Question on barrel length and harmonics

[Artificer]

Don did come in with the voice of reason.  Grin.

I would suggest most barrel makers and rifle builders of the 18th century also wondered what made rifles shoot better, but they didn't get hung up on science they didn't understand or wasn't invented yet.  They tried different things they did know and could control and that's why as Don mentioned, through trial and error they found a 42" rifle barrel worked best.  

I wonder if in the day if a bunch of them would have ever gotten together, would they argue about rifling twist, depth and style of rifling, etc?  I bet there may have been some heated discussions arising from that.  Grin.

I'll also readily admit there are so many human induced variations in loading muzzleloaders (especially from a pouch, primitive measure and horn) that those variations may well and probably do contribute more to variances than harmonics.  This brings to mind something I first saw the International shooters do when loading in the 1980's, though the "chunk gun" shooters may have done it years and years before that.

Some of the shooters had long brass tubes with a brass funnel soldered to them.  When they put the long tubes into the bore of their gun, the funnel would stick out just a bit from the muzzle.  The theory was that the powder going through that tube would not mix with powder residue of earlier shots and you would get a more consistant charge at the rear of the barrel.  I know we don't do that on the primitive range and wiping between shots does close to the same thing. (These shooters wiped between shots and then used the long tubes to get the powder down the barrel.)  They swore it aided in accuracy, though I'm not sure how much it helped as the targets they shot at were 50 and 100 meters.

  

[rich pierce]

I will ask a simple question.  If I rest my flintlock over a log, on the bench, or against a tree, will it affect the shot?  If I rest it on the muzzle versus the forearm?  How much at 100 yards would ordinary weight of an average 9 pound rifle affect the point of impact?

[Dr. Tim-Boone]

Well, when I rest my flintlock against a tree it seems accurate enough to get the deer in my sights!! And I have more confidence than when I have to shoot offhand with no rest........... course I am getting a little old......

[jwh1947]

Richpierce, regarding your reasonable questions.  From my experience, I would answer "yes," "yes," and "a good minute of angle." 

[FL-Flintlock]

The simple answer is "don't know until you try".

It's going to depend on how the rifle responds both to the shot and to the applied stress when rested at various points.  The combination of rigidity of the barrel & stock combination will determin how much, if any, defelection will be caused by the static weight of the bridge length between the muzzle and butt.  If the barrel has a lot of flex to it, resting it on the muzzle may cause it to climb more or may prevent it from moving as much.

[Joe Stein]

The old timers used Roger Fisher's method of gaining accuracy: "
Also last thing would be to unbreach the B        lay the barrel in the spring muzzle downstream and let the evil spirits run out.  Must be at full moon on a clear night and best at midnite and better still if you visit the pow wow lady just before.... Wink" 

[Pete G.]

  In a perfect rifle barrel it matters not one wit where a bullet/load comes out along the curve of the waveform for accuracy purposes as it will always set up the same vibration and exit at the same point in the curve. 

..........assuming you have identical velocity from one shot to the next, which does not happen in the real world.

[Artificer]

Richpiece's question and jwh1947 and FL-Flinter's replies got me to thinking why some people have no faith in bench resting a rifle, be it a ML or a modern rifle.  I fully agree that resting a long rifle close to the muzzle would induce variations you would never see when using a ML in the offhand or almost any other position.   

I've bench rested modern and ML rifles for over 30 years all over the country.  I do it to see what the rifle is capable of shooting, as best I can figuring I'm still inducing some human error variables, but not nearly as many as shooting off hand.  With ML, it helps develop the best accuracy load, though I don't file and move the sights from the bench.  That is done from shooting it offhand. 

I've seen folks rest a muzzleloader near the muzzle when they bench rest it for accuracy.  Then they complain when their groups are different and way off when they shoot it offhand.  I've shown a number of people how to more closely simulate what a rifle will shoot from offhand, by how you rest in when bench resting.  But if one doesn't closely simulate in bench resting how the rifle is held in offhand, then you won't get accurate results from the bench.

What many people don't know is a rifle can perform better or worse by the pressures you put on it when you hold it.  If you grip a forearm on a long rifle too hard with your supporting hand, it will induce pressure on the barrel that will make it shoot less accurately.  FL-Flinter's example of only a couple pounds of pressure on a barrel bending the barrel applies there.

I have to admit I was extremely skeptical of how differing pressures on the forearm and grip could cause significant differences in accuracy in a rifle.  This was until I was an Armorer on The Marine Corps Rifle Team.  We built super heavy NM M14's with heavy barrels, double lugged and torque screws, and glass bedded them into walnut stocks that were so fat only a railroad tie placed along side them made them look "sort of thin."   (These are much more like the bench rest guns used in NMLRA shooting than long rifles.)  From our super expensive machine rest, all these rifles had to shoot a 10 shot group less than 2 1/2" at 300 yards before we issued them to Team Members.   Very VERY rarely, though, the rifles "wouldn't shoot" in the hands of a shooter, though. 

