Rifle Scopes PRS stock/ scope position

[MJY65]

I'd sure appreciate a little insight on setting up my new rifle. I just got a JP LRP-07 with PRS stock. I'm mounting a 5.5-22 NF on it with the JP one piece mount. In many of the photos, you see the mount all the way forward on the receiver with the cantilever overhanging the hand guard. As I am setting things up, there is no way I can get comfortable with anything close to that. With my cheek on the adjustable riser, I need to bring the mount all the way to the back of the receiver to get a full scope picture. (LOP is all the way in, riser all the way down)

Am I missing something, or do most guys really like to shoot with the scopes way out there?

Thanks,
Mike

 

[T2CH]

Re: PRS stock/ scope position

You need the base all the way to the rear of the receiver? So the eye piece is hanging over the stock?

I think you need to adjust your length of pull on the Stock. I usually start my optics off with the eye piece sitting over the charging handle. The adjust from there.

 

[BasraBoy]

Re: PRS stock/ scope position

In your preferred/optimised position -

1) can you see through the scope with no tunneling or shading?
2) can you get into position comfortably and repeatedly behind the rifle without discomfort or stress or muscle strain?
3) is your shooting consistent?

If yes, what's the problem?

Or am I missing the point?

Is it just because it "looks different/wrong"?

Maybe a pic would better help illustrate the "problem"?

 

[Genius.]

Re: PRS stock/ scope position

In the pictures you see where is the eye piece?

It could be the mount and how it's configured.

I have a Larue mount and it is set as far back as it can to still allow work of the charging handle.

 

[MJY65]

Re: PRS stock/ scope position

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: T2CH</div><div class="ubbcode-body">You need the base all the way to the rear of the receiver? So the eye piece is hanging over the stock?

I think you need to adjust your length of pull on the Stock. I usually start my optics off with the eye piece sitting over the charging handle. The adjust from there. </div></div>

Yes. the eyepiece is overhanging the stock. The LOP is all the way in, so it is as short as it gets.

 

[MJY65]

Re: PRS stock/ scope position

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">In your preferred/optimised position -

1) can you see through the scope with no tunneling or shading?
2) can you get into position comfortably and repeatedly behind the rifle without discomfort or stress or muscle strain?
3) is your shooting consistent?

If yes, what's the problem?

Or am I missing the point?

Is it just because it "looks different/wrong"?

Maybe a pic would better help illustrate the "problem"? </div></div>

Yes to questions 1 and 2. 3 is unknown as I'm doing my initial set up and haven't fired it yet, or even tightened things beyond finger tight.

I don't think it is necessarily a problem, but it made me question things when you see mounts positioned 3-4 inches farther forward than this. With the scope in its present location, the eyepiece is 3 1/2 inches from my eye. That sure seems about right.

 

[MJY65]

Re: PRS stock/ scope position

Here's what it looks like:

 

[BasraBoy]

Re: PRS stock/ scope position

Compared to my bolt guns I'd say that looks pretty similar.

Shoot it and see what happens.

I'm not familiar with your upper - but it looks quite a bit different to, say, a standard AR. Are you sure you're not comparing apples to oranges when you say "it looks different"?

I'd say if it works.....go with it.

 

[MJY65]

Re: PRS stock/ scope position

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">Compared to my bolt guns I'd say that looks pretty similar.

Shoot it and see what happens.

I'm not familiar with your upper - but it looks quite a bit different to, say, a standard AR. Are you sure you're not comparing apples to oranges when you say "it looks different"?

I'd say if it works.....go with it. </div></div>

It is a side charging 308, so the upper/rail is about 1" longer than a 5.56. That certainly accounts for some of the difference, but not all. Probably more individual differences in body type and shooting style. Since it is pretty clear that I will never need the cantilever function, I'm actually considering going with a Spuhr mount instead. The rail-comb dimension on the JP is already about 1/8" higher, so I think I could probably go with the lower 1.18" standard mount rather than the 1.46 AR model.

