First, please avoid the spray-on lubes . . . they will put on WAAAAY too much goopy. The scant trace of paste floor wax is all you need. Yes, I have tried no-lube-at-all PPCBoos, and have found that the PPatch tends to friction-catch in the caseneck and bunch-up just outside the casemouth, as a result. So, I favor the very-light-lube-via-wax approach, because it DOES lube the seating PPCBoo yet it does not fill up the paper's pores with non-gaseous material.
What Happened: Your PPatch sized-down to the point where it was "harder than lead alloys" and then the last three thousandths of size-down was via core size-down-and-lengthening. Upon emerging from the die, the core sprang back up a half thousandth.
I have been trying to get that point across, here, for some time. The PPatch will work better if it is NOT sized down that far. The PPatch gets that hard when it is squished down around half of its added thickness. So:
- For a PPCBoo using a pre-sized-down CBoo core: CHECK FOR CORE SIZE-DOWN on every batch, using a test-PPCBoo dried with a hair-drier-then-sized-down. If you get ANY core size-down, then you need to switch to a thinner paper. or
- For a PPCBoo where you are doing the size-down only after doing the PPatch, then you WILL be COUNTING on this hard-patch-sized-down-the-core thingy. In that case: if the post-sizing core diameter is less than your barrel's land-to-land diameter, then switch to a thinner paper.
The third way, of course, is to size-down the CBoo core then patch up to the desired diameter and let the PPCBoo's entry into the rifling, combined with the core's obturation, compress the PPatch. I like that option best, as it traps the most air in the patch, for that hyper-succulent pneumatic-ride-&-sealing effect.
LBT Blue is awesome for groove-&-GC CBoos, but it will tend to fill up the paper pores and is non-gaseous. Try the VERY LIGHT paste-wax application . . . . barely enough to notice at all. It lubes the patch but does not fill its interstices with goopy-nongaseous-material. That is a pretty difficult thing to beat, especially with way-hard-to-smear high-viscosity blue-goopy.I've got another batch final sized to 0.3095"D with some lightly lubed with the NRA formula and some lightly lubed with LBT Blue. We'll see how these fly next week. The loads shot at the 100 yd. range were 41 gr. H4895 and 43 gr. WW748 behind an LBT 150 CB and the Lyman 311291.
Hope springs eternal!
Best regards,
CJR
The adventure goads ever-onward-and-oops-ward!
Zeek
P.S., CJR, my version of your kindly parting salutation goes, "Hope springs infernal in the humans unabreast!"