When that happened, we gave the rifle to "our living machine rest" MSgt Russ Martin to shoot and test.  He would apply differing amounts of sling, hand and grip pressure and could tell you EXACTLY how to hold the rifle to shoot the best out of it.  If Russ could not get the rifle to shoot, then we completely rebuilt the rifle - even though a couple of times we put the rifle BACK on the machine rest and they shot within the 2 1/2" group size standards.

OK, so how does this apply to ML's?  When I first got involved with the International Muzzleloading Team, I passed this information along to our shooters.  Yeah, most of them thought it was "Hocus Pocus" when I first brought it up.  However, one of our better shooters got to thinking about it and realized he had tried different pressures on his ML's to get a couple rifles to shoot better in the offhand without realizing it.  After realizing it, he tried different pressures on the fore end and grip on some of his off hand rifles and sure enough, it worked the same on ML's as modern rifles.  It even helped a couple of the flintlock musket shooters. 
 

[FL-Flintlock]

Artificer,

Resting the rifle near the muzzle doesn't "induce vibrations", the vibrations are induced from the trigger, lock, cap/primer (if applicable) main charge burn and movement of the projectile down the bore.  The vibrations run through the whole gun just like waves in a pan of water so vibrations induces by the lock reach the muzzle long before the projectile even starts moving and it may force the barrel above or below the nominal plane established with the barrel at assumed rest (yes, "assumed" because as stated before, everything in the environment that is above theoretical "absolute zero", 0° Kelvin/Rankine or -459.67°F, does induce some level of vibration/movement in everything.  In the real world, thermal energy induction and differentials caused by sunlight, breezes and the stock should never be discounted as they are the most likely environmental conditions to cause accuracy problems within the gun.)

Back to the point - any time you place a gun on a rest be it mechanical or human, you're inserting fulcrum points.  As the vibrations and annular pressure waves pass through the length of the gun, they're going to interact with the fulcrum points and how they react depends upon the conditions of each individual shot fired.  No two rounds, no matter how carefully prepared, are ever "identical", close but not exactly the same other than by pure random chance.  

As it relates to how you rest or hold a long rifle or modern rifle, the actions and reactions related to vibration and annular pressure waves follows the same lines.  The more the stock interacts with the barrel, the more variables you're adding into the equation and removing as many variables as possible was my focus during the development of Ultra-RVC.  Just as taking a barreled action from the stock and placing it in a machine rest can completely change the level of accuracy, it does little more than prove that mechanical interaction with the stock is very much real and thus the more the stock can be isolated from the action and barrel, the less negative affect it has.  

On a full-stock, and especially a long rifle, the variables of the equation are increased exponentially purely in relation to the length of both barrel and stock.  If we look back in history, many of the shooters using cross-sticks did so with a leather sling joining sticks and being the only thing in direct contact with the rifle - the same applies to what became known as the Creedmoor style of resting the stock/barrel between the instep and ankle as opposed to using a more solid rest; whether or not it was known at the time remains debatable but in effect the purpose of both methods was to help reduce the amount of vibrations being reflected back into the gun by using a rest that absorbs vibration and annular pressure waves.

The second point that is primary to long rifles are how the annular pressure waves affect accuracy because the barrels are normally pinned to the stock in multiple places throughout the length of the barrel.  When the annular pressure waves traverse the barrel, the stock is playing a key roll in the resultant outcome of how much and to what direction/angle the muzzle moves.

Third condition that is primarily associated with a long rifle is the actual barrel length itself.  Even a "hot load" pushing a PRB well in excess of 2,000 fps still has the ball in the barrel for a long time which, of course, gives the barrel all that much more time to move around before the ball exits.  On the other hand, the fact cannot be disputed that the PRB has considerable advantages over conical bullets because of its extremely small bearing surface and the nature of the patch to respond to the changes in the bore diameter caused by the annular pressure waves.  However, the affects of annular pressure waves on have on changing the plane of the muzzle before the ball exits cannot be discounted nor can the fact that the much lower frequency produced by black powder brings the vibration frequency created by the main charge much closer to the frequency of the annular pressure waves which means they do have a higher probability of combining to create radical changes in the muzzle plane which is why you'll hear people often complain about "that one d--- flier!" that has no other plausible explanation.

