20 vs. 12 gauge for hunting

I have hunted deer for many years with flintlock rifles but never got into blackpowder for small game and bird hunting. I aim to change that and start hunting with a fowler. Since I will still plan to use rifle for big game, shooting round ball will not be the primary objective although for the sake of versatility I would still plan to become proficient with round ball so that the fowler could serve as a back-up gun to the longrifle. As far as historical sentiment is concerned, I'd ultimately prefer a fowler that is more PC to the period before rifles where common, say early to mid 18th century.

What factors to consider when choosing between 20 and 12 gauge for hunting squirrel, rabbit, pheasant, and turkey? And is one gauge or caliber more PC for the first half of the 18th century?

I think you will find there were geographic, chronological and personal preferences that feed into what was common.
And what was common may or may not be well represented now.

Saying that I like 14g cause I have one and no one can say it is a modern size. I think it equates to 69 calibre like all those old time muskets.
So I would suggest have a look at what the muskets that prevailed were and there you have it.

Guns tended to be smaller in civilian hands, and smaller then many would use today. There were twelve and ten bore guns in civilian hands in the early eighteenth century and beyond till today.
However we see lots of smoothies made in the 28- 20 bore range. Even gentlemen’s fowling pieces and early double barrels are smaller then the 12s often carried today
A 20 bore is more then enough for turkey as 12 or 20 cylinder bore needs a twenty five yard or so range. The extra umph you need for a forty yard shot from a full choke just won’t pay off by going bigger.
A .62 ball will drop any animal in North America, just as dead as a .75.

A 12 bore will do anything a 20 will but a 20 will never do what a 12 will. That said if I required a nod to PC I’d go 16 bore.

My 20g has always done anything my 12g has done. Bigger is not always better, just bigger, read greedier!

Is it true that the 12 bore will throw a wider pattern than the 20 if using the same load?

No, larger bores will throw a better pattern due to the shorter shot column.

I'd offer a third choice: 16 gauge. As far as I know ALL barrel blank makers offer smoothbore contoured barrels based on two blanks (swamped, at least). The 16 bore is a 20 bored out. So 16 is lighter than either the 12 or the 20. That was what swayed me. I wanted light as practically possible in a 42" barrel.

Shoots a 1 ounce ball and was a common size in the 18th century.

And what Phil says: they trick is to find a "square" load of shot. As tall as it is wide. But I find a little more shot than powder (by volume) keeps the patterns relatively tight. Mine's cylinder bored so one has to stay realistic. I have a jug choked 12, and that option does inprove patterns.

Stumpkiller said:

I'd offer a third choice: 16 gauge. As far as I know ALL barrel blank makers offer smoothbore contoured barrels based on two blanks (swamped, at least). The 16 bore is a 20 bored out. So 16 is lighter than either the 12 or the 20. That was what swayed me. I wanted light as practically possible in a 42" barrel.

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I like 16 gauge too but I should have said in my original post that the reason for asking specifically about 12 vs 20 is because I am trying to choose between two kits, one is available only in 20, the other in 12.

I'd read once that examining ledgers showed .58 to be perhaps the most common fowling piece in the mid-18th Century. That said, other bore sizes existed, and many in large numbers. I happen to like the 20 gauge as it has dropped pheasant on the wing, uses a bit less shot than the 12, and I find (strictly anecdotal experience) that 20 gauge stuff is a bit easier to find.

Depends on several factors; not just the gauge/bore.
A 20 gauge with cylinder choke will throw a wider pattern than a 12 with full or modified choke, for example, even though the 20 has fewer pellets in a load.

It has been my understanding for 60 odd years, that the shot column or charge when properly loaded, should be the same height as the bore diameter, regardless of guage.

Please recall the "410 gauge" is actually a caliber not a "guage".
A "guage" or "bore" is the number of bore diameter round balls it takes to make a pound.

Phil Coffins said:

No, larger bores will throw a better pattern due to the shorter shot column.

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Myth. Assumption.

ugly old guy said:

Depends on several factors; not just the gauge/bore.
A 20 gauge with cylinder choke will throw a wider pattern than a 12 with full or modified choke, for example, even though the 20 has fewer pellets in a load.

It has been my understanding for 60 odd years, that the shot column or charge when properly loaded, should be the same height as the bore diameter, regardless of guage.

Please recall the "410 gauge" is actually a caliber not a "guage".
A "guage" or "bore" is the number of bore diameter round balls it takes to make a pound.

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Nope, the 410 is a bore measurement as is a 22 shotshell. Gauges are gauges. Calibre's can cover both and is another bastardisation of our language.
A 12gauge is not a bore. Never has been in fact only twenty years ago Americans use to take delight in admonishing any Brit using the term bore for a common shotgun guage!
A bore is a measurement usually across the diameter of a tube or circular hole.
A guage uses another measuring method and usually has a wider tolerance in actual measurements often observed for example in 12g by a wide variation in barrel diameters when measured.

For a few years I have been using an old Manton 15 ga. percussion double. Using the square load of 2 1/2 drams of powder and an ounce of shot it does well.

Britsmoothy said:

Myth. Assumption.

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Show me your data.

Phil Coffins said:

Show me your data.

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I don't have any.

Unmentionable 20ga magnum loads equal standard 12 ga loads, even more easily replicated in a 20ga muzzleloading gun. Also the 20 is more compatable to a round ball load, in my opinion. I have fired .69 prb out of a 12ga single to good effect, but the 20a prb load is all that is needed and more efficient to boot. Just sayin'.

ugly old guy said:

Depends on several factors; not just the gauge/bore.
A 20 gauge with cylinder choke will throw a wider pattern than a 12 with full or modified choke, for example, even though the 20 has fewer pellets in a load.

It has been my understanding for 60 odd years, that the shot column or charge when properly loaded, should be the same height as the bore diameter, regardless of guage.

Please recall the "410 gauge" is actually a caliber not a "guage".
A "guage" or "bore" is the number of bore diameter round balls it takes to make a pound.

Click to expand...

Sir, so using a volume measure, one can load same height loads, right?

Yesterday I tried this load in my 12 gauge modified and improved cylinder choked side by side:
82 gns 2f Goex, nitro card, 90 gns #7 & 8 shot, over-shot-card, .5" OxYoke lubed cushion wad with pretty awesome results at 25 yds. Without the lubed wad loaded last, the improved cylinder was hardly on paper. Inspired by "Skycheifs load"

Britsmoothy said:

I don't have any.

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But.....