Does Bore Size Matter?

[MikeC]

I'm thinking about a .62 smoothbore for my next gun. Got to thinking for bird shot does bore size matter much when it comes to front loaders. From what I read the majority says volume to volume measurements of powder and shot typically work well, at least to start.

So I was thinking what is the difference if I have a .62 or .58 and I'm using say 90 grain measurements in each. What is the benefit of one over the other when it comes to shot loads, their both the same. I would think the smaller bore would give a tighter pattern...no?

Mike

 

90 gr is a stout load for a .62 or .58 smoothie. Bore size matters in its extremes--that is the same load in a 12 gauge vs a .410 would produce a very different shot string. You have to test which load patterns best in each gun, but typically for a .62 (20 gauge) it will be more like 70 gr and an equal volume shot. The difference between .58 and .62 is 24 gauge vs 20 gauge, not very much...

 

[Iron Jim Rackham]

No. If you anticipate doing any wing shooting, neither gauge is a good choice. However, 7/8ths of an ounce fired through a 20 gauge should yield a tighter pattern than 7/8th's through a 24 gauge.
Best loads are obtained when the shot column is nearly as wide as it is high. In a smaller bore, the same volume of shot will create a column considerably taller than wider, and your patterns will suffer.

While a 20 gauge is a popular choice, it is inferior to a 12 gauge for shot loads. I think the popularity of 20's is a function of availibility rather than performance. There are simply a lot more 20 gauge barrels out there. If you were having a gun built for wing shooting, go with a 12 gauge, and you won't be undergunned. Unless the fowler is intended as a present to a woman or child, a 12 gauge is a much better option.

 

[roundball]

However, 7/8ths of an ounce fired through a 20 gauge should yield a tighter pattern than 7/8th's through a 24 gauge.

...why would that be the case?

 

[Iron Jim Rackham]

The taller the shot column is, relative to it's width, the worse the pattern will be. There is not much difference between a .24 gauge and a .20 gauge, but the 20 gauge should handle 7/8ths better than the 24, simply because the same volume of shot in the 24 gauge will create a taller column. If you have both a .20 gauge and .24 gauge, try it. I think you'll see that the .20 gauge handles 7/8th better. A .24 gauge should be pushing 3/4 of shot. You can load a muzzleloading shotgun with as much mischief as you want, but best patterns in a .24 gauge will be achieved with about 3/4 ounces of shot. Figure 7/8th in a .20, 1 oz in a 16, and 1 1/4 in a 12.
Some shooters will exceed these loads, but optimum loads will be achieved with those cited. I read somewhere that a turkey hunter used 1 5/8th ounces of shot in a 20 gauge, and found the notion ridiculously funny. It's a 10 gauge load in a 20 gauge gun, but he swore by it. To each his own I suppose.

 

[spottedpony]

Also the longer shot column such as one would see in a smaller vs larger guage, assuming equal weight of shot, has a higher percentage of shot in contact with the bore, thus deforming more shot as it scrubs the bore, & will result in more "flyers" creating a more eratic pattern. & bore leading will be a bit worse as a result also.

 

[Ridge]

I'm not sure that there is any truth to it (my never owning a 12 gauge and all) but I've always heard that 12's shoot shot better and 20's shoot round balls better.

That probably explains the popularity of the 20.

 

[MikeC]

Thanks all that replied.

The 90 grains was just a figurative number I plucked out of the air.

I thought it would not make a difference or the tighter bore would yield tighter patterns being it's tighter to begin with.

I guess the answer lies in the height of the column in relation to the diameter of the bore.

I was looking at the smoothie to be used for everything from squirrals to turkey with shot and predators to deer sized game with ball. Primary use being squirrals and turkey.

So what do you all feel would be the best bore size based on my intended uses. I would guess a 20 would be minuimn for turkey based on what was stated regarding shot height in relation to bore size.

 

[Rebel]

I have taken a few turkeys with a .20 flinter and i know a lot of other fellas use them. They are a good all around gun. Big enough ball for deer and ekl and enough shot for quail, grouse, squirrels, and turkeys.

