Newbie question

[jimbo14]

Hey guys,

First time loading for my rifle. I'm a handgun guy. Savage 111 Trophy Hunter in .223. It has the pencil barrel and I'm learning the ropes on this thing, then I'll swap out the barrel. I've been reading a fair amount and have watched a bunch of videos from Erik Cortina and some others. I realize this is a topic where there are a variety of ways to figure out a load, but I'm trying out this path first:

Using Varget, and 69 grain Sierra Match King, here is my powder charge test at 100m. First string went low charge (23.9gr) to high charge (26.0), in 0.3 grain increments, 1 shot per target. I let the barrel cool, and then fired a similar string, but went high charge down to low.



The method I'm attempting to try is to look for a stable elevation powder charge range, then narrow in there and try different seating depths to look for the best group.

Am I right thinking a powder charge of 24.9 to 25.0 grains looks good (between the two targets on the left side of the middle piece of paper)?

fwiw, chrono values:

grains/velocity

23.9.....2715
24.2.....2726
24.5.....2783
24.8.....2824
25.1.....2842
25.4.....2904
25.7.....2936
26.0.....2989

Thanks!

 

[rral22]

It looks like a good place to start real testing. The first thing I would do is load up 10 in that range and shoot a real group or two. A sample size of 2 is not indicative of very much. A gun/load that is actually capable of only 3 MOA may well place two shots on top of each other just by chance. You need many more samples before drawing any conclusions. I would leave seating depth changes to the last variable with which I would experiment after I had what I would hope is a good powder charge.

 

[Leatherstocking]

I think you are on the correct path.
Shooting a few 5 shot groups is a good idea. If the load is for hunting, you should cool the barrel down between shots. It’s the first shot from a cold, dirty barrel that counts!

 

[fingers284]

Not sure if the 111 trophy hunter has the same rifling twist as my Axis in .223 but my groups noticeably open up with heavier than 50 gr slugs. Mostly tight clover leaf with 50 down to 45 and mostly "one hole" 45>40 gr. The 55 and up still appear "stabilized" for the most part (no evidence of key hole starting) but groups open up to almost an inch.

 

[jimbo14]

Thanks guys.

I forgot to mention that the chrono list was from a separate batch. I did the next two strings of 8 shots after, (no chrono on the target shots). The velocity spread in the chrono list was roughly reflected in the elevation changes on the subsequent strings.

I think this rifle (from several years ago), has a 1:9 twist rate. The barrel is quite thin, so I think that's why the impact elevation changes so much with minor changes in powder charge most of the time. The barrel must be whipping about under the pressure. I expected to see some elevation changes, but not this much at 100m.

This is practice for precision shooting, not hunting. I'll load up a bunch in the upper 24.x grain range and shoot some groups tomorrow. The wind should be fairly low so it'll be a good time to test.

 

[deadeyes40]

Looks like the 25.7 grain rounds were closest to point of aim and almost as tight as the 25.1 grain rounds. The 26.0 grain rounds look to be breaking each other, Just high and left of point of aim. Assuming there are no pressure issues with the 26.0 grain rounds, you should try a few 5 shot groups with them as well.

 

[jimbo14]

Looks like the 25.7 grain rounds were closest to point of aim and almost as tight as the 25.1 grain rounds. The 26.0 grain rounds look to be breaking each other, Just high and left of point of aim. Assuming there are no pressure issues with the 26.0 grain rounds, you should try a few 5 shot groups with them as well.

The scope was zeroed with different ammo, (AR223 bulk stuff), and at a slightly shorter distance. I gave the scope a few clicks here at home to get the new test ammo closer to POA. I'm aligned with rral22's way of thinking that the group size is largely irrelevant here due to only two rounds fired at each powder weight. It's like shooting two single-shot powder charge ladders, where the second shot is trying to confirm I didn't yank the rifle in a bad way. lol!

I've made some more ammo, all at 25.0 grains, since both the chrono and targets showed stability in that velocity range. Some ammo to chrono, looking for a low ES to confirm I can make something consistent, and I decided to try a bunch of seating depths in 3-shot groups.