Question on Chamber Length - Page 2

Bruce Day · 03-15-2010, 07:33 PM

Fair enough Dean. However, the box lids lead to two erroneous assumptions, that these shells are 2 3/4" when fired and require chambers of 2 3/4". That's why we get the same question so many times. If I wasn't aware of the Bell findings and hadn't actually measured these shells, as Austin also just did, I would get confused also. Then also Parker chambers are notoriously hard to measure accurately and people often think they are shorter than they are.

You're probably right about the shooter not the gun. These Parker 20ga's are nasty ( to me anyway) with a 1 oz load but I have a little Browning Superposed in 20 that the 1 oz loads feel much better in. The Browning doesn't weigh but a couple ounces more....no explanation from me.

Autumn Daze · 03-15-2010, 07:51 PM

I may be wrong but I think the felt recoil in my O/U is less than my SxS guns.

Dean Romig · 03-15-2010, 07:57 PM

Softer especially in the lower barrel too, right?

It all has to do with the line of force. A higher stocked Parker will deliver much lighter perceived recoil than one of those with 3" DAH.

Autumn Daze · 03-15-2010, 08:06 PM

Ya..I guess.... I shoot lower barrel first. I tried it on a Parker by turning it on its side..Didn,t quite work out to well...

Pete Margiotta · 03-15-2010, 08:22 PM

Thanks for all the good information. I will not touch the chamber and try the gun with some light target loads. There were several references to "these light 20s", I weighed this one at 7 pounds. When I said there were 40 percent case colors let me say that I did not think the colors were that brilliant. I will try to post some pictures when I figure out how to do it.

Regarding the question how I measured the chamber length, I used a starrett telescoping gage set to .685 diameter and placed it into the chamber until it stopped, then I measured the depth on the handle of the gage. thanks again

Autumn Daze · 03-15-2010, 08:30 PM

Pete,Be sure to keep in mind that chambers are tapered..698-.685. Ooops never mind!

Labowner · 03-15-2010, 08:51 PM

20ga. AA hulls 7/8 oz. 16.5 grs. 800x Rem 209p Rem RXP-20
7500 PSI 1200 fps.

Scott has a great 3/4 oz. load maybe he will post it.

I've loaded this down with about 15grs. 800x and you can shoot them all day.

Reloading data for the twenty stinks, open a new reloading book and there isn't one 3/4 oz load in it, but they list them for the 12ga., don't get it, there should be loads down to 5/8 oz.

Austin W Hogan · 03-15-2010, 09:28 PM

With respect to Mr Margiotta's question, and my post of a few days ago, his measurement may reflect chamber taper, and not chamber length.
I have attached page 17 of the current SAAMI ANSI standard. Note that the length specification for modern 12 ga cases is 2.76 - .100 inches, tolerance - .250. Remington and Winchester cases measure 2.66. This is 1/32 inch over 2 5/8, probably well within tolerances for paper and plastic. Also note the plus tolerance is zero.

I would like to call your attention to the modern chamber and forcing cone drawing below the case drawing. The modern 5 degree forcing cone makes the Parker forcing cone look like a bore obstruction by comparison. Although modern ammunition seems trivially longer, an extra 1/8 of chamber length is a great safety factor in the case of a case separation or other shell failure.

Best, Austin

Researcher · 03-15-2010, 10:02 PM

Is this thread led off by my old friend Pete from down in Charles County and the Potomac River Gun Club at Rum Point? How is that Gene Mahoney pup of yours? I got a Mahoney setter in 2005.

I usually use our friend Morris Baker's 2 1/2 inch 20-gauge shells in my 0-frame 20-gauge VH-Grade, but I wouldn;t be above using my 3/4 ounce reloads in Remington STS hulls if the need arose. The chambers in my gun measure 2 3/8 inch, which is the way Parker Bros. chambered these old guns, 1/8 inch shorter then the 2 1/2 inch paper shells they were intended for. See pages 164 to 169 of The Parker Story.

Dave

Bill Murphy · 03-16-2010, 09:59 AM

Austin, thanks for bringing up the most important reason for not fooling with forcing cones and chambers. If a plastic hull separates from the brass and goes into the barrel far enough to allow another shell to be inserted behind it, your gun will blow up. Not that it might blow up, it will blow up. The forcing cone in an old gun will safely restrict a plastic shell from going past the cone and you will not be able to insert a shell behind the obstruction. Such an error will usually not go to the point of gun damage in a double barrel shotgun, but in a pump or automatic with a relieved forcing cone, it would be very easy to make an expensive mistake.