So for 6mm Creedmoor, the two calculations are: The method of determining case volume to bore area ratio is described here, with a handy table: I use the following calculation, from post #3 in this thread: This is a measure of the overbore-ness of the case. Maximum case capacity: calculated from an average of cases, convex water surface (be very sure to tap out all the water bubbles just before you top it up).Bullet weight: calculated from an average of 10 bullets.Case length: calculated from an average of cases.Bullet length: calculated from an average of 10 bullets.But you can only do this once you have set all the static variables correctly. The key here is to adjust the burn rate of the powder until your muzzle velocity matches your Strelock validated velocity. I don’t like running out of ammo on extended trips! If new brass and a new powder lot enters the equation, a new drop test is mandatory. The powder performance in extremes of altitude and temperature is very important to understand, and I do see tangible differences between mid-winter and mid-summer.Īlso, I batch reload in increments of 100 or 200, and recently in 6.5 Creedmoor, 300. 500m higher and 20☌ colder) I will do a fresh drop test. But altitude, air pressure and temperature can all muck around with velocity and drops data, so if I move to new ground that is significantly different to where I normally shoot (e.g. Minor differences in the BC of the bullet to published data are dealt with by altering velocity. However, there are some other variables to consider. This is the number I use for all future ballistic calculations. The average distance from the centreline of the cross to each POI is used as the value to enter into Strelock, which spits out a recalculated velocity. I set up a board of sufficient height at typically 300m and 500m, place the cross hair on a large cross drawn on the board, then shoot a 5 shot group. Firstly, I carefully set all the meteorological variables to the weather on the day, and use the GPS to set altitude. The process with which I validate trajectory is using Strelock Pro. I use drops data over chrono data, and as you know then go out and shoot goats in the high shoulder at 600m+. Drop tests are used to validate your trajectory, and assuming you have got your ES and SD down to low numbers, then drops data is very accurate. I say this having tested Lab Radar, MagnetoSpeed and el cheapo Pro Chrono next to each other, and getting different readings. ![]() If you don’t, you’re stuck with your chronograph readings, which in my experience can be a bit off. If you can’t drop test your loads at distances well past your zero, don’t bother with this. Others will inevitably have different ideas, happy to hear them! Also remember I’m relatively new to Quickload, only been using it about 3 years or so.īefore we go any further, here’s the important bit. Having communicated directly with Helmut Broemel in Germany (writer, owner) I’m happy with my process. This is the process I use to tune Quickload to the powder I am using. Asked for some more Quickload information, so here y’are.
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