I really wanted to like the BKL scope mount

I bought a BKL-260 one-piece scope mount and sat here staring at it for 2 months while my scope was on backorder. It's such a beautiful piece of machining. My dad, who was a machinist for most of his working career, agrees that it's a really nice looking piece of work. Couldn't wait to put it to use. Then the day came, my scope was finally delivered, and this mount proved to be a disappointment.

They give detailed instructions how to install it on the BKL website, with suggested torque rating. I followed the directions exactly, tightening each base bolt in sequence to the recommended 35 in/lb. I have a pre-calibrated Presta torque wrench rated for 4 Newton Meters made for installing bicycle parts. If you convert the units you'll see that 4Nm = 35.4 in/lb. When it gets to 4Nm it slips, stops applying force.

The first 2 allen bolts stripped their base threads long before they got to 35 in/lb. Aluminum is much too soft a material to stand up to that kind of torque apparently. You'd think I'd learn my lesson after stripping the first bolt, but some days I'm not that bright and not realizing what happened, I went ahead and stripped the second bolt before the bulb went on in my brain. Obviously I tightened the next 4 allen bolts well below the suggested torque rating. I'm sure 4 bolts is plenty to hold the mount on my relatively low-powered rifle but I lost 33% of my holding bolts and that's the kind of thing that will nag my brain forever.

Next problem, mounting the scope in the rings. The clearance between the bottom of the rings and the flat top of the base looks to be about 1/8". But the turret box at the bottom of my scope hangs down slightly more than that, so the scope is actually sitting on the base rather than in the rings. I didn't notice this at first and realized as I was tightening the top rings that it was applying bending force to the scope along its axis with the turret box as fulcrum. Not good.

So I went back to my 2-piece Sportsmatch rings, which incidentally hold 35 in/lb at the base no problem. I think they're steel instead of aluminum.

I sent BKL an email last week, not making any demands, merely informing them of my experience and suggesting they might want to reconsider their recommended torque rating. I haven't heard anything back from them yet. I threw away the packaging and paperwork a long time ago so I don't have any illusions about getting a refund. I don't care about that anyway, I just want to put this information out there so that others don't have the same experiences I did.
 
Please note that it's not my intention to disparage BKL Technologies as a company, or this particular mount, in any way. If you can avoid the 2 issues I encountered, I'm sure it's a fine scope mount.

Well said. BKL has been a highly regarded company in the rimfire world for a long time and the specific mount is simply incorrect for your application. That doesn't address the stripping issue which certainly should not have happened. I have several sets of BKL rings on both rimfire and air guns and all have worked very well. I have several sets of the aforementioned Sportsmatch rings also and view them as first rate. Hopefully you can get your problem solved and you will have better luck in the future.
 
were the screws long enough?, I ask because you did not post all information about your problem,,what gun, what size dovetail, how long is the striped potion compared to the screw diameter. There should be 1-1/2 (1.5) times diameter for proper thread engagement , also a lubricated screw will stripe out with less torque force ,compared to a dry screw

you could do a heli-coil repair,,,and I have ground down the surface where your scope hits the mount on one of my UTG 3/8 dovetail 1' mounts
 
were the screws long enough?, I ask because you did not post all information about your problem,,what gun, what size dovetail, how long is the striped potion compared to the screw diameter. There should be 1-1/2 (1.5) times diameter for proper thread engagement , also a lubricated screw will stripe out with less torque force ,compared to a dry screw

you could do a heli-coil repair,,,and I have ground down the surface where your scope hits the mount on one of my UTG 3/8 dovetail 1' mounts


Yes, the screws are long enough. HW30, 11mm dovetail, Leupold 3-9x33 EFR scope.

Looking at the thread holes with a 10x loupe I can see that there are no intact threads left in the first hole. The bolt falls out when I turn the mount on its side and tap it. Totally stripped out. Several crescent shaped pieces of aluminum fell out when I removed the bolt. The second one is in slightly better shape, there are enough threads left to hold the bolt in place but not enough threads to tighten it down much.

I believe the main issue is that the suggested torque rating is too high for this material. I followed the manufacturer's installation instructions to the letter and it failed. Again, the other 4 bolts work fine when torqued down much less.

