Getz barrel harmonics?

[volatpluvia]

I had a Getz golden age barrel, 42 inch 'c' profile in .54 caliber.  It was pretty thin at the waist.  I couldn't bench it on the sand bags.  If I laid the upper forearm on the bags it shot a round pattern not a group.  If I put the lower forearm on the bag it disbursed the shots vertically.  I had to cradle the lower forearm in my hand and lay MY forearm on the bag, then it would shoot a nice group.  Don said this should never happen.  I shot it mostly at informal shoots and did get to hunt one season before ecnomics forced me to sell it.  I did not need to bench it, and it shot well offhand.  Is this harmonics?
León

[Mike Brooks]

I would say you had a pin that was in a bind. That being said, I have never shot ML well off the bench untill recently. It's a learned skill and is harder than it seems it should be.
 I could tell you my own similar stories to yours and how I fixed the problem but I'd have to bring in modern guns so I guess I won't go there.
 A "C" weight barrel in .54 is going to have alot of whip and will be difficult to shoot off of a rest.

[Chrisweiler]

Mike

I would say you had a pin that was in a bind.

Mike could you explain this a little further, any advice on how the pins/lugs should be fitted into the stock?

Thanks

[rich pierce]

I'm no physicist but it seems to me that barrel harmonics could be a different issue from a barrel that is simply "bent" when rested on a firm surface.  Let's say a barrel was thin enough that when anchored at both ends, pressure in the middle could deflect it.  Anyone who has tried to turn a long thin rod on a lathe should know this happens.   The tool pushes as well as cuts.  If this happens with a thin walled barrel rested on a firm surface because of the weight of the gun and pressures put on it during shooting, we might be able to leave aside "harmonics" which is vibration at some level, and actual bending which would vary shot to shot depending on exactly where on the forearm the gun is rested and varying handling pressure shot to shot.  Throwing this out there as an idea with very little knowledge of physics behind it.

[Joe S.]

did you try putting your bags as close to the breech as possible right up to the trigger guard?another bag at the toe to level if off?Leave the barrel from the middle out to the muzzle free and see how it shoots.

[Mike Brooks]

Mike

I would say you had a pin that was in a bind.

Mike could you explain this a little further, any advice on how the pins/lugs should be fitted into the stock?

Thanks

Lugs must be slotted and the pin must have free travel in the slot. also the wood must be removed forward and aft of the lug so it won't bind either.

[little joe]

I was always told by some of the old timers that harmonics was not a problem in muzzleloading.  Could we have created a problem by going to thinner and radically swamped  barrels. The demand today is for skinny, lighter barrels, as that is the demand today.

[hanshi]

Interesting post.  After thinking about it I believe swamped barrels have been just a little more difficult for me to bench than straight barrels.  Now this is mostly inconclusive as I've not kept any records.  In general, I've found longrifles to be exceedingly difficult to bench; the exact opposite of my experience with suppository shooters.  I've been to the range any number of times and disappointed with bench results, simply sat on a stool and shot freehand to much greater success.

I've removed all my barrels at least once and verified the lugs were slotted.  If one was suspect I used a wire saw to open it up.  A lot of the problem, I know, rests with these 70 year old eyes.  I am having real problems with cataracts.  It's probably more the result of the perversity of our universe than anything else - humor me.  That's as good an explanation as any.....   

[smylee grouch]

There are times when a person thinks his gun just won't shoot or group well when in fact it might be hisbench shooting technique causing some of the problem. There are some bench shooting procedures for shooting a group and different ones for sighting in. Consistency is of course the number one factor in both methods. Gun placement on the level bags is another. Recoil coming straight back as much as possible will help too.

[Mike Brooks]

In general ML's have too much drop for me to shoot off the bench, or for that matter off hand too. My ML squirrel rifle has 3" drop at the heel and it's a real bear to bench, and shoot off hand as well. I just can't shoot well with my head sticking way up in the air with nothing to firmly cheek. The latest "Game Creepers" rifle I built for myself has 2 3/8 drop at the heel and shoots well benched and off hand...or I should say "better" instead of "well" as I can't see well with out glass anymore, but it is at least comfortable.

[smylee grouch]

Shooting a rifle with a lot of drop off the bench can cause extra problems for sure. I have seen shooters shoot those guns canting more than with a straighter stock. Even just a tiny amount of cant will throw your shots high and to one side and you won't even know why thinking it's just a flyer or some such. This will be exaggerated the farther out the target is.

[Dennis Glazener]

I suspect this will open a can of worms but I thought "harmonics" in regard to a barrel, would be its oscillation (barrel whip) caused by firing.. To me the harmonics, as long as consistent, would have no bearing on the accuracy (repeatability) of a rifle. If something caused the barrel to put off inconsistent oscillation it would, in theory cause the bullet to exit the barrel slightly different than it did on previous shots. The barrel pin problem that Mike mentions certainly would affect the oscillation of the barrel as would firing with differing positioning of the forearm on a sand bag rest.

We are talking very small differences in barrel movement and it would certainly take an extremely accurate rifle/rifleman to notice the difference.

