Hi all,

I have a question about prone shooting with an AR-15 that has a LPV optic. I have 16” BCM carbine with a Trijicon TR25 1-6x optic, which has pretty generous eye relief. I have the stock set 1 click in from the full extension on a 6-position buffer tube (I’m 6’2” tall). I have the eye-relief on my optic setup such that it works great for all standing, sitting, kneeling positions with the stock in this position. The rear of the optic is just a bit forward of the rear of the charging handle (pretty standard setup). My problem is the prone position.

When I get into the prone position and setup behind the rifle, my eye is way too close to the optic and I thus get significant scope shadow and it’s nearly unusable. In order to get proper eye relief I need to push the rifle forward completely off my shoulder. That’s obviously not correct. I’m not quite how to address my prone shooting position technique, and I must be missing something obvious. If someone could give me some tips that would be great. Thanks!

Chris

When I was an instructor in the service we had iron sights. And the trick to get the shooter to make sure they had a good repeatable cheek weld was, that we had them place the tip of their nose against the charging handle. This way the head was always in the same place regardless of wethere it was light or dark or that they were in prone, sitting,kneeling or standing positions.

I have a c-more on one of my AR’s, I have the sight far enough forward that I can focus on it when my nose is just touching the charging handle.

Were I in your position, I would start indexing my nose against the charging handle and then move the trijicon sight forward.

I don’t do the charging handle trick, but it may work for you.

Otherwise, because my face/eye is closest to the scope when shooting from the prone and because the prone permits the least variation in head position, I put the scope so it’s properly located for that position. I then just adjust my head and stock weld as necessary when shooting from other positions. In effect that’s the same as indexing one’s nose to the charging handle, but just somewhat farther back.

NTCH is not optimal with a 1-6. Set the scope as far foreword as you can. May need to get more offset on your mount. The New LPVO scopes have really big eye relief, some
in excess of 4”.

Some people will say that you need to hunch over to get in to the rifle while standing. I personally hate it.

We all have different body dimensions, therefore few techniques, positions, or setups will work for all.

It is common that the prone position requires a slightly different cheek/head/eyebox position, as compared to other positions. It is common that your head is further forward on the stock with prone.

Your scope location is common for an LPV -- actually, it's pretty close for just about any optic. Assuming your stock is quickly adjustable, I suggest extending it a position or two longer when shooting from prone. A couple of light marks on the stock works -- I use a small silver sharpie mark on my black adjustable AR stock.

I do not believe NTCH works well with modern optics. I just checked on my carbines -- I can place three fingers between my nose and the charging handles. That's about 2-1/4" to 2-1/2".

It's fallacy to think that one sling and stock setup can accommodate all possible shooting positions (standing, kneeling, prone, etc).

I would bias the default setup to match what you do the most and note quick adjustments as fritz notes (I use orange sharpie paint pen marks on my buffer tubes to show normal position and prone).

I don't recall have this issue (at least not enough that it's an... issue. lol) I've been looking at some old match photos to see if I'm doing anything unusual looking to compensate, but don't see it.

How square up/in line are you with the rifle? I was wondering if a more sideways 11 o'clock-ish rifle position would help you.

Thanks for the replies, guys. When I shoot standing I like to have a relaxed neck/head position, not craning my neck much. My stance is sort of bladed, with feet maybe at 45 degree angle, learning a bit forward, weight on balls of feet, etc. A pretty modern stance. When shooting, I have a 3 fingers distance between the tip of my nose and the charging handle. I shoot probably 80% from that position.

I only have 1 click left to extend the stock. I will try that when shooting prone. The optic is mounted in a LaRue SPR-1.5 mount and it's at the picatinny rail furthest forward on the receiver. Any further forward and it would be over lapping the BCM KMR fail.

I'll experiment and see what I can do. Thanks for the info.

Another thing to consider is seeing if you have any room to move the optic any further forward in the mount - might give you a bit more if you are out of receiver space.

Thanks. Yes, I do have room to move the optic forward in the mount. But the OCD in me wants to keep it centered! Doh.

quote:

Originally posted by Chris17404:
Yes, I do have room to move the optic forward in the mount. But the OCD in me wants to keep it centered!

It all depends on whether you prefer shooting well or trying to maximize your mount's feng shui.

The Larue SPR mount is well designed. If the mount's screws are properly torqued, you can have the SPR's rings away from the center of the scope's mount region. However, I do not recommend placing the SPR's clamping area right up against the erector or the start of the ocular -- leave a little space.

You will learn how to better adapt you shooting technique for various shooting positions and buttstock lengths. Understand that some things should be consistent across shooting positions:
- eyebox position. Eliminate the donuts and shading.

- cheekweld pressure. Inconsistent pressure negatively affects accuracy and point of impact.

- body alignment behind the gun. Assuming you're not using a sling for support, your shoulders and hips should be square to the rifle -- i.e. aligned 90 degrees to the bore. Twisting or canting your upper body (often to the right of the point of aim) will negatively affect the way you manage recoil. Granted, there's not a lot of recoil in an AR-15. But there's enough recoil -- compounded by the BCG moving back & forth, and the mechanics of an AR trigger -- that most people shoot an AR-15 with noticeably worse accuracy than than a comparable caliber bolt action rifle. Try to work out scope, stock, and cheek weld issues so that you are square to the AR15 in all positions.

Understand that shooting with a sling for support is a whole different situation, as most slung positions require us to be bladed to the right of POA -- for a right handed shooter.

quote:

Originally posted by fritz:
However, I do not recommend placing the SPR's clamping area right up against the erector or the start of the ocular -- leave a little space.

I believe you’ve offered that advice before, but I forgot to ask then. So now: why is that?
Is it because the scope tube starts to flare out (increase in diameter) at those points, or is there some other reason?

At one time I thought snugging the erector against a ring would help prevent slippage under recoil. I don’t do it any more, and still don’t have any problems, but it seemed like a good idea then.

fritz... Thank you for that info. I am a novice at the prone position. I understand your comments on eyebox position and cheekweld pressure, but I struggled to visualize/understand your comments on body alignment behind the gun. Is there a good diagram or tutorial online that provides a visual description as well as an explanation of proper body alignment in prone behind a scoped AR-15? Both with and without a sling would be great.

Fritz is trying to describe your shoulders being at a 90degree angle to the bore of the rifle.

Imagine a T, the long leg is the barrel and the cross, are your shoulders. You can google “prone rifle position” and see images, many show a shooter who is at some angle other then directly behind the rifle.


This is a good example

If you use a sling, you will be off at a different angle, but will look like This. Or This, the guy in the prone is offset at a 45 degree angle from the axis of the bore

MikeinNC... thank you for that explanation and pictures. That helps tremendously. I’ll experiment with this tomorrow when I go to the range. Thanks again.

Here's a video of Jacob Bynum, owner of the Rifles Only shooting school. It's my understanding the clip was originally made to show that a rifles point of impact doesn't change with different positions -- as long as the shooter has good technique.

FYI, Jacob isn't completely square to the rifle in the video. As I see it, if the bore is pointed at 12 o'clock, his chest/shoulders are pointed to about 12:30. In other words, he's pointed slightly to the right, which often occurs with right-handed shooters. Something he and his instructors have told me I need to stop doing.

Maybe I'll rib Jacob about this the next time I see him. But probably not.

positional shooting