cty100

does anyone have a calculating program to figure est. speed for a load. IE .270 win 22" barrel 57 gr. of IMR4831 130 gr. gameking cci 200 lr primer temp around 80 degrees.
thanks chris

homers brother

The only really RELIABLE method of determining velocity of your handloads requires the use of a chronograph. Everything else is just a "guess".

You can extrapolate based upon what your loading manual provides for velocity data, however the results vary widely - or so has been my own experience. Based on what you provide, you might see velocities ranging from 3026 fps to 3054 fps, depending on which loading data you use (I just happened to have two manuals handy to look at).

Further, ACTUAL performance in the field can be significantly different. In one case recently, that amounted to nearly 330 fps difference than what the manual showed from as the load's velocity versus what was recorded by the chronograph.

So, I wish I'd have bought a chronograph sooner - like, when I started reloading. If you reload and don't have one, you're leaving one performance variable in the dark.

eldeguello

You can get estimated results from loading manuals or other reloading data sources. But there is no formula or computer to calculate an estimated velocity Except for Powley's reloading calculator. I believe it is available on-line. But it only works for IMR powders.