Questions about smooth rifle (smoothbore w/rifle sights) accuracy

[Maven]

I asked these questions on another forum, but didn't get satisfactory responses.  Before I pose my questions, by accuracy I mean 1" - 1.5" groups  or less @ 50 yds. from a rest.
1) Does barrel length make a difference?  E.g., is a 26" bbl. less accurate than a 42" or 44" bbl.?
2) Does caliber make a difference in accuracy?
3) When shooting a patched round ball, must you also use an overpowder wad for best accuracy?
4) Do powder granulation and charge weight (volume) make a difference.  E.g., is FFg in .50cal. or larger bbls. likely to produce tighter groups than FFFg?  Also, is the best accuracy to be found with the lightest, moderate, or heaviest powder charges?
5) For a given caliber, how tightly must a patched RB fit the bbl. to achieve the best accuracy?

Thanks in advance for your help!

[roundball]

I asked these questions on another forum, but didn't get satisfactory responses.  Before I pose my questions, by accuracy I mean 1" - 1.5" groups  or less @ 50 yds. from a rest.

I'll provide some answers based strictly on my personal experience with GM .54cal and .62cal Flint smoothbore barrels which had adjustable rear rifle sights...however, you may also find them unsatisfactory.

In my experience at 50yds when I got a group that small it was not the norm...my goal, and experience is to keep them all inside a 3" aim point sticker which they do.

 
1) Does barrel length make a difference?  E.g., is a 26" bbl. less accurate than a 42" or 44" bbl.?

Can't say, mine are both 33" length

2) Does caliber make a difference in accuracy?

My .54cal has consistently been a bit more accurate than the .62cal, enough to notice but not enough to get excited about.

3) When shooting a patched round ball, must you also use an overpowder wad for best accuracy?

I could not use OP wads in either caliber without getting occasional fliers...so I don't use them.

4) Do powder granulation and charge weight (volume) make a difference.  E.g., is FFg in .50cal. or larger bbls. likely to produce tighter groups than FFFg?

Yes, 3F is always as accurate or more accurate for me in both gauges...and I like the reduced fouling and speed, so I use Goex 3F...same results with shot loads as well.
(same in all my rifle calibers too... .40/.45/.50/.54/.58/.62 cals).

Also, is the best accuracy to be found with the lightest, moderate, or heaviest powder charges?

Heavy powder charges give me the best PRB smoothbore accuracy, and my conclusion is that the heavier charge keeps it under a full head of steam longer...an assumed benefit since there is no rifling rotation.

5) For a given caliber, how tightly must a patched RB fit the bbl. to achieve the best accuracy?

My GM .62cal was actually a .610"...while I could start a .600" ball with .015" patch with some difficulty using a short starter, accuracy was not good enough for me...I then tried .595" balls with .018" patches and got much better accuracy.

I will close with this...none of what I just posted may apply to your smoothbore what-so-ever...and I am a believer that there are enough slight variations in smoothbore barrels, powders, patches, lubes, balls, etc, that there a fair chance two identical smoothbore barrels may not like the same precise load configuration either.

[Dphariss]

The smoothbore is not going to do 1.5" at 50 except as a fluke.

4" is more realistic maybe a little less probably more.
Usually a thick patch works best. I used a 480 ball and a ticking patch and 100 grains of FFg Goex in a 50 I have to get the best 50 yard group. About 3.5" or a little more for 5 shots. It will often put 3 pretty close together but there are always fliers with a SB that open the group. I could put money on it shooting under 4 at 50 and feel pretty safe, but for me SBs are notorious for failing when needed most.

With 490-495 balls and thinner patches I never found a load that would shoot under 2"+ at 25 yards much less 50.
Shooters love to make claims about how good their SBs shoot and I am sure there are some pretty good groups out there shot with SB guns. But if it won't repeat on command its just a example of all errors  stacking right to shoot a good group.

