versifier
03-15-2012, 07:21 AM
I finally got around to testing some 150gr cast bullet loads in my Contender carbine. It started life as a standard T/C 24" .300Whisper 1/10" twist carbine barrel that I had OTT rechamber to .30/223. Balistically it is a rimless .30-30 that uses about half the powder for the same velocities as the ancient cartridge. Recoil is cut in half, too, a real bonus is such a lightweight rifle. This is a deer rifle though it is accurate enough to be a good paper puncher, so I do not shoot anything heavier than 150gr to keep the velocities high enough so the bullets don't drop too much over its 200yd practical range and retain enough energy for a clean kill. Haven't had a chance to kill anything but varmints with it yet though.
Using H335 or its surp equvilent it easily does MOA with Sierra 125gr spitzers and 110gr RN's, but I wanted to see what it would do with some cast. I have two appropriate bullets, 120gr FNGC and 150gr FNGC. I have begun testing with the 150's first. Initial tests with 2400 passed the pieplate test @ 50yds, but just barely, no decent groups. Switching to H335 there was an immediate improvement with groups running between 1-1.5" often with three or four overlapping. Next trip to the range I will be moving out to 100yds and setting up the chrono. I am expecting 2" groups with it and will be happy if it lives up to those modest expectations. Interestingly, the POI shift from the 125gr jacketed zero was about 4" to the left with no elevation difference. I like H335 in the .223 family because you can fill the case to the bullet base and not go overpressure. I do not compress them as doing so with a ball powder can cause major pressure spikes and I look scary enough as it is. Then I will start with the 120's and see if it will get the groups down to MOA.
Using H335 or its surp equvilent it easily does MOA with Sierra 125gr spitzers and 110gr RN's, but I wanted to see what it would do with some cast. I have two appropriate bullets, 120gr FNGC and 150gr FNGC. I have begun testing with the 150's first. Initial tests with 2400 passed the pieplate test @ 50yds, but just barely, no decent groups. Switching to H335 there was an immediate improvement with groups running between 1-1.5" often with three or four overlapping. Next trip to the range I will be moving out to 100yds and setting up the chrono. I am expecting 2" groups with it and will be happy if it lives up to those modest expectations. Interestingly, the POI shift from the 125gr jacketed zero was about 4" to the left with no elevation difference. I like H335 in the .223 family because you can fill the case to the bullet base and not go overpressure. I do not compress them as doing so with a ball powder can cause major pressure spikes and I look scary enough as it is. Then I will start with the 120's and see if it will get the groups down to MOA.