A recent thread showed photos of some lovely doubles. In reading the descriptions, I noted that they had long bar actions. Can someone explain what a long bar action is, and why it is the better solution.
Thanks
Bfly

Have a look at / do a search on

Webley PHV1 and Webley Screw Grip actions.


Also have a look at Champlin Arms web site
as he often describes them as Long Bar actions.

You can see that the water table of the action is quite a bit longer than on other actions (see a Greener or some other makes).

This means the mating surface that the flats of the barrels sits on is large.

More coming later.
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Another advantage is the locking mechanism can be farther away from the hinge pin. The farther it is the more mechanical advantage it has at keeping the barrels locked up.

The length of the "bar" is what primarily distinguishes an action made for a shotgun vs an action made for a double rifle.

As Aaron correctly points out, the longer the bar (within reason) the more leverage there is over the lockup. There is also more metal to prevent the action from stretching under the higher pressures and increased back-thrust of double rifle cartridges.

You’re probably familiar with the proclaimed strength of Winchester’s model 21 and all of the “blue pills” it successfully digested while other shotguns in the same test gave up the ghost after only a handful of proof rounds. Look no farther than the bar length on a Model 21 for the reason why. It is much longer than the comparable Fox or Parker of the same era, and it is also what gives the 21 its legendary strength. The 21 is more like a double rifle action (in bar length) than a shotgun.

Contrary to this logic, most double rifles made today have bar lengths that are more like shotgun actions (in length.)

I encourage customers to compare the bar lengths on the current made doubles before they purchase, as I'm quite surprised at how short some of them are. If you measure them, you might be surprised too.

I imagine the greatest benefit of a long bar would be found in actions with serious top fasteners, where it should reduce leverage from the whip of the barrels. Without that I wonder if it might even be subject to a greater bending tendency than a short bar.

From pics I've seen, the Winchester M21 seems not to have a top fastener, though, or even a front underbite, so is an interesting divergence from the European norm. I've never understood the importance of a front underbite either, but it does require a bridge that some say can take pressure off the cross pin if mated properly with the lump for the rear underbite.

Thanks, that all makes perfect sense. I just never cease to be amazed at what a bunch of craftsmen with a couple files and scrapers could make from a chunk of steel. Just poetry in our hands.
Bfly

Another advantage of a long bar is the barrels swing down less to clear the chambers.

Dave

new_guy "Look no farther than the bar length on a Model 21 for the reason why. It is much longer than the comparable Fox or Parker of the same era, and it is also what gives the 21 its legendary strength."

Ain't so! The "legendary strength" you speak about, is gained largely from the much superior alloy steel used in model 21s, 4140 steel, while the steel used in the Fox, Parker, and similar was simply common low carbon mild steel. The tensile strength, yield strength, of 4140 is many times that of the mild steel, allowing for the "legendary strength you speak about.

quote:

Originally posted by nopride2:
Another advantage of a long bar is the barrels swing down less to clear the chambers.

Dave

The above was Winchester's reason for the long bar, not strength! The Mod 21 Winchester was meant to be used in shotgun competition and the shallow opening for ejection and re-loading was a real plus in competition! The Mod 21 would not make a good choice for conversion to a serious double rifle, with it lack of three point lock-up.

Still the long bar does make a properly made double rifle with all the common lock-ups stronger than the same with like lack-ups and a shorter bar. The shallow opening of the long bar is even more important in a double rifle used for dangerous game for it's fast re-loading.
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Glad to see the alloy was mentioned as it certainly does have a large roll to play in the strength of the actions.

My Father was a Blacksmith and Farrier. I recall a couple of farriers making horse shoes from sucker rod and they would last two to three times as long as mild steel shoes. They could be reset time after time. When I was a Bladesmith, the steel chosen made enormous differences in the quality of the blade. Beyond that the heat treatment it received was what set a world class blade apart from the rest.

An example was a test done with two blades of the same dimensions, forged from the same steel at the same time. One was properly annealed, heat treated and tempered, the other was just hardened and tempered to attain the same rockwell hardness. During the bend test, the properly heat treated blade was bent to 90 degrees without cracking, and returned to have only a 15 degree set. The other blade broke in two at about 45 degrees.

Metalurgy is of paramount imprtance, and the treatment of the steel brings out the best it can offer. I suspect Winchester paid attention to those details.

Cool stuff.

Thanks for the education Jack, Bailey and others.