Alex Hamilton
04-17-2014, 11:06 AM
Hi, Guys,
I was at Bisley yesterday to test a new load combination for my 308Win target rifle and after 15 rounds I noticed dark "smears" in the bore about 2" from the throat. 2"beyound that the bore was clear. I also had a very similar black depodit on case necks. When I got home I pushed through a piece of paper kitchen towel wrapped round the jag and the deposit in the bore was removed completely. It also rubbed of easily off the case necks. The deposit was only on the parallel sides of the neck. Nothing on the shoulder, nor on the rest of the case. My gut feeling is that it was bullet lube, but I would appreciate your views.
The load was Lee 310160R bullet, cast in pure linotype, gas checked and lubricated with NRA 50-50. The powder charge was 27grs of Accurate 2015 (aka Lovex S060) in Prvi Partizan cases and large rifle primers. I had no usual indicators of high pressure. In fact, I would have said that the load could take another grain of powder, because I saw a few unburned powder granules in the bore. Accuracy was excellent at 200yds - about 2MOA group, despite fishtailing wind from 6 to 9 o'clock.
The barrel groove size is .308" and the barrel is very little used. One pass of the paper wrapped round the jag restored the bore to mirror finish and I could not detect any slivers of lead on paper patch.
If any expert on this list could clear up this mystery, I'd be very grateful.
Best regards,
Alex in UK.
I was at Bisley yesterday to test a new load combination for my 308Win target rifle and after 15 rounds I noticed dark "smears" in the bore about 2" from the throat. 2"beyound that the bore was clear. I also had a very similar black depodit on case necks. When I got home I pushed through a piece of paper kitchen towel wrapped round the jag and the deposit in the bore was removed completely. It also rubbed of easily off the case necks. The deposit was only on the parallel sides of the neck. Nothing on the shoulder, nor on the rest of the case. My gut feeling is that it was bullet lube, but I would appreciate your views.
The load was Lee 310160R bullet, cast in pure linotype, gas checked and lubricated with NRA 50-50. The powder charge was 27grs of Accurate 2015 (aka Lovex S060) in Prvi Partizan cases and large rifle primers. I had no usual indicators of high pressure. In fact, I would have said that the load could take another grain of powder, because I saw a few unburned powder granules in the bore. Accuracy was excellent at 200yds - about 2MOA group, despite fishtailing wind from 6 to 9 o'clock.
The barrel groove size is .308" and the barrel is very little used. One pass of the paper wrapped round the jag restored the bore to mirror finish and I could not detect any slivers of lead on paper patch.
If any expert on this list could clear up this mystery, I'd be very grateful.
Best regards,
Alex in UK.