Proofing barrel only for accuracy?

[beleg2]

Hi,
I want to try some barrels I have for accuracy without having to make a rifle.
I plan to make a breech plug/adapter to fire it with an underhammer action.
I would like to see pictures and description of some feature to do it.
One member did it some time ago IIRC.

Thank you very much for your patience and advises.
Martin

[Acer Saccharum]

If you look up Hugh Toenjes posts in the 'for sale' section, he has had a number of barrels for sale, showing targets, and talked about the machine rest he used to test the barrels.

[Dphariss]

Hi,
I want to try some barrels I have for accuracy without having to make a rifle.
I plan to make a breech plug/adapter to fire it with an underhammer action.
I would like to see pictures and description of some feature to do it.
One member did it some time ago IIRC.

Thank you very much for your patience and advises.
Martin

Waste of time. Set it up with the under hammer action and shoot it before completely finishing the gun.
How the barrel shoots in some fixture may be far different than how it shoots in a gun.
Barrels can be very particular in where they are rested etc so shooting one on a fixture is more hype than fact at least in some cases.
The percussion system used and the brand of caps can be a factor for example. Minor differences in how the charge is ignited from shot to shot can cause different points of impact.
Dan

[beleg2]

Thanks Dphariss.
Just want to have a proof of accuracy potential the same way I saw Hugh Toenjes did.

Martin

[msw]

At the risk of FtDH (Flog the Dead Horse), I think Dan got it in one.  Remember that this is, at the end of the day, a resonant mechanism, and that the vibrations of the barrel will be effected by any of a number of factors, including (f'rinstance) where the lugs are placed, and how snug or loose they are in relation to the stock.  Also where the sights are placed (and what they weigh) and where the barrel is breeched (and at what tension) and where the touch hole is located, and what kind of flint is used or what brand of percussion cap, and that's why, with a given rifle, if you change any of the nodes along the 'string' (in this case the barrel) you will make subtle changes on the rate of vibration and therefore in the downrange strike of the projectile.

Put without the technospeak:

save your bucks, man, use the extra money to buy more powder, and then go down to the range and burn the powder:

make good smoke!

(just one guy's opinion)

[LRB]

   What you're saying makes a good argument for full length glass bedding.

[Acer Saccharum]

I believe if a barrel won't shoot well at all, it will show up in the jig. It will probably get worse when aimed by hand.

Good point, Keith. Keep us on track.

[beleg2]

Thank to all for your advises.

I will try an intermediate option fixing the barrels to an underhammer action and setting a scope.
I have some barrelsrifled on the same machine but some of them looks better that the other so I would like to know if I can see those differences on the target.
Just want to see their potential.
I will post results on "over the fence".

Thanks
Martin

[Acer Saccharum]

Beleg, I am interested to see your results. These are barrels you rifle yourself?

Tom

[beleg2]

Hi,
No they were rifles by my friend Saverio Bonazza, the man that introduce me to muzzleloading.
I have plans to make a rifling machine someday.

This is his rifling machine that have not been in use for 4 years after he pass away.



Thanks again for all helping and interest.

[Roger Fisher]

The sweet spot the sweet spot, very important in more ways (and activities) than you may think

i/e the sweet spot where to rest the rifle when shooting from a rest (or chunk) mine happens to be 11 inches from muzzle on chunk gun and just behind the center pipe on my offhander...   Harmonics I do believe.

[Dphariss]

   What you're saying makes a good argument for full length glass bedding.

This is not true either. If anything it is an argument for 1/2 stock or no forestock at all as in ML slug guns.
The rifles built as pure match rifles by 1850 or even before often have no wood forward of the lock. See
http://www.shumwaypublisher.com/store/shop/item.asp?itemid=12&catid=4
And Ned Roberts "The ML Caplock Rifle".

Putting a barrel is a jig and shooting it will show if its bad or not, it will not necessarily show if its good except when shot in the jig exactly as it was originally shot in the jig.
If a barrel is made a uniform material, has uniform internal dimensions, has a uniform or slight gain twist and is not excessively stressed when the machine work is done, or if stress relieved afterwards it will likely shoot fine.
If the barrel has a variation in bore dimension or a twist that slows at the muzzle it may not shoot very well. Guns shooting bullets are really bad about the "reverse gain" twist at the muzzle and its something really serious shooters in the modern world check for.
Putting a barrel is a jig or something like Pope's V rest may change the harmonics of a barrel with bad stresses and cause it too shoot much better than in a stock or rested in just one spot on the barrel.
HOWEVER, it is possible to experiment and find the sweet spot where the barrel likes to be rested and this may  produce almost magical results. The clamp on/bolt on muzzle rests on dedicated bench guns are not usually put on by guess and by golly. They are put on at the spot that produces the proper harmonics for best accuracy. This is done in several ways experimentation at the range is one and the most obvious. I have read of slug gunmakers clamping the breech of the barrel in a vise, spreading powdered sugar on the top flat them striking the barrel to set up vibrations. The pattern formed by the sugar would determine where the rest should be installed.
Controlling/changing/understanding the harmonics of a barrel is just part of the game.

Dan

[jwh1947]

Ole, Martin, I submit my comment only as a personal opinion.  I go with the guys here that suggest that it may be an exercise in futility.  Once put on the gun, then, believe me, you can 'tweak it" if necessary.  I can show you a picture of a simple hand cranked pressure machine at Springfield Armory that was used to straighten M1 Garand barrels.  They used their eyesight and a bright light, bounced into the barrel where they could see shades of light where there were "bends."  They straightened them to USGI tolerances.  Also, period gunsmiths in 1800's used a thread run through the barrel to gain the same  visual control.  Once you apply the barrel to the gun, the harmonics are different.

I am no expert on any of this.  Just one who has straightened barrels with a leg vise and a USGI barrel wrench ( OK, yes, and a shot of Rakija  ).  No joke.  They work fine. 

Hope all's fine in Argentina.  We appreciate some foreign input on ALR.  I want to know more about hunting and fishing in your country.  Pura Vida, Wayne