Okay finally got out to try out the new Chrono (Pro Chrono) and to get some 10mm data. Here were the conditions: Ovecast Temp 61 F Pressure 29.99 Altitude 1020' Load data: Starline Brass CCI 350 Primers Powder IMR 800x Also used a light crimp with Lee FCD Pistol is a stock G20sf. Okay first data is with Berry's 180 grain FP. I had worked up the load to a max published of 8.7. Here is my 8 shot string: 1135 1135 1104 1203 1131 1108 1115 1128 Not sure what happened with the 1203. No pressure signs, no glock smiles. Otherwise accuracy seemed really good. Recoil was snappy but easily controllable. Next string is with the 135 grain Noslers with 12.0 charge: 1510 1515 1522 1538 1501 Fairly light recoil, no pressure signs, very accurate. Next is 135 Nosler with 12.5 charge: 1556 1561 1561 1576 1580 These had snappy recoil and flattened primers. No glock smiles. Same above with 12.6: 1610 1633 1675 1677 1647 Snappy recoil, flattened primers, no glock smiles Finally went to 12.7: 1705 Glock smile showed and I was done. Flattened primer. Did not want to test anymore. I am gonna go back to 12.0 as it seems fast enough for me and will not tear up my brass. Some notes on the chrono. I do like the ProChono only one error the whole time I shot. I will need to get the cord to hook up my laptop as being on a controlled range does not let you select the things you need in a timely manner. Wanna kill these ads? We can help!