Shooting PP in military rifle

[martinibelgian]

A some of you will know by now, I shoot Martini rifles in competition - and military rifles in the service rifle competitions. Military rifle competition here requires shooting dirty, blowtubing is allowed however.
A while ago, I had serious accuracy issues developing with my PP loads - they just wouldn't group anymore. No change of load, just patterning instead of grouping...

Tried several things - thicker grease cookies, more blowtubing, to no avail. At 1st I thought it was a rifle issue v(my main competition rifle, a Steyr-Martini Roumanian army issue) - but it turned out to be a common issue for all my rifles which had been shooting well with PP. I tried lubing the patches, more / less neck tension - no ceegar.

One of the only remaining variables was the lube I was using for the lube cookie - so I finally made a new batch, also with a different oil (castor oil this time, 30/70 oil / beeswax). Pretty hard cookie though - I did load some rounds for my Peabody - Martini Turkish, and tried them yesterday. As by magic, I again had a pretty nice group - success! And me pretty happy, I might add...

As to what happened to the old lube, no idea - it was about 2 years old and up to half a year ago, it had been performing well. Then everything turned bad. Consistency looked right, it wasn't burnt - but regardless, it wouldn't perform, where the fresh lube performs ike a champ.

[beltfed]

Old lube went rancid...?\
beltfed/arnie

[martinibelgian]

Nt that I could see, at any rate. And it still worked well with GG bullets. But maybe PP requires more from lube? Some volatile elements from the wax/ oil that disappeared with time? I don't know, but...