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Gauge vs Load patterns

4K views 18 replies 12 participants last post by  oldthompson 
#1 ·
I shoot skeet and SC 12ga. Have a question about subgauge shot and patterns

Does a 7/8 oz load ( 8 or 9 shot) from a 20 or 28ga pattern the same as 7/8 load from a 12 Ga using same chokes?

Thanks
 
#3 ·
I agree with Randy, BUT what I found was when we all went to 3/4 oz in 20 gauge the patterns from MY guns improved even when we had to use the 7/8 wad. And they improved again when the 3/4 oz wad became available. 3/4 is all I load for 20 gauge now, skeet, SC and game.....
 
#5 ·
54bullwinkle said:
Thanks
I guess my real question is that if you shoot the same number of pellets from a 12 or 28 bore and pattern them similar is degree of difficulty of hitting clays any different?
The problem is, there is no reason to do that. You cannot have more pellets in a pattern than what you started with, which is why essentially everyone in 27 yard ATA trap uses 1-1/8 oz. loads, and the winners use premium target 1-1/8 oz. loads at that. More is more.

It gets closer as the targets get close, as in American skeet. Still, if there was no difference at all, having 12 / 20 / 28 gauge / .410 bore classes in skeet would be ludicrous. I'll quote Bruce Buck:

The Connecticut Travelers subgauge handicap system was worked out over a period of time. They keep detailed records of every shot fired at each event. This is is a good thing for the Travelers. Since they shoot a finite number of courses in the course of the year, after a while things start to fall in place. I started by guesstimating the handicap and then adjusted it as the numbers rolled in. It took about two years of data to finalize.

12 ga = 0
16 ga = +3
20 ga = +5
28 ga = +10
410 bore = +20


Pump or SxS configuration gets an additional +5 birds, thus a .410 pump would get +25 added to their raw score. Shot loads per gauge are the same as in NSSA skeet, except that the 16 ga gets one oz.

Having said this, as I understand it, the handicap is no longer in place for the 20 gauge and larger. It seems that shooters were getting pretty proficient with their 20 gauges, and with the handicap, they were winning a disproportionate number of shoots.

One of the biggest problems with handicapping a subgauge is that the gauge itself is only part of the equation. We operate on the assumption that the shooter's main gun is a 12, so when he shoots subgauge he's using something he's not really fully familiar with. So there's a "different gun" quotient to the handicap in addition to the shotcharge. That's why few people shoot 7/8 oz as well in a 20 as they do in the 12. I'm not aware of any 20 gauge guns being seriously used in ISSF Olympic competition, even though the 24 gram (7/8 oz) load would work well in either the 20 or 12.
 
#7 ·
I do not find a difference in one ounce of shot coming out of my 20 gauge or my 12 gauge if velocities are comparable. I shot flats of inexpensive 1 ounce 20 gauge heavy field loads. These are slower than the 1 ounce high brass shells at 1220 fps. I shot those shells for skeet and sporting clays for a couple of years. I would use a 12 gauge with 1 ounce loads at 1200 fps some rounds and the 20 with one ounce loads other rounds. My scores did not drop when shooting the 20. In fact I shot some of my best scores with the 20. To me it did not matter which gauge the ounce of shot came out of.
 
#8 ·
Thanks for the responses
After doing a bit of searching I found a great article on the topic in Field and Stream (excluding .410 )

When shooting the same number/ size / velocity pellets from different bores, larger bore guns will pattern slightly better. ( theoretically). The reason is that there are more deformed fliers in a small bore because the shot stack is higher.
 
#9 ·
It doesn't quite work that way, for if it was unflinchingly true the 20 gauge would embarrass any 28 gauge with 3/4 or 7/8 oz. loads.

https://www.fieldandstream.com/articles ... ogun-ammo/

. . . might be the article you are referring to.
"Test Loads :
- 20-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1165 fps (Modified choke)
- 12-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1235 fps (Modified choke)
Results: The 12-gauge delivered a 50.7 percent pattern with 202 pellets in a 30-inch circle at 40 yards. The 20 did just 39.6 percent with 149 pellets inside the circle. The 12 achieved slightly deeper penetration (2.875 inches vs. 2.5625) in gelatin at 30 yards, likely due to the higher muzzle velocity. The high-speed camera showed no statistical difference between the lengths of the shot strings, which averaged 55 inches for the 12-gauge and 57 for the 20 at 20 yards."

The fundamental problem with one-incident pseudo-reporting is 1) using soft shot and, more importantly, 2) assuming that a choke marked "Modified" means anything. A "Modified" choke prints 60% of its pattern inside a 30 inch circle at 40 yards, regardless of gauge.

Horribly mis-marked choke tubes are nothing new.
 
#10 ·
54 -- Here's some info on this topic that I've posted before.

