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View Full Version : AK optics mounting - modifying the BP-02



Canonshooter
09-23-07, 08:36
Like most other AK owners, I tried a number of different optics and mounting solutions and was never really satisfied with any of them. My first optic was the Russian-made PK-AS, which is actually an awesome optic but like all other Russian models, sat off center of the bore axis or way too high. Here is a pic of the PK-AS on my Krebs AK-103k;

http://www.canonshooter.com/photos2/ak103k-1.jpg

What may not be very evident in this photo is that the optic sits directly above the siderail mount, offset to the left of the bore. I could never get used to this arrangement - even using my left eye pulled my cheek off the stock.

The next set up I tried was an EOTech on an Ultimak. This was better than the PK-AS, but still not IMO ideal. The Ultimak mount works very well but gets pretty damned hot after extensive use with the optic absorbing that heat. I also did not care for not being able to remove the gas tube (the Ultimak replaces the standard gas tube) without having to re-zero the optic. Not a big deal, but overall I still contined to look for a better solution.

The next set up I tried was an Aimpoint CompC3 on a BP-02 siderail low mount (http://tantal.kalashnikov.guns.ru/bstmounts.html). The Weaver rail is long enough to accept two scope rings, but since I only needed room for one ring I cut the rail down in length. The result of this is shown below;

http://www.canonshooter.com/photos2/BP02Comp3-1.jpg

This was an improvement over the Ultimak/EOTech set up in terms of the heat problems and gas tube removal/cleaning, and was far easier to use than the PK-AS. But as you can see in the photo above, the rail is not centered over the bore and the optic still sits rather high. Picking up on an idea by another AK owner, I decided to modify the BP-02 mount to (1) center the optic over the bore and (2) get the optic as low as possible.

As you can see from the photos of the BP-02 mount, the rail sits on top of the mount. However, there is a recess between the two shoulders of the mount that the rail mounts to that is essentially wasted space. Since the Aimpoint needs only one ring, the idea is to cut the rail down so that it will fit between the two shoulders. This lowers the optic by about 3/16" and allows the rail to be positioned so that the optic is centered over the bore.

The process is actually quite simple; cut the rail down to fit between the two shoulders of the BP-02 and secure the rail in place. I carefully cut the rail so that it's square and "friction fitted" it between the two shoulders. This allows the actual mount to absorb the recoil instead of the screws that mount the rail. Once I hade the rail positioned perfectly over the bore - and as square as possible - I used two brass machine screws with nuts to secure the rail and secured them with Loctite. Below are some photos of the modified mount;

http://www.canonshooter.com/photos2/bp02mod-1.jpg
The screws & nuts were postioned to not interfere with the Aimpoint ring.


http://www.canonshooter.com/photos2/bp02mod-2.jpg
This shows how far the rail had to be shifted to get it over the center of the bore. The holes on the top of the shoulders were where the rail was originally mounted.


http://www.canonshooter.com/photos2/bp02mod-3.jpg
Once the screws & nuts were secured, I used a file to square-off the round-head screws and provide clearance to the receiver cover (of which there is plenty).


http://www.canonshooter.com/photos2/bp02mod-4.jpg
The optic now sits considerably lower than before. If someone made a ring that was about 3/16" lower, co-witness would be possible.


http://www.canonshooter.com/photos2/bp02mod-5.jpg
Optic is now centered over the bore.

This is by far the best set up I have tried. It's reasonably low - though not low enought to co-witness - and allows a decent cheek weld. The quick-detach BP-02 mount is sturdy and holds zero very well. All-in-all, until Mark Larue comes out with his mount that will allow co-witness, this is IMO the best set-up for mounting an Aimpoint on an AK.

I hope you find this post useful!

Chief_Wiggum
09-23-07, 09:45
Nice work! I really like that setup. If only my AK had side rails :D

Kisara
09-23-07, 16:57
Very impressive work! Looks like a factory job.

Canonshooter
09-23-07, 17:34
Thanks for the kudos! I'm hoping Larue comes through with a mount - something that "reaches over from the side" with the ring to get the Aimpoint down close to the receiver cover would be awesome.

edwin907
10-09-07, 15:49
Modified my BP-02 rail today & mounted the T-1.

I's especially like to thank Canonshooter for not only his idea but his support and responces to my inquiries.

For those interested in this, the latest model of the mount has not only the two "shoulders" that the rail mounts to but also a center support the same size which must be cut off in order to do Canonshooter's brilliant modification.

Not a problem however, mount it in the vise cushioned by a piece of conveyor belt (or whatever you have in your shop) so as not to scratch up the finish, and the center support is quick work with a hacksaw.
Of course it won't match the height of the rest of the top of the mount, but a few minutes with a file fixes that.
Then wipe it down a couple of times with some Aluminum Black and it looks perfect.