How it relates to ML's is that I've bedded several half & full-stock rifles and pistols with my flexible compound with very good results.  A full-stock I had, .40 swamped percussion, refused to shoot acceptable groups bench or free hand, after bedding the groups were more than acceptable and it didn't care if it was a sand bag or human hand under the forearm but nothing is a cure-all especially if there are other issues going on.

[Dphariss]

Frankly if the shooter does not take the time to learn how to shoot from the bench, not canting the rifle etc., take the time to work up a load, how to rest the rifle for best accuracy (depending on the rifle) he will not get best  results and may well think shooting from the bench is a waste of time.
MLs guns make bench shooting more difficult since moving from position between shots is the kiss of death in modern BR shooting. So ML shooters have to be very careful with positioning when getting behind the gun again after loading. Failure to do this carefully and uniformly will result in increases in group size.
If all this is done barrel harmonics will also be taken care of in mot cases.

From reading here and on other forums many shooters are not that concerned with accuracy anyway. They shoot large novelty targets at some "re-enactment" or perhaps never shoot past 50 yards at big game and if it will shoot 6" at 50 its good enough.  When with some work the same barrel may well shoot 1-2" at 100. But they don't care.
If you run dedicated rifle matches that require actually shooting well most "re-enactors" in our area will not participate. Just a fact. They don't know the history of rifle matches or the rifles used, how to shoot, care for the rifle so it will maintain it accuracy etc etc. They are, in too many cases, more concerned with how they look than how they shoot.

Dan

[Darkhorse]

Granted some of this talk is over my head (most) but everything said is still relative to my 40+ years of rifle shooting. And I've developed  methods that I use on every problem rifle and ML I build.
First, I absolutely love the BOSS system. It took over a year but my .300 shoots 3 shots into a measured .250 " and after a cool down will put subsequent shots into the same hole. This is plenty good for a sporter weight hunter. Wherever that majic point in barrel harmonics is, this device allows a dedicated shooter to find it. We won't go into my load prep for these tests here.
So that proves  there is something to the harmonics issue. I just don't believe it affects ML barrels to a great extent.
After bad experiences with wood and humidity I seal every spot I possibly can on my ML's.
All my pin holes in the lugs are slotted and larger than the pin to prevent binding when the barrel gets hot or the wood possibly warps.
I must get cheap maple cause it always trys to warp down the barrel channel when wood is removed. So now I plan for this and try to leave enough inside and out to cut it out instead of bending the stock to pin the barrel. Bending the end of a stock can't help accuracy. Though I have one .54 that must be bent everytime the barrel is taken out and replaced and it has'nt seemed to hurt accuracy in the least.
This last may be blasphemy but I open up the mortice in the bottom of the barrel channel and a little up the sides, then glass bed the barrel with Accra Gel. I think it helps stabilize the wood and it makes me feel better.
And since I don't put a 24X scope on these flinters to check out the true accuracy all this is probably a moot point anyway.

[Artificer]

Good post, Darkhorse

"All my pin holes in the lugs are slotted and larger than the pin to prevent binding when the barrel gets hot or the wood possibly warps."

This actually helps keep down negative nodes of vibration as well as for the reasons you mentioned.

[Artificer]

I agree that most reenactors shoot very little or almost none at all and that is from French and Indian War (though not as much in that time period) through Civil War reenacting.  I've always thought that was a real shame and they were missing out on something fun and a real learning experience.  Also, how can you be as authentic if you have never shot live rounds in your period arm and don't know it's accuracy potential and how best to use it?  

When I was doing Continental Marine or an Early Trader/Free Trapper impression at Historic Fort Wayne (1812 period) - I knew exactly how well my Brown Bess Fusil (Carbine) shot and what it was capable of shooting - even with swan shot.  I competed with my flint longrifle so what I carried that at reenactments, I knew how it shot as well.  Heck, I even did some trapping so I knew something about that and wouldn't sound like a fool when I talked to the public.  When we did Brush's Company of Militia (1812 period) there and right after I got my Charleville Musket, I went out and shot it with live rounds.  I never shot it as much as my Bess, but I knew where it hit and what it was capable of doing.  

When I was doing Confederate Marine, I not only shot the two band Enfield rifle I carried for accuracy out to 200 yards, but actually shot a full 40 rounds one afternoon on the 100 meter range with the service minie' ball and 60 grain charges.  Bruised my shoulder pretty bad and it hurt bad for a couple days, but I KNEW what it was like to have shot a "full issue" of service loads.  Never, NEVER did that again, though.  Grin.  When I commanded a Confederate Infantry unit, I shot my Colt revolver a good deal to know what it was like and actually practiced the sword manual often with my built up/restored Model 1851 foot officer's sword.  

