Problem rifle

[Kurt]

Change the firing pin and load 50 rounds in Jamison brass, see if the groups hold then.Then pull the breechblock and make sure there's no primer/brass material building up in the firing pin hole/bushing.

Don,

I was hoping you would give me the secret pass word to get past Henry the Gremlin that keeps pushing the bullets out of line when I shoot.

I have so much brass for the 2.4 now that I could sell it for scrap and pay for the CPA
I did pull the pin and made sure no brass or crud was in the channel before I put it away last night. It was clean.
How are you getting along with your 2.4? don't hear you mention it.
I didn't want CPA to use their reamer after I looked at their print Gail sent me so I had one made. Might be a mistake but it will be my mistake if I made it wrong.

[Lumpy Grits]

Kurt-Have you 'sluged' the bore ck'n for tight or loose spots on the bbl you now have mounted?
Also-How much clearance do you have from the front of the rec'r, to the back of the forearm?
Gary

[Don McDowell]

Change the firing pin and load 50 rounds in Jamison brass, see if the groups hold then.Then pull the breechblock and make sure there's no primer/brass material building up in the firing pin hole/bushing.

Don,

I was hoping you would give me the secret pass word to get past Henry the Gremlin that keeps pushing the bullets out of line when I shoot.

I have so much brass for the 2.4 now that I could sell it for scrap and pay for the CPA
I did pull the pin and made sure no brass or crud was in the channel before I put it away last night. It was clean.
How are you getting along with your 2.4? don't hear you mention it.
I didn't want CPA to use their reamer after I looked at their print Gail sent me so I had one made. Might be a mistake but it will be my mistake if I made it wrong.

Haven't shot my 2.4 since the last 1000 yd target at Raton. And during that little affair, fired 8,9,10,10 in sighters 10,10,x in score, and then the wind went to pot and never got back on target. Other than that pretty darn good.
Fired back to back x's during the 1000 at Byers, but the guys pulling the target goofed around so darn long pulling and marking , we lost the mirage and the wind switched, but the score was still decent.

[laowho]

This is fascinating stuff. What an opportunity into what makes a rifle tick. Somebody needs to come up with a "rifle resonator." What about trying some Finite Element Analysis on it? I know some have done it but don't know how the program works. For example,

"POWERFUL TOOL.... This analysis was done with the LS-DYNA Finite Element Code. This software is a very powerful tool for analyzing the dynamic and static loading of structures. It was used here to calculate the rifle's response to the high pressure gas that forces the bullet out of a barrel when it is fired. For early calculations, the breach end of the barrel was fixed in space which treats the barrel as a cantilever beam. The results showed that a more complex model was required to capture the dynamics of the complete rifle. There is a vertical plane of symmetry in the model and only motions in the vertical direction are calculated. In the movies on the Barrel Dynamics Page, the displacements are greatly amplified so that they can be viewed."

http://www.varmintal.com/alite.htm

It's the "more complex model required for dynamics of complete rifle" that pertains here. Maybe there is some such? "Dynamic" element analysis? But things would still be abstracted. Or maybe a quick test could be conducted with an inexpensive tuner? Otherwise, I'm trying to imagine the entire rifle fired while encased in gelatin to preserve/observe trace anomalies. A portable EMG device?

http://www.omicsonline.org/2161-0533/ima...7-g001.gif

LOL. Just babbling.

[Kurt]

laowho
When I shot bench rest and small bore silhouettes we used to make barrel donuts to tune the barrel harmonics and they worked for tuning the barrel vibrations to reduce groups by fraction of an inch. I never made one for a black powder rifle to see just how much of an impact it would have. But you can do just about the same thing when you use cross sticks where you place the barrel. It's not hard to find the null in a powder rifle and some place the sticks where the null is, but I don't think that is the full answer. Sometimes just sliding the barrel for or aft from the null shows a improvement.
One wouldn't think at the low pressures of black powder in the heavy barrels 1" thicker or more it would show up. But it does.

[laowho]

Kurt, The null point and barrel harmonics are 2 different things, and the tuner doesn't apply to the null point as far as I understand it. When I was reading up I found a lotta confusion over what constituted nodes and what these represented. More often than not people confused the null point with the type of FEA being conducted, but FEA was strictly linear when it came to harmonics, and so others developed OCW and OBT to account for fuller harmonics dynamics. But if you say that cross-stick "null"ification approximates what the tuner accomplishes, I'll have to take your word. That said, I'm not suggesting that it's strictly a barrel harmonics issue. Hardly. I was only half-heartedly suggesting that it would be an affordable 1st step wh/ might possibly eliminate the barrel as an isolated factor. Maybe? Just thinking out loud, and still somewhat in awe of all that's going on. Will be following this eagerly.

[rdnck]

It's not the barrel. This rifle is on its third barrel. Something else is causing the problem. Shoot straight, rdnck.

[Don McDowell]

100 Jamison brass, and if that doesn't cure the problem I'll buy all 100 of those brass from you.
Still would change the firing pin and make sure there's no burrs etc. bothering the pin.

[laowho]

Yer right rdnck. Even if we're talkin about the complete rifle harmonics, and not just the barrel, managing to tame it w/ a tuner/de-resonator still wouldn't diagnose/identify a problem elsewhere on the rifle. I remember reading this a while back

http://www.thehighroad.org/archive/index...31949.html

General consensus was that bedding was required, tho some found as simple a thing as screw torque was the culprit, and barrel rub. Don't mind me fellas--I just like lookin into things.

[Ironramrod]

Did this rifle ever take a fall off a bench, car hood, or whatever onto a really solid substrate (e.g. concrete) in the past?