Twist rate question...

[2lookindown]

hlary, Lots of good readin... I played a lot of golf... You could spin the golf ball with a cut across the ball from right to left and cause the ball to slice to the right the ball bites the air and the rotation causes the ball to go right handed... If you push out from left to right it causes a hook from right to left... if you top the ball it causes a downward rotation with causes the ball to dive down.... If the round ball comes out of the barrel it should try to bite the air in the way of the twist cut.... Would a fast twist be worse on the air bite ?

 I have another question... Why do most guys load the (mold cut off) outward Wouldn't this cause more of an air problem and cause it to fly off coarse Why not load the cut off straight down and not have that in the equation ?

[gumboman]

hlary...this is a very interesting article. I read it with great interest. Bookmarked it so i can go back and try to absorb it all. I am rereading the book Muzzleloaders Then and Now by Walter Cline. I have read it several times over the years and always pick up something new. Mr. Cline was an avid old gun enthusiast and was associated with many like minded shooters of the time. Early 20th century period. He talks quite a lot about twists. From what I can glean is that during the golden age calibers ranged from 38 to 42 mostly. Twists were primarily 48. Others were slower. Mr. Cline states his most favorite weapon was a 42 caliber long gun he named Long Tom. It was a very accurate shooter out to 200 yards. It's twist rate was 1/2 turn in the length of it's 48 inch barrel. That makes for a 96 twist and makes me wonder why my 90 twist in 62 caliber won't group. I am perplexed.

[Candle Snuffer]

I have another question... Why do most guys load the (mold cut off) outward Wouldn't this cause more of an air problem and cause it to fly off coarse Why not load the cut off straight down and not have that in the equation ?

The Bevel brothers addressed this question in an article in MuzzleBlast some years back, though they were doing their testing for the purpose of chunk gun shooting if I remember.  I don't recall how far they shot (perhaps 50 - 60 yards)?  I also kind of recall they found no difference.

I would think that shooting with the spur down at longer ranges (say 100 yards) and the spur not being completely and absolutely centered "down" (as you would not be able to see it), you run the risk of the ball rotating "off balance" - as best as I can describe.  However, loading the spur up - you have a better chance of that spur being centered which should not effect the flight of the ball at longer ranges, say out to 100 yards.  I guess it kind of equates to balancing a rotating tire...

[Candle Snuffer]

I am perplexed.

Just fishing here Gumboman...  Is this a full stock rifle with the barrel pinned to the stock?  If so, did you elongate the underlugs of the barrel a bit where the pin passes through?

I only bring this up because it was something I forgot to do on a flintlock rifle build I did about 10 years ago.  I could not get that .45 to group consistantly no matter what combination of, charge - patch & ball I used.  I had that barrel out of its stock three times looking for something I missed and checking it for straightness.  Finally it dawned on me,,, I didn't elongate the underlugs after drilling for pinning the barrel to the stock.

Long story short, it shoots straight to this day since I corrected my error.

Just throwing this out there, in case? 

[Dphariss]

http://www.leverguns.com/articles/wosika.htm

anyone seen or read this before? It's an interesting read and address primarily the twist rate per caliber and charge/muzzle velocity for long distance accuracy. Also leaves some questions unanswered.

This article is a classic example of people being compelled to write about something they have no clue about.

Dan

[zimmerstutzen]

Twist means nothing without also considering the configuration of the lands and grooves.  Some rifling can be to shallow to grip the patch at higher speeds.  Other types of rifling may grip the PRB better despite having the same twist. 

A slow twist is more forgiving of heavy charges.

However, for a small caliber target rifle, I would prefer a fast pistol twist  i can shoot longer and more accurately with minimal powder.  The paper target doesn't ever care whether the ball is moving at 400 ft per sec or 1900 ft per sec

The lower the powder charge the less likely to lose accuracy due to competitor fatigue

[gumboman]

Great feedback from all. Exactly what I am seeking in my efforts to make this expensive gun project pan out.

Most of my range session have used swaged balls from Buffalo Bullet Company. No sprue to deal with. I did recently buy some cast balls thinking the problem could be the swaged balls. I loaded with sprue up. No change in grouping.

The gun is a half stock, underhammer action. It's design emulates the Pacific Rifle Company's Zephyr. I do not have the fore arm attached at this time. In fact my last trip to the range was done before I installed the hangers for fore arm pins. I do have a number of drilled and tapped holes in the barrel. Four on top for my vintage styled Malcolm scope. Four on the bottom for my under rib.

