New project: .177 slug gun

[bandg]

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[Ribbonstone]

This is the trap I think I fell into.

Finding that one that would shoot Piledriversmake me think there had to be a "secret" even thought it's a simple old QB78 barrel (askinny version from the 78S).   If there is a "secret:, it's not twist rate.diameter, coke (or lack of choke), length, velocity, bolt probe shape, probe length, or anything else I can measure.

The "trap"was that it made me ignore the 13-14 rifles that didn't shoot them well as if they were the "freaks" rather than that single example being the "freak".

Not the only time there was the occasional test result that defies all the other results...a "one off".

Not that all of the others were totally wild....some were (tipping and KeyHoles) while others just shoot poorly (but with round holes).

JUst like there is no "perfect"pellet that is a 100% sure bet to shoot well...evidently there is also no "imperfect" pellet that doesn't have some rare rifle that will shoot it.

For what it's sorth, on other froums, when H&N reannounced the Piledrivers, Harry bought up a stash in Austrailia from the orginal UK based company that introduced them.  Have no clue if H&N changed diameters or other features, but he was getting much better results with the originals that I ever could(but Yarrah has both skills and some very nicely tuned up airguns).

[skorec]

 Can someone put 21 gr Piledriver put in to Kolbe's calculator with TR: 1:17,7”.
I can not understand why the grouping is better at 980 FPS then at 850 FPS.

At bought velocity I have the same flyers ( 20% 2-3*MOA flyers )

[Motorhead]

Can someone put 21 gr Piledriver put in to Kolbe's calculator with TR: 1:17,7”.
I can not understand why the grouping is better at 980 FPS then at 850 FPS.

At bought velocity I have the same flyers ( 20% 2-3*MOA flyers )

My WAG is a faster spin rate of the projectile and the stability it provides when shot at the higher velocity.

[rsterne]

NOE made the shorter version and they even have some with a HP.... 24 gr. FN or 22 gr. HP....



Bob