 

[Iron Jim Rackham]

A 20 gauge is fine for squirrels and is widely used for turkeys...by muzzeloaders. I think most centerfire hunters use 12 gauge guns because they are so much more lethal, and the availability of modern 12 gauge guns isn't an issue. Muzzleloaders use .20 gauge guns because 20 gauge tubes are available from so many sources. A 20 gauge has and will harvest anything from squirrels to deer. If you want to shoot turkeys or limb rats out to 25 yards, a 20 gauge will do the job. If however, you want to extend your range for turkeys, or shoot flying, a 12 gauge is preferable.

A 12 gauge will throw ball as well as a 20 but with more felt recoil. A 12 gauge ball of say 715 diameter will weigh in the 500 grain neighborhood, whereas a 20 gauge ball of .600 diameter will weigh in around 300 grains. With 3 drams of powder behind a 500 grain ball you will feel more recoil than with 3 drams behind a 300 grain ball.

I think smoothbore roundball accuracy is problematical at any distance beyond 50 yards, and haven't noticed 20's shooting any better than 12's. If you're wife or children share your interest in muzzleloading, a 20 gauge may be somewhat more manageable for them, but frankly gun fit determines recoil as much as bore size. I have taught hundreds of boys and girls to shoot flint trap, and have always trained them on a 12 gauge. I always tell them they have to be twelve to shoot a 12 gauge and I've never lost a student because of recoil. I have them shoot 3 drams of FFG and 1 1/4 ounces of shot, and they break more clays than shoulders. Generally kids are result oriented, and they will like what they do well at, and dislike what they do poorly with. They prefer a flint 12 gauge to a 20 gauge double, because they break more birds with the 12.

 

[roundball]

"...I read somewhere that a turkey hunter used 1 5/8th ounces of shot in a 20 gauge, and found the notion ridiculously funny. It's a 10 gauge load in a 20 gauge gun, but he swore by it. To each his own I suppose.

Actually, I think your statement is "ridiculously funny" but like you said to each his own :grin:....the main problem with it is that it's a generalization out of context.

If you'll check the information of this well established gentleman's website, you'll see where his turkey load has been publicized and copied successfully for years and years.
[url] http://members.aye.net/~bspen/SmoothboreLoads.html[/url]

What you need to understand is that a turkey load is completely different than worrying about filling the sky with shot for close skeet targets at a mere 21 yards...the best turkey pattern is a small, tight, long range one and is actually best served by a long shot string.

I'm one who uses this gentleman's .62cal turkey load in my own .62cal Flint smoothbore and it averages 16 #6's in a 5" circle at 40yds...an excellent turkey load that's not "ridiculously funny" at all...it's all about context...you have to remember the context.
:grin:

 

[MikeC]

Jim...Very sound advice. The 12 does sound like it's a much better choice for me. The gun is for myself and I'm no stranger to recoil so that is not even a factor. My daughter shoots my .36 and my wife prefers to shop :snore:.

I would guess from your post a rocklock 12 is hard to come by as is, the problem is further compounded being I shoot left handed. So who makes 12 gauge barrels.

 

[Rebel]

You can get an .11 ga, .75 cal, from Early Rustic Arms in a few different styles. Probably get one made left handed too.

 

[CrackStock]

TVM is here -- look up Slash. They can build you a left handed smoothbore.

CS

 

[Iron Jim Rackham]

The majority of my shots are between 25 and 35 yards with a full jug choked 12 gauge. I have often brought down pheasants beyond forty yards with 3 drams of powder and 1 1/4 ounces of shot. Pretty good reach from a standard load.

1 5/8th ounces of shot in a 20 gauge is virtually a proof load. 7/8th's is fine for wing shooting. 1 ounce is a stiff load, and 1 1/4 ounces is heavy, in a 20 gauge. 1 5/8ths is close to a double load.

