by B.B. Pelletier

Part 1

Yes, that really is a link to Part 1 of this report. But I combined it with Part 3 of the report on the Hammerli Razor, so it may confuse you. I bet most of you forgot that I was doing this test, so here’s the background.

Background
BKL mounts are of interest to airgunners, especially those who shoot springers, because they claim to hold fast to 11 mm dovetail grooves with clamping pressure, alone. Back in the days when I wrote The Airgun Letter, I had occasion to test that claim and found that it came up short. The rings did move from the recoil of a lowly CZ 631 spring rifle.

The BKL company soldiered on until 2007, when they quietly left the marketplace. They were quite popular with airgunners. In late 2008, AutoNumatic, the parent company of AirForce Airguns, bought the BKL company, including all its rights and work in-process. In early 2009, they brought the first new BKL rings to market and throughout the year quietly built up inventory as the word spread that they were back.

The test
I started my test of the very popular 260 MB model in September 2009. I selected the Hammerli Razor as a testbed simply because I happened to be testing it at the time, though the Razor has a pretty snappy recoil. The gun was shot over 100 times for accuracy then about an additional 400 shots after that. I say about because to tell the truth I lost count somewhere during the test. However, a lot of shots went through the rifle with the BKL one-piece model 260 MB rings mounted. And the scope it was holding was a Bushnell Trophy 6-18x, which is not a light scope. If there was going to be movement, this combination should have produced it.


BKL 260 has six clamping screws, shown here. The three holes accept a clamping screw that can spread the clamp jaws to go on a rifle with a larger-width dovetail.

Here are photos of the four witness tapes at the start of the test and at the finish. One is at each corner of the base of the mount.


Tape at the left rear of base when first installed.


At the end of the test, tape at the left rear of base shows no movement.


Tape at the left front of base when first installed.


At the end of the test, tape at the left front of base shows no movement.


Tape at the right front of base when first installed.


At the end of the test, tape at the right front of base shows no movement.


Tape at the right rear of base when first installed. If the mount moves, it will either curl the tape or move away from it. Either way it will be visible.


At the end of the test, tape at the right rear of base shows no movement.

So, there you go. No detectable movement of this BKL mount holding a heavy scope for about 500 shots on a briskly recoiling spring rifle.

The next test
But you know what? That’s not enough. We all know there are spring rifles that have legendary recoil. Guns like the Webley Patriot that was also sold by the old Beeman company as the Kodiak. That rifle has been known to break scopes with its vicious recoil. We won’t be satisfied until the mount proves its strength on a brute like that!

I don’t own a Webley Patriot or a Beeman Kodiak; but, fortunately, John McCaslin, the owner of AirForce Airguns does, and I’m using it for this test. If the BKL 260 MB can ride out another 500 shots, this time on a Webley Patriot, then there won’t be much anyone can say, except that it works as advertised.

Why a scope mount without a scope stop?
It’s time to answer the big question. Why would anyone need a scope mount that doesn’t have a scope stop built in? Well, for many airguns, there’s no need whatsoever. Pneumatics and CO2 guns don’t have enough recoil to put a strain on a scope ring set no matter how large the scope in them might be. And even some spring guns such as the new Bronco have such low recoil that any good scope ring set will hold without a positive scope stop.

But as spring guns start to develop power, their recoil becomes both quicker and more pronounced. Remember, it was a Slavia 631 that defeated the first BKL mount I tested. Riding out the recoil of a Webley Patriot would be the ultimate challenge for a mount that holds by clamping pressure, alone.

I’ll switch the scope to the Patriot and give you a full report.