Here are a few of my pattern numbers comparing the performance of two Winchester AA Target factory loadings with 1-ounce of #8 lead shot through 20- and 12-gauge guns. They don't have the exact same load components (not sure how you could do that anyway), but close enough to show the patterning differences of the two gauges, in these two guns anyway.

Patterning results from 20- and 12-gauge Browning Citori's with 28" Invector-plus barrels and Briley flush chokes (patterns average of five, 30" post-shot scribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).

20-Gauge Browning Invector-plus w/ 28" barrel and Briley flush chokes
Winchester AA Heavy Target Load
1 oz #8 lead (410 pellets) @ 1,165 fps
30 YARDS -- CYL / pattern 216 (53%)
30 YARDS -- SK / pattern 237 (58%)
30 YARDS -- IC / pattern 276 (67%)
30 YARDS -- M / pattern 341 (83%)
40 YARDS -- IM / pattern 270 (66%)
40 YARDS -- XF / pattern 291 (71%)

12-Gauge Browning Invector-plus w/ 28" barrel and Briley flush chokes
Winchester AA Extra-Lite Target Load
1 oz #8 lead (393 pellets) @ 1,180 fps
30 YARDS -- CYL / pattern 218 (55%)
30 YARDS -- SK / pattern 256 (65%)
30 YARDS -- IC / pattern 305 (78%)
40 YARDS -- LM / pattern 251 (64%)
40 YARDS -- M / pattern 292 (74%)
40 YARDS -- IM / pattern 295 (75%)

Obviously, the only way to really know how a load/choke combo will perform in your gun/choke is to pattern it!

That said, there are some general tendencies concerning this 20- vs 12-gauge question that can be made. A 12-gauge is usually more efficient than a 20 gauge; it usually takes a degree or two of choke tighter in the 20 gauge to reach similar 12 gauge pattern density; and when you get beyond ~40 yards, the 12 gauge will almost always be capable of putting more pellets in the pattern than the 20 gauge.

Remember, a load's effectiveness is dependent on its ability to provide adequate pattern density with pellets having sufficient pellet energy for the bird or target at the distance the shot is taken! In practical terms, there is little difference in "effectiveness" when the same payload and shot size is used IF the barrel is choked properly to attain adequate pattern density at the distance they are used.

Good luck!
 
#11 ·
"Test Loads :
- 20-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1165 fps (Modified choke)
- 12-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1235 fps (Modified choke)
Results: The 12-gauge delivered a 50.7 percent pattern with 202 pellets in a 30-inch circle at 40 yards. The 20 did just 39.6 percent with 149 pellets inside the circle.
Joe Hunter said:
20-Gauge
40 YARDS -- IM / pattern 270 (66%)

12-Gauge
Winchester AA Extra-Lite Target Load
1 oz #8 lead (393 pellets) @ 1,180 fps
40 YARDS -- M / pattern 292 (74%)
Who is telling the truth, Joe Hunter or Federal? :shock: :shock: :shock:

Federal got only 50.7 % @ 40 yards with a Mod choke out of a 12 gauge.
Joe Hunter managed 66% with a 20 gauge with a IM choke, and 74% with a 12 gauge Mod choke. Yet, if you believe Federal . . . 50.7% is typical with a 12 gauge.

A "Modified" choke should print about 60% at 40 yards, regardless of gauge.

This is like being a cashier-- wrong is wrong, over is just as bad as being under. A choke marking is SUPPOSED to mean something. As Joe just showed . . . it doesn't mean anything specific.
 
#12 ·
The point of all this "BS" being that what is marked on the choke or choke tube is not necessarily what patterns the individual gun and load will actually deliver.

PATTERN THE GUN to be sure. And remember, no two patterns are alike - they are statistical, but within limits.
 
#13 ·
I would think that say 1 ounce in a 12 gauge would have a wider foot print leaving the barrel than 1 ounce in say a 20 gauge and that the patter for the 12 gauge then might be a little wider. I am of the old school that more is better, so in 12 gauge I am still shooting 1 1/8 ounce for skeet.

Bob
 
#14 ·
To ignore every thing else. The 12 would have the largest diameter core pattern until the payload gets too lite resulting in a pattern not dense enough. That may be less than 3/4 ounce. The 28 gauge with 3/4 of shot and just 13.0 grains of powder is a very efficient load. I tend to just move down a gauge when I want less shot. (12-1) (20-7/8) (28-3/4) works fine for me.
 