I won't know till I hit the range tomorrow, but to my surprise I think I might prefer the little Micro T-1 to the ML-2 in this application. I'm planning on trying both.
Two eyes open it doesn't interfere with your vision at all, and yes it is too high to co-witness but who wants all that iron sight stuff interfering with your sight picture anyhow.
I doubt there is a more reliable red dot sight available and the chance of it going down is pretty low.


http://i192.photobucket.com/albums/z238/edwin907/A1RT1.jpg


http://i192.photobucket.com/albums/z238/edwin907/A1RT1a.jpg

Canonshooter
10-09-07, 18:03
Edwin, looks like the mod worked out well - I look forward to your range report!

BTW, you do find the 4 MOA dot to be a better defined circle than the 2 MOA?

edwin907
10-09-07, 18:11
do find the 4 MOA dot to be a better defined circle than the 2 MOA?

With my eyesight, they are about the same. With the 3X magnifier on my ARs, they clean right up and both are well defined.
I have a M3 2MOA on my 10.5" LMT SBR, and I can't really say I prefer it to my ML2 4MOA unless using the magnifier, and even then it seems to be easier to holdover for long shots with the 4 MOA.

I guess I like 'em all!

Canonshooter
10-09-07, 18:20
Edwin, thanks. I was hoping the 4 MOA dot would look more like a defined circle for those of us with less-than-optimal eyesight. The 2 MOA dot looks more like a ill-shaped star to me, making precise aim at longer distances difficult. But for staying in the A-zone on an IDPA target out past 100 yards it is fine. And of course, it's extremely fast on closer targets.

Nice job on that sight!

TOrrock
10-09-07, 18:32
Outstanding work.

I'd think about sending you my mount to do that to, but you'd have to have the rifle too to center it....:mad:

Canonshooter
10-09-07, 18:46
I'd think about sending you my mount to do that to, but you'd have to have the rifle too to center it....:mad:

Not neccessarily. Simply mark the new centerline on the mount by sighting down the irons.

edwin907
10-09-07, 20:19
It looks like it would be easy to increase the offset by sanding/filing the mating surfaces of the upper and lower parts of the clamp, or decrease the offset by shimming them.

There is obviously considerable variance in these mounts as well as the rails they mount on.

My mount has the rail postioned about 5mm (best I can tell from the photos) to the left of where Canonshooter has mounted his. Mine is about 1.0-1.2 mm left off dead center.

Canonshooter
10-10-07, 07:40
The toughest part is to make sure the Weaver rail is as parallel to the bore as possible when re-mounting it. I did so by "eyeballing" it. At 100 yards, I only needed about 3 inches of windage correction after I modified the mount. After I changed the ring and rotated the Aimpoint 90 degrees to position the battery compartment to the left, I wasn't even on paper any more!

Like Edwin said, if your off center a few mm one way or the other it's no big deal.

Frag
10-10-07, 08:11
edwin can you take a picture from the rear of the rifle so we can see it over the bore?

Looks great, nice job and thanks for the pictures.


Modified my BP-02 rail today & mounted the T-1.
http://i192.photobucket.com/albums/z238/edwin907/A1RT1.jpg
http://i192.photobucket.com/albums/z238/edwin907/A1RT1a.jpg

edwin907
10-10-07, 09:38
After a morning at the range I've decided that as much as I like the Micro Aimpoint on the A1R on the modified mount the ML2 is the optic for this rifle.
Maybe it's because I'm used to the bigger series on the ARs, but I feel more "combat effective" with the ML2.
In rapid fire drills I never felt like I was going to lose the dot on the T-1, but the ML2 was smoother, easier.

I'm putting the Micro T-1 back on the M92 Krink where it's small size is a real plus and I actually seemed to shoot better, just as fast, tighter groups, with it than the ML2. Now the question for it, receiver or hand guard mount?

I originally used the original screws and some nuts I had that fit to bolt the rail to the mount, but I replaced them last night with two larger bolts Mark LaRue sent me with a light mount and a couple of nuts. I was able to center my rail exactly when I carefully opened the holes up for the larger hex bolts with a circular file.

Don't know if you'd still want a photo, as it's exactly like Canonshooter's setup now, same ring, modified mount, with a ML2 Aimpoint.
Canonshooter, I feel like I owe you more than a thank you!

edwin907
10-10-07, 09:40
The toughest part is to make sure the Weaver rail is as parallel to the bore as possible when re-mounting it. I did so by "eyeballing" it. At 100 yards, I only needed about 3 inches of windage correction after I modified the mount. After I changed the ring and rotated the Aimpoint 90 degrees to position the battery compartment to the left, I wasn't even on paper any more!