Dan

[George Sutton]

Smoothbores are a different beast. I own three, an old Centermark, a Ken Netting Fowler, and a smooth rifle by Butch Daryl.  The Centermark and the Netting are .62 caliber. Both have only front sights. The Daryl gun is .72 caliber, has front and rear sights and is jug choked.

The Centermark shoots like a rifle out to 25 yds. I use a .600 RB, a .010 cotton patch 65 grains of 3F with 30 grains of Cream of Wheat as a buffer over the main charge. I use spit for lube. It's hard to load, I have to short start the ball.  At 50 yds. the groups open up considerably. I've killed deer with this gun but limit my shots to 50 yds.

The Netting likes 70 grains of 3F, .600 RB, a .010 linen patch seated directly onto the main charge, spit for lube. I can shoot nines and tens at both 25 and 50 yds. Easy to load, I can start the ball with the ramrod.

The Daryl gun uses 75 Gr. 3F, .710 RB, .010 greased patch. I can hit bowling pins pretty consistantly at 100 yds with it. I don't know why. It may be the rear sight or possibly the jug choke plays a big part. I can start the ball with my thumb. It kicks like a mule.

A friend of mine has a Charlie Wallingford smooth rifle that I would give my eye teeth to own. It shoots like a rifle out to 100 yards. It's .54 caliber uses 65 grains of 3F, .010 cotton patch, spit lube. Patched ball seated directly onto the main charge. He also has to use a short starter to start the ball.

Over the years I've had other smoothbores that I couldn't get to shoot to my liking so they went down the road.

I learned years ago that smoothbores are like women, They are all a little tempermental and sometimes hard to live with.

Centershot

[northmn]

A smooth rifle is its own kind of beastie.  It is essentially a rifle weight smoothbore barreled gun.  Most of the recreations we see today use a fowler barrel (as I am doing on one).  When I shot smoothbores I can only concur with what has been said about their practical range.  Some seem to want to build a smoothbore and shoot roundball out of them almost exclusivley.  I find that puzzling as a smoothbore is primarily a weapon that shoots shot and can be used with roundball.  I suppose a smooth rifle could be said to shoot roundball and can use shot as a rifle barrel weight firearm is not as manageable as a fowler.  About the best you can do with a smoothbore to get the best accuracy is like with a rilfe and weigh and inspect the ball.  As to other points, a five shot group does not mean a lot in a hunting weapon unless it is fired out of a cold clean barrel, each shot.  That is a discussion in itself, but sometimes a gun will shoot 2-3 shots about the same and very tightly then start acting up on the 3-5 shots if fired warm.

DP

[Daryl]

My findings coincide with the other guys.  Adding rifle sights greatly increases the accuracy of smoothbores for those with failing eyesight as defining the centre of the breech when aiming is very important.

The very best shooting I've seen with a smooth rifle, was a little .44 smoothbore I once had.  I jug choked about .005" per side for use with shot yet still not enough to destroy round ball shooting. Bunny hunting with round balls was a 25 yard, head-shot game on snowshoe hares.  It would make a very small 1" hole for 5 shots at 25 yards and still hold onto 2" to 2 1/2" at 50 yards shot of the bags. The RB load was a .424" ball and .020" denim patch with 65gr. 2F.  It was a very consistant shooter and I do feel the jug choking helped, but I am at a loss as to explain why. I once shot 8 out of 10 on Trap with this gun, using 1/2oz. shot with 45gr. of 3F.  I used .410 plastic wads with 2 1/10" hard cards down on the powder.  It show very nicely rounded, 25" evenly spaced patterns at 25 to 30 yards, in every way, superior to any 3" .410 shotguns I've patterned.  (hint, 2 1/2" .410's come much closer)

The best group accuracy I've seen with a larger bored smoothbore is a 1" group at 25 yards, shot by 3 different guys, same gun - 6 shots total, each firing 2. We were using 80gr. 2f, a .600" ball and a .020" denim patch, iirc - and needed a short starter for loading - I don't remember the lube.  Taylor now has that gun, an English Fowler he made with/for LB.