#16 ·
RandyWakeman said:
"Test Loads :
- 20-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1165 fps (Modified choke)
- 12-gauge 1-ounce loads of Game-Shok Upland No. 71⁄2 shot at 1235 fps (Modified choke)
Results: The 12-gauge delivered a 50.7 percent pattern with 202 pellets in a 30-inch circle at 40 yards. The 20 did just 39.6 percent with 149 pellets inside the circle.
Joe Hunter said:
20-Gauge
40 YARDS -- IM / pattern 270 (66%)

12-Gauge
Winchester AA Extra-Lite Target Load
1 oz #8 lead (393 pellets) @ 1,180 fps
40 YARDS -- M / pattern 292 (74%)
Who is telling the truth, Joe Hunter or Federal? :shock: :shock: :shock:

Federal got only 50.7 % @ 40 yards with a Mod choke out of a 12 gauge.
Joe Hunter managed 66% with a 20 gauge with a IM choke, and 74% with a 12 gauge Mod choke. Yet, if you believe Federal . . . 50.7% is typical with a 12 gauge.

A "Modified" choke should print about 60% at 40 yards, regardless of gauge.

This is like being a cashier-- wrong is wrong, over is just as bad as being under. A choke marking is SUPPOSED to mean something. As Joe just showed . . . it doesn't mean anything specific.
Ya can't compare pancakes with french toast. Change the shot size and load, things can improve. 20-gauge 7⁄8-ounce loads of Game-Shok Upland No. 6 gives similar percentage patterns as 20-Gauge Browning Invector-plus w/ 28" barrel and Briley flush chokes
Winchester AA Heavy Target Load (1oz). Gee, wonder if shot hardness had any effect??

From the https://www.fieldandstream.com/articles ... ogun-ammo/

Test Loads:
- .410 11⁄16-ounce loads of Game-Shok Upland No. 6 shot at 1135 fps (Full choke)
- 20-gauge 7⁄8-ounce loads of Game-Shok Upland No. 6 shot at 1210 fps (Modified choke)
Results: Unlike other gauges, which are patterned at 40 yards, .410s are typically patterned at 25 yards. We picked 30 yards as a compromise distance and to reflect the shorter ranges at which beginners shoot. The Full choke .410 shot 87.8 percent patterns at 30 yards, while the Modified 20 shot 84.6 percent.
 
#17 ·
some thoughts. In the Olympics , they have to shoot 24gram loads. That is 6/7th of an oz.

So less than a typical 7/8th oz 20gauge load. YET-- no one shoots the Olympic disciplines w/ anything other than a 12g.

I have a 20g that came from the factory w/ a .010 overbore from nominal 20g in both bbls. Both bbls miked the marked chokes of Mod and I Mod.YET they threw the tightest patterns that I have ever seen --like super turkey full and laser full. They were death to 60 yd doves in Argentina but not very useful for day to day shooting (and I like tight chokes) so I had Briley put their screw choke system in the gun.
 
#18 ·
Gentlemen,

In my case I want patterns that will kill birds at 20-45 yards, and every time I change my gun and my shot size the pattered changes also. I need what my father called a killing pattern for birds. Just because the pattern will break a clay is no proof that the pattern will kill a bird. Each time you change guns the pattern will change, even using the same gauge gun. Changing the gauge of the gun even with the same choke size changes everything also. I do find that using #6 shot with the same chokes even in different gauge L.C. Smith guns, gives me a very similar killing pattern. With RST SpredR shells I get real nice killing patterns from my L.C. Smith double guns, no matter if the gun is a 12, 16 or 20 gauge, as long as the guns are all choked the same. The modern L.C. Smith 28 gauge is completely different, because it shoots extremely tight patterns even with IC chokes.

This is why I use RST or Poly SpredR #8's under the 1st trigger to kill birds flushed 20-30 yards, and #6's under the 2nd trigger for birds shot at over 30 to 45 yards. I get the killing patterns I need in this manner, out of my L.C. Smith double guns.

all the best,

Pine Creek/Dave
L.C. Smith Man

Grouse & Woodcock hunting is not just a sport in our family, it's our traditional way of life.
 
#19 ·
54bullwinkle said:
Thanks
I guess my real question is that if you shoot the same number of pellets from a 12 or 28 bore and pattern them similar is degree of difficulty of hitting clays any different?
Here is something to consider -

A thirty inch diameter pattern at forty yards is a thirty inch pattern at forty yards no matter if it is an ounce and and eighth or only three-quarters ounce shot. Does not matter, the spread is the same no matter the number of pellets.

But, the density of the pattern is diminished as the number of pellets diminishes. It might take a lot of pellets to bring down a live bird. But a clay target is a kill no matter if it is chipped or smoked.

So, the question is really not one of *****. The question is- "Can a clay target fly through my pattern or not?"

Some people think I am some kind of expert when they see me chipping clays with a 28ga. and a mere 3/4oz. at the clay field. No expert here. I got the same thirty inch pattern as everybody else. I don't have the pattern density so I can't smoke 'em. But I got enough pattern density to chip. A chip is still scored a hit.
 
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