rockrat
04-20-2016, 09:55 PM
Just rechambered a barrel from 300 blackout to 30-223. We have varmint silhouette matches once a month and thought I would try it out. Had a bit of trouble with the rechamber as there was a tiny piece of metal in the chamber that I missed and it threw my headspace off. Had to re-cut the back of the barrel and rechamber. finally got it headspaced.
Made some cases and sized them in a set of Redding 300 whisper/30-221 dies. Got them loaded with 844. Figured it was too slow and sure enough it was. Next was Benchmark, also too slow. Kind of tough without hardly any loading data out there. Back to the bench and try a bit faster powder and re-shoot for function/bullet speed/ pressure signs. X-terminator wasn't too bad, but not much speed. Went next to AA2015br and things looked better, but only getting 2444fps with the Hornady 110gr, but it was 100fps faster than the x-term loads. Case should run bullets faster.
Figured I would try AA1680 as that is what the 7.62x40wt uses well. Upped the charge from the x40 load data and went and re-shot today. Loaded a few first to try and find upper limit of powder charge. Did, and then backed down from there (blew a primer in the 150gr bullet load, on the first shot--dropped it and looks better).
Took the chrony out and hit 2800fps with the Hornady 110gr vmax and 2600fps with the 125 speer tnt. I will be backing the 110gr Vmax down as accuracy was OK, but not great. The 125gr tnt shot very well. Only took one shot with the 150gr ww powerpoints I have had for decades. Will re-try the 1680 and x-term powders tomorrow with the 150gr Winchester bullets.
Will try to hit the range tomorrow and check for velocity and accuracy. Then its on to boolits. Probably work with the NOE 311-155, a 135gr swc, and a shortened version of the 30-165sil. Might have to try the 30-165sil too.
Found a set of Lyman 300blackout dies I bought at our last gunshow and tried them. Worked much better as they didn't size the case shoulder down so much. .002" vs .006".
This is in a XR100 Remington single shot with a Rem-nut and a McGowan barrel 1-10" twist.
Made some cases and sized them in a set of Redding 300 whisper/30-221 dies. Got them loaded with 844. Figured it was too slow and sure enough it was. Next was Benchmark, also too slow. Kind of tough without hardly any loading data out there. Back to the bench and try a bit faster powder and re-shoot for function/bullet speed/ pressure signs. X-terminator wasn't too bad, but not much speed. Went next to AA2015br and things looked better, but only getting 2444fps with the Hornady 110gr, but it was 100fps faster than the x-term loads. Case should run bullets faster.
Figured I would try AA1680 as that is what the 7.62x40wt uses well. Upped the charge from the x40 load data and went and re-shot today. Loaded a few first to try and find upper limit of powder charge. Did, and then backed down from there (blew a primer in the 150gr bullet load, on the first shot--dropped it and looks better).
Took the chrony out and hit 2800fps with the Hornady 110gr vmax and 2600fps with the 125 speer tnt. I will be backing the 110gr Vmax down as accuracy was OK, but not great. The 125gr tnt shot very well. Only took one shot with the 150gr ww powerpoints I have had for decades. Will re-try the 1680 and x-term powders tomorrow with the 150gr Winchester bullets.
Will try to hit the range tomorrow and check for velocity and accuracy. Then its on to boolits. Probably work with the NOE 311-155, a 135gr swc, and a shortened version of the 30-165sil. Might have to try the 30-165sil too.
Found a set of Lyman 300blackout dies I bought at our last gunshow and tried them. Worked much better as they didn't size the case shoulder down so much. .002" vs .006".
This is in a XR100 Remington single shot with a Rem-nut and a McGowan barrel 1-10" twist.