Ive been using both Strelok and Shooter apps to calculate ballistics for my 300 RUM. Other than making an error when zeroing my turret (which I will be checking this weekend) Does anyone have any ideas of why I would be off by 1 moa? I have shot various ranges out to 840 and every time i have to subtract 1 moa from what the calculator gives me. If it helps, i am using 215 berger hybrids, 89.5 g h100, 3.79 c.o.l., leupold mk4 er/t, 20 moa base. Any help is appreciated
Muzzle velocity may be off and need to be trued as stated earlier. I will be going through the same with my my 300 RUM next week. Just settled on a load of 91 gr H1000, Rem brass, Fed 215 Match primers, COAL 3.843". Want to shoot some drops and get a custom turret ordered but I am running out of time. What is your velocity? I am getting 2988 fps at 1000ft elevation over a chronograph but in another thread guys think it should going over 3000 fps. Also only 6 fps ES.
could be a few things or a combination of many. Make sure you check your turrets to be sure you know how much they move per click. It sounds like that could be at least part of your problem. Many scopes turrets, including high quality ones, don't match up when you check their actual adjustments to what they list.
Make sure the BC you entered is correct for the profile you selected. (IE. G7 or G1). Odds are if it is a big number like .475 its a G1 BC, and if it is a smaller number like .288 that would be your G1 BC. Your bullet will have both BC numbers, but typically companies advertise the G1 because it looks more impressive.
Second go online and find an independent BC study of your bullet. I reload Nosler Accubonds and learned they over estimated their BC by around 4%. Doesn't seem like much, but I was experiencing the same thing you were and after making the above changes the ballistic program I was using was spot on.
Last use your programs verification feature if it has one.