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HK91 Scope mount considerations

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19K views 54 replies 13 participants last post by  slowmover  
#1 ·
I'd like to put forward some possible HK91 setup scenarios to work through some considerations before purchasing a mount and scope for my lovely .308. I know this may be an overdone topic but technology and accessories do evolve so I'm hoping this will not be redundant.

I'm leaning toward a B&T Universal picatinny mount with a Trijicon VCOG 1-8x. This B&T mount seems to be not too low (so to not interfere with irons) nor too high.

I do like the idea of the mid-range B&T rail which has the hole for the iron sights, but I fear it may be too high since I want to run my "standard" Hk wood stock. I fear that mounting it that high will necessitate me having an awkward cheek weld on the standard stock. Is this true?

Another option I like is using an HK stanag claw mount, though again, I am concerned about the height and cheek weld situation. If I can get over that, I would like to use a Nightforce 1-8x or similar. The Nightforce has 30mm tube. If I could somehow find the HK claw mount with built in scope rings that would be cool and I believe would work with the NF scope, but those HK mounts seem rare.

So it seems as though the HK Stanag claw mount is more realistic. Can anyone shed light on how the Stanag mounting works on the HK claw mounts? Do I need aftermarket scope rings that screw into the Stanag ports on the claw mount?

Prost!
 
#2 ·
There is a factory scope mount with integral 30mm rings. Usually supplied with 1" adapters.

The STANAG mount is best mated with a STANAG scope, mostly a fixed 4-power from Hensoldt.

Be aware you will need to obtain a scope with very short (<3") eye relief in order to not sprain your neck.

Conelrad
 
#3 · (Edited)
The HK factory claw mount is the way to go. They are not really scarce but they are very expensive. Search around they are out there. Like Conelrad said above the stanag works great the way it was intended with the Hensoldt with the integral rail which mounts directly to the mount. I also opted 20 years ago to purchase an a A.R.M.S HK style claw lock Picatinny mount and it works well ( pic below)… put a good set of rings and a good scope on it and it will also hold zero after removal and reinstallation. The STANAG (Standard NATO agreement) mount is much easier to locate and there are in fact many of them surplus out there for a pretty decent price ,there is a company called “mounting solutions” that carries rings that will attach and even a picatinny rail that will attach in the place of the rings. Do some searching the stuff is out there. The other problem , the height of the mount can be an issue. There is a small arched see-through window in the factory HK claw mount but it has limited use. It’s not hard to add a cheek riser to the HK factory stock and there are HK factory stocks with the cheek riser but they are very hard to find and extremely expensive these days. I really haven’t tried the B&T or any of the other aftermarket clamp on low profile mounts that are out there simply because I already had the HK factory stuff so I really can’t comment on those.
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#4 · (Edited)
I'm leaning toward a B&T Universal picatinny mount with a Trijicon VCOG 1-8x. This B&T mount seems to be not too low (so to not interfere with irons) nor too high.

I do like the idea of the mid-range B&T rail which has the hole for the iron sights, but I fear it may be too high since I want to run my "standard" Hk wood stock.

Another option I like is using an HK stanag claw mount, though again, I am concerned about the height and cheek weld situation. If I can get over that,
my opinion. is go with the B&T low profile mount. once you put it on it the rifle it never needs to come off. I used LOC-TITE on the screws when I put mine on more than 20 years ago, and it hasn't budge since then

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as for "cheek to stock", regardless of which mount you go with, low profile, claw, the scope it's going to sit high so it clears the rear sight. unless you take off the rear sight if you are going to use the low profile mount, so the scope sits lower with low scope rings

simple solution is use a cheek riser. there is no shortage of cheek riser out there that will position your head and eyes in line to the scope.

the cheek riser I bought years and years and years ago is a CHEROKEE CHEEK RISER. it fit on a standard G3/91 stock using the take down pin holes on the stock.

they still make them.
HK Cheek Piece, Quick Detach for your Fixed Stock HK91, G3, C308, PTR91, HK33, HK93, V93, C93, HKK-1307, RTG Parts (robertrtg.com)



not too long ago a member here made a cheek riser from a picture that a German soldier was using from KYDEX, it's pretty slick :)
 
#5 · (Edited)
the cheek riser I bought years and years and years ago is a CHEROKEE CHEEK RISER. it fit on a standard G3/91 stock using the take down pin holes on the stock.