Maybe some math whiz could tell us how much certain movements at the muzzle are magnified at say 100 Yards all else staying the same. Its simple math but I don't have enough fingers and toes to figure it
Dennis

[Mike Brooks]

I suspect this will open a can of worms but I thought "harmonics" in regard to a barrel, would be its oscillation (barrel whip) caused by firing.. To me the harmonics, as long as consistent, would have no bearing on the accuracy (repeatability) of a rifle. If something caused the barrel to put off inconsistent oscillation it would, in theory cause the bullet to exit the barrel slightly different than it did on previous shots. The barrel pin problem that Mike mentions certainly would affect the oscillation of the barrel as would firing with differing positioning of the forearm on a sand bag rest.

We are talking very small differences in barrel movement and it would certainly take an extremely accurate rifle/rifleman to notice the difference.

Maybe some math whiz could tell us how much certain movements at the muzzle are magnified at say 100 Yards all else staying the same. Its simple math but I don't have enough fingers and toes to figure it
Dennis

I agree mostly. Probably most inaccuracy with a ML with open iron sights is due to sighting errors and slight variance in powder charges/loading procedures than barrel harmonics.

[Bob Roller]

In general ML's have too much drop for me to shoot off the bench, or for that matter off hand too. My ML squirrel rifle has 3" drop at the heel and it's a real bear to bench, and shoot off hand as well. I just can't shoot well with my head sticking way up in the air with nothing to firmly cheek. The latest "Game Creepers" rifle I built for myself has 2 3/8 drop at the heel and shoots well benched and off hand...or I should say "better" instead of "well" as I can't see well with out glass anymore, but it is at least comfortable.

Another reason to take a closer look at the fine English rifles both flint and percussion.
I don't think I've ever seen an English rifle with a radical drop in the stock.
The game creepers gun is a good idea.

Bob Roller

[nosrettap1958]

Not really much of a sample size to discuss 'Harmonics' of barrels but commenting on that same train of thought your specific barrel being a 'C' weight 54 caliber just has too much whip in it.

Anyone else that has a same weight and caliber barrel experience the same problems?

[smylee grouch]

Excellent observation Bob and on e I agree with for sure.

[volatpluvia]

Barrel whip sounds more like it.  The barrel really was thin at the waste.  Maybe I should have taken it to Sedona, Arizona.  The beautiful people think it is the place of harmonic convergence of the Universe, haw, haw!
The rifle shot so well off hand that I really saw no need to bench it.  I just thought the whole thing interesting.  And I had not slotted the lugs.  I thought the larger hole though the lug than the pin would be enough.  Apparantly for offhand it was.

[JCKelly]

Just a fairly ignorant thought - have you considered violating all muzzle loading ethics and glass bedding the thing with something from Brownells? Don't tell & maybe no one will ever know you did it. Wonder if that barrel might maybe vibrate a bit less?
Just wondering, can't quote any experience.

[smallpatch]

We are taught so slot our lugs, and the wood around them to allow for barrel/wood expansion differences...... so how would glass bedding help all that?  Especially with a swamped barrel.

[bob in the woods]

My .54 has a 42 inch C weight swamped barrel and is exceptionally accurate. I use it in matches, both off the log and off hand . Never had a problem with "harmonics"   as long as I find the "spot" to rest the rifle , as well as the load it likes the best.

[Hungry Horse]

I personally have never seen an antique rifle with slotted lugs unless it used barrel keys, instead of pins.

  Hungry Horse

[Marcruger]

My personal opinion is that just about any BP powered rifle needs a different technique - muzzleloader or BPCR.

I think it is due to how slow the lead moves down the barrel in relative terms. 

That slow velocity allows the rifle to jump and whip before the ball leaves the barrel.

The solution I have found is to hold the forearm tight, and lay the back of my hand on the front bag.  My other elbow is tucked down into a big beanbag I have.  That gives me steady aim, but with the rifle itself touching nothing but me.  I recoil with the gun, and it seems to print to the same POI as offhand.  I hear that folks with hard kicking rifles like English double stopping rifles do the same.

I hope this helps.  Marc

[Daryl]

My personal opinion is that just about any BP powered rifle needs a different technique - muzzleloader or BPCR.

I think it is due to how slow the lead moves down the barrel in relative terms. 

That slow velocity allows the rifle to jump and whip before the ball leaves the barrel.

The solution I have found is to hold the forearm tight, and lay the back of my hand on the front bag.  My other elbow is tucked down into a big beanbag I have.  That gives me steady aim, but with the rifle itself touching nothing but me.  I recoil with the gun, and it seems to print to the same POI as offhand.  I hear that folks with hard kicking rifles like English double stopping rifles do the same.

I hope this helps.  Marc

Exactly!!!!!!!!!!!spot-on Marc.

[little joe]

At our local club we are limited to 25 and 50 yd matches. Several mos. ago I won the match with a couple 48,s and several x,s felt pretty good for this old man. The next mo. mt targets were so bad I did not turn them in. Same gun,same load,ball,patch and light conditions. It was not the gun so I started looking at myself and the problem was how I was using the bench. To often we blame our weapons when the problem is ourselves and how we apply ourselves, mentally and physically.

[nosrettap1958]

The first thing you do when you buy a new rifle is find out how the rifles performs. Clamp it down or rest it over sand bags anyway you want to do it but you have to take yourself out of the equation as much as you can when 'sighting in a rifle.' After 'working up a load' then you find out what you can do with that rifle.

No two rifles are the same.