Lubed pellets vs velocity spread

[Scotchmo]

After reading some of the other thoughts and experiences in this thread, I did some more testing. It's looking like it's not necessarily the lube that is causing the variation in velocity. It's looking like it's the head size that is the primary determination with the lube possibly making it more obvious.

I have a pellet sizer that can improve some batches of pellets. The un-sized pellets w/lube did not show the large velocity spread. But they did not really show much accuracy improvement either. Only the sized pellets have a very noticeable increase in accuracy.

I can reduce the average head size further by tumbling, but I already discovered that too much and velocity varies more and then accuracy degrades fast. I already ruined one large batch of pellets that way after tumbling for 17 hours. They had no friction going into the sizer so were way undersized. They pushed through the barrel with only light resistance.

The latest batch is tumble cleaned in light dish detergent for an hour. Then rinse/dry/lube/size. The sizer seems to run smoother if I lube the pellets before sizing. And then I use no additional lube after that. They still seem accurate and I'm getting a fairly tight velocity spread. But I have not shot all that many yet. I've got to prep enough for the upcoming Oregon match (leaving in two days).

I'll need to reevaluate again after I make/install a light weight hammer.

[nced]

I tested lubed pellets for accuracy in a single gun a few years ago but results were indeterminate. Since then, I have occasionally run strings of lubed pellets over the chronograph in the garage but always experienced velocity spreads that were 2x or 3x times as great as unlubed pellets. A tight velocity spread is an easily measured value that translates to better accuracy for far shots, so the poor velocity spreads in the lubed pellets caused me to investigate no further.

I'm currently working on a new gun and have been getting minor/moderate shifting in poi. I'm shooting CPH 10.5gr@900fps and had read that they are the most likely to benefit from lubing. I already determined that weighing and sizing gave some small accuracy improvements. I decided to once again try lubing.

Velocity spread of the lubed CPH was disappointing, but I decided to go ahead and do an accuracy test. My backyard range is 25 yards so velocity spread should not affect it too much. I did not have a lot of time, but initial accuracy tests showed a significant improvement over unlubed pellets. No wandering poi over a string of about 30 shots.

I shoot field target so need accuracy out to 55yds. I calculated the vertical poi variation from the increased velocity spread and determined that the accuracy improvements should more than compensate for that. I've got an FT match tomorrow, so I'll be able to get a better test at all distances.

If it proves out, I'll work to figure out how to reduce the velocity spread in the lubed pellets. That will likely involve a lighter hammer.

Interesting! I lube pellets for my spring piston .177 cal R9 & HW95 simply to reduce bore fouling when shooting the hard lead die marked and dated boxed Crosman Premiers, however I could detect no difference in accuracy or velocity if lubed or unlubed. Well......I use Slick50 OneLube for lubing which will diesel and I pay careful attention to the lubing process so a film of lube is only deposited on the pellet rifling surfaces. LOL....if the lube gets into the pellet skirts and diesels there will be a change in velocity.