Practical reloading technique for 1,000 yards

[Racalman]

I need to improve my .308 handload's accuracy at 1,000 yards. I'm happy with the components (Berger 185gn Juggernaut, Lapua case, Federal Gold Match primer, N550 powder) but I need to tweak the powder weight and then bullet jump for best performance.

So, for those with the relevant experience, what's the best practical way of doing this? Is it:

• Tightest group at 100 yards?
  Lowest Extreme Spread of muzzle velocity?
  Dan Newberry's OCW technique?
  The Ladder Test?
  Something else I haven't thought of yet?

[JSC]

Personally, I've always gone with the OCW method, using a chrono and Quickload to predict a near to optimum load, then fine tuning by testing at 600 yds minimum.

100/200yd testing with a load that's close to optimum isn't going to be conclusive enough IMO.

If you really want to fine tune you should also pay attention to neck tension (turning the necks and some form of adjustable resizing is essential for this) and also pointing the bullets and weight sorting them. But others may think different, of course.

[artiglio]

Link is to a very long thread, which has lots to think about and sets out one way of developing a load.

http://forum.accurateshooter.com/thread ... s.3814361/

[WelshShooter]

I don't have experience of developing a load for purely for 1,000 yards, but there's a wealth of information on the 6mmbr website for handloading for 308win.

http://www.6mmbr.com/308Win.html

[rox]

I need to improve my .308 handload's accuracy at 1,000 yards.
So, for those with the relevant experience, what's the best practical way of doing this?

What sort of elevation groups are you getting at the moment?

I usually start with a ramp of charges at a 0.2 or 0.3 interval across a broad range of interest at a selected length/jump. Figure 1 show results from a recent effort.

There look to be a couple of possible interesting flat spots, but these are possibly within chrono error.

Next I shot 5 rounds at each charge weight at 0.1 grain intervals across the 2 possible flat spots, to get an initial feel for any promising loads. The results are shown in figure 2.

The load at 1.6 grains over my starting charge looks interesting, so I took this to 1000 yards to test (although I often do this at 900, since you can see the long range grouping potential of 155 grain bullets better at 900, whereas at 1000 they are closer to the ballistic limit and much more affected by atmospherics. Figure 3 shows results from this step.

Next - there is no next. I don't need to do anything more with that, so I take them to a match. Figure 4 shows the results on a fairly challenging wind day. Maybe if you need to further refine it, this is the time to mess about with changing seating depth.


Figure 1: Initial charge ramp



Figure 2: Normalised 5 shot ES



Figure 3: 1000 yard test



Figure 4: Match Day

[Racalman]

What sort of elevation groups are you getting at the moment?

I usually start with a ramp of charges at a 0.2 or 0.3 interval across a broad range of interest at a selected length/jump. Figure 1 show results from a recent effort.

The last time I measured my current load at 1,000 yards on the electronic targets I had five shots within 1.6MOA on a calm day. I measured ES last week over 10 shots and got a disappointing 34fps.

Was your ramp created using a single shot at each charge weight?

Thanks everyone else for your suggestions. Some bedtime reading there!

[rox]

Was your ramp created using a single shot at each charge weight?

Yes. It's really just a case of establishing the approximate velocity at a given charge. I used to do 2 at each weight, but it's still statistically insignificant so I switched to 1.

[Racalman]

Was your ramp created using a single shot at each charge weight?

Yes. It's really just a case of establishing the approximate velocity at a given charge. I used to do 2 at each weight, but it's still statistically insignificant so I switched to 1.

OK thanks. I'll have a go at this.

[Racalman]

And here we have the results of my ramp test.

My current load is 46.5gn so it looks as though reducing this slightly might be beneficial.

I shall repeat the test either side of 46.0gn in 0.1gn increments.