Powder Coated Bullets and Load Data

[gman]

I'm just curious as to why some have mentioned the need to reduce loads 4-5% when swapping from traditional lubed cast bullets to pc'd bullets. I'm loading same powder charges with the powder coated versions that I was using for the lubed versions. I do see a gain in velocity but also accuracy is either just as good or in some cases so far better. Have any of you experienced any problems or seen anything that makes you say this? Always open to learning.

 

[Ian]

It's only a problem if the gain in velocity is a problem. Examples are subsonic, suppressed loads being pushed supersonic or an accuracy node being overshot by the additional velocity. If you want your MV to stay the same and the only change being made is the switch to PC from traditional lube, a ~5% reduction in powder charge is in order for starters, particularly since with any significant component change the powder charge should be taken down to near starting load data and reworked anyway.

 

[fiver]

that covers it for me too.
there's nothing dangerous really. [the speed comes from the slippery of the coating]
the 4-5% drop just brings the velocity back inline where you had it before.

 

[gman]

Okay. I understand backing off to try to keep velocity equal. Just wanted to make sure I was not missing something I should be noticing.