AB Doppler PDM

[jaybic]

Hello,
Recently I was fortunate enough to shoot a PRS match in WI where the folks from AB had their Doppler there to do PDMs for folks and I had mine done. It is for a 6BRA shooting a 105 hybrid at 2880(2860 by my V3). It left me wondering a few things. The tube had about 1900 rounds on it when I did it.

1: as the barrel round count goes up and it begins to loose speed, do I need to add powder to offset that or will it the PDM essentially "fall out of tune" if I dont? Sorry to put my ignorance on display but I am not quite sure how to manage this for best results.

I also just put a brand new barrel on and am going to the GG in TN and am going to do this one as well. I was told that the ideal conditions to do the PDM is a brand new barrel with 200=300 rounds on it and then buy enough of one lot of bullets to shoot the barrel out(which I did....3k of them) Thoughts or insight on this topic is very much appreciated.

Thanks,

Jamie

 

[azred33]

I will defer to wiser minds, but I understood that a PDM is a measurement of the bullet's efficiency/trajectory as shot from your rifle. As your barrel changes most of the effect will be on muzzle velocity and that is trued with the Calculate MV function. I believe that anytime you see shots not lining up with the device's solution, it is time to re-true with Calculate MV. A new barrel would certainly change the gun and would require a new Calculate MV.

 

[jaybic]

I must admit, I would have thought there would be more info and opinions on this topic. oh well, thanks anyway.

Jamie