I don't believe high rings should be necessary for this particular scope. It's a compact scope with only a 33mm objective. When you pay this much for a quality item you shouldn't have to re-tap threads or grind anything to make it work in my opinion. As far as I'm concerned it doesn't function properly and I've moved on to a different product that does.
 
I've had the exact issue with BKLs, and after it happened on the second mount I gave up on them. Good luck getting a replacement!


I'm not even going to try getting a replacement or a refund. It's not worth my time. A one-piece mount is overkill for this application and I've decided I prefer the more traditional appearance of 2-piece rings on this type of rifle anyway.
 
I've had the exact issue with BKLs, and after it happened on the second mount I gave up on them. Good luck getting a replacement!


I'm not even going to try getting a replacement or a refund. It's not worth my time. A one-piece mount is overkill for this application and I've decided I prefer the more traditional appearance of 2-piece rings on this type of rifle anyway.

That's $59.99 to throw away. Rather strange to throw away $60 just like that IMHO!!!

If that's the case I'll pay you shipping to take it off of your hands just PM me. I can just tap it and replace the screws and use it for my 22 AA PROSPORT I JUST RECENTLY BOUGHT!
 
This mount is a type where the extrusion must plastically (permanently) bend before the jaws will clamp the rail. There is no separate hinged or free clamp plate. So, much of the fastener torque is taken up just in bending the metal to close the jaws.

I have also stripped a screw on a similar BKL cantilever mount. It helps to put some antiseize paste on the screw threads - you've got steel screws going into softer aluminum female threaded holes.

If the jaws are too wide to start with, it would help to pre-bend them in a vise to adjust to a tight slip fit to your guns scope rail before tightening the screws. Conversely, if the mount jaws are initially too narrow, you can use the screws in the alternative holes to spread the jaws open to pre-fit your rail.

Good luck,

Feinwerk
 
This mount is a type where the extrusion must plastically (permanently) bend before the jaws will clamp the rail. There is no separate hinged or free clamp plate. So, much of the fastener torque is taken up just in bending the metal to close the jaws.

I have also stripped a screw on a similar BKL cantilever mount. It helps to put some antiseize paste on the screw threads - you've got steel screws going into softer aluminum female threaded holes.

If the jaws are too wide to start with, it would help to pre-bend them in a vise to adjust to a tight slip fit to your guns scope rail before tightening the screws. Conversely, if the mount jaws are initially too narrow, you can use the screws in the alternative holes to spread the jaws open to pre-fit your rail.

Good luck,

Feinwerk

Good observation. I've had to expand a few sets using the screws but never had a set that was too wide that I can recall. Might depend on specific rail variances it seems.
 
I also bought a one piece for my EFR to find out it didn't clear it. Seems like most if my scopes, upon closer inspection, wouldn't. Or sportsmatch, for that matter. I didn't read the tightening instructions and though I'm familiar with the design of their clamping method, I tightened one more than the other and stripped it. As earlier advised, I tapped it and installed a larger and longer bolt. 

I also stripped a standard ring of theirs for no good reason. Tapped that one out, too. That's part of a mixed set of offset rings, which I have 2 pairs, that my EFRs just barely clear when attached one way only. They won't fit, the offset rings, any of my other scopes either.

So, 2 stripped and tapped, 1 mount relegated to a cheap scope with no middle under hang on a P17, and 2 sets with rings that only barely work on one scope I have.

There's nothing wrong with the quality. They are a great domestically-made product. But you pay for the metal in the one piece mounts and it's not the hardest aluminum you can get..but still they aren't the most expensive. I just think maybe they are a bit behind the scene on what's getting scoped these days?? My bad for sure on not measuring everything out, but my cavalier approach was that if they didn't work on one scope, they'd work on one of the other 7...

I just bought more UTG Pro POIs. And I see Warne has new horizontal split rings. Sportsmatch was on the list, too, but I'm shying away from BKL with my current scope set ups. There's good stuff in that mid/upper-mid price point range, IMHO. For my tasks. 
 
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I love these ccop steel rings i just got for $50ish bucks. A tad heavy but super awesome (non-adjustable) rings. Bad selection when it comes to 34 high rings on a budget. I think the 30 and 1 inch are like 25 or 30 bucks. I will vouch for them for the price.