doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Toplever hold-open

I noticed today, while cleaning my Dickinson after a dove shoot, that it does not have a hold-open feature for the top lever. IOW, the lever returns to center after you open the gun, then when you close it the lever rides over to the right and re-latches itself when the barrels seat.

Many (most) of my other nice doubles have a hold open feature that holds the top lever over to the right until the barrels are closed, at which time a trip is depressed and the top lever returns to center.

What are the advantages of the system that holds the lever to the right? There are more moving parts to it which means more to go wrong and wear out. I can see that the hold-open system may make the barrels a tad easier to close the last little bit, but is there any other reason for it? Most all O/U guns seem to have this hold-open as well. There must be a reason for it to be so prevalent.

Very few doubles equipped with either Purdey style double under bites or even a single undebite will be equipped with a hold open mechanism. Some very early Greener G guns were so equipped but that was dropped pretty early on. No need for that mechanism when the shape of the bite pushes the bolt back, which is tied directly to the top lever work.

American guns that are only equipped with something like a rotary top bolt need the hold open mechanism so the rotary bolt stays out of the way so you can close the gun.

Many O/U’s are so equipped for a very similar reason as the American rotary bolt….its there to keep the bolt or bolts out of the way until the gun is closed.

Thanks, Dustin. So, it's totally related to the bolting design.

I tend to like the simpler designs more. No hold-open mechanism = less stuff to wear out and break.

But, sometimes the simplicity counteracts itself, such as in the case of a Fox. Extremely low number of moving parts, but having a rotary bolt it needs the hold-open feature to assist in closing the gun, adding more parts.

Best, SRH

If the Fox had a cam operated lever release, the characteristic noise you hear when closing a Fox would not be present. I love the Fox "noise".

while udders go clunk, duh fox go clink...

Actually, Ed, the Fox goes "CLINK", or is it "CLANK"? All I know is that I like it.

Some early Syracuse Lefevers are bolted by the so-called Pivot Lever system, in which a spring loaded bolt is retracted to open the gun, and the lever then returns to center under spring tension, and the bolt extends. The bolt is cammed back by the rib extension upon closing. This is pretty similar to the even earlier Thumb Push opening system. Dan Lever incorporated a method to tighten up bolting as it wore and the gun became loose. However, I've seen very few in need of tightening, even though all of these guns are over 125 years old.

Somewhere around serial number 15,000, Lefever used the more conventional top lever which was held open until the trip mechanism permitted it to return. The system used a single bolting point on the top rib extension, and the bolt had a very slight taper which allowed the bolt and lever to gradually move toward center, or even left, as the bolt and bolting surfaces gradually wore. Apparently Dan Lefever felt this was an improvement over the earlier system that wasn't self-compensating for wear. He was able to eliminate the adjustments for wear, but had to add the lever trip mechanism.

His last guns employed a cross bolt, which of course required a top lever that is held open until the trip is activated. The cross bolt had a very slight taper, and there is an adjustment screw to permit the cross bolt to travel slightly further as wear occurred.

It seems to be a combination of the design, engineering, cost, difficulty of machining, and the fit and quality of the materials that determines which makes of guns wore out prematurely, and which stood the test of time.

Two guns with double under bolts, that feature a lever hold open. An Italian Prandelli and Gasperini and a Spanish Ugartechea:





The reason becomes clear with a quick examination. Both guns have hidden third fasteners that have to be held out of the way when you go to close them, just as Dustin pointed out. Not common.The Italian gun has a hidden round bolt, operated by the top lever, and the Spanish gun has a very well fitted “Purdey nose” on the breech face.

For what it is worth, both are 3” guns wearing European magnum proof. Not sure why they thought they needed a third bolt, but, that might have something to do with it.

Best,
Ted

Dustin;

I thought it would maybe be helpful to the others who have limited knowledge of the Purdey double under bites to add a couple of things to your excellent explanation. 1) the forward lump underbite does not hold the barrels closed. As you describe it is shaped and cut to hold the locking under bolt to the rear until the barrels are closed enough to allow the locking under bolt to enter the rear lump bite to hold he barrels closed. 2) The fitting and timing of the release of the locking under bolt by the forward lump under bite is critical; and because it's action cannot be seen this fitting must be done very carefully. The proper timing of the locking under bolt is for the forward lump to hold the locking under bolt rearward until the rear lump bite has a clearance of .001" to .002" between it bottom surface and the bottom of the locking under bolt; then releasing the locking under bolt to where it can move forward under it's entire spring force "slamming" the barrels down ward. "Slamming" is not a particular good word for this but it gives the reader the understanding of the force. The timing of the closing of the locking under bolt in large caliber nitro express double barrels rifles is very critical--especially double rifles used for "stopping rifles".

Very nice, thanks.