The most accurate smoothbore I've shot at 50 yards was Taylor's Brown Bess, loaded with a .735" WW ball, .030" denim patch, moose snot for lube & 100gr. 2F.  The 5 shot group was 2 1/2" - standing with side rest on a barricade, BUT -  only one group was shot.  That ball/patch combination requires a short starter, of course as the measurement comes to .795, loaded in a .774" bore, for .0105" compression on each side.  Incidentally, it is a fairly easy loading combination in that gun - go figure - technique is the important factor, of course. Spend patches are reusable.

The second most accurate smoothbore I've shot was a 20 bore Taylor was doing some work on for a guy from Missouri.  I managed a nice round 3" group off the bags for 5 consecutive shots. Only one group was shot. We used a .595" ball if I remember correctly, with moose snot lube and 85gr. 2F.  The combination was too tight for the owner to use, of course, but we wanted to see what the gun would do with a descent hunting load and round ball. I think the balls were pure lead for this test.  If mine and hunting for moose, I'd be using 100gr. to 120gr. 2F.  3 drams (or thereabouts) is not a heavy enough load for longer range shooting, to 100 yards, that is.

When shooting our trail which is not smoothbore friendly, guys are finally discovering that to shoot with any certainty at longer 50 to 100 yard ranges on the steel targets, they have to up their powder charges.  Some use loads of 65gr. as standard, some 80gr. Upping the charges to 85gr. or 90gr. puts more lead on steel when the ranges are at the outside of the smoothbore's normal 'accuracy' range, which is close.

Using heavier charges for round ball in smoothbores was stuck home for me when working up loads for my 12 bore double ctg. gun.  There are 3 different loads listed for smooth 12's in W.W.Greener's book. 115gr. 150gr. and 191gr.  They are close to 4 1/4 drams, 5 1/2 drams and 7 drams, there being 27.3gr. in a dram.  The heavier the charge I used in that 12 bore, the better the accuracy - at all ranges to 8 inches at 100 yards- 2 lefts, 2 rights. Many groups using the full 7 dram charge showed this accuracy - it was consistant.

[Maven]

All, Thank you for your thoughtful and detailed replies.  You've certainly answered my questions and educated me about the ways (whims?) of smooth rifles!

[SCLoyalist]

You might find this article of some interest.   It's not about smooth rifles as such, but does talk about load issues in getting a smoothbore to group.

http://members.aye.net/~bspen/SmoothboreLoads.html

I looked at some shoot results posted on nmlra.org.   In 'Sighted Smoothbore' matches they shoot a 8 ring black big bull target at 50 yds.   Winning scores were mid-40s, which doesn't say anything necessarily about group, but does say they could keep their shots more or less all in the 6 inch diameter bull.   Those scores were only a few points higher than the (unsighted) Smoothbore matches.   In both sighted and unsighted smoothbore matches, for 100 yards the target used  is the "200Yard" with a 12 inch diameter black 8 ring.   The top scores tend to be upper 30s for both sighted and unsighted, indicating to me neither class of gun is capable of reliably keeping their shots in the black at 100 yds.

[Leatherbelly]

  A smooth rifle with a long swamped or straight octagon with rifle sights should group good at fifty. "Point of deer" at seventy five to a hundred.

[Mike R]

just an anecdote:  one of my buddies is a gunsmith who has made many MLing rifles over the years and was a past NMLRA competition shooter [and ex-Marine sniper].  A couple years ago he made a smooth rifle of .50 and took it to a rendezvous to try to sell it.  With no takers, he was induced to enter a rifle shoot with it--he had not even shot it before.  He guessed at a load and used a patched ball over the powder as in a normal rifle.  He won the shoot, beating an all rifle field.  I was not present, so I cannot tell you the details of the shoot, but I gathered it was a typical rondy shoot with a variety of targets and ranges.  I would think that a rifle-built smoothbore would in general outshoot a fowler-built one with rd ball.

