Indoor range for shotgun patterning?

[GAgunLAWbooklet]

I want to pattern a couple of shotguns the technically correct way, to determine how well they're choked.
One one of them, I suspect the % of pellets that land in the 30" circle at 40 yards will correspond to a wider choke than what's marked on the gun.
Although 40 yards is really far for a hunting distance, except for special turkey guns with extra-full chokes and special turkey shells, 40 yards has been the standard distance for patterning choked sporting shotguns for generations. Not all sources agree on what % of pellets must strike within the 30" circle to be called a particular grade of choke, but all sources agree on the distance of 40 yds for doing that choke-testing patterning.

Of course, if you only want to know what your gun does with a particular load at a particular distance, without regard to what the "choke" level is called, that's fine. Shoot that distance.
Home defense shotguns should probably be tested at 15 yards, which is way longer than the average shooting-an-intruder scenario calls for, but which is the shortest distance at which choke makes any visible difference.

 

[GAgunLAWbooklet]

Bumping this thread a year later with more info.
Several months ago I did test pattern that Marlin Goose Gun (bolt action, 30" bbl.) outdoors at 40 yards in the woods. I measured 40 yards worth of string in my garage workshop the night before and stretched that string in the woods to get an accurate 40 yard measurement.

I used plain rolls of white paper which I got from the Marietta Daily Journal newspaper; they call them "roll ends" and they're only a few bucks for a big fat roll of paper.

If I remember right, the Marlin shotgun, 12 gauge full choke, actually performed a little bit weaker than "full" should. It patterened at about 67% or 68% of the pellets that hit within the 30 inch circle. Even with small birdshot like a #8 lead shot, there were huge gaps in the pattern were a clay disk or a small bird could avoid getting a single pellet hit. So I think that particular Marlin shotgun, despite having a freakishly long barrel and what's called a full choke, is best used to 25 or 30 yard maximum ranges.

 

[boomdad]

Go to an outdoor range because you'll be shooting outside anyways. Unless you have an optic it won't matter.

 

[GAgunLAWbooklet]

...

Today I pattern tested an Ithaca model 37 featherlight. It has a 28 inch plain barrel with a short orange light gathering or fiber optic plastic front sight called "TruGlow."

The barrel is not explicitly marked as to what fixed choke it has, but I see the number to stamped on it just a few inches forward of the receiver. I think this is the code for a modified choke.
1= Imp Cyl
2= Mod
3= ?
4= Full

I did not measure 40 yards nor did I use a string. I paced-off 40 large steps, which from experience I know should be 95% accurate as measuring.

I made a 40" x 48" rectangle of butchers' paper, fired from 40 yards, and then drew a 30 inch circle around the highest concentration of the pellets. (You always shoot first and draw the circle second just in case the pellets did not shoot dead center around what you hoped was your aiming point.)


I actually cut open one shell and counted the No. 6 birdshot pellets. There were 222 of them. Numerous online resources say that 1 ounce of #6 lead birdshot should have 225 pellets, so the Federal ammo factory did a good job of putting in almost the exact number.

One of my shells scored 120 strikes in the circle. Another shell did 127 in the circle.

So that's about 55% in my 40 yard pattern. That puts the actual choke on this gun tighter than improved cylinder, but more wide-throwing than a modified choke should be.

There were big gaps in between the pellet strikes. A few orange clay targets and a couple of beer cans could have fit within the 30 inch circle and not be shattered or punctured. It looks like this 16 ga. shotgun should also be limited to 25 or 30 yards if you want to make sure you're going to hit the target with at least a couple of pellets.

 

[gh1950]

Even with small birdshot like a #8 lead shot, there were huge gaps in the pattern were a clay disk or a small bird could avoid getting a single pellet hit.

Probably not.

Probably not unless you are one of those guys that shot doves off of power lines.

Your shot pattern is about 12 feet long. The "hole" on your pattern would have to be the area of the target plus the area of the target covers in the time the shot string moves 12 feet.

Your first reaction is that the distance the target moves is insignificant but it isn't.

 

[GAgunLAWbooklet]

Your argumentative "contribution" to this thread is duly noted.
You are welcome to go pattern your own shotgun that you regularly break clays with at 40 yards and kill small birds with at 40 yards.
Post the pics here and show us what your pattern looks like.

 

[alevinson91]

So if I’m not mistaken, the governors gun club in kennesaw allows you to. You can shoot skeet and trap, and they cut really nice deals before 5 on weekdays

 

[Plinker66]

Regular screw in chokes don’t tighten up a pattern as advertised, imo.

If you want a tight pattern at 40 yards you gotta buy a full length full choke barrel. Imo.

 

[lostchild]

I think that the point was that if your shot string was indeed 12 feet long at that range, only an unknown percentage of shot would have hit a target moving through your pattern, so number of actual pellet strikes would be less than on a static object.

 

[handloader]

I think that the point was that if your shot string was indeed 12 feet long at that range, only an unknown percentage of shot would have hit a target moving through your pattern, so number of actual pellet strikes would be less than on a static object.

When your target is flying into your shot at a 90ish degree angle, dispersion within reason is your friend. Although I do not claim to know how long the pattern would be, the more acute the angle, the easier the target becomes to hit by leaps and bounds.