I don't know if they still make them
[/QUOTE]


I did have one of those old Cherokee cheek risers it was a great piece of gear, Clever and solid the way it attached to the takedown pin holes in the stock.…. I can’t even remember what happened to it it’s been so long ago , it may be in a box in my attic. Doubt they are still around… Main reason I advocate for the claw mounts is for removability and reinstallation option without changing zero.

WOW THEY DO STILL MAKE THEM . Recommend
 
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#7 · (Edited)
#10 · (Edited)
If the post was directed at mine:

The BCR was $110(?). See the website. This one was originally for a FAL as I recall. I believe I was first with a G3 type. Talked with owner before order made. (Time gone by has fuzzed purchase details).

Rock Solid, a good description.

This buttstock + riser is an interim step as the LOP is still too short. I’ve a MAGPUL PRS2-340 waiting for some mods.

.
 
#9 · (Edited)
I've since gone with a Magpul PRS stock, but I added a Victor Universal Cheek Riser on the original stock to get the proper cheek contact. It's adjustable with supplied shim plates, but does normally require 2 vertical holes in the stock. I didn't want to drill, so I fastened mine with heavy duty 2-sided adhesive tape.

When I was setting mine up, the Cherokee risers were not available, but with a low mount scope like mine (sights removed) it would have been too high anyway.
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Magpul stock -
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#11 ·
Thanks for all of the good replies and info.

I’ll address some of my takeaways and add some questions. If I get anything wrong please correct or add anything I missed.

Conelrad, as for the eye relief, the Trijicon VCOG has a 4” eye relief, would that be ok? From the quick research I did on eye relief, that would help in terms of reaching your neck up to the scope….

According to Corporal JJ, it sounds like the HK claw mount iron sights holes aren’t super great to use. I do wonder about other claw mounts, or B&T mounts that have the window.

Uncle Billy, I didn’t realize those B&T mounts have been around so long! If I opt to go with removing the rear sight, and setting up the scope as low as possible, would I need to add a cheek riser? The Trijicon VCOG 1-8x doesn’t use scope rings, it mounts directly to picatinny, so I guess it would be one of those things where I’d have to buy and see.

I may go with the cheek riser solution, or possibly with the Magpul stock.

Finally, anybody tried using the Spuhr stock with scopes? I see that Spuhr offers two types of additional cheek risers, so again, I guess it could be one of those things that I just need to buy, install, and see how it goes.

Direction I'm thinking about going: Low profile B&T picatinny mount. Trijicon Vcog 1-8x. Hopefully I don't need to remove rear iron. And if wood stock is too low for cheek weld, I'll throw on the Spuhr stock, and if it's still too low, they have cheek risers.
 
#14 ·
If you want to maintain the classic wood look and not have to use a cheek riser, I would remove the rear drum and put the optic as low as possible. The front sight tower may be an issue. The 91 that I scoped, I cut the top out of the ring. The issue with scoping some of these HK rifles is that you end up with a goofy high height over bore.
 
#16 ·
If you want to maintain the classic wood look and not have to use a cheek riser, I would remove the rear drum and put the optic as low as possible. The front sight tower may be an issue. The 91 that I scoped, I cut the top out of the ring. The issue with scoping some of these HK rifles is that you end up with a goofy high height over bore.
I've not found the front sight tower to be noticeable when viewing through the scope.

I recently removed the sight insert, but even with it in place, there wasn't any distortion or shadowing visible.
 
#18 ·
I used the Spuhr removeable top rail along with their other hk parts then mounted an ARMS #63 QD mount.

the ARMS #63 with dual locking levers is extremely stable. The ARMS mount has a built in STANAG set of mounting holes in it. So I have removed my fero z-24 scope from its hk claw mount and transferred it to that ARMS mount.

the ARMS mount mounted on top of the Spuhr top rail with its cumberbund front mount and the Fero Z-24 clear the rear sight and are above the front sight. uses the short Spuhr cheekpiece.

i have also acquired three additional ARMS #63 mounts and Weaver 6 point low mounts that allow QD changes to mount different optics.