 

[2ndamendfan]

Re: PRS stock/ scope position

MJY65, I know what you are talking about. I look at all the pic's on the manufactures web sites and the cantilever is out over the hand guards. The cantilever is suppose to allow "proper" scope positioning. I have no idea how people would shoot something like that. I have mine positioned all the way reward and still could use 3/8s to 1/2 inch more. if it wasn't a 20moa mount I would flip it around.

 

[19Scout77]

Re: PRS stock/ scope position

My guess is you are shooting off of a bench...

 

[sawman556]

Re: PRS stock/ scope position

I usually get my LOP right then find my cheek weld. I the put my 4 fingers against my eye, kind of like in a salute form, and bump my ocular to that. That's where I start and then I'll adjust as needed. Works for me.

 

[BasraBoy]

Re: PRS stock/ scope position

Re: "proper" scope positioning and cantilever mounts - to my way of thinking the cantilever mount fulfils a specific need.

Looking at your rig, I can't see what a cantilever mount would contribute - other than the one you are running seems to be necessary to place your scope rings in the correct position on the scope?

However I run a 2.5-10x24 Compact NXS in an LT104. This sits on a Vltor VIS3, two notches in front of the BUIS. It is by no means the most extended cantilever that Larue make.

This places the eyepiece of the scope roughly level with the charging handle. It allows enough space below the scope to mount the BUIS and places the rings in the correct part of the scope tube. It also gives QD functionality if I want/need to use the iron sights.

In prone I run the UBR stock on the rifle to the maximum to get correct eye relief on the scope and also to accomodate my frame/get a comfortable and relaxed position.

If I had a longer, higher mag scope or a scope with longer eye relief, I would need to push that forward on the rail a lot further....how?

Get a mount with a greater forward reach on the cantilevered section or mount the existing mount further forward on the rail would be two solutions.

Do you need to do this?

Judging by your pic - no, I'd think not.

A good one piece like the Sphur or even a set of good rings (Badger/Seekins) would be a great solution.

Configure the rifle to your needs, don't worry about "does my scope look odd to you"

Just my £0.02

 

[smschulz]

Re: PRS stock/ scope position

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MJY65</div><div class="ubbcode-body">Here's what it looks like:

</div></div>

This looks about right although I might move it forward .5 ~ .75".
Measure about 3.5" back from the lens and that is 'about' where your eye should be.

 

[samnev]

Re: PRS stock/ scope position

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MJY65</div><div class="ubbcode-body">I'd sure appreciate a little insight on setting up my new rifle. I just got a JP LRP-07 with PRS stock. I'm mounting a 5.5-22 NF on it with the JP one piece mount. In many of the photos, you see the mount all the way forward on the receiver with the cantilever overhanging the hand guard. As I am setting things up, there is no way I can get comfortable with anything close to that. With my cheek on the adjustable riser, I need to bring the mount all the way to the back of the receiver to get a full scope picture. (LOP is all the way in, riser all the way down)

Am I missing something, or do most guys really like to shoot with the scopes way out there?

Thanks,
Mike </div></div>

I had exactly the same problem with the PRS stocks I put on my LMT MWS & Armalite. MY NF scopes on both hang well over the charging handle. Had to put a BCM Mod 3 Charging handle on both to make it easier to charge.

 

[Beef82]

Re: PRS stock/ scope position

Known "problem" with the PRS, if you want your face on the cheekpiece, which is way back to be clear of the charging handle, you will need either a very long eye relief scope or to mount it way back. The cantilever mounts are meant for those that run their ARs more in the nose to charging handle fashion and/or want full access to the charging handle or room to mount BUIS behind the mount/scope, and require a way to get it further forward than the reciever typically allows.
If you don't like it, really all you can do is change scopes, change stocks, or do like most and ignore the adjustable cheekpiece. As far as asthetics, rings or a straight mount would look better.

 

[Bradu]

Re: PRS stock/ scope position

Here is the way I set mine up. My check is almost off the comb on the PRS but I find it to work pretty good.

1. Adjust the length of pull to where you like it.
2. With a bipod on the front I shoulder it at the kitchen table as if I were taking a shot.
3. Then I move the scope to get the eye relief set and tighten down.
4. I usually close my eyes and shoulder the rifle multiple times to make sure it comes up in the same spot every time.
5. Then I torque it down once I'm sure that's where I want it.