So I did my first seating depth test ever yesterday with 185 VLDs in a custom 300wsm. I went by the book and loaded .13, .09, .05, and .01 off the lands, 6 rounds each and shot two round robins of 3 shot groups. In the book it makes it sound like it should be really obvious which depth they should like. I shot the groups at 200yds in about a 10 mph wind. I measured the MOA for each group along with the vertical spreads. Here's what I got...

Depth 1st Rd MOA 1st Rd VS 2nd Rd MOA 2nd Rd VS Ave MOA Ave VS

.13 1.97 1.78 1.16 2.49 1.56 2.14

.09 1.22 2.60 1.86 1.38 1.54 1.99

.05 2.34 5.00 1.47 1.69 1.91 3.35

.01 1.65 2.52 0.99 1.30 1.08 1.91

At first glance I feel like the .01 is the winner with .09 a close second. This is tough for me b/c I loaded some rounds for a hunt a month ago just randomly at .08 off the lands and it shot pretty consistently about .5 MOA. I was really hoping for some better results from one of the depths and I'm looking for advice on what I should do next. Thanks.

I apologize for the scrunched up data. I hope everyone can understand what I'm trying to show.

Sure wish we could put excel files on a post.

Sorry, I don't follow your chart to know what's what.

Sorry guys, I know it's not the greatest. The first column is seating depth, 2nd is 1st rd group size, then 1st rd vertical spread, 2nd rd size, 2nd rd spread, then the ave size, and ave spread. That help?

Warning: thread deviation

if you want, there is a roundabout option. Once you select the cells in excel, then once you right click on a program like Word, then there is an option to paste as a picture. Once the pic is generated, then you can do with it anything you can do with a pic and it will look exactly like the excel file.
I do this for work all the time.

Maybe try not to abbreviate so much.

Better??

Seating Depth.....1st Rd Size (MOA)........1st Rd Vert. Spread.........2nd Rd Size (MOA)...........2nd Rd Vert. Spread........Ave Group Size........Ave Vert. Spread

0.13.................1.97............................1.78..............................1.16..............................2.49...........................1.56.........................2.14

0.09.................1.22............................2.6................................1.86..............................1.38...........................1.54.........................1.99

0.05.................2.34............................5...................................1.47..............................1.69...........................1.91..........................3.35

0.01.................1.65............................2.52...............................0.99.............................1.3.............................1.08..........................1.91

Have you run an optimal charge weight test? I usually do an ocw with bergers
.020 off the once I've found my charge weight I seat them even then jump .010 increments

The periods help. How bout after a number put " for inches, and MOA where it belongs.

Those numbers confused the hell out of me until I replaced "rd" with "group". Makes a lot more sense. For me the results are inconclusive. Your group size certainly leads one to believe that the .01 is probably the best but the vertical is all over the map. You're juggling too many variables at once, atleast for me. I'd start with a bare minimum of accuracy, get it where it groups relatively small. Tweak the powder first, THEN the seating depth. Assuming you've already done that, THEN run a ladder at say, 300 yards. How you run the ladder is up to you, but you could start with powder charge, then once you got that settled, tweak it with seating depth. 200 may not be far enough to really show you where your shots are clustering together vertically.

If I'm reading this right .09 had a MOA of 1.22 inches? And a vertical spread of 2.6 inches?

If that's right it makes no sense to me....how can your vertical spread be larger than your MOA?

Screen shot, save pic, then upload it.

There is a button "PRTSC" in the top right of your keyboard. Click that, then open "Paint". Paste the screen shot there, crop it how you want, save it, then upload the picture.

It would be a lot easier if you could upload a file for people to open, just trying to help out!

Looking at your data, what did you do with the powder charge? How did you come up with the powder charge you used to test with the seating depth?

It looks like the rifle is not in it's accuracy node yet, and you are trying to fine tune the load that isn't in tune yet. Work the powder charge first, then the seating depth (if you are going to do the seating depth). I do not tune to the seating depth. I tune the ammo with the powder charge to the harmonics of the barrel. I know where most bullets need to be seated to shoot well, and go with that seating depth first. If it's a VLD, it WILL shoot best just touching the rifling (not jammed, not off the lands, but leaving a faint scratch mark on the ogive of the bullet after chambering and extracting a loaded round). If the rifle is a custom 300WSM, it should do 1 moa easy, and with the right shooter and loads, should be able to do 1/2 moa or better. The WSM cases are finicky to load for. So, they do take more work with load development. This is why it's important to start with the powder charge first.

But also, you haven't said anything on how you are shooting the groups (bipod, sand bags, lead sled, etc). Is the rifle bedded? What is your method for testing these (bench, prone, etc).

Shooting groups is not as easy as just pulling the trigger. You have to eliminate you as a shooter from the group errors. Meaning, I stay on the rifle the entire time during one group test. I shoot prone and sink into the rifle, snug into my shoulder, firm cheek pressure, and stay exactly in position on the rifle throughout the 3-5 rounds of each group. I do NOT come off the rifle at all. If you come off the rifle and change up your shoulder location, it will recoil different, and change the point of impact, which will effect your group. Sure, we are not talking much POI shift, but enough to open up a group to give you false data. I put all my test rounds right below my right hand so I can cycle the bolt and chamber the next round without coming off the rifle. Plus, if you are not naturally lined up with your natural point of aim, the rifle will be recoiling all over the place and hopping to the sides. I know shooters that I compete with that can not shoot a good 5 shot group if they had to. But they shoot targets at long ranges under stress extremely well.


Take a look at this target below. This is what I call a text book load work up. This was a custom 243 Win competition rifle shooting the 115 DTAC bullets shot at 300 yards. The only thing I am doing to the ammo is increasing the powder charge in small increments with each load.

Load A is in the middle, Load B is top left, Load C is top right, Load D is bottom left. All were shot in order, all rounds of Load A first, then all rounds of Load B, etc. Load A was an open group, and I only shot 4 rounds, since I knew this was not the load it liked. Next was Load B, top left. It had 3 rounds nice and tight, but were stringing the groups up and down. I knew immediately that the next load, Load C, top right, should be the accuracy node. So, I made 5 good shots, and it put them into a nice 1" group at 300 yards. Load D opened up again, and shows that I passed the accuracy node, so I only shot 4 rounds. Load work up complete in 18 rounds!!! (Plus a few sighters at 100 to get on paper and such). This normally doesn't happen this quick, but sometimes it does. 1 out of 4 rifles I have to make a return trip to the range with for a second range session to fine tune the load up, and/or start over with a different powder. But 3 out of 4 rifles, I can get right on the first trip with the proper loads.

Let's see if this works...

^^Way better^^

.01" is the answer

Nice job, You made it smart and easy. Thanks