OzFclass

I tried to develop a load with these about 4 months ago when my usual 105 berger hybrids were impossible to get. 6x47 lapua, 1:7 twist PacNor barrel. 30inch long with 500 rounds down the tube. Minor fire cracking around lands evident with bore scope but still shooting .4 moa. 3100 fps. Approximately 1 in every 7 rounds BLEW up at about 90 yards down range. Target at 100 yards was splattered with shrapnel that resembled a hit with .22 bird shot. After this I shot my remaining 20 rounds of loaded Bergers with NO blow ups. I was then able to buy some more Bergers and after another 300 rounds I had no more blow ups. Went back to the range with the last 12 loaded sierra's that I had and had three blow ups. From what I have found the new 6mm 110gns and the 6.5 mm 150gns use the same jacket design and ogive shape. If you do some investigating, you will find that the 150gn 6.5s have a history of blowing up also. Has anyone else had a problem with this happening ?

I have a friend who recently went through Berger 115s blowing up, Pacnor 1:7 twist barrel also - his is a 3-groove and I have read reports that they can chew the jackets up.

Willow, Interesting that the 115"s were coming apart . You are correct in that the PacNor is a three groove barrel. My gunsmith suggested that the width of the lands may contribute to the jackets coming apart. I have just had a new barrel fitted. This one is a Brux 4 groove 1:7 and haven't put any rounds through it yet to see what happens with the Sierra's. I have not had an issue with the 105 Hybrids in the PacNor barrel so I am at a loss to explain it other than the Sierra's must be thinner or softer jackets. Hopefully, I will get time to run some sierra's through it soon so I'll let you know the outcome.