Patterning your gun.

[Lance Bell]

So I'm just looking to see how others go about it. I make a 30" circle with a 12" circle in the center of that with a 1-1/2" in the middle of that as a hold point. I then set my distances usually 30 and 40 yards and start shooting, count pellet strikes and do the math.
My question is how many strikes or percentages do you look for to be satisfied with what your shooting? I try and find an even pattern that at 30 yards is better than 95%in the 30" circle, 80% or better at 40yards.

[Joe Hunter]

Here's something I put together about patterning. Hope this helps.

If you are patterning to assess your load and choke performance, not checking for your guns Point-of-Aim/Point-of-Impact (POA/POI), here is a short list of steps to follow.

First, you’ll want to make sure you use good methods so your data will be accurate and to allow you to make fair comparisons between loads, chokes, pellets, etc. Patterning the right way does take time and effort (another reason to do it right the first time), but it is the only way to find out what a load and/or choke is doing.

Steps for shotgun patterning:

1) Set up a pattern board (4' x 4') frame with a backing material like cardboard or particle board to attach the pattern sheets.

2) Get some large (40" x 40" minimum) pattern sheets of paper or cardboard. Many prefer to use 48” x 48” sheets of white paper. These large sheets will capture the majority of the pattern strikes and make identification of the densest 30-inch portion much easier. This is particularly true if you are going to be patterning at distances beyond 40 yards.

3) Measure off your shooting distance from muzzle to target. Yes, 40 yards is the industry standard for evaluating choke performance, and a good distance to pattern some loads, but you’ll want to pattern your loads/chokes at the distances you’ll be shooting your birds/targets. As an example, if you need a good 30-yard load/choke combo then pattern at that distance, and if you need a good 50-yard load/choke combo then you’ll want to shoot your patterns at 50 yards.

4) Now that you have a pattern board and some pattern sheets, attach a blank pattern sheet to the pattern board and fire one shot at the center of the sheet. This can be an offhand shot or shot from a bench, it doesn't really matter, since you are just trying to get the pattern reasonably centered on the paper. You can put an aim point in the center of the paper if you need it, but you don't have to, and it is only to give you an aim point. This aim point should not influence you when drawing the 30-inch pattern circle around the densest portion of the pattern, more on this later. As a side note, you may get some indications of POA/POI issues during this pattern testing, but that is not what we are concentrating on now. You may need to address it later though.

5) Remove the sheet from the pattern board and repeat the process. Remember, you must shoot a minimum of three patterns for an average and five or even 10 is better. Shotguns are not exacting instruments and variation between pattern numbers is the norm, so averaging is a must. And, shooting one pattern to get an idea of what it is going on with a load/choke can be misleading!

6) Now that you have shot your patterns, draw a post-shot 30-inch diameter circle (use a 15-inch piece of string with a pencil or a yard stick with holes 15-inches apart to scribe a 30-inch circle) around the densest portion of the pattern. Yes, do this after the shot not before. Why after the shot? Because, you are trying to evaluate the load/choke combo’s performance, not your ability to center a shot in a pre-drawn 30-inch circle!

7) Count the pellet strikes in the 30-inch circle and average your pattern numbers. You can then calculate a pattern percentage by dividing the average pattern count by the in-shell pellet count if you like. To get a true pattern percentage you will need to cut open and count the pellets in several unfired shells so you will have the true average in-shell pellet count. Remember, pattern percentages tell you about load/choke “efficiency” and if your load/choke combo is performing to factory standards, not necessarily how “effective” the load/choke will be at killing birds or breaking targets.

Important points to consider:

1) How many pellets did your load/choke combo put in the 30-inch circle? Birds of different sizes/types require different pattern densities to reliably hit the vital areas.

2) What size/type of shot were you using? Birds of different types/sizes require different amounts of pellet energy to penetrate the vital areas.

3) What yardage do you normally shoot your birds? Birds shot at longer distances will usually require larger pellets to maintain enough pellet energy to penetrate the vital areas.

4) What yardage was your load/choke capable of maintaining killing pattern densities? Longer distances usually require tighter chokes to maintain the minimum pattern density for the birds you are after. However, larger pellet sizes (BB and larger), particularly in the hard shot types like steel, do generally tend to pattern better from chokes with less than full choke constrictions.

5) Common sense should also tell you to pick the load/choke combo that gives the most consistent patterns and the one that has fairly good pellet distributed. Remember however, patterns are random events so there will always be some variation between patterns, areas void of shot, and some clumping of shot.

Effective patterns include:

1) Sufficient Pattern Density -- Enough pellet strikes in the 30-inch pattern to reliably hit the vital
areas (brain, spinal cord, heart or lungs) at the distance shot.

2) Adequate Pellet Energy -- Correct pellet size and mass to retain enough per-pellet energy to penetrate the
vital areas at the distance shot.

3) Proper Choke -- Enough choke to maintain adequate pattern density for the bird size/type at the distance
shot.

[mudpack]

1) Sufficient Pattern Density -- Enough pellet strikes in the 30-inch pattern to reliably hit the vital
areas (brain, spinal cord, heart or lungs) at the distance shot.

2) Adequate Pellet Energy -- Correct pellet size and mass to retain enough per-pellet energy to penetrate the
vital areas at the distance shot.

