Shooting prone ground effects

T

tangolima

New member
After some fiddling my AR in 5.56 shoots 10-round groups at 100yd consistently better than 1.5". I shoot sitting at bench about 3' off ground.

However when trying shooting in prone position, about 8" off ground, I notice the groups open up to 2". The degradation is mostly in windage, so the groups have shape of horizontal ovals.

Are there some ground effects in play here? I wouldn't be surprised seeing the dust kicked up by the muzzle flash.

-TL

Sent from my SM-N960U using Tapatalk
 
Last edited:
4

44 AMP

Staff
Try shooting off the bench with the rifle in your hands exactly the way you do in field positions (no bags, no rest, just you supporting the gun) and see how you do.

My guess is you won't do quite as well as shooting rested off sandbags...
 
R

Rimfire5

New member
Try raising your front rest or get a good steady bipod like a Sinclair F-Class and set the hight up.

I suspect that you are too hunched over when prone and it is impacting your ability to get a consistent set up.

The rifle is just as accurate from the prone position as from the bench.
However, your position isn't the same wrt the rifle so I suspect you will have to adjust it to get the same accuracy.
 
B

ballardw

New member
Unless there are changes in actual wind when shooting prone I would suggest that your prone position has one or more issues.

First thing I would check is for natural point of aim. Get into your prone position. Close eyes for a minute. Open. Are your sights still in alignment with the target? If not, your basic position is pointing you somewhere else and you are fighting that - constantly.

If your sights are to the left or right of the target move your whole body, not the rifle, not just twitch the sights, but your whole body until you can keep the sights on your target when repeating the "close eyes".

Note that tipping the rifle from left to right a small amount will have the affect of left/right "windage" changes. Sandbags may not be quite set up the same when prone allowing tipping under recoil (slight as that may be with 5.56 ) that your body position is allowing/not correcting.
 
S

stinkeypete

New member
My range has a shooting hut, then a concrete “bridge” the bullets go under, then a covered target hut. There is a wide shadow under the “bridge” (designed so ricochets off a ground hit can’t get over the backstop berm and knuckleheads can’t shoot over the backstop as well.

On very hot sunny days, I have seen dust-devils on both sections of “open” range.

Theoretically, one might get some ground thermal wind effects close to the ground.

Practically, I would wager that the rest and or hold is different when prone.

Experiment: shoot prone from a shooting table!
 
B

Bart B.

New member
Most horizontal stringing when in prone is caused by the front elbow being sideways a bit different for each shot.

Keep the front elbow fixed in place almost directly under the barrel while reloading and adjusting the sight.

What causes vertical shot stringing when in prone?
 
Last edited:
B

ballardw

New member
Bart B. said:
Most horizontal stringing when in prone is caused by the front elbow being sideways a bit different for each shot.
Click to expand...

OP says he is shooting off sandbags when prone. So elbow is less likely an issue.

What causes vertical shot stringing when in prone?
Click to expand...

I used to think breathing as the first culprit for vertical stringing when shooting prone. Depending on position and body shape, additional pressure on the diaphragm can magnify small differences in shot-to-shot consistency.
 
T

tangolima

New member
Thanks guys for your inputs. It is most likely that I wasn't in the best prone position and it has caused the windage variations. More practice is in order.

-TL

Sent from my SM-N960U using Tapatalk
 
B

Bart B.

New member
Most vertical shot stringing when shooting prone is caused by inconsistent stock butt vertical position in the shoulder.
 
Last edited:
J

jrinne0430

New member
I would agree that the something is occurring/changing (elbow, stock, cheek to stock position). Keep trying and make sure you are getting the same cheek to stock position/weld which will ensure you are getting a consistent sight picture.
 
Last edited:
Z

zeke

New member
Have noticed that need to make elevation adj when shooting prone at mid ranges (400-600 yds) It is consistent to all the rifles used with bipod and rear bag, and is a couple tenths mil or more at 600 yds. Am attributing it to how my body handles recoil in differing positions, with a sitting bench position allowing very slightly more lift.
 
T

tangolima

New member
I have noticed the change in elevation when the shooting position changed. Easily +/-1moa. At the begining it was frustrating as I thought there was something wrong with the equipment. Later I just accepted as a matter of life and tried to deal with that in the same way dealing with the ever present cross wind with varying strength.

In this particular case I am delighted to see little or no degradation in vertical spread; only horizontal spread worsened. Quitely it was I who was consistent shot-to-shot.

-TL

Sent from my SM-N960U using Tapatalk
 
B

Bart B.

New member
tangolima said:
I have noticed the change in elevation when the shooting position changed. Easily +/-1moa. At the begining it was frustrating as I thought there was something wrong with the equipment. Later I just accepted as a matter of life and tried to deal with that in the same way dealing with the ever present cross wind with varying strength.

In this particular case I am delighted to see little or no degradation in vertical spread; only horizontal spread worsened. Quitely it was I who was consistent shot-to-shot.

-TL

Sent from my SM-N960U using Tapatalk
Click to expand...
Horizontal shot stringing is usually caused by the trigger finger not holding still until the bullet leaves the barrel.

Finger flicking during barrel time moves the barrel to direct the bullet in the wrong direction.

Properly conducted ball and dummy exercises can help.
 
Last edited:
You must log in or register to reply here.
Top