Is 40 caliber the most accurate roundball

[kyridgerunner]

I've been told that the majority of the top offhand shooters prefer the 40 cal. Is this true? Anyone have any statistics or information to support this?

[smylee grouch]

Above targets shot with two different 40 cal GM barrels. Perc. target shot two groups at 50 yds. Sun changed for the 2nd 3 shots.  second target was 7 shots with two called fliers. Both these rifles were chunk gun style rifles.

[rich pierce]

A .40 has some advantages. Economical, no recoil, and typically shoot well at high velocity. I don’t think there’s a reason why it could be more accurate. Most bench or chunk guns I’ve seen were .50 or bigger to fight wind at longer range.

[kyridgerunner]

Thanks Rich and Smylee.  That's good shooting Smylee. Would you say it shoots flatter than heavier balls at a given velocity? Could a offhand shooter pretty well hold center on targets at 25,50 and 100 yards without worrying to much about ball drop?

[bob in the woods]

It's a matter of velocity.  All projectiles drop on their way to a target....from the moment they leave the barrel , onward.  The .40 just happens to be on a sweet spot re powder charge/ velocity/ recoil.  The most common caliber used at our club is .54
We have a number of 100 and even some 200 yard matches, and the larger ball holds up better .  BTW, the round ball loses velocity at a rapid rate, so I don't believe it's realistic to expect to "hold centre" at 25, 50 and 100 yards. If you are "on" at 50, you will undoubtably be low at 100

[WadePatton]

While we do not discuss modern guns here by caliber or action or implication much at all, suffice it to say myself and very many others here "came over" to the smokey side with a ton of experience and study in that other area.  And in that area there are indeed some magical combinations of internal ballistics that produce unusually uniform accuracy. I'll not name any of them, but they are pretty well known by those who sought one-hole groups and longest range accuracy (or were when I left that side a while back).

So naturally when I came to muzzleloading I also had the inclination that one of these roundball calibers could also have some "magical" ballistic properties that led to it having the "best" accuracy of them all.

I was also nudged in the direction of the 40 as I made such inquiries and investigation. But after much more study and a few years of experience I threw out that notion because for ultimate accuracy in roundballs, one needs to find the best mix of components and loading pressure consistency for accuracy in any bbl.  It likely helps if it is a premium, hand cut/lapped bbl and the shooter has excellent eyesight and motor control-and he/she shoots a lot.

I no longer think that any one caliber rules the target shooters' competitions. If that ever becomes the case, then okay--there's your caliber.

I've got a 40 in the works and a 30 in the plans---and I'm going to work hard to keep making one of them shoot better than the other. That should keep me busy for a day or three.    AND one of them will probably outshine the other, but there's no way to tell that before the shooting begins.

My opinion on it: No magic in a size, but only in the consistency of loading the components selected by rigorous load development and good skills and shooting techniques.

[smylee grouch]

I think Rich and Bob in the woods touched on an important fact. The faster the ball leaves the muzzle the farther it will go before bullet drop gets excessive. The 40 can do that because it won't beat you up with larger charges, less of a rainbow trajectory. The 40 will shoot well at 100 but if the wind picks up it will drift a lot so 50s on up are more popular for that kind of work. The 40 is one of the more popular at NMLRA type paper 25 and 50 yd. matches because of the cost to shoot, low recoil and flat trajectory.

[J Henry]

  the most accurate is the one you practice most with    Short answer

[Jeff Murray]

The weight, balance and fit of the rifle also have a big impact on offhand shooting.  Shooting off the bench will give you the best measure of the accuracy of the rifle.  Shooting off hand with a well sighted in rifle will tell you how well you shoot that rifle.  As noted above, target distance can affect the choice of caliber as well.  Out to 50 yards, my 32 with a hot load will match any caliber I have ever competed with.  Best target that rifle produced was on the NMLRA small six bull target at 50 yards off of cross sticks - 50/4X.  i still have it so I can delude myself into thinking I can still shoot that well.