3) Proper Choke -- Enough choke to maintain adequate pattern density for the bird size/type at the distance
shot.

That's about the long and short of it. Although #1 and #3 are closely related, shot size and payload also enter in...in a big way....to adequate patterns.
What Joe left out (and many do) is pattern distribution. Splotchy patterns, with areas of clumping and areas with few or no shot are not good for consistent results, no matter how many shot are in the 30" circle. I.e, percentages only tell a part of the story in patterning.
That's why it's important to pattern multiple examples of a given load/choke; one shot, or two, might give you adequate density and distribution, but the sixth, seventh, and eighth may show inconsistencies. You want a load/choke combination that you're confident will give you a good pattern every time you pull the trigger.

[3200 man]

Reading this fellas initial POST it's easy to see he needs more"beginners help" than pattern percentage help !

I will offer this , First you want to find out where your gun is shooting so , Lets start there shall we ?
With a rest aim (preferably off a benchrest) with bags for barrel support , you want to shoot at a + 13 yds away , you can do
this with a 8"X11" piece of paper with a + in the middle . This will with shims
allow you to adjust your GUNFIT so it's shooting 50/50 of the cross (aiming point) . Once that has been established , for
every 1/8" you raise the comb , the center of the pattern at 13 yds will raise 1" which equals 3" at 39 yds !
Now when you step back to 39 yds and AIM at the patterning papers + (center) , you'll want to shoot 3 of the same shells ,
this will adjust the Gaussian pellet placement so you can see what the chances are , you'll hit what you're shooting at !

Counting pellet holes for a percentage is really not necessary as you can adjust them with choke constriction !

[Jim Atlas]

I use a pallet as a backrest to staple the paper to. I collect the cardboard or cardstock placed on pallets by some shippers for target paper. But I've also used rolls of craft paper when I run out of free paper. For a circle tracing, I use a length of stiff plastic tubing.

Joe's method is more precise and translatable then the way I go about it. But he also shares his info as a thumbnail for others, whereas I'm trying to achieve something else, viz. determine how I feel about shooting at birds with a given load. The main differences are I pace off 40 strides rather then measure 40 yards, I shoot and analyze one pattern before deciding to continue patterning with a given load, and I don't count shot in the shell, because I dont figure percentages.
If the first pattern looks good, I'll shoot more to check for consistency. I don't work out percentages because I only care about how many shot hit the paper and where. And I use my stride because it's easier than a tape measure, and I know that my 40 paces are about 37 yards.
But whatever methods you use, be consistent. That way, you can compare results meaningfully.

[Lance Bell]

3200man I didn't realize I was such an idiot beginner . Thanks for your all knowing wisdom.

Everyone else thanks, there's a lot of ways to skin a cat and we all have our preference. I was just looking to see how others go about it. I enjoy tinkering with different chokes and loads in the off season. It's fun to see how the same load from a different manufacturer can react at times alot different through the same choke. Seeing how the was opens is also something I look for. Thanks

[3200 man]

3200man I didn't realize I was such an idiot beginner . Thanks for your all knowing wisdom.

Everyone else thanks, there's a lot of ways to skin a cat and we all have our preference. I was just looking to see how others go about it. I enjoy tinkering with different chokes and loads in the off season. It's fun to see how the same load from a different manufacturer can react at times alot different through the same choke. Seeing how the was opens is also something I look for. Thanks

Glad you took this advice with a grain of salt , the advice was for others as well as you , if it slipped your mind !
As you already know , if , your guns POI isn't where you are looking , the pattern it shoots is meaningless

[Sagebrush]

Way back when I started reloading steel pellets. I also used a table,chair, a sand bag for the stock (not barrel) and tried
to place the pattern at the center of my pattern paper.

I found out that the different powders that I used, did not all go where I was aiming..................
some were a little left or right and 800-x shot low.

I also loaded Bismuth with buffer that had the best pattern/accuracy of all the "Standard Steel pellets" out to 70 yards
with the #2 size pellets.

It came down to a good choke and accepting 45-55 yards as a maximum range, that would kill cleanly on my birds,
where and how I hunt.

If you don't reload, just learn where your load is going and adjust for it.
Tight groups.

[Heronk]

In answer to your question about how many pellets you actually need in your 30" circle to kill birds consistently, do a search for Tom Roster's steel shot lethality table. It will tell you what size pellets and what pellet counts you need for different size birds at different ranges.

[Yuchi1]

I am an advocate of ascertaining where your shotgun is hitting (POA vs. POI) first and foremost as if she isn’t shooting where you’re looking (pointing) then you are forced to employ “Kentucky windage” in making the payload impact where the target is heading and that’s another variable that’s both detrimental and unnecessary.

Once she’s centering the pattern where you are looking, the job of attaining adequate pellet density for the range(s) that you expect to be operating within becomes the next step.

Remember, wing shooting is an endeavor in probability and not an exact science so look for a series of patterns that exhibit the best pellet dispersion necessary for your particular situation. Expecting perfection will soon lead you to making beads at the insane asylum. The primary benefit of this pattern work will be the confidence it gives you when the trigger is slapped in front of the bird and that is immeasurable in value. When you know what you know and you know it, the battle is won.