"Parker: daylight visible at face of breech after 10 rounds; left side of frame cracking after 26 rounds; forearm wood split at 275 rounds; buttstock split at 300 rounds; daylight at breech too great for firing after 305
You think that frame wasn't flexing?? Again this was as I recall having been posted here before, a Trojan grade, the only hammerless Parker made without the doll's head.
Personally I knew some 40+ yrs ago, when the Berettas were coming into this country via Galef as Silver & Golden Snipes that the front surface of the locking bolt cheek was designed to take the load upon firing from the trunnions, thought everyone new it. I didn't per se know it pulled them free of the trunnions, just supposed it augmented them & perhaps that was the case then.
The test referenced on Greener's cross bolt can be read on pages 154-56 of his ninth edition & showed a clear superiority to a top fastening. After normal loads were exceeded the frame did begin to flex without the topbolt but never did with it installed. The test itself was carried out by the "Field", not by Greener himself. The Greener gun was selected because it was easy to adapt to use the same gun both with & without the top bolt so was not a test of one brand against another, just of the bolting. A piece of silver paper was stretched across the joint so any flexing would break the paper.
My ca 1863 W & C Scott pinfire has a hinge pin & a single underbolt to contain all forces. The parts of a 21 are some beefier & made of modern alloy steel but there was no basic improvement of design.
The frame of a break action dbl is a bent lever. Without that top connection if you put enough pressure on it, it will flex. With a proper top connection the bbls are likely to let go before the frame. One notes this is exactly what happened on the "Parker G's" (with doll's head) on which Bell ran the tests on guns with both damascus & steel bbls. Their first failures was when the chambers let go.