[Daryl]

I agree, Mike - the heavier(thicker) the barrel, the greater the accuracy potential.

[Maven]

All, Thanks once again for your thoughtful and illuminating replies.  You've certainly answered my questions and given me something to think about before I purchase another flintlock.

[Daryl]

All, Thanks once again for your thoughtful and illuminating replies.  You've certainly answered my questions and given me something to think about before I purchase another flintlock.

Don't delay - flintlocks are the ONLY way to travel!

[JCKelly]

I, too, appreciate this summary of smooth-bore experience. Have a jug-choked 20 ga Caywood, which due to various Geezer conditions have yet to shoot. About to work up a load. Convinced to use relatively thick, well lubed patches.
This is a great summary by experienced shooters. All I know about smoothbores is what I read in the papers. My reading includes several earlier discussions of this subject:
28 ga smoothbore accuracy/howmuch drop Jan 19-25, 2009. (find on page 21 today)
Sanding balls for better accuracy July 10, 2009  (page 8 today) 
20 ga smooth accuracy Nove 28-Dec 28 2008 (find on p24 today)

[northmn]

I would suggest that for most shooters the accuracy problem lies more in the lack of sights than the accuracy level.  50 Yards is not all that close a shot in some areas of woods I hunt.  Also the use of sights in the field might be a little more accurate. 

DP

[Daryl]

I tried my lightly choked 20 bore 1/2 stocked English gun out yesterday for the first time. I started with 70gr. 2F as well as 82gr. (3 drams).  The 3 dram load was a bit more consistant.  I used a .019" stretchy pocket drill 100% cotton patch wet with WWasher fluid&soap with a .600" pure lead ball. I managed a 1 1/2" hole for about 6 or 7 shots offhand on our fouling shot/tie breaker board, about 18 to 20 yards range. I hit a lot of the gongs on the trail, even the 109 and 100yard ones, a bucket at the longer range and rabbit at 100. Missed a bunch, too.  There were 7 shooters, and only one rifle, a commerical .50 - but all guns were flintlocks.  Of the smoothbores there was one 28 bore and one 24 bore, the other 4 were 20 bores.  Taylor did very well indeed with his Penn. Fowler using around 88gr. of 2f for shots over 50 yards.  I found the 70gr. charge would not shoot well in my gun at anything longer than about 40 yards range so used 82gr., which is 3Drams for most of the course.  I'll make up another charger for 90gr. and use that for most target shooting on the trail from now on.

[RonT]

I built a .375 smoothbore flinter that I get consistant ~2" @25-30 yds.   In trying to get the thing to group found that a .360 ball, ~.018 ticking patch, and a pinch of blown in type celulose insulation over powder got me to those groups. 
It's my squirrel gun and I have taken ~2 dozen so far this year, all head shots, longest ~25 yds.    "Gotta' know yer limits"
R   

[Daryl]

Ron - if the 'filler' is necesssary, you could try Reminton's buffering material or Winchester's 'Grex'. Both are designed as fillers and won't burn. I am unsure if the insulation will melt to the bore or not. If it doesn't, it will be cheaper than the others of course.

[SCLoyalist]

 In trying to get the thing to group found that a .360 ball, ~.018 ticking patch, and a pinch of blown in type celulose insulation over powder got me to those groups.     

Instead of insulation, have you tried corn meal or cream of wheat?  I have a 40 cal rifle that used to positively eat thick pillow ticking patches, and putting about 1/2" of cream of wheat between powder and patch provided enough insulation from the flames where recovered patches are completely unscorched and whole.

[RonT]

Don't know if the filler is necessary or not.  Started using the blown in type ~1980 in my NW Trade gun after seeing the aftermath of a house fire where the studs had burnt completely out between leaving the insulation intact.
Haven't experianced any cleaning problems, and it seems to shoot OK.
I have two 5 gal. plastic buckets full of the stuff...scavanged from a demolished house so cost isn't an issue.
R