Junior1942's 7.62x39 SKS loads + with LeveRevolution
Junior1942’s7.62x39 loads
During the latest thread on LeveRevolution Powder Junior1942 PM’d me asking about the 30-30 testing I had done with the RCBS 30-180-FN and that powder.He asked about the test and was trying to correlate the psi’s from that test to the 7.62x39 for possible use in his YugoSKS.He primarily was interested to see if the LeveRevolution powder would give him a bit better performance under his COWW cast bullets which weight 197 gr.Isuggested there was no sense trying to correlate when I could pressure test in the 7.62x39 also.I suggested he send some bullets and the data for his other powder loads and I would pressure test those also.Junior thought that was agreat idea.He asked how many bullets?I told him a hundred minimum.
Junior scrounged around and found about a hundred (104 to be exact) he had already cast and said he’d cast up some more and send ’em if need be.He said a few were wrinkled.Told him they’d be fine for the initial LeveRevolution work up as we were interested there was the psi. I got the bullets a couple days later.They were sized at .314, had Hornady GCs and were lubed with LLA.The BHN measured 11 – 12.I proceeded to check out the Mini Mk X Mauser I would use for the test.Unfortunately the strain gauge had partially cracked for some reason.It hadn’t been used in over 2 years and the change in location, temperatures and humidity are my guess why.Called the company to order some more gauges and they would take about 6 – 7 weeks.Told Junior and he was a bit down over that.However, in about 2 weeks a package showed upwith the strain gauges.
IPM’d Junior and told him I was ready to test and asked a couple clarification questions about his standard loads.I didn’t hear back from Junior and just assumed he was away or busy.I did not know he had gone to the big range.I proceeded with the test and will post the results here…..for Junior…..rest in peace, may the sun always be to your back, the wind in your face and all your shots fly true.
Test rifle; Interarms Mini Mk X
Caliber; 7.63x39
Bore; .301
Groove; .311
Barrel length/twist; 20”/1-9.5”
Sights; Bushnell 4X scope
Testequipment; Oehler M43 PBL
Range; Sara Park, Lake Havasu City, AZ
Test range; 100 yards, solid cement benches
Rest; Hoppe’s front and leather sand bag (rabbit ear) rear
Test shots; due to limited number of bullets not all test strings had 10 shots. Some had less but not less than 7 shots.The LeveRevolution psi workup had 2 shots per powder charge.
Attachment 112982
The test was conducted on two separate days early in the mornings. This gave the least heat (this is the desert with day time temps running 105 – 115) at daybreak (85 – 90) and the least wind. Juniors standard loads and the LeveRevolution psi work up was conducted on the 1st day along with a LeveRevolution psi workup with a 175 gr C314041 cast bullet of my own. The second day was the test of 3 loads of the LeveRevolution under Juniors 30-180-FNs and 3 loads under my own C314041.
The 1st day’s tests;
Reference ammunition test; The CIP Pmap (Maximum Average Pressure) for the 7.62x39 cartridge is 51,500 psi (peizo-transducer or strain gauge. Three factory loads were tested to set a base line for the mini Mk X.
Attachment 112983