300 wm - load development 2

[DoubleGobble00]

I tried 5 different loads and shot them through my chrono for group. These were shot a 200 yards. Currently, they look pretty bad. My question is, should I just look at ES and SD and ignore group size until I change seating depth to improve the groups? Below are the specs and results.

300 WM
ABM 1x brass
215 M
H1000
Berger 215
200 yards











DoubleG

 

[Deviant]

Use your load with the lowest SD and tighten it up with the Berger seating depth test. I usually do a ladder and find my nodes and max load then follow that with a seating depth test and it almost always produces tiny groups. Your seating depth has more effect on group size than any other factor in my experience.

 

[Buxndiverdux]

With the data you provided, I would recommend a Berger jump test at the 78gr load since your SD and ES are really good.

So try .010, .050, .090, and .130 and you should see a good jump to tweak.
I only load 2 of each jump because half the time I don't need to shoot a 3rd.

 

[dfanonymous]

What kind of chrono are you using?
Also what's the load up for? Are you just trying to get nice close groups and call it a day or will you stick with the load for awhile and be running drop tables for distance?

 

[DoubleGobble00]

Thanks. I was hoping the seating depth might tighten them up a bit. Right now I'm 0.10 off lands. I will give that a try. I might also try 80 since the shots were 3007, 3008, then 2950. I'm thinking the 2950 was a fluke.

I'm running a cheap Pro Chronograph. It is one that uses light to read the speed. I hope it is food enough to use.

I want to get all my guns shooting 1/2 moa or less at 1000 yards if possible.

 

[therifleman556]

Tagging in. There's usually something useful in these threads. I'd also like to know how trustworthy the optical chronograph is. I have a Caldwell and sometimes wonder.

 

[Buxndiverdux]

For what it's worth, I have run a pro chrono simultaneously with a magneto speed and there is no real pattern of mathematical reconciliation.

The magneto speed does work out when confirming drops on paper, with the input data from Advanced Ballistics software. Taking the average of several shots over several different days of range work for software input.

 

[BEEMAN]

30 thou off has worked good with the 215 in a few 300 Win Mags. Your speeds are similar to mine. I get 3000 fps with 79 gr H1000 out of a 26" Brux. I stopped there as I think I must be close to max. Speed is good and it shoots great.

 

[ppoole]

Try the seating depth test like others have said also what is your water volume on average between three fired cases. If you have a different volume than pressure will be all over the place. Assuming you have a 26 inch barrel the accuracy node is normally 2950 from what I have read from several people shooting these, I'm going to start this week with mine.

Also what dies do you use and what neck tension? Neck tension has a huge effect on es as well as as. Your 79 shows less than 1 moa but bad es so that is what I am getting at. I would love to see the numbers with a magneto speed. I had the same chronograph and and am reworking my 7 mag now (changing primers) because if what I saw. If you are over .0025 neck tension that could be it in a Nutt shell.

Definitely try seating depth first even if that is not the culprit you need seating depth anyway.

 

[DoubleGobble00]

I'm not sure how accurate the pro chronograph is either. I just got it but have shot in cloudy conditions each time so far. It would be great to compare one day. I hope it works cause I just got it.

I'll definitely try seating depth. The neck tension is a good thought also. I'm using Wilson neck and seater dies. So far I've only tried my 334 bushing. It should have about .002 bite after spring back. I do have bushings 336 to 333 to test. I had light bite with 335 so that might help.

I have a 28" barrel so I'd like to get close to 3000 FPS. My max load is 81.5 which got 3020. I may shoot my 80 load again since it was around 2950.

I don't know the water volume. I've never checked that before. Why do you typically do this?

 

[ppoole]

3000 should be attainable with 28 inch barrel. I had issues with my pro chrono and my magneto speed sporter basically showed me I had 25 fps extreme spread. My velocity was also 90 fps faster than it was on the pro chronograph. Check seating depth and then try neck tension.

 

[DoubleGobble00]

Interesting... so my velocity could be faster... I need to find someone with a magneto to check my velocity. I can get 3000 about a grain under max. I'm surprised how fast the 300 WM will push that 215.

 

[Heym500]

Try Fed. 210

 

[Chase723]

Can you only shoot at 200? If you can't afford a magneto speed but can shoot further (like 500) shoot a ladder at that distance. Use your ballistic calculator to true/determine your velocity. If you have a node that shoots 1/2 MOA at 500. You can bet that the center of that node will have a low ES/SD. Also you know it will shoot 1/2 MOA at 500. Usually if it can do that at 500 it'll do it at 1000.