[Daryl]

  the most accurate is the one you practice most with    Short answer

DITTO

Many years ago, I made a decision to shoot only my .69 short barreled (31") English styled rifle, starting in the fall and culminating at the Hefley Creek Rendezvous the next Aug/Sept.
 I went through 25 pounds of 2F GOEX that year & I placed 1st in every event I entered, except for the BP ctg. event. Oh well.  IIRC, I entered 6 ML events at that shoot. These events
usually average over 50 shooters each.
Those were the days! 

[Scota4570]

I do not think there is any caliber that is inherently and mechanically more accurate.  That kind of accuracy is dependent on the design and quality of the barrel.  IN no specific order I think that these things are important to mechanical accuracy.

-Good internal finish
-no tight or loose spots
- appropriate twist rate.
-a little choke is good, no choke is fine, a flared muzzle is bad. 
-lands about 30-40% of groove width.
-Grooves that not too deep to make a patch seal, this relates to the width of the grooves.  I think that you should be able  to get a fabric impression, in the grooves on a test ball.

It is my experience that deep grooves do not shoot as well as deep enough grooves.  Wide lands make loading difficult.  Deep grooves and wide lands create an impossible situation where a good patch seal and reasonable ease of loading are impossible.  It may be possible with and extreme combination but the ball will be deformed by loading which limits accuracy again.   I believe that the ball slugging up in to deep grooves works in larger calibers.  I believe than in small calibers it takes a lot of powder to get the same effect due to lower stationary momentum of small balls.   

Ergonomic accuracy is determined by things like loadability and recoil.  40 cal is a very good choice for these factors.  Tiny calibers are hard to load consistently.  Large calibers kick and promote a flinch.

[Jim Filipski]

I do know that my 2 most accurate flintlocks I own are a .40 caliber ( Bobby Hoyt rebore from a 42" .32cal Green Mountain barrel) And my custom .54 Getz .38" with a fancy coned muzzle! Both when shot from the bench at 75 yards usually make a ragged hole with 3 to 5 shots

[Candle Snuffer]

I feel what you shoot the most will be the most accurate (for you) from the distances you've practiced from... Many years back I had Ed Rayl make me a 7/8" x 36" barrel in .40 caliber with 1 in 72 twist with .010 round bottom rifling... Over the years I have found this rifle to be very accurate no matter what the charge regardless if I use; 3fg / 2fg / and yes, even 1fg. Fouling has never been an issue on any / all of the 5 shot strings I've taken - and I do not wipe the bore between my shots with this rifle, and I'm shooting 40 and 45 grain charge's. I get tight grouping from both 25 and 50 yards, and even playing around with it at 70 yards I get very good grouping with a 50 grain charge. And the thing I love most is that I don't need to swab between shots. (Not even when using the; 2fg and 1fg BP in this .40).

So,,, is the .40 more accurate over my; .45's / .50's / .54's??? Nope!!! They are all accurate because I took the time to work up an accurate load for each of them... Would I ever use a .40 caliber for 100 yard work? Probably not, but I wouldn't hesitate to use it out to 70 yards. 

[kyridgerunner]

Thanks to everyone for the replies and info. I have a .54 that shoots one big ragged hole off the bench at 50 yards so maybe I'll just call that my offhand gun. It certainly bucks the wind a lot better than my 40's or 45's. Believe it or not - those tight little groups with my .54 are when using 35 grs of 3F. That's less powder than I use in my 40. so it's economical to shoot and the recoil isn't bad at all.

