I tried retumbo in mine today.
127 LRX with 81.5gr retumbo and fed 215M was 3445fps shot 1.3"@200.
I went higher but the ES's opened up and started getting pressure at 82.5gr
I wondering if anyone has tried RL 17 in the 280 rem with 120gr bullets. I have had great success with RL17 and 110gr TTSX in the 270. I'm just wondering if the same speed gain can be expected from the 280.