20 v 12

ammo.crafter · August 31, 2014, 06:33 AM

What is the basic down-range difference between a one ounce load of #8 shot moving at 1200 f/s fired from a 20 gauge shotgun and a 12 gauge shotgun?

g.willikers · August 31, 2014, 08:04 AM

Most likely, just the pattern, maybe, depending on the choice of chokes.

Creek Henry · August 31, 2014, 09:06 AM

As far as I can tell in the field, none. Choke and how well you can handle/shoot the gun are the noticeable differences.

BigJimP · August 31, 2014, 12:01 PM

There is no difference.....1 oz of 8's at 1200 fps...is identical out of a 12ga, 16ga or a 20ga....

jmr40 · August 31, 2014, 01:08 PM

The shorter shot string of the 12 should be an advantage. The 12 will have fewer pellets contacting the barrel. Which in theory means fewer pellets damaged in the bore.

Virginian · August 31, 2014, 01:44 PM

With modern loads - with plastic shotcups, no difference.

eastbank · August 31, 2014, 02:29 PM

i have been trying to shoot a 25-25 at singles trap with my 20ga shotguns and the best i,ve been able to do is 23-25,s. shooting 7/8 oz #7.5 and 8 shot. i have shot quite a few 25-25,s and 50-50,s with 12ga shotguns. the one 25-25 i,m realy proud of is the one i shot with a remington model 1900 12ga with 32 inch steel barrels choked F&F made in 1906, that one realy ment a lot to me. we are going to shoot singles trap this afternoon, if it don,t rain and i want to shoot a old win model 12 tounament grade 12ga made in 1928 and a rem 1100 20ga on a 12ga frame that mike orlan put chokes tubes in it. eastbank. IT RAINED,I DID GET ONE ROUND OF TRAP IN AND SHOT A 23-25 WITH THE BT-100.

A400 Fan · August 31, 2014, 06:47 PM

The pattern steel will tell you all you need to know

ammo.crafter · August 31, 2014, 06:52 PM

So then a 20ga should have more felt recoil then a 12ga due to gun weight. Assume both shotguns are exactly the same with the exception of gauge.
With the same choke tubes being used, can you assume the 12ga will have a distinctly larger pattern than the 20ga?

Virginian · August 31, 2014, 08:18 PM

Recoil is a function of weight and speed of ejecta (shot, shotcup, and gasses) and the weight of the gun. 20 gauges are usually lighter, but not always.

Dreaming100Straight · September 3, 2014, 09:41 PM

the pattern may appear identical seen in 2 dimensions, but iirc, zippy said the shot 20's shot string was longer.

Virginian · September 4, 2014, 04:45 AM

If you take the time to do the trigonometry - I did, another fragment of my life I will never get back - you will see that the effects due to the difference in shot string lengths is way, way too small to worry about.

Dreaming100Straight · September 6, 2014, 07:10 PM

Did you factor in the reduced interface of the surface of shot cup to inner barrel wall and the relative heat dispersion factors (assuming thicker walls for a 12 than a 20)? This assume no one has a water cooled shotgun. Just kidding.

Virginian · September 6, 2014, 08:38 PM

DO wha....?

**44 AMP** · September 8, 2014, 09:43 AM

With everything else as equal as possible, the difference will be the length of the shot string.

This is something a pattern board will not show you.

Does the length of the shot string make a difference? Some say yes, others say no.

When shooting at a bird, the shorter shot string of the 12ga means there will be more pellets in the pattern on the same plane as the bird at the instant of contact.

The longer shot column of the 20 means more pellets will still be "on the way there" when the first ones hit the bird than a 12 ga.

Some say this makes a difference. some say it doesn't. Personally, I don't know. I have several 12s, and NO 20s. But that's just me...

MarkCO · September 14, 2014, 11:29 AM

Like others have stated, the 20 will have a longer shot string. If you are shooting static targets, there is no difference. The faster the target is moving at an angle to your bore axis, the larger the effect. For most practical purposes, the difference is negligible with good quality loads.

The differences start to get more obvious once you leave the #8 1 ounce load. In most cases the favor goes to the 12g, but in some. it goes to the 20g.

August 31, 2014, 06:33 AM	#1
ammo.crafter Senior Member Join Date: June 25, 2006 Location: The Keystone State Posts: 1,970	20 v 12 What is the basic down-range difference between a one ounce load of #8 shot moving at 1200 f/s fired from a 20 gauge shotgun and a 12 gauge shotgun? __________________ "Peace is that brief glorious moment in history when everybody stands around reloading". --Thomas Jefferson

August 31, 2014, 08:04 AM	#2
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	Most likely, just the pattern, maybe, depending on the choice of chokes. __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.”

August 31, 2014, 01:44 PM	#6
Virginian Senior Member Join Date: February 11, 2012 Location: Williamsburg, Va. Posts: 1,528	With modern loads - with plastic shotcups, no difference. __________________ What could have happened... did.