Like Edwin said, if your off center a few mm one way or the other it's no big deal.

I was worried about this with the Micro T-1, as it has less adjustment than the regular Aimpoints, but no big deal at all.

Canonshooter, are you a lefty shooter, I see you run your Aimpoint like me with the battery compartment on the lefty.

Canonshooter
10-10-07, 10:54
Edwin, thanks for the report. Your conclusions make sense.

I am a righty, but prefer operating the Aimpoint control with the support hand - one less reason to remove the shooting hand from the grip.

edwin907
10-14-07, 13:34
Here's the final setup.

http://i192.photobucket.com/albums/z238/edwin907/Aim.jpg

http://i192.photobucket.com/albums/z238/edwin907/Aim2.jpg

http://i192.photobucket.com/albums/z238/edwin907/Aim3.jpg

Canonshooter
10-14-07, 13:39
Edwin, looks good to me! :D

I like the sling swivel adapters too.

Frag
10-14-07, 17:06
Here's the final setup.
edwin this has got to be one of the sweetest setup I have come across in a very long time.

Great job and in good taste which makes the rifle look (and probably) feel amazing. I thank you for taking the time to share with the community.

Sweet Setup!!!

Jay Cunningham
10-14-07, 19:25
Very nicely done.

Somebody (hint, hint) should start offering fixed stocks and lower handguards that come standard with the QD sling attachments points (x2 even better, a set close to the receiver and a set out towards the ends)

One question - do you have a good mounting option for a white light?

edwin907
10-14-07, 20:57
Thanks for the compliments you guys.

The sling setup is very important to a rifle and the addition of the ability to properly position a Vickers sling on this rifle means it's one rifle that I would pick up for use.
And you're right, somebody should make a stock set with QD fittings, but the factory setup is actually great for right handed shooters, and us leftys are pretty small in number. This QD setup wasn't difficult to install, is very solid, and makes it a pleasure to use the rifle as a left handed shooter.
The furniture can easily be modified by anyone willing to take some time with a power drill.

Canonshooter's BP02 modification is what really makes this rifle however, it is a dream to shoot with the Aimpoint mounted over the bore. The cheekweld is excellent, slightly "heads up" which seems to aid in your two eyes open vision. It is very fast to acquire targets and even though some complain about the additional weight of the milled receiver, all the weight including that of the mount and Aimpoint is centrally located making it easy to swing but very controllable on recoil.

The Znich tactical light works well, but certainly isn't QD and is about as bright as you'd expect. A Malkoff P60 equipped Surefire Scout light like I have on my MRP SBR 10.5" would be a much better solution, except my second one is already on my M92 Krink!
Mounted to the PRI 3" rail at the bottom of the hand guard either inline or with an offset mount it would be ideal unless your light needs are for something with greater range.

edwin907
10-25-07, 11:18
I had to replace one of the bolts holding the rail to the mount because it cracked, so I re-zeroed it at the range today.

Not the best effort at 100 yards, but a pretty effective rapid fire drill with the A1R and a waffle mag of Golden Tiger ammo, prone, resting the hand guard on the range bag, 50 yard zero on the Aimpoint.


http://i192.photobucket.com/albums/z238/edwin907/Target.jpg

Sleeb
10-14-08, 17:58
Here's the final setup.

http://i192.photobucket.com/albums/z238/edwin907/Aim.jpg


Whow Edwin, I really love what you did to that AK, it's like I dreamed of making my Airsoft version of the 74 like, without the Bipods though :)

Anyways, what I was wondering was which Flash Hider it is you've put on their? I instantly fell in love with it. I tried searching google and all I could find was this 1 page selling it: http://www.blackjackbuffers.com/index.php?main_page=product_info&products_id=475

and I doubt that "Com-block AK Flash Hider" is its real name, so any help would be much apreciated^^

jdp710
10-14-08, 21:09
I'm not edwin but I got mine when I bought my SLR 107 FR from arsenal when they first came out. You can buy them here.

http://www.k-var.com/shop/product.php?productid=16963&cat=0&page=1

RAM Engineer
10-15-08, 07:09
Thanks for the compliments you guys.

The sling setup is very important to a rifle and the addition of the ability to properly position a Vickers sling on this rifle means it's one rifle that I would pick up for use.
And you're right, somebody should make a stock set with QD fittings, but the factory setup is actually great for right handed shooters, and us leftys are pretty small in number. This QD setup wasn't difficult to install, is very solid, and makes it a pleasure to use the rifle as a left handed shooter.
The furniture can easily be modified by anyone willing to take some time with a power drill.

What parts would I need to perform a similar mod to my AK stocks?