And SCloyalist, I will try the corn meal next trip to the range. I have been using Goex 2f and have ordered some Swiss 2f to try. I have doubts that the powder will make any significant difference but worth trying.

This barrel has not been stressed relieved. According to the maker stress relieving is not necessary in a muzzleloader because it will not heat up as in a modern high powered rifle. Any feedback on this from the forum members?

[Dphariss]

This barrel has not been stressed relieved. According to the maker stress relieving is not necessary in a muzzleloader because it will not heat up as in a modern high powered rifle. Any feedback on this from the forum members?

Cut rifled barrels are not stressed as badly as button rifled barrels. If the steel was properly normalized before the barrel making started its probably OK. But I doubt it was. If its got a high lead/phosphorus/sulfur content normalizing may not be a good idea either....
Button rifled barrels MUST be normalized after buttoning to maintain bore dimensions.
Dan

[Dphariss]

Twist means nothing without also considering the configuration of the lands and grooves.  Some rifling can be to shallow to grip the patch at higher speeds.  Other types of rifling may grip the PRB better despite having the same twist. 

A slow twist is more forgiving of heavy charges.

However, for a small caliber target rifle, I would prefer a fast pistol twist  i can shoot longer and more accurately with minimal powder.  The paper target doesn't ever care whether the ball is moving at 400 ft per sec or 1900 ft per sec

The lower the powder charge the less likely to lose accuracy due to competitor fatigue

This does not take into account that pistol twists are too fast even for some pistol uses. For a large bore general use pistol 22" twists are not needed or particularly desirable IMO. Its fine for 25 yard pistol competitions. Not so good if the pistol is used for backup/protection in big game hunting.
22" is faster than many cartridges rifles of the 19th century used to stabilize bullets. The various Winchester 50 calibers using 300 gr bullets had factory twists in the 60" range. The 50 caliber Sharps used 36" twists for all calibers. The Gov't twist for 50-70 was 42" IIRC. A 22" twist in a 45 will stabilize a 500 gr RN bullet to its terminal distance. Something around 3000 yards.

22" twist RB rifles? If shooting 25 yards its one thing. Shooting 50-100 is something else.
Wind drift is a MAJOR factor is group size. While this may not be important in some places we routinely shooting it winds that in the east would have the match abandoned for the day. Low velocity will not only increase wind drift the fast twist will increase the vertical component of wind drift as well.
So while a small caliber low velocity load might work in an ideal condition at 25 yards. In the real world its probably going to lose more matches than it wins.
The twists we use today were not arrived at by happenstance. Twists in the 25-30" range were used in RB rifles in the 18th and 19th c and proved to be problematical for practical use in rifles.
Also low velocity increases barrel time and this in not a good idea either.

Dan

[Hungry Horse]

 Round balls tiller steer, that means they steer from the rear. If you load sprue down, you will experience more fliers than if you load sprue up. Interestingly enough swedged round balls make very little difference.


                                Hungry Horse

[shifty]

    Dan,In the Lyman 2nd edition BP Handbook&Loading Manual ,on page 285 it lists a 44 cal Walker Revolver as having a 1-48" twist rifling,is this info correct?I don't know if that is for the orginal Walker or a repro.
     I agree with you on the fast twist for a pistol barrel that some are too fast if used for hunting,I have a 50 cal. Kentucky style with 1-48" twist barrel 16" long,I have shot up to 60grns in it ,but practice mostly with 40grns FFg Goex,the farthest I have shot with it is 50yds off a shooting stick getting about 3 1/2" =3shot group with 50grns  for me that is good,I don't think the 1-22" twist or faster would do that with this charge.
    I have a 32cal Crockett Rifle and 30grns FFFg Goex is as high as I can go with it and still get a good group, the best groups are with 15 grns,and I think it has a 1-48" twist rifling ,I would like to try one with about 1-60" twist.

[zimmerstutzen]

Again the preference for a fast pistol twist in a small caliber for match shooting is different than hunting.  Frankly, a small caliber for hunting is counter to itself.  You aren't going to take a bear with a 32 round ball whether it is traveling 400 fps or 1200 fps.  There is only so much advantage to be gained by a high velocity round ball of small caliber.  It loses it's energy too fast as is travels down range.   On rabbits and squirrels it doesn't matter that  much.  Anything larger more than 50 yds out is too far for a small caliber round ball no matter what twist.

