Optics on precision AR’s- Help!! What & How??

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Optics on precision AR’s- Help!! What & How??

Hey all!!

I need a little advice. I am building what I consider a precision AR in .223. It has an extra heavy Stainless ER Shaw barrel with an OD of 0.925, quad rail low profile gas block, YHM free float tube, Cerro forge A3 flat top upper, Bushmaster lower, etc.

I bought what I thought was the perfect scope for it, a Millett 'Buck Gold' scope off the board. This scope is 6-25x56mm objective with a 30mm tube. This one has a side adjustable focus, with a duplex reticle, and semi-target turrets, with caps for protection. This was affordable, and is a big scope.

For Ring I bought an ARMS dual throw leave mount with 30mm rings and spacers to give a height of about 0.95 (measured where the ring contacts the top of the base to where the scope touches the bottom curve of the lower half of the ring).

Now the height is pretty well bang on. But I can not get the eye relief correct. I put the mount as far forward as I felt I could, and started with an SP1 fixed stock. To short, fine. Moved to an A2 standard style, about 1" or so longer (13.5 Length of pull). Still to short. Fine, go to a Vltor club foot carbine style stock all the way out (about 14.5" LOP), I still can not get it right, and can not move the scope any farther forward.

After loosing more hair, and messing arround most of the nigh, I guess the scope is to big and may need a more compact style. I have a Leupold VarXIII compact 4.5-14x50 with a 30mm tube, Mil-dot and side focus on my precision rig. But I really do not want to disturb this set up, unless it is sure to work.

Further, as careful as I was, the ARMS rings seem to be marking the scope as I slide it to try to get proper eye relief. Now on th Millet, im not heart broken, but I sure do not want to scratch up my pricy Leupy.

I was wondering if there were any words of wisdom any of you might be able to share with me. Are mounting optics on AR’s always this time consuming and frustrating, or am I missing something here.

Appreciate all and any help from those that have experience and know what there doing, because I sure a heck must not.

Regards and all the best

AbH
 
Does it have adjustable eye relief on the rear of the scope?
It must,my $50 chineese 6-24x50 even has it,give that a few turns
 
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You know, I do not know, however I bought the scope off the board, and it came with all the orriginal documentaion and I wil have a look.

further, when I started I was using the highest setting 25x. It got so bad that I turned it all the way down to 6x, and could still not get it.

Regards

AbH
 
It's gotta be in the book,read that and then start twistin' ;)

Picture034.jpg

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Thats a nice rig. What weight do you feed it? 77gr?

I've been thinking about putting together a similar spr forgery. Would like something that delivers out past 600m in spades.

what's your experiences with it?
 
Like RobAK says,, you need a mount or rail that will allow you to mount your scope forward of where your flat-top ends. There are many types and variations to choose from.

In the past I have used the Armalite mount, which gives you about another inch to play with, but ditched it in favor of a GG&G Scout Rail which is more flexible.
 
Hi,

Further to the OP's question, availability of the LaRue seems very problematic; a few came in and that was that, as best as I can tell. Wolverine lists some GG&G accessories, but seem to focus on other brands for rails. I don't think the Armalite mount would allow a scope to clear an ARMS buis, and it doesn't get the scope far enough forward anyway.

I'd spring for the GG&G Scout rail + Rings is somebody stocked these (ideally a sponsor).

Don't want to hyjack the thread, but I think the OP and me are looking for the same solution.

Cheers,
outnumbered
 
I know that SOCOM Supply has brought Larue accessories in before, maybe contact them if that's the route you want to go. I wouldn't know about GG&G.

sprint said:
Thats a nice rig. What weight do you feed it? 77gr?

I've been thinking about putting together a similar spr forgery. Would like something that delivers out past 600m in spades.

what's your experiences with it?
Click to expand...

So far I've used the Blackhills 77gr and the Lapua 69gr. The upper is a RRA NMA4, and the 1/8 match barrel loved both rounds.
My range only goes to 400m but consistently hitting the few inches of remaining gong at that distance is not a problem.
 
