone to sitting position and my point of impact (and likely confidence) was off.

Something to think about.

Steve

 

[338 Mollett]

Without due diligence one prone match I just threw down my rest and rear bag to get a zero trying to save time and ammo before I slung up to shoot my string for score.After shooting 2 or 3 x's I slung up only to completely miss the black at 300 yds.

 

[Keith Glasscock]

If you intend to shoot prone with a bipod - zero that way. When you come back in a few days/months and the zero is off, it isn't the scope, it is your technique.

This is what makes F/TR so difficult to shoot well. Most people assume that the rifle does the work, but that is only half of the truth. The shooter must interfere with the rifle exactly the same way every shot.

 

[Lapua40X]

If you plant your rifle on the ground with a bipod on one end and a back at the butt you bend your rifle when you plant your face on the cheek piece.

Hmmmmm

 

[Lapua40X]

Food for thought...When I shoot from the bench and then to the prone my scope isn't anywhere close to where I need the correct eye relief. Maybe it's just me !!

Me too. I set my eye relief for the position I will use in competition and just live with the changes I have to make at the bench. Frustrating some times though ....

 

[mike a]

If you plant your rifle on the ground with a bipod on one end and a back at the butt you bend your rifle when you plant your face on the cheek piece.

If I turn it upside down will it unbend? Ha ha just kidding.

 

[ireload2]

I think they have that problem in Australia

If I turn it upside down will it unbend? Ha ha just kidding.