Best way to pattern shotgun
 

I have a high grade non Parker 12 gauge SBT. The barrels was cut down. I would like to perform a meaningful pattern check and would like to get some advise.
What distance and what size shot and weight should I use?

Phil, do you plan to shoot trap with it or hunt with it... or both?

But I think an accepted standard is a 30” circle at 40 yards with 1 1/8 ounces of either 7 1/2 or 8 shot.

I would however, put a black spot in the center of it that you’ll aim at so you’ll know how the gun prints the pattern - high, low, left or right.






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Most books on shooting would have instructions. Avail. at your local library.

formal patterning is done at 40 yards in a 30" circle (except a .410 - that's 30 yards)

but if you take game closer, grouse or woodcock for example - you might want to see what the pattern looks like with the shot you use at the range your average shot is taken- and that might be different for each barrel if you really want to experiment

Most of the books talk about standard size circles distances and shot percentages. That’s fine but I use the same practical test for all my guns

12 inch circle drawn on a sheet of cardboard, black marker 3 inch disk in the center. Full test I shoot it at 10 20 30 40 & 50 yards. Most times use 20 30 & 40. Changing paper Shoot each multiple times to weed out poor point of impact shots. Back home eyeball each I get a good idea of gun and loads performance on targets I am likely to shoot.

Lot of shots in a full test. Two barrels 3-5 distances more than one load and multiple shots to confirm sure POI. 20 shots or more. Have a 12 inch plywood disk with 3 inch center cut out, fast job to make up a target. Won’t give percentages to compare with standards but gives a real idea of my gun and loads performance.

William

Thanks guys for the information. Dean I bought it about 10 years ago and have shot dove with it with good success, but never trap. I plan to sell at some point and I figure since the barrel has been modified a potential buyer will ask how does it pattern? So I thought I would get some ideas and pattern this shotgun as if for trap.