[2lookindown]

Again the preference for a fast pistol twist in a small caliber for match shooting is different than hunting.  Frankly, a small caliber for hunting is counter to itself.  You aren't going to take a bear with a 32 round ball whether it is traveling 400 fps or 1200 fps.  There is only so much advantage to be gained by a high velocity round ball of small caliber.  It loses it's energy too fast as is travels down range.   On rabbits and squirrels it doesn't matter that  much.  Anything larger more than 50 yds out is too far for a small caliber round ball no matter what twist.

Zimmy, I shoot farther than that with my 22 cal  air gun that is only 150 feet... Maybe these guns won't shoot with my air gun I was hoping to build my 32 cal to shoot at least 75 yards otherwise I'll just throw rocks...

[Standing Bear]

Don't worry 2  The .32will shoot to 100 with no problem.  A friend of mine had a Bill Large barreld flintlock that he shot in the wind at Brady TX using IIRC 75-80 gr FFg and won a 100 yard offhand match.  Said that little .32 ball wasn't in the air long.

I had one that shot 5 shot groups at 50 yards that looked like a dime.
TC

[willyr]

Anectdotal or not, a .32 with a slow twist will shoot at 100 yards. It ain't gonna do it with a .310 ball that can be thumb started.
Bill

[2lookindown]

I was hoping to build my 32 cal to shoot at least 75 yards otherwise I'll just throw rocks...

Based on the anecdotal examples from the first page of this thread, e.g. the 44 score on a 100 yd big bull, the 100 yd performance of the Watts rifle, Max Vickery's use, etc,   looks to me like the potential for 100 yd performance is going to be there, the trick being to find an accurate load for the barrel.   Now, when it gets to 100 yds, the ball can't have more than about 100 ft-lbs of energy left, so your targets will have to be selected accordingly.

SCLoyalist, I will let you try and catch one of those 32's at a hundred yards if you want It should bust your melon pretty hard... A 22 lr is still moving fast enough to kill a man at 100 yards....

[Dphariss]

I was hoping to build my 32 cal to shoot at least 75 yards otherwise I'll just throw rocks...

Based on the anecdotal examples from the first page of this thread, e.g. the 44 score on a 100 yd big bull, the 100 yd performance of the Watts rifle, Max Vickery's use, etc,   looks to me like the potential for 100 yd performance is going to be there, the trick being to find an accurate load for the barrel.   Now, when it gets to 100 yds, the ball can't have more than about 100 ft-lbs of energy left, so your targets will have to be selected accordingly.

Energy is largely irrelevant in BP arms be they round ball rifles or 45-100s.
Energy as a gauge of effectiveness relies on velocity and it does not even really work there. Large game can absorb several times their weight in cumulative energy and still stomp the shooter into a gooey puddle. So its really PENETRATION and PLACEMENT.  As a result a 243 will out energy many BP arms that are better killers on larger animals. The 32 is a very effective small game caliber for animals to about the size of a woodchuck or even a coyote, though the later are pretty tough from longer shots. It would not occur to me to not shoot a coyote at 100 with a 32 nor would I doubt it had the PENETRATION to kill a one at that distance. With a warm load the ball will be doing near 1000 fps at 100 and a 32 lead ball at this velocity is a pretty nasty projectile. Not something I would shoot a deer with at 100 unless really hungry then I would risk it.

I once shot a fox at 150 yards with a 36. I failed to hold high enough and broke both front legs just below the chest and had to finish the fox when I approached. This was late 1960s and the fox was worth 10 bucks at the time (about 30 gallons of regular gas). Except it was mangy and only looked red at a distance
So don't sell these small bores short. Like all MLs they are range limited and rifles need to be chosen with the game in mind. But for a plinker or a target gun or small game? Pretty hard to beat a 32.

Dan

[2lookindown]

Dan, That is one reason I wanted to build a 32 on a 1:66 twist... I figured I could pump it up a little if I need to and not lose the accuracy.... I may be wrong but I think it will work if I can see the sights....

[Dphariss]

Dan, That is one reason I wanted to build a 32 on a 1:66 twist... I figured I could pump it up a little if I need to and not lose the accuracy.... I may be wrong but I think it will work if I can see the sights....

I doubt that there is a nickles worth of difference between a 48 and a 66 up to at least 50 caliber and probably to 62 at least. One of the most accurate rifles I even owned was a Douglas 50 cal. 48" twist "Hawken" barrel used 90 grains of fff. In fact the rifle I shot the fox with had a 48 twist 7 groove Douglas made for Golden Age arms.
The 66 will work fine, but I just don't think it will shoot any better loaded hot than a 48. A friend has a 32 with a 66 and has been very impressed with it. My first rifle was a 66 twist 32. So I certainly would not deter anyone who wants a 66 twist 32.

