Browning Buckmark - Can't Open Slide With Hammer Uncocked?

[millertyme]

Sounds like my Buckmark, too. I've thought about adding something like the one off the brianenos.com forum. Since I haven't added the holographic sight just yet and since I still have the strength of my youth it's not that big of a problem right now. I just try not to drop the hammer on an empty chamber.

 

[gvf]

Dropping hammer on empty chamber not recommended? Why is that. Think I only know of revolvers in terms of that.

 

[millertyme]

Well, if you drop the hammer on an empty chamber you'll have to deal with the difficulty of racking the slide against the full power of the spring. Not a safety thing, not a mechanical thing, just to avoid the problem of the pulling back the slide. Keep it cocked.

 

[Swami]

My Buckmark has thousands of rounds through it, and does the same thing. I make it a rule to never dry-fire it; as long as the hammer's still up the slide racks very easily and smoothly. I love this little pistol, and am glad to read it's not only mine doing this!

 

[gvf]

Right, got it.


So, why is the spring so tight on Buckmarks? Altho come to think of it, my Colt 1911 wasn't that much easier for me to open slide with hammer down. I usually cocked it first. Now it's a bit easier - (of course that was just before finding that the slide was chamfered hopelessly, anyone want a Bright SS, one of a thousand run of the Colt Silver Star? Great door stop.)

 

[ForumSurfer]

So, why is the spring so tight on Buckmarks?

I don't know and I don't care since the silly thing likes to shoot even the cheapest and dirtiest ammo I can find with zero issues. I seem to be happiest the federal competition bulk packs. The price is right and the accuracy is pretty close to CCI minimags. If I switch to CCI, I have to adjust the sights as the POI shifts. I found my ammo and I'm stocking up on it. Between myself and my son, I can't keep the accumulated stash very high. I like it so much, I may get a second one and a race tree.

My son has the same problem, though. I experimented and dropped the hammer before letting him shoot. He had a heck of a time racking it.

 

[mister2]

So, why is the spring so tight on Buckmarks?

There are 2 components:

1. hammer - and this is a function of the mainspring, which seems as stiff as the Browning HP spring, and the design of the hammer itself, meaning the point at which the spring acts in relation to the fulcrum (pin) point.

2. slide rail - the operator racks the slide, which in turn pushes the hammer back. It depends on where the slide pushes on the hammer.

As an analogy, let me use the example of loosening the lugnuts when I get a flat. If I have a short wrench, it takes me actually jumping on the end of it to loosen the nut. If I have a looong wrench (or a cheater pipe to slip over the short one) I can actually break the nuts loose with just leaning on the end.

The same principle works in the BM. The slide rail comes from the factory cut at virtually a right angle, i.e., very small radius on the end of the rail. [Aside: in my earlier post, I posted pictures of the slide rail, pointing to the corner of the slide which acts against the hammer.]

This places the "push" we give the slide very close to the hammer fulcrum point, or where the pin is. This then makes the mainspring feel heavier than it really is, because of the lever effect, or leverage. [Another aside: In 1911s, the firing pin stop comes in a variety of radii, increased on purpose between wars because the older models were "hard to rack". The BHPs had a similar development on their firing pin stop.]

The explanation ends here. It's important to understand why the darn thing is so hard to rack before any intelligent solution can be proposed....and there's a few out there.

 

[rondog]

Huh, good info here! I just thought my Buckmark didn't like me.

 

[gvf]

Well, MISTER2, you certainly know the answer to my question.


On my Buckmark, the hammer is closer to one side of the slide than the other, as close to touching as you can get - perhaps it is touching. This normal? (I see no unusual marks around there on either the side of the slide or the hammer - or the rear of the slide shown in your photo.)

Also, on your photos of the places that would show wear, aside from the locations, do the views also show actual wear marks?

Thanks

 

[mister2]

gvf,

A couple of things:

I've replaced the photo with a larger one that shows the correct edge that works on the hammer. It's hard to say what it started as, because I got my BM used with an unspecified round count. How much of that edge came from the factory versus how much is wear and tear, is uncertain.

The hammer is closer to one side of the slide (the right side) because it is offset slightly, and this is evident looking directly down on it with the slide removed.

Having said that, let me add to my response to your question,

So, why is the spring so tight on Buckmarks?

You asked "why", I earlier answered with a "how". Here's my attempt at the "why".

Consider the BM and the 1911 conversions, and let's include a popular pocket 22, the Bersa Thunder. All these 3 designs work on a blowback principle. The BM slide, compared to the 1911 conversion slide, or a BERSA Thunder slide, has less mass, which means the slide of the BM would "blow back" sooner, and faster, than other designs. In order to slow down this recoil impulse, the designer has three options: 1) a stronger recoil spring, 2) a stronger mainspring (and thus, greater hammer resistance), and 3) locating the point at which the slide pushes back on the hammer to increase the hammer's leverage.

1. Recoil spring cannot absorb the entire blowback impulse alone, otherwise it would slam the slide forward as hard as it came back, so it works in combination with the hammer,...

2. ...using the force of the recoiling slide to work against the mainspring and cock the hammer.

3. By configuring the slide rail so it contacts the hammer close to its pin or fulcrum point, the design makes it initially very difficult to push back the hammer but as it moves back the hammer gets easier and easier to push, because of the changing geometry.

By combining all three, the pistol has used the energy of the 22lr cartridge to extract, eject, cock hammer and chamber another round (or lock back in the case of the last round). As a side effect, it also becomes initially difficult to rack the slide with the hammer down.

And that's why, compared to other pistols, it's hard to rack the BM slide.

 

[gvf]

Thanks. Very interesting!