Determining shotgun patterns

[JFrost]

Is there a formula to determine a shotguns pattern?

Such as: (barrel length) + (round type) + (choke) = 2 feet across at 10 yards. (Something like that?)

Whats the standard wisdom on figuring the effect of a round at varying ranges? If I have 00 buck, how close do you need to be to keep the pattern (which I assume continues to expand indefinitely) small enough to keep it on target?

Also, if everything stays the same except the type of round, would bird shot create a larger or smaller pattern then 00 buck at equal distances? (lighter vs. heavier)

 

[SideArmed]

I can't asnwer as to the science or mathmatics involved in figuring it out.

But I can say it is easy enough to just get out there and throw some shot down range and test it out. Just a couple of weekends ago I wanted to see what some #6 shot looked like through my home defense shot gun so I took about 7 sheets of cardboard about 4'x2' and shot them at different distances ranging from 7 yards to 20 yards. easy enough to go out and see real world results.

In another week or so I will be testing different loads at different distances. I will try to remember to take pictures and post them up.

 

[Westside]

Is there a formula to determine a shotguns pattern?

Such as: (barrel length) + (round type) + (choke) = 2 feet across at 10 yards. (Something like that?)

Whats the standard wisdom on figuring the effect of a round at varying ranges? If I have 00 buck, how close do you need to be to keep the pattern (which I assume continues to expand indefinitely) small enough to keep it on target?
This would depend on the size of your target. Human, Sporting Clay, bird, etc. Also need to know what you actually mean "keep it on target". Does that mean every pellet hits the target, an "effective" amount hits the target, etc. I hate to state/ask obvious stuff but I/we need to know what info you are looking for to give proper answers.

Also, if everything stays the same except the type of round, would bird shot create a larger or smaller pattern then 00 buck at equal distances? (lighter vs. heavier)

That being said. Your best bet is to go by a package of poster board and draw circle with a diameter of 30 inches and place a dot in the center. Then take your gun and stand at whatever distance you are planning to shoot at and send different combinations,(powder load, shot size&quantiy, and choke sizes), down range. And then use whatever gets the results you want.

 

[Zoub]

Is there a formula to determine a shotguns pattern?

Such as: (barrel length) + (round type) + (choke) = 2 feet across at 10 yards. (Something like that?)

No because that is bad science and myth. Remove barrel length, it only affects velocity and even 10" of barrel length on shotgun does not make much of a difference at HD ranges.

Choke equals a known diamter at a known distance with a measurable result (perentage of shot in that circle)

read this
Shotguns / Understanding Shotgun Shot Patterns

then study choke some more

than study factors that affect patterns

then study Ft/lbs. More projectiles in a 3" magnum load are not always more lethal then less projectiles in a smaller load. It is about ft/lbs per shot.

Or if you are lazy, buck kills the crap out of stuff up to 25 yards in most guns but you can't be sure until you pattern your gun and your load of choice on paper.

After that, there are things you can do to alter the performance of your gun through mods to the gun or ammo selection.

 

[Kirk Freeman]

If one thing is consistent, it is that they are inconsistent.

Whats the standard wisdom on figuring the effect of a round at varying ranges?

Go shoot your gun with different ammunition and find out.

If you want wide, go Remington or Winchester lead buckshot.

If you want tight, go Hornady TAP buckshot or the new Federal load (Flite Control).

The ammo controls over the weapon with buckshot.

Also, if everything stays the same except the type of round, would bird shot create a larger or smaller pattern then 00 buck at equal distances?

Depends, on the birdshot load, the gun, etc.

Just had a shotgun class last week. My gun shot very tight with the buckshot load I was using (Hornady TAP) but very wide with the Wal-Mart birdshot I was using. Different load, different pattern.

 

[JFrost]

read this
Shotguns / Understanding Shotgun Shot Patterns

then study choke some more

.

Good grief.

Thanks for the responses, they certainly answer the question...which would be "No". lol

This question came about because of this thread;

https://www.indianagunowners.com/fo..._prepper_with_a_shotgun_for_main_defense.html

Just wondered how closely you could pin down the shotguns performance.

 

[Kirk Freeman]

Just wondered how closely you could pin down the shotguns performance.

With a very thick thumb.

You have to shoot them. All of them.

It depends on the gun and the ammo and different ammo lots can give different results.

Once you get deeper into this, you will hear the 1" for every yard, but remember that study was done several years ago with different ammo than is available today.

Shoot your gun, Federal makes range cards that you can fill out and tape to the stock of the weapon like you do for rifles. May be worth your while.

 

[Zoub]

You don't pin down shotguns, they pin you down. It's a Zen thing.

See the other thread

 

[RichardR]

With a very thick thumb.

You have to shoot them. All of them.

It depends on the gun and the ammo and different ammo lots can give different results.

Once you get deeper into this, you will hear the 1" for every yard, but remember that study was done several years ago with different ammo than is available today.

Shoot your gun, Federal makes range cards that you can fill out and tape to the stock of the weapon like you do for rifles. May be worth your while.

Kirk is right on.

You really have to pattern your shotgun with all of the various loads to see what it will do at what ranges.

