doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 1st & last Parker

Murphy, I would suspect 2.5" chambers in a 1910 gun. I used the old 12-70 chamber gauge expedient of a 20 ga. hull with crimp cut off stuffed in a 12 ga. hull until 20 base rim sits on the opened crimp of the 12. On this 1920 Parker, there was no interference with this "gauge" seating easily by hand in the extractor rim cut and the gun closing easily. I'll get some guff for this but I think it's close enuf as a "GO-NO-GO" to allow me to shoot sub 8000psi 70mm with confidence that I am not creating wild pressure excursions. The four hulls from the actual shots I got off at skeet Sunday looked fine in the crimp area.

jack

It has been previously stated here on the board that Parker delibretly chambered their guns 1/8" short for the intended shell length. Many of the earlier guns were no doubt intended for the 2 5/8" shell. By 1910 I highly suspect most Parkers were intended to be able to handle the 2 3/4" shell, definitely so by 1920.

I can in no wise prove it, but also highly suspect they just continued chambering to 2 5/8" & stated the guns were built for 2 3/4" shells. In any case placing a 20ga hull inside a 12ga one will not detect a short chamber "UNLESS" the chamber ends in a distinct step which I have never seen a chamber so cut. I do though understand a few Very Early shotguns had such chambers.
Put the 20ga inside the 12ga but leave it protruding about an inch from the end of the 12 then insert it into the chamber & see how far it is pushed back into the 12ga hull. This will show just how far the 20ga rim will enter the cone & very quickly point out the fallacy of this method.
Note also the head of the 20ga hull ahead of the rim is not a tight enough fit in the 12ga hull to give you any more feel of the chamber end than just using an empty 12ga hull alone.

My friend Miller doesn't need my support to be proven correct. However, I was curious as to how far off this 20/12 method could be. I assembled the "gauge" and inserted it into a chamber of my favorite Lefever. This chamber is exactly 2-3/4" to the start of the FC(I lengthened these chambers, myself). The 12/20 combo was compressed to a length of 3.004", giving the false impression that the chamber was 1/4" longer than it actually is. The 20 ga. rim diameter was .763", .035" smaller than the forward end of the 12 ga. chamber should be (.798"). Not a usable gauge, IMO.

Got that "20 in the 12" from "Wilhelm Gregor," the disappearing Alaskan hogrider. I tried the "slip the bullet to find the rifling" method suggested by Jim and got 2-27/32" OA case rim to case rim. No doubt the 20 ga. rim is in the cone. Howsomeever, what is important to me is that the wall of the 20 shell base is a slip fit in the 12 crimp area. The crimp is not allowed to collapse and will not collapse if it either hits the cone of protrudes into same. If there is no reduction in the OD of the fully open crimp (and that full diamater is maintained in my view by this "gauge") then there's no appreciable occlusion of the cone and likely no appreciable pressure excursion. I have at least two 12 ga. guns which will NOT close on this gauge so it sure as the devil is a GO-NO-GO some of the time some of the guns. Note also that the 20 base is a tight enuf fit in the 12 crimp area to hold its position in Jim's "test" so I think it's effective in holding the open crimp OD. Incidentally, the wall of a plastic hull is considerably thinner than the wall of a paper hull; a fortuitous advantage of new school ammo in old school guns. Wilhelm's invention does give a feel for "fit" if not "bottom of hole" if the barrels are off the gun and only hand pressure used to chamber the gauge with the extractor already retracted. OMO.

jack

Is Wilhelm Gregor still around? He was always fun to chat with but I haven't heard of him for a long time.
Thanks for reminding me of him.

He showed briefly about a yr or two back (exercised/exorcised a few demons) and rode off again. I believe the dolphin lover who lives inside of the outside also does this periodically.

jack

I like him. Lot of common sense.

Jim/Miller:

Tried the "gage" again with the 20 rim inside the wall of the crimp area of 12 ga. Remmy Gun Club hull. OD pretty close to .792"<.8" (maybe .797"). Barrels off, lashup under finger pressure seated to expose 12 base rim outside the rim cut. Remmy hull is underlength on nominal by a 32nd so I'd say the end of the chamber is under 2-3/4", probably 3/32nds less= 2-21/32" or nominally 2-5/8". Admittedly a lotta guesstimation.

jack

A few more notes on this go/no-go gage. The inside dia of a 12ga hull will be some larger than the standard bore of the gun (.729") often around .750". The head of a 20ga will go to about .700", definitely not large enough to provide a resistance to the end of the 12 ga from enterong the cone. In all the case I tried this on if the 20ga rim actually entered the 12ga mouth it then became too tight to reach the end of the chamber. The only way Ican see for it too work at all would be if the 12ga hull mouth had just the right amount of skiving for the rim of the 20 to just seat inside the end. None of the combinations I tried proved to be of any value whatever. In placing the cut down 20 into the mouth of a fired 12ga crimp memory is what keeps the 20 from just sliding freely.
I don't recall now what hulls I had on hand when i tried this several years ago upon first hearing it, but on all the ones I tried when the rim was pushed inside the 12 the od was swelled to over the .800" dimension & on some would go no more than about half the chamber depth. I quickly lost all interest in the method. It is noted also that Parker is one of the American companies which has often been mentioned here as one who intentionally chambered their guns 1/8" short of nominal shell length, thus that 2 5/8" chamber is probably right for a gun intended for use with 2 3/4" shells.

I like the hard card wad stuck flush in the end of a new hull that you intend to use...if it goes in easily no worries.... IF wall thickness checks out at chamber/cone junction.

This has all been proven to be pretty moot if we start with 6k to 8k loads...hasn't it?

Best,
Mark