Bullet surface finish & how this can affect given poi

[Northridge]

Has anyone ever performed a bullet drag test in regard to jacket surface finish on a bullet at 1000. Yards? Example does a smoother finish hit at a different point on paper than a rougher finish? Does general body oils affect flight of bullets vs say a bullet with less hand oil or no had oil from general reloading. Does a bullet fly different that has Ben wiped with rubbing alcohol or some other general degreaser. Does one powder residue bond to a given bullet in ignition more than another perhaps affecting its given flight path or not?

Shawn williams

 

[6MMsteve]

Time for the experts

 

[Canadian bushman]

It does make a difference, but its so small it would be near impossible to isolate all other variables to the point where you could quantify it.

It would have to be a pretty rough finish to trump things like, bearing surface and meplat deviations.

When i was turning my own solids i played with it a little, but i was more focused on avoiding finish problems then i was trying to quantify them. I found as long as the finish was under about 40-60RA most finish deviations made no difference.

 

[Laurie]

The Dyer 308 'HBC' 155s used to have a really dull, rough looking surface finish when they were made in Australia. Presumably, unlike Bergers etc they weren't tumbled to polish them up after they came out of the form dies. They shot to 1,000 yards in FTR as well as anything from other makers, and were exclusively used by the Australian 'Target Rifle' national team with great success. I reckon drag factors are 99.9% the result of shape not surface finish - the rifling marks engraved on the shank will have a greater effect on drag.