There is no "short cut" around that process, at least not that I am aware of.

 

[esrice]

Kirk is right on.

You really have to pattern your shotgun with all of the various loads to see what it will do at what ranges.

There is no "short cut" around that process, at least not that I am aware of.

Amen.

Here is a very detailed report lovemywoods put together when he patterned his new shotgun: https://www.indianagunowners.com/fo...he_pattern_of_various_brands_of_buckshot.html

 

[redneckmedic]

Just for arguments sake.... I wouldn't want the 1.2" pattern for SD....I would want the 5" circle. I think butcher paper (<$20 @Sam's Club) is great for this kind of stuff.

 

[RichardR]

Just for arguments sake.... I wouldn't want the 1.2" pattern for SD....I would want the 5" circle. I think butcher paper (<$20 @Sam's Club) is great for this kind of stuff.

If you really want a big spread, try some Sellier & Bellot unplated, felt wadded, 00 magnum's w/12 pellets.

The patterns I get out of those are huge in my shotguns.

 

[Shootin'IN]

Just for arguments sake.... I wouldn't want the 1.2" pattern for SD....I would want the 5" circle. I think butcher paper (<$20 @Sam's Club) is great for this kind of stuff.

To check my pattern I use the back side of Christmas wrapping paper, it is large enough to get the whole pattern on about 36" x 36" out at 45 yds. away that would be with a normal turkey choke.

 

[lovemachine]

Just for arguments sake.... I wouldn't want the 1.2" pattern for SD....I would want the 5" circle. I think butcher paper (<$20 @Sam's Club) is great for this kind of stuff.

If you really want a big spread, try some Sellier & Bellot unplated, felt wadded, 00 magnum's w/12 pellets.

The patterns I get out of those are huge in my shotguns.

Wouldnt you want tight patterns for controlled accuracy?

 

[Zoub]

Wouldnt you want tight patterns for controlled accuracy?

It speaks to how you view the shotgun. If you only visualize making hits then you want a tight pattern. You can and will miss shots but you are not focused on that fact, you don't even consider missing. I can make follow up shots and reload. I am more worried about running out of ammo then missing. Once you pick up a shotgun it is good to have an exit strategy if the situation is bigger than you realized. AKA get to a rifle

At close range a tight pattern puts 9 or more .30 caliber balls in a target at the same time giving massive destruction and shock to the target. More so than a slug that over penetrates and takes unused ft/lbs with it. But you tend to either hit or miss completely.

The tight pattern also helps ensure kills to 25 yards and allows you to shoot further if need be, say to 50 yards.

Need be is often defined as shooting at vermin or situations in which ethical kills are a non-issue, be it animal or human. Regardless of choke, you have to be thinking very clearly before you decide to go throwing handfulls of .30 caliber balls all over the neighborhood.

I use shotguns as defensive weapons from the center of my property or buildings going no further than my own property lines. I don't plan to go walking about with one off my property. I know my safe shooting lanes.

I prefer tight patterns for destructive power and to give me better control of where I put the shot to destroy what I am aiming at and where it goes if I miss.

Inside the house, if you measure the farthest shot you can take, say down a hallway and your pattern covers 50% of the open space found at that distance, your gun is scary as hell to people on the other end. That application requires a pattern that gets wide fast. You will blow up more walls, furniture and pets but it is a bit more forgiving on point of aim on moving targets. Go outside and shoot at something far away and a dove will fall from the sky while turf is blowing up in your yard.

 

[redneckmedic]

Wouldnt you want tight patterns for controlled accuracy?

Thats a good point, one not worth debating... I would rather talk about tissue damage.... although the more I think about it, its kinda of a moot point, direct hit to center mass=bad day either way.

 

[Zoub]

No one being shot at will stop to argue with you about your selection in choke, gauge or caliber. When windshields and furniture start blowing up all around them, people tend to start moving away and take cover.

They may take cover and ask you what the hell you are shooting at, in which case you reply "You, you SOB! Now stand still so I don't miss this time."

 

[lovemachine]

Thats a good point, one not worth debating... I would rather talk about tissue damage.... although the more I think about it, its kinda of a moot point, direct hit to center mass=bad day either way.

Talk away! I'm interested, very interested. I'm new to shotguns and Im wanting to learn as much as I can.

Zoub's response, I'm going to have to reread it to understand it better. Hard to read posts that make you think like that while running the Lathe

 

[redneckmedic]

Talk away! I'm interested, very interested. I'm new to shotguns and Im wanting to learn as much as I can.

Zoub's response, I'm going to have to reread it to understand it better. Hard to read posts that make you think like that while running the Lathe

we can talk it over with pictures at a trauma class.... I would get carpal tunnel trying to chase my tell explaining it here

 

[Zoub]

Talk away! I'm interested, very interested. I'm new to shotguns and Im wanting to learn as much as I can.

Zoub's response, I'm going to have to reread it to understand it better. Hard to read posts that make you think like that while running the Lathe

While running a Lathe? Safety first



Luckily there is a medic here. Just drive up to Racine and I will show you how this crap works. It is cheaper than a finger in a lathe.