[Daryl]

I found my Goodoien .40 cal barrel to be very accurate, however it was not more accurate than the .45 Green Mountain barrel I also had for the same stock. When I was shooting
well, they both would make 1/2" to 3/4" 5 shot groups at 50 yards from a rest.  The .40 had a .398" bore, with .010" square rifling twisted at 48" to a turn. The Green Mountain .45]
barrel also had .010" square rifling, and a .450" bore & a 60" rate of twist.
I used a .398" as well as ..400" balls in the Goodoien barrel, with .0225" denim and .0235"mattress ticking patching - equal accuracy from both.
I have made the same sized groups at 50yards, with my .58's and with my .69.
I find it interesting, that many of the 100 and 200yard bench shooters use .69 calibre rifles which stands to reason. These 'boys' also use HUGE powder charges.

[Jeff Murray]

"Huge Charges" are obviously relative to caliber but the faster your ball gets to the target, the less time the "devil wind" has to mess with it, or so I thought.  Looking at Lyman's Black Powder Handbook for wind drift at 1500 and 1000 fps muzzle velocities in calibers from .350 to .735, I was surprised that wind drift with the 1000 fps muzzle velocity was generally 1.5 to 2.0 inches less at 100 yards than a 1500 fps muzzle velocity.  Retained velocity at 100 yards was generally around 75% except for the .440 round ball which was 85%.  The .440 also had the lease amount of drift at 100 yards.  Don't know if there was something special about their .440 but the results were not what I expected.  The .735 ball performed the second best at a muzzle velocity of 1000 fps.  There were no stats for 1500 fps for the .735 round ball.  Wonder why??? 

[kyridgerunner]

Thanks guys.

Jeff - I've never seen, let alone shot, either a .350, 440 or .735 round ball but I'm assuming that the more commonly used round balls that are close to those diameters, i.e., .32, .40, .45 and .72's would have pretty much the same wind drift at those given velocities. ( I need to get the Lyman Handbook) That's very interesting info. Do you think that the ball's RPM has anything to do with that? I'm just assuming that the faster the ball is pushed down the barrel the higher the RPM.
I've been experimenting with lower powder charges, that is: lower than those commonly used, and getting very good accuracy. For instance 35 grs in a .54 and 50 grs. in a .58. That's all the way out to 100 yards. (The recent powder shortage scare kind of prompted those tests) That seems to jive with the Lyman data.

Daryl - Based on your comments I got myself some .025 denim. As you've said - it goes down easy with bore sized balls and shoots good. Tks.

[Daryl]

They load a lot easier, with a nice, smoothly radiused crown.  This is very similar to the shape "Corbin" uses on their metal moving dies,
for drawing various metals.
A nice smooth bore is also a requirement.

[Mule Brain]

Shot this 100yd off hand with my .40, and so far it's my best. My rifle likes 40 grains fff, .395 ball, and .018 ticking patch.

 


This is an interview with LC Rice, and it's pretty informative

Courtesy of Black Powder Mag   

[Dphariss]

I've been told that the majority of the top offhand shooters prefer the 40 cal. Is this true? Anyone have any statistics or information to support this?

I doubt it. Some of the best offhand shooting I ever did, about 40 years ago , was with a 50 cal that was at least a inch too long in the buttstock.

Other things.
 The only thing that will reduce wind drift to any extent  is ball size.
1500 vs 1000 fps. The projectile needs to be started at AT LEAST 1600 and preferably 2000. But with the RB nothing works. The ballistic co-efficient is so low that even at 2000 it will drop into the high drag 1600 or less velocity until it falls subsonic at 1050 or so.
What to do? Use the most accurate load. It will likely be 1600 fps or higher.
Judging the wind is critical but since a minor change will greatly effect a RB.
So, based on my experience, trying the beat the wind with a PRB is basically a waste of time. A change of a 5 MPH is hard to detect but it WILL have an effect on the RB and will likely push it out of the  10 ring and maybe out of the black. Its just part of the game and it effects everyone at the match. If you can put up wind flags/streamers and learn to read them and shoot for a condition.
I have fought the wind with RBs, BPCR and modern HP in various matches.
Wind at the firing line/first part of the bullets flight will have more effect at the target than the wind right at the target will.
AND the amount of wind drift is determined by how much TIME the bullet loses going to the target. And RBs lose a lot the BC starts with a .0 the better BPCR bullets run in the mid .3s and maybe .4 but the velocity here is usually right at the high drag velocity 1200-1400 usually. And they hold it for a time. Most ML bullets people might shoot are very poor but better than the RB since anything is.
So work on your offhand shooting, natural point of aim etc. And learn to read the wind try to shoot in the same or similar condition if time allows. Its all you can do. Caliber? Shoot what you like. For a 60-100 yard match rifle I would likely use a 50. But I live on the Eastern front of  the Rockies and the wind blows here.

