doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Beretta BL-series Lockup Design?

I was looking at a newly acquired S57E last night and just noticed that there isn't a "lug" lock up, etc. on this action - surely the lock up is not only the two little "pins" that project from the action face? (I apologize if I am not using the proper terms for the action parts). Anyway, I am hoping someone on the forum can tell me how this action actually works to provide a solid lockup and also provide pictures/diagram/etc? Are there any diagrams/pictures/descriptions available on how the Beretta BL-3,4,5 and S55/56/57 actions lock? Thanks in advance!

The major stress on a double gun is "Axial". On many designs nothing contains this but the hinge pin. Some models have auxilarry fastenings for this purpose, ie cross bolt, rotary bolt, doll's head, forward face of rear lug on a dbl underlug etc,etc. All these require proper & precise fitting to be of benefit. Many think of the most requirement being a rotational bolt. Both W W Greener & Dan Lefever stated many years ago a gun could be kept from opening by merely wrapping ones thumb over the bbl. Those "Two Litle Pins" are entirely adequate to hold the bbls closed & if you note, at least on most Berettas, the lug the pins enter are recessed into the frame wall thus supplementing the hinge joints against the axial thrust, a feature lacking on many O/Us.

Yep. Note the position of the hinge trunions. I think Westley Richards first built an O/U in this general fashion. Beretta sells these by the boatload and they are strong and durable. It's nothing less than a brilliant design, and most guns from Italia use a variation on the theme, thus 'the Italian gun'.

There's more to it all than the number and size of locking bolts...

Thanks, guys! I have owned BL-series Berettas since the '70s and they are still solid. I hadn't really thought about how they locked up until I recently bought the S57E in 20 gauge - the gun is still locking up real solid but the release lever is not to the right of center so I was a bit concerned about it. This is a 28 inch barrelled sweetie that weighs only 5lb 14oz. My BL-3 in 20 ga with 26 inch barrels weighs 5lb 12oz. These are really nice upland guns that carry easily all day. A good one is a real value in my opinion. Thanks again.

The tapered locking pins automatically compensate for wear because they are spring loaded. The fact that the lever is moved left slightly is witness to the fact that the pins are protruding farther into their holes in the monoblock as they and the holes wear. The axial thrust is taken by the shoulders of the monoblock where they seat in the frame cuts. On Beretta target guns and the SO series those shoulders are replaceable to compensate for wear. The action trunnions do not take any thrust if the gun is fitted properly. The fact that the locking surfaces are located far from the trunnions reduces the loads on them because of the increased length of the effective lever arm.

OB

Be sure to keep the locking pins,their respective holes, and the pivot trunnions clean and lubed with your favorite lube. I like grease. They will last a very long time with normal use.
As OB said, the shoulders pull the barrels back against the standing breech and relieve the load from the trunnions. I was wondering out loud one time as to why the replaceable shoulders would ever experience wear. I wondered out loud in front of the right person and he 'splained it to me. Brilliant engineering. Rich Cole told me once he had never replaced a set of trunnions, even though they too are replaceable. I guess that's why they don't wear much, if at all. I have seen the holes for the locking pins wear pretty badly on rental guns at ranges but they are probably handled poorly and rarely, if ever, cleaned and lubed.

On Beretta 68X (X=2,6, etc.), the holes which engage the locking pins are ordinarily worn more by the weight of the barrels causing the pins to drag over the rear radius of the hole as the gun is opened, than by firing or by closing the gun. Several gunsmiths have told me that moving the top lever to the right until the pins are entirely withdrawn prior to opening the action reduces rounding of the rear radius, greatly prolonging the period between rebuilds. (I'm only discussing opening Beretta 68X and similar actions. No, I don't hold back the top lever until the action is closed! No, I don't want to discuss any aspect of closing double gun actions!!!)

Those two pins are actually the ends of a single U-shaped part. That lock-up system is still used on all Beretta 68x-series O/U's today. It has been very successful.

In my experience, the parts that wore were not the pins but the holes in the monoblock that the pins fit into. With even a little wear, you can easily see that the holes are no longer round, they are oval, having worn on the bottom. As they wear, the top lever moves to the center and sometimes to left of center. The gun continues to lock up tightly, but eventually wear will cause the gun to pop open when fired. This is not a safety hazard, as the gun will open only a crack, and will not fire again while open. It is, however, a sign that the gun is overdue for an oversize locking lug. The lugs come in several sizes, and when the holes are too big for the largest lugs, they can be drilled out and fitted with bushings so you can start over with the smallest lug. Thus there is no limit to the number of times the locking mechanism can be tightened up to compensate for wear.

The gun in question S57E was made at a time when Beretta were using Best quality materials and I have yet to see a 55/56 or 57 show severely worn locking pin holes, however the modern S682's and their like are another matter, 2 years of heavy trap use will see the holes severely out of round and needing rebuilding, material qualities have been degraded to the point where reliability of lower end Beretta is comparable to Spanish low end. Beretta have tried to play in the low end through to high end guns and have damaged thier reputation along the way, the DT10 is a standing example of Junk at inflated prices and is evidenced by thier poor resale price. Your S57E should give you many years of reliable shooting.

hotrack

Various posters have explained that the U shaped pin set is not only common to the BL and 57 series, but presently used on the 680 series guns being sold by the boxcar load today. The replaceable shoulder system of the 682 Model is not used on lesser priced models and they seem to survive just fine. I am not entirely sure that the locking lug holes are the wear point. I have tens of thousands of rounds through one barrel set of a five barrel set 682, few rounds through the other four sets. When the pin set was replaced when the gun was about 15 years old (because of well worn lever position), the unused barrel sets showed a lever position similar to the well used set. I think the pins were wearing as well as the holes, maybe more. With either the old or new pin set, the lever position was similar on all barrel sets. Mr. Cole's observation that the trunnions don't seem to wear parellels my experience with my high mileage 682. It opens and closes like it is still breaking in. Precise fit of the side walls of 680 series actions as well as careful cleaning prevents wear on the trunnions. The tight fit of the shoulders helps also, I assume, but only one of my five barrel sets was fitted at the factory so the assumption would be that some of my shoulders are not as well fitted as others. I think the shoulders are a nice touch, but not neccesary to the longevity of the gun.