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Birdhunter

The Greener Crossbolt is in no way a gimmick except in the case of cheap and/or poorly made guns. I have a Merkel 247SL and the fit and finish is superb. In fact, all Merkels I've owned were fit in the same way. The Greener Crossbolt has been widely copied and, in many cases, disastrously so. The underbolt alone does not counter the destructive trio (axial, radial, bending) of firing forces. Tests have shown that, with just underbolts in operation, the barrels can still separate from the standing breech. This is common knowledge today. This gaping action works against the angle of the frame (which is slightly rounded and not a right angle for a good reason). British gunmakers (Purdey, Holland's, Greener) responded to the inadequacies of underbolting by introducing "top fasteners," which held the barrel face to the standing breech. Of course, Greener's bolt is the most famous. Operating in unison with the tang lever, the crossbolt's bite frustrates axial and radial forces while also dampening the harmful impulses of bending pressures.

It is therefore one of the most versatile, if not the most versatile, of all top fasteners, because its placement and power oppose ALL THREE adverse forces. The only other truly viable top fastener is a well fitted Westley Richards style Doll's head.

To say the the crossbolt is a gimmick and useless is simply, from an engineering standpoint, wrong.

The Greener Crossbolt is also insurance against cracking and premature looseness in lightweight game guns and rifles on boxlocks and bar action side locks, both of which have their frames weekened internally by transverse bolts, inletting, and machined areas.

Proper fit and finish are essential for utmost efficiency, but producers of garden variety doubles have taken undue liberties with Greener's invention while still capitalizing on his famous name. Claiming their product as a "Greener-type" crossbolt, they have inserted square or flat crossbolts instead of the original round bolt and, in some cases, they have given the rib extension nothing more than a notch or pair of stubby arms. What a joke. In quest of high profits, these makers have done horrible jobs of fitting. The result is but a Christmas Tree ornament. Extensions open at the rear or offerering only stubby arms cannot retard axial forces or hold securely against bending pressures. Again, this is an engineering fact.

Properly fitted, the dowel's rear half holds securely against the barrels' thrusts and, even on a relatively small diameter bolt, the rear half of it's circumference provides considerable bearing surface. In turn, the rib extension need be drilled with only a small hole, thereby leaving it stronger than if it were cut for a useless square bolt with equal bearing surface.

I won't even get into the value of well-fitted and properly filed side clips!

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Edited by Der_Jaeger (31/12/08 09:33 PM)

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