I've also seen on the opposite side.  I wish we could get more shooters interested in reenacting.  

At the NSSA Spring and Fall nationals for over a quarter of a century, I often heard comments about reenactors never firing a live round.  These were by guys who dressed up in Polyester "Gas Station Gray" or  "Blue Light Special Blue" work clothes with stripes and stuff sewn or stuck on them.  (I have to say the NSSA went to strongly encouraging authentic civil war clothing in the late 90's and early 21st century and most shooters now do dress pretty authentic.)  When I heard that about reenactors, I would ask them how many times they shot their rifle muskets with standard 60 grain powder charges.  Most of them had rarely if ever shot a service load as the charges they were using were around 30 grains.  When I told them I was a reenactor and had shot a full 40 rounds with 60 grain loads in a couple hours, they were a little embarrassed.  Some would say, "Yeah, Gus, but you're DIFFERENT."  

Innternational Muzzle Loading shooters shoot both original and reproduction long rifles and other rifles, muskets, fowlers, shotguns, revolvers and pistols and only a few of them re-enact.  They have found some very interesting things out, especially by shooting the originals, that really adds to our knowledge .

Back to longrifles, only.  Personally, I don't care how a person who buys, builds or has a long rifle built for him/herself uses the thing.  I'd like to see the person shoot it and reenact with it if they are so inclined,  but even if they only buy an authentic rifle to hang over the fireplace - that's one more rifle out there.  Maybe the next owner will shoot it if the current one doesn't.  What is important is that with each new long rifle built, we keep or have more builders entering and continuing to build the rifles.  It not only has kept the tradition alive, but those of us who have been around since the 60's or 70's have seen an incredible increase in parts and pieces that we only could dream about back then.  The advances in recreating some incredible pieces in these years has been dramatic.  So whatever  keeps things going and improving on longrifles, it is a blessing to anyone who is interested or will become interested in the future.

OK, I'm hopping off my soap box now.  Sorry to have gone astray from the subject.  

[Darkhorse]

Forgot the "benchrest" issue in my earlier post.
Many years ago we had rifle, ML and shotgun competitions at several gun clubs across central Georgia. These shoots got quite competitive with ex-servicemen plus members of the Special Marksmanship unit at Ft. Benning often attending.
I was young and could only afford a Rem. 788 with a birch stock. I rebuilt the trigger assembly and floated the barrel and sealed the whole thing. The barrel was floated to the point where in 4 position shooting with a tight sling the POA never changed.
I did all my sighting in off a solid benchrest. Experience proved that I could then go to any position with or without a tight sling and if I did my part the rifle would shoot X's all day long.
All my eastern and western hunting to include several shots in excess of 400 yards all proved the same thing.
Same with my flintlocks or caplocks. I shoot a lot of squirrels with a .40 flint and all I go for is head shots. It doesn't matter if it's offhand, over a limb or against a tree. And the rifle is always sighted in off a bench.
It was only after I started participating in forums did I realize some folks couldn't achieve the same results. I just don't understand it with a good set up weapon.
I had excellent rifle training early on. All I can say is some of these people might need to get some of the same.
From my limited point of view either their techniques and rifles need a tuneup or they just can't shoot as well as they think.
Is there something I'm missing here?

[PeterB]

Lots of good points here. I remember Lt Billy Anderson attending a centerfire bench shoot and a fellow lent him a gun and showed him the load to use (he rolled his own for the shoot). Billy simply said after that he followed the usual shooter's routine like putting little head pressure on the stock, etc. Yup, he won...and set a world record. The gun owner said he didn't even lend him his best gun. So knowing how to shoot is extremely important.

Centerfire guns are often free floated. As a custom gun maker, I never liked doing that, but my best gun made use of harmonics in anunusual way. There were two points of attachment to the stock at the barrel half way point which were variable in pressure bymicrometer adjustments. Through experience, the best accuracy was 9 clicks of pressure. This would be applied each time I shot the gun since moisture would change the pressure in between shootings.

Now a M/L barrel has many attachment points so this complicates the matter. These all change the harmonics of the gun to a point that would be hard to calculate.

One other point. Wood can significantly change points of impact due to moisure gain and loss. It is likely less important in M/L's since it is much thinner, but it is a good idea to lessen the change. Be sure to apply finish on the interior areas of the wood: barrel channel, under the lock, screw holes, interior of the patchbox, under the butt plate, etc. Another matter is the resistance of various finishes to moisture intrusion. Frankly, Linseed oil is $#@* for this point. Government tests rate its resistance at 15% while Tru-Oil which includes Linseed Oil in its formula is rated at 75%. That is 5 times better. Just a point to keep in mind for your next project. The two look a lot alike when finish is applied.