Case lube affecting muzzle velocity (9mm)?

[MilkMyDuds]

I recently started using Dillon case lube (spray bottle) for my 9mm reloading. It has made the loading much easier on both SDB and 650.

However, I am also noticing that while everything else stayed the same, muzzle velocity has increased from 880fps to 910fps (I am shooting 147gr bullet making 130PF). The only thing that changed is that I have started using Dillon case lube, which I know is a lanolin/alcohol based lube.

I applied lube as instructions say. I spray a couple times onto 200 cases laying side ways inside a zipbag then roll and shake them for 20 seconds. I do not clean up the lube on the finished rounds.

Did anyone else notice this? How could case lube increase MV? Could it be somehow some lube got into the neck of the cases? If that's the case, how one can avoid it?

Thanks.

[jstagn]

Maybe the weather (temp, humidity) has changed????

[Youngeyes]

I'd look at everything else before the lube. Temp changes, new bottle of powder, COL changes etc. How many rounds have you chrono'd and what was the SD? Was the 880-910 shift the avg velocity?

[Hi-Power Jack]

How many rounds have you chrono'd and what was the SD? Was the 880-910 shift the avg velocity?

+1. I'd suspect a small sample size and insignificant velocity change, first.

If you run 25 of each and still get a delta, then I'd check everything else

except the lube.

[MilkMyDuds]

Testing were done on 3 different range visits since I got my 650. Temp should not be a factor as the non-lubed and lubed groups average has been very consistent across 3 visits within the same group. I took 10 shots averages but did not calculate standard deviations, because the MVs vary very little (thanks to Dillon's powder measure) in the 5-10 FPS range.

There is no OAL change, nothing changed. I double checked all the dies as tight as they can be with the Hornady lock rings. I am very puzzled what else could have been. I have been using the same 4lbs Titegroup bottle for the past couple months.

I did the comparison specifically to find out if I can get away from cleaning case lube from finished rounds in an attempt to minimize the overhead in reloading. I posted in another topic asking if people usually wipe off case lube for 9mm, and most folks answered unless it's ammo for major matches they do not. I was simply curious what case lube can do on finished rounds.

Did anyone else do the same experiment? Please try it and let me know what you find out.

[racnsoonr]

Small crimp change?

[MilkMyDuds]

Small crimp change?

Crimp die on 650 is sitting on the furthest corner where accidental touch on the turn knob on top (I use Lee) is the least possible. And besides, I load 100 lubed cases and 100 non-lubed cases within one sitting, the chance of any die setting change is almost nil. In addition, I did 3 such sittings over the span of 2 weeks, and yielded same results. This excludes the possibility of any die setting changes. The only action I perform in between lubed and non-lubed is to load brass into case feeder. I don't see how that could consistently change my die setting (then change back next time I load non-lubed brass into the feeder)?

Edited July 27, 2015 by MilkMyDuds

[goldfieldshooter]

Is this affecting the accuracy of the load? The feel of the recoil or the split times? If not, I wouldn't worry about it. I have used the same load for years and it does vary from time to time because there are so many variables in reloading. That is why you never get the exact velocity that the reloading manual tells you. If you do, get a lottery ticket.

As for wiping case lube from finished rounds; that cuts into the beer drinking time. I you are not putting a load on, and it looks like you are not, and you are only shooting 130 - 132 PF, it is just something else to do that is not neccesary. Check on this site about case lube in rounds. You will find a screed of posts and it boils down to that 'it make no difference'.

My 2c worth.

Coatesy

[MilkMyDuds]

I did not notice big differences in group size on targets, nor felt recoil. I started suspecting my chrono may be acting up, though it gave the same MV readings for non-lubed across different visits, and same for lubed. I guess next visit I will test lubed first then non-lubed see if the chrono's reading varies based on how long it sits under the Texas sun.

[9x45]

This was an interesting read

http://precisionrifleblog.com/2012/07/20/chronograph-accuracy-tips-15-practical-tips-to-increase-accuracy-reliability/

[Hi-Power Jack]

This was an interesting read

http://precisionrifleblog.com/2012/07/20/chronograph-accuracy-tips-15-practical-tips-to-increase-accuracy-reliability/

Twenty years later, I got some great ideas from that article ...

Where were you and this article when I was Only 50 years old?

[Youngeyes]

Great article. Thanks for sharing that.

[rev1911]

On a somewhat related tangent... do your finished rounds feel sticky the next day? I think two full sprays for just a couple hundred cases is too much.

I found that with one full spray for about 300 cases in a gallon ziplock, then dumping them on a towel for a minute before loading, the press runs just as smoothly but there is much less residue afterwards.

With how well controlled your testing seems to be, I'm very curious how a batch with only half your regular amount of lube would chrono!

[MilkMyDuds]

Yes my finished rounds are still sticky next day. I need to reduce the amount Dillon lube I use.

A couple more range visits since last time, I found it is most likely my chrono's acting up, or maybe I tilted it a bit in my previous testing setups. I could not detect obvious differences between lubed vs non-lubed batches after I started using a better tripod with a level bubble. It helps to make sure the chrono is level.

Thanks for that great article linked above.