RobAK:

That is good to know, as the extra heavy barrel I have has a 1in8 twist as well, and was not sure If I would be able to use bullets that heavy.

On a Related note:

a. What mount did you end up using, and what height rings??

b. How do you like that PRS stock, and was it worth the investment??

At this point, and I may regret this, but I am going to try with that Leupy VarXIII 4.5-14x50 I have and see what happens. I really do prefer the quality of this optic to the Millet, and I would prefer to use it. I bought it due to budget constraints, but I just do not see the point of spending $1,700 building a rifle and puting inexpensive optics on it.

I welcome all notes and comments

regards

AbH

If wors comes to work
 
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a. What mound did you end up using, and what height rings??
Click to expand...

I've got the Larue SPR 1.5 mount, and the 30mm rings that come with it.

b. How do you like that PRS stock, and was it worth the investment??
Click to expand...

I really like the adjustment potential in it, but to tell the truth it is set to my "happy place" in the pics above, and as you can see I have the butt plate out less than 1 cm, and the comb is level, so I probably didn't need the PRS. But, it is damn ###y!

I just do not see the point of spending $1,700 building a rifle and puting inexpensive optics on it.
Click to expand...

I hear you. The 3-9X Leupold scope I have on mine I got for a great deal.The Docter Optic goes without saying that it's great for close shots.

Be sure to post how your project turns out. IMO building what YOU feel is the ideal gun for the task you set is some of the most fun of the whole thing.
 
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+1 on the Larue SPR mount.

I had the ARMS dual-lever mount with some TPS rings that I used to mount a Tasco Super Sniper on my AR. It worked out since I was able to use the mount to bridge across my upper's rail and the rail on the Troy FF handguard. I've heard this isn't optimal, but the 2 rails aligned well, and I figured the mount would take any stress since the rings were bolted onto the mount and not one piece.
 
rhs said:
+1 on the Larue SPR mount.

........... worked out since I was able to use the mount to bridge across my upper's rail and the rail on the Troy FF handguard
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Well slap me arround and call me stupid.

I have a quad rail YHM free float tube. I never thougth of bridging the gap.

not sure the rails are milspec, but there is one way to find out.

Thx.

AbH
 
No slapping required ;) Hope it works out for you.

I had good luck with that setup (ARMS #19A/TPS rings). I just ended up going with the Larue since I was going to be swapping between my MR/T and an Aimpoint and I figured the Larue would give me better return to zero. If the scope were going to stay there semi-permanently, the ARMS setup would have been great.
 
rhs:

I must admit I am a fan of YHM gear, and What I am contemplating, getting one of their long rail risers (I beleive they make a 7.0" as well as a 11.25" if required), and then haveing the Rail riser bridge the gap and then put my rings on top of that.

I already know that I want total hight of somewhere between 0.95-1.10(measured from where the ring contacts the top of the base to where the scope touches the bottom curve of the lower half of the ring), and then purchase proper ring height accordingly. The rub, as I see it, is where the bell of the objective lense will end up. Getting a rail to long will interfer with proper mounting, and getting one to short will not give proper eye releif.

I can only see one determining that through experimentaion, using a smaller riser/ring/mounted scope set up of similar height, and then simply move it down the railes to see where proper eye releif ends up, double & tripple checking to ensure proper postition, and then take mesurements and work back to what length of riser is requried. Thats the best I can come up with.

regards

AbH
 
Nightforce 2.5x10 NXS I think is the best deal in a higher end optic. Their smaller profile is perfect for the AR and the scope overall is better than the MK series of Leopold scopes (imho)
 
Don't bridge the gap, it's not a good idea. The forearm can flex somewhat and this will be transmitted back to your scope. At a minimum you'll have problems with your zero, worst case scenario you could bend your scope slightly.

Only solution is a Larue mount or an extended rail in order to get the proper eye relief.

BTW, Ronin, what you're talking about is the diopter adjustment. You adjust the diopter until you can see the clearest. If you wear glasses the diopter may have enough adjustment that you don't need them while shooting. No such thing as adjustable eye relief, although it will change slightly on most scopes as you change magnification.
 
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