Choke size
 

I have a Parker letter describing my gun it states that my guns chokes were : Patterned 255 pellets with size 7 shot in a 40" circle at 40 yards.
What would that be in choke size ?

I hope I didn't make a typo. 30" circle at 40 yards. 255 pellets should equal full choke.

Thanks,
Parker must have used a standard load for all their testing.
Does anyone know of a chart that wold show the results of that testing in Parkers ? and what that load might have been.

In earlier times, no standard shot size, shot weight, range, target shape, or target size. In later times, 30" circle at 40 yards with various loads. I have seen loads from #9 to 00 buckshot.

Thanks,
This gun was made in 1923 and the chokes were patterned RH 255 pellets and LH 255 pellets of size 7 shot in a 40" circle at 40 yards. Just trying to figure of what this might equate to in today's chokes.

Chuck answered your question in an earlier post.

Aware of that, however,
Would there be a difference in 30" and 40" circle at the same distance ?
Seems that there would be,

Your letter should have read 255 pellets in a 30" circle at 40 yards which is also the standard for a 12 ga. today. Your number of pellets in a 40" circle should be lower than a 30" circle at the same distance. I'm sending you a revised letter.

If I did the math correctly, Tatham had approximately 325 pellets in 1 1/8 oz. of size 7 shot so 255 / 325 = .788 % which is a full choke

Okay thanks..

Chuck, you lost me here. Just making sure I don’t have an egregious misunderstanding of patterning. Shouldn’t the number of pellets in a 40” circle be higher than a 30” at the same distance?