August 31, 2014, 06:52 PM	#9
ammo.crafter Senior Member Join Date: June 25, 2006 Location: The Keystone State Posts: 1,970	Thanks. So then a 20ga should have more felt recoil then a 12ga due to gun weight. Assume both shotguns are exactly the same with the exception of gauge. With the same choke tubes being used, can you assume the 12ga will have a distinctly larger pattern than the 20ga? __________________ "Peace is that brief glorious moment in history when everybody stands around reloading". --Thomas Jefferson

August 31, 2014, 08:18 PM	#10
Virginian Senior Member Join Date: February 11, 2012 Location: Williamsburg, Va. Posts: 1,528	Recoil is a function of weight and speed of ejecta (shot, shotcup, and gasses) and the weight of the gun. 20 gauges are usually lighter, but not always. __________________ What could have happened... did.

August 31, 2014, 09:06 AM	#3
Creek Henry Senior Member Join Date: October 23, 2009 Location: Dallas Posts: 514	As far as I can tell in the field, none. Choke and how well you can handle/shoot the gun are the noticeable differences.

August 31, 2014, 12:01 PM	#4
BigJimP Senior Member Join Date: February 23, 2005 Posts: 13,195	There is no difference.....1 oz of 8's at 1200 fps...is identical out of a 12ga, 16ga or a 20ga....

August 31, 2014, 01:08 PM	#5
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,809	The shorter shot string of the 12 should be an advantage. The 12 will have fewer pellets contacting the barrel. Which in theory means fewer pellets damaged in the bore.

August 31, 2014, 02:29 PM	#7
eastbank Senior Member Join Date: February 7, 2008 Location: pa. Posts: 2,450	i have been trying to shoot a 25-25 at singles trap with my 20ga shotguns and the best i,ve been able to do is 23-25,s. shooting 7/8 oz #7.5 and 8 shot. i have shot quite a few 25-25,s and 50-50,s with 12ga shotguns. the one 25-25 i,m realy proud of is the one i shot with a remington model 1900 12ga with 32 inch steel barrels choked F&F made in 1906, that one realy ment a lot to me. we are going to shoot singles trap this afternoon, if it don,t rain and i want to shoot a old win model 12 tounament grade 12ga made in 1928 and a rem 1100 20ga on a 12ga frame that mike orlan put chokes tubes in it. eastbank. IT RAINED,I DID GET ONE ROUND OF TRAP IN AND SHOT A 23-25 WITH THE BT-100. Last edited by eastbank; September 1, 2014 at 04:19 AM.

August 31, 2014, 06:47 PM	#8
A400 Fan Junior member Join Date: June 17, 2014 Posts: 242	The pattern steel will tell you all you need to know

September 3, 2014, 09:41 PM	#11
Dreaming100Straight Senior Member Join Date: February 3, 2013 Posts: 1,235	the pattern may appear identical seen in 2 dimensions, but iirc, zippy said the shot 20's shot string was longer.

September 4, 2014, 04:45 AM	#12
Virginian Senior Member Join Date: February 11, 2012 Location: Williamsburg, Va. Posts: 1,528	If you take the time to do the trigonometry - I did, another fragment of my life I will never get back - you will see that the effects due to the difference in shot string lengths is way, way too small to worry about. __________________ What could have happened... did.

September 6, 2014, 07:10 PM	#13
Dreaming100Straight Senior Member Join Date: February 3, 2013 Posts: 1,235	Did you factor in the reduced interface of the surface of shot cup to inner barrel wall and the relative heat dispersion factors (assuming thicker walls for a 12 than a 20)? This assume no one has a water cooled shotgun. Just kidding.

September 6, 2014, 08:38 PM	#14
Virginian Senior Member Join Date: February 11, 2012 Location: Williamsburg, Va. Posts: 1,528	DO wha....? __________________ What could have happened... did.

September 8, 2014, 09:43 AM	#15
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,846	With everything else as equal as possible, the difference will be the length of the shot string. This is something a pattern board will not show you. Does the length of the shot string make a difference? Some say yes, others say no. When shooting at a bird, the shorter shot string of the 12ga means there will be more pellets in the pattern on the same plane as the bird at the instant of contact. The longer shot column of the 20 means more pellets will still be "on the way there" when the first ones hit the bird than a 12 ga. Some say this makes a difference. some say it doesn't. Personally, I don't know. I have several 12s, and NO 20s. But that's just me... __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

September 14, 2014, 11:29 AM	#16
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,308	Like others have stated, the 20 will have a longer shot string. If you are shooting static targets, there is no difference. The faster the target is moving at an angle to your bore axis, the larger the effect. For most practical purposes, the difference is negligible with good quality loads. The differences start to get more obvious once you leave the #8 1 ounce load. In most cases the favor goes to the 12g, but in some. it goes to the 20g. __________________ Good Shooting, MarkCO www.CarbonArms.us