Dan

[LH]

http://www.leverguns.com/articles/wosika.htm

anyone seen or read this before? It's an interesting read and address primarily the twist rate per caliber and charge/muzzle velocity for long distance accuracy. Also leaves some questions unanswered.

This article is a classic example of people being compelled to write about something they have no clue about.

Dan

Dan,  have you done any testing on your own to check this guy's theory out?  A couple of years ago I shot the musket agg at Friendship using my 1803 Harpers Ferry and roundballs.  There is a 200 yard target in that agg, and after days and days of testing at 200,  I never came up with a load that would come anywhere close to the group size I felt it should,  which would be about 2x the 100yd groups.  My barrel is a .54 with a 1:56 twist.  I got curious enough to try some 200yd groups with my .40 cal. rifle which has a 48 twist and the results were about the same.  That being the 200yd groups of both guns are typically 6 to 8 times bigger than the same gun/load at 100.  If I thought this guy was right,  I'd hunt me up a 70something twist barrel for my musket,  but I'm not sold on it to the point that I'd be willing to put that much time and $ into finding out.  Just wondering if anybody has tried to verify this slow twist/ long range idea?

[Dphariss]

http://www.leverguns.com/articles/wosika.htm

anyone seen or read this before? It's an interesting read and address primarily the twist rate per caliber and charge/muzzle velocity for long distance accuracy. Also leaves some questions unanswered.

This article is a classic example of people being compelled to write about something they have no clue about.

Dan

Dan,  have you done any testing on your own to check this guy's theory out?  A couple of years ago I shot the musket agg at Friendship using my 1803 Harpers Ferry and roundballs.  There is a 200 yard target in that agg, and after days and days of testing at 200,  I never came up with a load that would come anywhere close to the group size I felt it should,  which would be about 2x the 100yd groups.  My barrel is a .54 with a 1:56 twist.  I got curious enough to try some 200yd groups with my .40 cal. rifle which has a 48 twist and the results were about the same.  That being the 200yd groups of both guns are typically 6 to 8 times bigger than the same gun/load at 100.  If I thought this guy was right,  I'd hunt me up a 70something twist barrel for my musket,  but I'm not sold on it to the point that I'd be willing to put that much time and $ into finding out.  Just wondering if anybody has tried to verify this slow twist/ long range idea?

Its not the twist. Its more likely powder charge related or loading process related or the WEATHER.
The RB is EXTREMELY sensitive to wind. In shooting my 66 twist 54 at 200 with a peep sight I could get around 6" for 5-6 shots unless the wind came up  And I mean anything you can FEEL on your face.  I was using 90 gr of FFF Swiss. This load makes about 1900 fps. I WIPED EVERY SHOT. . If I didn't wipe it blew the groups. Best is wet patch, but not too wet, both sides up and down and 1-2 dry patches both sides, BUT DO IT THE SAME every time and make SURE the wet patches are all equally wet. They should not be dripping and should be prepared the day before to let them equalize. I use a small wide mouth plastic jar.  For target work shooting patches I use water soluble oil about 7:1to 5:1 mix then allow the water to all evaporate before the patches are used. So this has to be done at least the day before.
If its possible to feel any fouling when the ball is pushed down chances are it will hurt the group and this is magnified at 200 yards.
Its also necessary to load with uniform seating pressure on the powder. Vary this and the velocity will vary and it may well result in increases vertical dispersion.

If a 56 or 48 twist will not work a 72 probably will not either.  
So if you shoot 200 and are trying for group size/testing you need wind flags at about 3-4 points and the ability to READ them right.
In a 10 mph wind a 50 caliber RB will drift about 3-4 feet (depending on whose ballistics calculator you use) at 200 so even a 5 mph puff while a ball is in flight will produce a LOT of change in the balls impact point. The ball will start to do really strange things at longer distances including changes in the vertical induced by the wind.

The sights are another issue. If using barrel sights make some shaders.

These are sheet brass.

Shooting 60 yards sometimes my sighter/backer target hopefully looks like this there are a couple of sighters and 8 or 9 score shots in the big hole. The one to the left  is 2 sighters IIRC and one was a puff of wind I did not notice or was unreadable that added 2.2" to the string.


Sometimes they look like this. Sighter/backer targets for 3 different shooters. Note the horizontal dispersion. It was a bad day for wind at 60 yards.

 We used to have 1-3 wind flags.

Lately we have limited it to one.

People that agonize over twists for the RB would be better off doing more shooting with different lubes, balls sizes and powder charges. Better yet getting Dutch Shoultz's  information on accuracy with the PRB then doing the shooting.