If you like shooting 1 5/8th ounces shoot it in a 10 gauge. I think it's an irresponsible load in a 20 gauge gun, not unlike advocating double charging a gun for hunting. Better loads, safer pressures, and more enjoyable shooting are obtainable with
"reasonable" 20 gauge loads. Different gauges have different applications. If a .20 gauge gun could do it all, there wouldn't be the plethora of gauges available to shooters over the centuries. I'd love to find another source that advocates 1 5/8th ounce of shot besides the one you cited. I've never encountered an advocacy of that heavy a load in a 20 gauge, but I'd be happy
to read about it, if you can direct me to another source that recommends it.

 

[Iron Jim Rackham]

They are not as ubiquitous as 20's but they're out there.Contact Mike Brooks. The man is to gunmaking what Mozart was to music.I don't know who he would recommend for barrels but Getz and Colerain both make (made) 12 gauge guns. Have it jug choked as well. I like a full choked gun, but other chokes are available.

3 drams of powder a 1 1/4 ounces of shot in a 12 gauge is an average load. If 12 year olds take it in stride, you'll never notice it. Frankly, the flash of a flintlock and the report and recoil of a gun are something I never notice when shooting.
You're so focused on bagging birds or breaking clays you never notice any of those things. In that sense even muzzleloaders are automatic arms because they perform automatically if you acquire good instincts and stay focused.

 

[mbritt]

I think the advantage of useing a larger bore gun is so you can get a better pattern when shooting a larger volume of shot. It's been my experience that a one ounce load in a 20 ga kills just fine, so I don't see the point in using a larger size gun shooting a heavier load. It makes makes a difference carrying a heavier gun at the end of a day spent walking the fields and woods.

 

The British did extensive testing and experimentation with fowler/shotgun loads years ago and their work is the basis of most modern shotgun loads. They "wrote the book", but many folks cannot read and continue to make the same errors of the pre-British testing--no sense reinventing the wheel--the Brits did it for you. Check out the standard game loads listed on shotgun shells for oz of shot and drams of powder. Iron Jim is right. In a 20 gauge, 7/8 to 1 oz is a standard to heavy load. Overloading a shotgun is typically not the best route--especially with cylinder bores.

 

[Mike Brooks]

Well Iron Jim, I've had some pretty different results shooting shot out of flint fowlers. I had a 28 bore with a 48" barrel that shoot full choke styled patterns with anything you wanted to load in it. I generally loaded an ounce and equal powder. But, that pattern was deceptive. It shot a column or long cylinder type of pattern. It wasn't worth a damn for wing shooting. For turkys or squirels it was great as they were standing still and caught the whole column of shot. I've had similar results with long barreled 24 bores and 20 bores.
I've shot jug choked 10 bores with as much as 2 5/8 oz loads...incredible pattern results out to 50 yards for turkeys. I also have a 12 bore with interchangeable barrels that I loaned to an avid turkey hunter that killed a big tom with it at 40 yards. Loaded stoutly with 2 oz shot.
What most folks don't understand is you're not limited by the volume of a shot shell when you're loading flint muzzleloaders.

Wing shooting is generally a different story, as I've found no advantage to bigish loads shooting pheasants. I don't think I've ever loaded more than a ounce and a quarter in a 12 bore for wing shooting.
Maybe what I'm trying to get at here is to point out the versatility of the flint smooth bore, You can load them to suit your needs, and they will perform well for you. You have many more options than the limits of a modern cartridge gun.

 

[roundball]

To be sure we're clear...I take no issue with whatever anybody wants to use...please enjoy your chosen approach for making close shots at skeet or squirrels.

In this case I happen to follow the turkey load advice on the referenced web site by choice and will continue to do so...and by the way, it has nothing to do with my ability to "read"...but has everything to do with my ability to "think outside the box".

For example, it's also been said that a "well established" practice of measuring powder was "to cover a ball in the palm of one's hand"...another was to "blow down a barrel after a shot", etc...but I don't do those things either. :grin:

The gentleman's recommended turkey load works extremely well and is an outstanding tight patterning long range turkey load in my .62cal GM Flint smoothbore, so the comment about overloading something seems not to apply in this case.

I agree it would be than needed for a s