The height increase of the rail, ARMS mount and the Weaver rings allowed me with the use of Spuhr tallest cheekpiece to mount larger, longer, bigger objective lens scopes and have a proper cheek wield. Clears the charging handle fairly well and fits over the sights.

I have a vortex viper PSTll 5x25x50 as one of these setups.

another has a vortex viper 2.5x10 HST on it.

i can also mount directly to the Spuhr top rail my vortex holo sight and a vortex 6x magnifier.

or a Vortex strike fire ll RDS.

everything can also be transferred to my ar-15 with its various top receivers
 
#19 ·
Thanks for all the information. I've been chewing over all the options and I have a few more questions.

Must the claw mounts, specifically the HK one with integrated 30mm rings, be mounted to that "saddle" that is directly in front of the iron sights, or is it possible to move the claw mount forward?

Also, does anyone have that specific claw mount on hand? And could they measure the mounting distance between the two rings? I think the best place to measure from would be from the back edge of the ring (closest to shooter) to the front edge of the front ring (edge closest to muzzle). The Nightforce 1-8x has a mounting distance of 5.7" (144mm). Looking at pictures of the Hk claw mounts and measuring on my hk91, it appears that distance is about 4.7". That should give me plenty of room to slide the scope a little forward to account for the 3.7" eye relief. It would definitely suck to buy the expensive HK claw mount and the ergonomics be off. Though I guess I could sell it off. Then go with the B&T Picatinny, and mount it from there.
 
#20 ·
There are actually two molded saddles on the top of the receiver that it fits in. I am not home right now but I would be happy to give you those measurements later.
 
#21 ·
I was in your shoes and thought it was a great idea to scope a G3K. Original factory German barrel. Well it isn't a good idea. I needed 13 inches of stock to get the eye relief off the kahles. 13 inches is longer than the regular A2 and clubfoot. You would need MSG90 or PSG1. The 91 is a 2+ moa gun. The mount and scope are 1lb each. You won't be happy. The 91 is perfectly suited to a red dot.
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#29 ·
My 1A A2 with 155 gr SMK Palmas. 100 yds.

First pic from last Friday: Second last Monday. SA ball ammo does around 2-3".

Replaced the Z24 with a SWFA 1-4 on a B&T. Reticle easier on these old eyes. Gosh-awful trigger tho. Bill Springfield trigger is inbound. Guess I'll find out.

View attachment 331418 View attachment 331419
These groups are very good and completely serviceable for anything practical.
 
#30 ·
The hk guys mentioned using a hk only claw mount and shimming the mounting pads claw areas even tighter.

I mounted a Spuhr cumberbund top rail then a ARMS #63 QD double locking lever mount to it and removed my FERO-z-24 from its hk claw and mounted it on the ARMS mount as it has STANAG holes in it and does have a tiny open hole in its design to barely allow iron sight use.

on my other optional scopes i used Weaver 6 point low mount scope rings. Two vortex vipers. One 5x25x50 pst ll and the other a 2.5x10x44 HS

all premounted on separate weaver/ARMS setups.

the Spuhr top rail and the ARMS #63 and the 6 point weavers are very solid together and appear to be very good at holding zero when removed and remounted. I did this versus Un mount the scopes from the rings to swap optics.

I also have a Vortex holo sight and their 6x magnifier that can be mounted as well as a vortex red dot.

the 30 year old group was with a shepherd 1” tube dual reticle scope on a slightly windy afternoon when the tight group guys had left the range already

 
#34 · (Edited)
My lightly modified HK91. It is actually a shooter.
View attachment 331451
Nice shooter. I think it might benefit from the narrower front sight post? Past a certain distance the post is too wide in my experience

looked at those in 1990. No autos in Kalifornia unless i wanted to be in the serious gun biz. Then you had inspections. Pass. Too much muzzle climb in auto back then. But as a suppression weapon its the best. Rare closed bolt design.