choke question

[Bill Murphy]

Bore micrometer, the one that most of us use, Skeets brand, Brownell's catalog, about $95.

[Mike of the Mountain]

Originally Posted by Paul Ehlers

Just to add my two cents worth to this discussion.

All of the above posters are spot-on with their explanation of choking. Parker themselves relied heavily on the patterning board for the purposes of determining the choking of a particular set of barrels.

I have several PGCA letters on the various Parkers I have owned. In a majority of these letters Parker in their records recorded choking as percentage of a certain size of pellet patterning in a specific size of circle at a specified yardage. As an example "left barrel patterns 180 pellets of #7 shot in a 30" circle at 40yards distance"

In my small sampling of letters. I have found this to be the normal means the factory used to determine choking. I do have a few letters where the chokes are stated as Full & Full, IC-Mod etc. My conclusion based on the letters I have seen is that Parker spent a lot of time at the patterning board to get their chokes just right for any particular gun.

Bottom line is the only way to really determine how your gun is choked is to spend time at the patterning board.

Yup, Paul nailed it. Fox did the same thing. They patterned the guns for specific chokes. I see it would be the technologically correct way to get the actual choke/pattern combo instead of the modern industry standardization, but I wonder if there was more to it than that? Issue with components and reliability? Difference in individual barrel smiths and the way they made their product? Difference in machining? Anyone know?

[Double Lab]

Originally Posted by Mike Koneski

Issue with components and reliability? Difference in individual barrel smiths and the way they made their product? Difference in machining? Anyone know?

I don't know for sure Mike, but probably a combination of all of the above. Of all the things that fascinate me the most about Parkers and Foxes are their attention to their choking. A true shame to screw with them.
.

[Mike of the Mountain]

I need to make an addendum to my post. Fox did pattern some guns when it was requested to be certain percentages or with a specific load, they didn't pattern every gun. That would be expensive!!

[Dean Romig]

I've seen a lot of Parker hang tags, including many Trojans, and I have never seen one that hasn't been patterned.




.

[Double Lab]

Great point Dean (as usual) but today we would be unable to duplicate Parker's load. So getting back to John's OP, John, pattern your gun for point of impact, then try different loads as see which ones your gun likes. Don't worry about your chokes. You can get them tighter or more open by changing loads. Shoot a few hundred clays with it and you'll get a feel for her performance.

[Pa SxS]

Attached is a graph that Austin Hogan made. As you can see, around S/N 65k and before 1891, the bores were oversized. After 1891 or so, the bore diameter was brought down to nominal size of .730 or so.

The majority of entries in the order books do not show what the chokes should be. When chokes are listed, an example would be RH cyl, LH full, or RH modified/LH full. Occasionally in the order book you could sometimes see the customer wanted a certain number of pellets for each barrel, the size of the shot, the distance, and the diameter of the circle. In some cases, they also indicated what powder to use, what pellet size, and the weight of the pellets.

If it's not listed in the order book but we have a stock book entry for this gun, we can get an idea of the choke by looking at how many pellets hit within the circle. Problem is is that when they copied the stock books the scanner wasn't long enough to include all the info found in the stock book. Depending on how the book was placed in the copier the patterning info is not there or just the pellet count can be seen or you may see the pellet count and the size of the shot, or in the best case, you see the number of pellets, the size of the pellet, the distance, and the diameter of the circle. This is why we want to get access again to the original records. If the chokes were different in both barrels, each barrel would have it's pellet count. If only one entry for the number of pellets, both barrels were the same choke. Also remember that a #8 size shot varied depending on who manufactured the shot. I think Parker mostly used Tatham shot. See the attachment.

The original stock books had more information after the patterning column and I think it showed what powder was used and some additional information at the end of the page. This is why we want to get access again to the original records.

[William Davis]

That's the one

William

[6pt-Sika]

I've got one at the shop that looks like a set of calipers but with about six inch depth capabilities . Don't really care for it however but it's better then nothing . I do have a good friend that has a nicer one that's good for everything from 10 gauge to 410 and that thing from Brownells was like $700 !

[Ed Blake]

I'll second the Skeets gauge. I believe the Parker Story talks about the change in bore diameter happened in the early 1890s. Austin Hogan did research on this also. The 1879 lifter I had had bores of .750 with about 30/1000s choke in each barrel. I miss Austin. Every time he spoke I learned something new about Parkers.