How many Rounds For Testing?


February 17, 2011, 01:04 PM
I am just beginning to reload I am going to start to try and find a good round for my M1 and am looking for advice. I will be using IMR 4895 with a 150 gr bullet and would like to vary the powder load to find what my rifle likes best. How many rounds of a specific powder load will give a good measure of performance. With the enblocs 8 seems to be the logical answer but is this enough or too many?


If you enjoyed reading about "How many Rounds For Testing?" here in archive, you'll LOVE our community. Come join today for the full version!
February 17, 2011, 01:19 PM
I usually use 5-10.

Most the time I start with 5 each of a grain or two apart going from 10%under max to max load. Once I find the set that that is closest, I load 5 each for a total of 20 or so that will fill the gap. Also while shooting, checking each set for any signs of pressure or odd performance.

for example:

if the 5.2-5.6 seems best, then I load

Then pick the best. Granted my numbers are completely arbitrary, but that is just to get the idea presented in another light.

February 17, 2011, 01:31 PM
I usually load 3 rounds for initial test loads. In your case, with a Garand, I would load 4 so you could get 2 test loads in an enbloc.


February 17, 2011, 03:24 PM
I load in groups of 10 so I can get two five shot groupings. For a Garand I would cut it back to eight so I could get two four shot groups out of each en block and one test level per pass.

I usually load n 0.5 grain increments on smaller cases like 223 on the big boys, 308 and up, I look at two grain jumps.


February 17, 2011, 03:36 PM
Thin barreled rifles, like pre 64 featherweights, their barrels start to walk after three rounds.

Your Garand, you will need to shoot a group. And not a two or three shot group. Rack grade Garands fling shots in unpredictable patterns. Shoot at least 8 shots before you decide on a favorite load.

That will also give you an idea on whether you have an function issues through the clip.

Friendly, Don't Fire!
February 17, 2011, 03:38 PM
I agree with what all the others stated.

February 17, 2011, 05:56 PM
"...With the enblocs 8..." Easiest way to keep 'em separated too. Eight isn't necessary, it's just easier to load a clip of each load.
Put a piece of masking tape on the clip with the load on it. Work up the load from the starting load, going up in half grain increments. Starting load of IMR4895 is 49.0. Max is 53.0. It'll take 8 clips.
"...Rack grade Garands fling shots..." CMP 'grades' are about the condition of the rifle. Rack grades are the roughest. Muzzle and throat erosion is higher. Crown may be nicked too.

February 17, 2011, 07:22 PM
8 it is. Thanks for the input.


If you enjoyed reading about "How many Rounds For Testing?" here in archive, you'll LOVE our community. Come join today for the full version!