Re: 20g Field Grade
Posted by Phil Carr on June 16, 2021, 6:47 am, in reply to "Re: 20g Field Grade"
Doc Drew’s information under frequently asked questions on this forum. |
Note: for some reason when I copied and pasted the columns do not line up under the choke measurements.
With the information you provided your barrels have .020 and .040 of choke.
What were the choke dimensions for L.C. Smith shotguns?
The average bore and choke dimensions (inches) were:
Gauge Bore Improved Cylinder Modified Full
12. 0.732 0.725 0.710 0.695
16 0.662 0.657 0.639 0.629
20 0.615 0.610 0.595 0.585
Starting in 1907, Hunter Arms catalogs included the following statement:
"All Smith Guns are bored full choke unless otherwise ordered. We bore all our guns according to our Multiplied Choke Bore System, which has made the Smith Gun famous the world over for long-distance, close-shooting and hard-hitting qualities. We can bore a gun as follows using the twelve-gauge gun as a standard distance, forty yards; circle, thirty-inch; shot, Tatham’s chilled No. 7 1/2, one and one-quarter ounces; American Association Measure, 345 pellets to the ounce or 431 to the load."
Full choke……………………..70 per cent or 301 for pattern.
One-half choke………………..60 per cent or 258 for pattern.
One-quarter choke…………….50 per cent or 215 for pattern.
Improved cylinder……………..45 per cent or 193 for pattern.
True cylinder…………………..35 per cent or 150 for pattern.
After about 1940, 28” and 30” barrels were choked right modified (60% pattern) and left full (70% pattern) unless otherwise specified. 26” barrels in 20, 16, and 12 gauge were choked right improved cylinder (45% pattern) and left modified.
Please note the 16g bore was .650 into the early 1930s and pre-1913 16g chokes have been measured with constriction greater than .040" .