Gotta run.
Dan

[2lookindown]

I have shot a lot a rifles.... They have a ballistic coefficient bullet for the caliber & twist..... In the case of the muzzle loader & the round ball we have the bullet and now we need to find the best ballistic coefficient barrel and powder charge.... Makes the game a little different.... I can't wait till my barrel gets here...

[LH]

Well,  I'm still at a loss.  My load components and technique is a lot like what you describe and I shoot in my yard, so most of my 200yd tests were done early in the mornings when there was no detectable wind. I can wait for those days.  I had surveyors tape strips on cane poles every 50 yards, and you're absolutely right about a little wind playing heck with a roundball.  And at times I have been able to get half a dozen shots in a row to print under a foot at 200, but my ten shot groups are invariably 18 to 24" while the 100yd ten shot groups are 3 or 4".  I've tried Goex and Swiss in fffg and ffg from 45 gr up to 100gr.  .530's and .535's with every patch cloth I have from .012 up to .024.  And cannot count on better than foot and a half 10 shot groups?   I took an M98 mauser up there with the issue battle sights and using cast bullets was easily able to get groups in the 4 to 6" range.  So I don't think I'm completely blind or suffering from palsey.  Something weird happens to a roundball between 100 and 200 yards when I shoot it though.  I was going to do a test of shooting some groups at 100, 120, 140, etc to see if there was a point where they go to hades.  Not much happens over the first 100yards though.  About 1.5 to 2" at 50yds,  and about 3 to 5" at 100.   I only shoot 10 shot groups when testing.  

[Dphariss]

Well,  I'm still at a loss.  My load components and technique is a lot like what you describe and I shoot in my yard, so most of my 200yd tests were done early in the mornings when there was no detectable wind. I can wait for those days.  I had surveyors tape strips on cane poles every 50 yards, and you're absolutely right about a little wind playing heck with a roundball.  And at times I have been able to get half a dozen shots in a row to print under a foot at 200, but my ten shot groups are invariably 18 to 24" while the 100yd ten shot groups are 3 or 4".  I've tried Goex and Swiss in fffg and ffg from 45 gr up to 100gr.  .530's and .535's with every patch cloth I have from .012 up to .024.  And cannot count on better than foot and a half 10 shot groups?   I took an M98 mauser up there with the issue battle sights and using cast bullets was easily able to get groups in the 4 to 6" range.  So I don't think I'm completely blind or suffering from palsey.  Something weird happens to a roundball between 100 and 200 yards when I shoot it though.  I was going to do a test of shooting some groups at 100, 120, 140, etc to see if there was a point where they go to hades.  Not much happens over the first 100yards though.  About 1.5 to 2" at 50yds,  and about 3 to 5" at 100.   I only shoot 10 shot groups when testing.  

3-4" is pretty big for "good day" groups with a PRB. They should be more like an inch. I would slug the barrels looking for tight and loose spots. 1/2 round barrels are POISON in a rifle ML or otherwise. Swamped barrels are not all that great either. So your 1803 may have a built in handicap. My experience with 1/2 oct rifle barrels is that I would not own one if I wanted best accuracy.
The best barrel on the market for price and accuracy is a Green Mountain 1" or 1 1/8" x 42" in 45-54 caliber. The next choice is to go to someone like Jim Mclemore and tell him what caliber and dimension you want and let him decide the twist.
Are you weighing your balls to eliminate culls? Store bought swaged balls are seldom round and often have a rather pronounced "belt" if they are measured. Balls should weigh within 1 grain of the median weight. If the lot of balls has most of the balls weighing 185.7 then the minimum weight for a keeper is 184.7. The ones that are a grain or more heavier, and there should only be a few, are OK. If you have a LOT of heavy ones then the median weight needs to be raised or the mould is not being closed properly.  Lighter than -1 grain? They have problems. Surprisingly big ones based on my machining BPCR bullets years ago looking for flaws. I found them.... So I weight to 1 grain. A digital scale makes this a lot faster.
RBs are different than bullets in not only the alloy but how the  projectile shrinks as it solidifies so it might not be as important. But I have serious trust issues with a bullet that is more than 1 grain light.
Gotta run, have 150 or so balls to weigh, patches to cut and some gun work to do too....
Dan

 

[2lookindown]

Dan, Just ordered the book from Dutch.... It sounded interesting from what I read on his sight.... Maybe that will keep me occupied till my barrel gets here... Thanks  Jeff Norris "2LookinDown"