Quick Reloading Question

Well I made it out to the range for a couple hrs today to do some load testing on my 270WSM with 150 VLDs. Here is a picture of the best group group and the groups on either side of it. I'm thinking that since the groups on either side of the best groups are decent groups, that I'm safe to just go with the load that shot the 0.31 group? I'm still going to load up enough for 3 or 4 groups to test that one load and verify that wasn't a fluke group but wanted to see if you guys agreed with me.




Also, here are 3 groups from my 300wsm, same load to validate it being a good load. I'm assuming it's safe to say that the one bullet that didn't group well was probably me and not the rifle considering 8 of 9 shots were good?

That's what I would do. Do you have a chrono? Some of the guys here say that when the groups "string" they ask what the Extreme Spread is from shot 1 to shot 3. Make sense? Looks like 56.5 could be the winner if you can duplicate consistently. If so , I would buy up a ton of 4350 and Bergers and call it good. .31 is a hell of a group!!!

I will have a chrono for the next shoot to check the ES

Not sure what rifle you're shooting or what your personal standard is for accuracy, but all your groups look good to me. I presume these are at 100 yards. My only concern would be the fact that your POI moved about one-half inch between 56.0 gr and 56.5 gr. I'd guess that's about 20-25 fps difference in velocity. I have found that IMR 4350 is quite temperature-sensitive, resulting in significant differences in velocity. If you intend to shoot this load at lower temperatures, your POI shift and group size could change even more. I would run the tests again, with a chrono, at 55.5, 56.0 and 56.5 gr to replicate lower temperatures/velocities to verify how much further POI and group size might change.

Yeah I thought the POI move was interesting but this is the first time I've heard anyone say IMR4350 was temp sensative...anyone else see the same?

Yes, IMR 4350 will be a temp sensitive. If you do the load work up in 80 degree weather, and you are hunting in the 30 degrees, it can change up your accuracy node. But, this is a hunting gun. I still use IMR 4350 in my personal 270 Win ammo with a 130 grain bullet because it shoots really good and fast. It's a great powder.

I see your groups as a common load work up indicators. Your groups string a little before the sweet spot, and open back up after the sweet spot. Getting a WSM to shoot well can be a challenge. I'd run your 56.5 load, and zero that load for 100 or 200 yard, and go hunting!

IMR 4350 is my go-to powder that I have used for over 30 years. In my .270 Win with a 140 gr bullet, which I have tested extensively, the difference in velocity between 30 and 90 degrees is about 80-100 fps. Your results could be very different. Out to say 300 yards, the trajectory difference is very small, unless your barrel harmonics start to move everything around. It's important to find a node where changes in velocity, for whatever reason, don't change the POI.

Thanks papa45. I make a habit of shooting a hunting rifle within a day or 2 of each hunt I go on so hopefully that helps me make the small adjustments needed for POI changes during different times of the year. What's your pet load for those 140s and IMR 4350 for your 270win? My wife just bought "her rifle" in .270 win and I was considering loading 140SST's for her as a great all-around load that won't break the bank for anything deer size and below.

ltsheets, your private message inbox is full. Clean it up and I'll send you some info.

Thanks for the heads up. I cleaned it up a bit.