doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com So, how strong are NID's?

So, like most of the debates on strength of designs, it all becomes academic once you get past what's required for strength, fatique and wear. ...unless, of course, you shoot proof loads.

If a modern retest is to be scheduled, surely a Trojan and a doll's head Parker should be included. Just as a matter of information, it is my understanding that the replaceable "cheek things" or whatever they are called on a 680 series Beretta are not to give additional friction to the locking mechanism, but (big news for everyone who for years had assumed otherwise) they are to force the monobloc assembly slightly away from the trunnions during the firing process. Well, to be honest, Beretta engineers are a lot more gun savvy than turn of the century Parker mechanics. We have read for years that we shouldn't believe the "multi bolt" guys when they describe the activities of the various cross bolts because "they are rarely all in contact with anything at the same time". Miller would have us believe that the Parker frame flexes enough to put the doll's head into action when heavy proof loads are shot. My opinion is that if the load is heavy enough to flex the frame so far as to use the doll's head for support, the gun is gone. At least the rib extension is in serious danger of fracturing. What do you guys think? What does Sherman Bell think?

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.

Back to the original question. The NID, like most of its contempories, is strong enough! I usually do not participate in these peeing contests but any gun that is still spewing lead after 75 ish years is ok in my book.

Thanks for the comments, Walt. I agree with you that the excess strength of some of these guns is not needed in normal use. However, Miller and I are not in a peeing contest, I am learning a lot from his recollections and knowledge. By the way, Miller, one of my Parkers, a DH Grade hammerless pigeon gun, was made without doll's head by specification and it seems to be holding up pretty well after 106 years. As you know, I will not be feeding it any proof loads to further test it. I stand by my statement that if the frame flexes enough to put the doll's head into action, the gun is gone. Both Olin's test and Sherman Bell's test are at least some proof of that.

8-bore;
I totally agree the Parker frame is stout enough to hold up to all normal use without the doll's head, as is also the Lefever as proved by the DS grade which omited it. Where I believe it definately would come into play would be on loads heavier than normal as used in this So-Called "Test". I would have to dig out the old issue & re-read, but as I recall from Bell's test the frame itself was undamaged & was said it could likely still be re-fitted with bbls & be usable. I personally would take that as positive proof the Doll's Head was working. What it is there for is "IF" a heavier load than normal gets fired it "Stops" the bending/flexing before it can cause frame stretching. The thrust comes straight back along the bore axis. Containing it from both above & below that axis is far more efficient than from only one side & depending totally upon the strength of the frame. This is basic mechanics, know ever since the "Clevise" (shackle) was designed to hitch a mule to a plow. Incidently I have hitched a few mules, perhaps that is why I understand the principal involved. I do not believe the Win engineers mised this when they chose the Trojan over the more common VH, but that's just my opinion. Incidently I have tried a couple of Lefevers on which the ball screws had been loosened & with the ball backed out of engagement upon closing the bls they snug right up against the breech with the top lever still centered. Even with the ball tight there can be no more than about a .001" clearance on that doll's head. There in lies the secret for any top fastening, IT Has To Fit, or it is of no value. It has been shown, that in spite of A T Brown's original design intent, the vast majority of rotary bolts built over the yrs do not fulfill their mission. This likely was the short coming of the NID "Tested" by Win. Perhaps they picked it to be sure, who knows.