[Hungry Horse]

 I think a lot of old stories about the legendary .40 caliber were started back when most replica guns were one in forty eight twist no matter what caliber they were. This is a very good twist rate for .40 caliber. It also coincidentally happened at a time that many nation records were held by shooters shooting .40 caliber guns.

 Hungry Horse

[Dphariss]

I think a lot of old stories about the legendary .40 caliber were started back when most replica guns were one in forty eight twist no matter what caliber they were. This is a very good twist rate for .40 caliber. It also coincidentally happened at a time that many nation records were held by shooters shooting .40 caliber guns.

 Hungry Horse

The 48 twist works very well in everything to at least 54 caliber and probably beyond. This twist conformed to the “one turn in the barrel length” that was the common practice in England and Continental Europe. Since the common rifle in the  American Colonies and later was “four foot” the 4 foot twist was considered correct and it is. One the the most accurate rifles I ever owned as barreled with the Douglas “Hawken” barrel 48” twist in 50 caliber and I shot 90 gr of fff.
I don’t know why Douglas, for example, used a 66 twist or why the modern barrel makers have twisted them so slow.  I consider it a mistake at least in calibers smaller than 58 or 62. I had a 36”  62 with a 48” twist I was going to test in my cleaning vise but never got around to it. I have since cut two pistol barrels from it so its now a little short.

[Frank]

I think a lot of old stories about the legendary .40 caliber were started back when most replica guns were one in forty eight twist no matter what caliber they were. This is a very good twist rate for .40 caliber. It also coincidentally happened at a time that many nation records were held by shooters shooting .40 caliber guns.

 Hungry Horse

The 48 twist works very well in everything to at least 54 caliber and probably beyond. This twist conformed to the “one turn in the barrel length” that was the common practice in England and Continental Europe. Since the common rifle in the  American Colonies and later was “four foot” the 4 foot twist was considered correct and it is. One the the most accurate rifles I ever owned as barreled with the Douglas “Hawken” barrel 48” twist in 50 caliber and I shot 90 gr of fff.
I don’t know why Douglas, for example, used a 66 twist or why the modern barrel makers have twisted them so slow.  I consider it a mistake at least in calibers smaller than 58 or 62. I had a 36”  62 with a 48” twist I was going to test in my cleaning vise but never got around to it. I have since cut two pistol barrels from it so its now a little short.

I agree with your assessment of the 1 in 48 twist and apparently so did Sam and Jacob Hawken as all their rifles were a 1 in 48 twist regardless of caliber.

[Daryl]

My .58 Musketoon, made a 3" 5-shot group off the bags at 100 meters using 75gr. 2F GOEX producing 1,308fps with a .575" ball and .022" denim patch lubed
with spit.  I figured that was a decent group considering the rifle has only a 24" barrel and the mil-spec sights are not very precise. Oh yeah- 48" ROT.
Taylor's .66 cal. Joseph Lang rifle, with the first load we picked to test, 85gr. 2F GOEX, .650" ball & .020" cotton, shot a 1.9" x 2.4", 5 shot group at 100meters
off a rest. It also has a 48" ROT.

[recurve]

Green mtn .50 100yrds bench the high 2 before I filed the rear sight , it's a  sight in target

same barrel and load at 50yrds

here's my Bobby Hoyt 30 at 50 before sight ajustment