Load dev 308

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MartyK2500

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Hi, i am in the process of rebarelling.
I want as little downtime possible and get good loads out asap for 2018 season.

In 2017, here is how i would load dev. 308 LP lapua brass, CCI BR2 primers, Varget, 175 SMK
5 Shot groups. Starting at 42.1gr and climb up in 0.3gr increments. 10 thou off the lands.
I would chose group that would have a nice group just over and just under it. Example : My 43gr Varget wasnt the best group, but was solid, and 42.7gr and 43.3gr we're also nice.
Then i would take my 43gr, and load a few rounds, still in 5 shot groups. 20 thou off land, 15 thou off lands, 10...,5...,touching, 5 thou jam (this one i would closely monitor for pressure).

Anything else could be added (or removed) to get nice loads out, in under 3-4 range visits?
 
Never tried that test will have to look into it.
Last year i was taught to look at groups only. Each load was a new group on a new target.
I would pick the load that yielded good results, between two good groups. Then change seating depth to tune accuracy.

Will google ladder test and see whats up with that
 
Your procedure sounds perfect.

I would repeat it with a different bullet, too, because some barrels do much better with a different bullet (unless the 175SMK result is so good there is no room for improvement.)
 
10-4, you know something i had not even considered.
Having a match barrel come in (cdn made ibi barrels), and just figured my 'ol 175SMK that had me regularly shoot 0.6moa (and sometimes better) in a factory savage pipe was the go to bullet.

If my match barrel is somewhat hard to find nodes or hard to shoot well, i will try something else.
Just can't afford shooting 1$ pills called Berger, 175SMK is pretty much my max budget considering other components.
 
Mystic Precision said:
https://www.longrangehunting.com/articles/load-tuning.281/

https://www.longrangehunting.com/articles/precision-reloading-for-long-range-hunting.17/

How I set up my loads with as few shots as possible.

Enjoy...

Jerry
Click to expand...

Thanks, looks like a good read. Actually started it (1st link) but off to work i go, i'll finish it later when i get back to the office.

maynard said:
Don’t be afraid to seat farther from the lands. I have seen guys jumping .040”-.08” and getting great results.
Click to expand...

That would make for some endless testing!
Maybe something i'd get into in downtime play around with OAL as much as that, for now i'll try to keep testing quicker.
I want rifle with load ready for april, no time to waste!

todbartell said:
Changing seating depth after finding an optimal charge weight, is pretty pointless. Back to square one
Click to expand...

When i was taught this, i was finding the logic behind it looked good.
Using a good load (not the best) that is between 2 good loads, is to settle for powder charge sensitivity. A less temperature sensitive load as the increments before and after also group.
Then seating depth is to tune accuracy.
 
I have played around with many techniques, and have changed my tune a fair bit as I learn more - but i seem to be staying on my last method... Similar to many of above mentioned ways....

1) Sight in rifle at 200, adjust to 400yds
2) Load 2 rounds each powder dose (in your case i would start at 41.5 and go to 45) in 0.3 gr increments, 20 thou off
3) Place two targets at 400yds (or 300) and shoot one of each round at the one target
4) Repeat with other rounds on 2nd target
5) Look for a corresponding 'flat spot' where bullet impacts have the least vertical spread on the two targets and note the powder dose
6) load up 3 or 6 rounds 0.2 gr on and either side of flat spot powder dose, shoot 3 shot groups with each load; repeat if you wish; you should see the load that works
7) You could then load this load with different seating depths and see if it makes a diff. SMK/TMK were very jump tolerant in my rifles, Bergers needed the tweak.
8) done

I will bet you find a load with your components 42 +/- 0.3 gr and the upper at 44.4 +/- 0.2gr!
 
6MT said:
Huh?! I always test depths after OCW is found. That's usually my final step in development.
Click to expand...

As you change seating depth closer or further from the lands, you change the pressure and velocity of the load. I would just seat .015" off the lands and tune powder charge if a guy wants to get a load developed with minimal effort
 
Jerry, in your article you mention not playing with seating depth.
Once lands distance are determine, was is your go to jump then?

ChrisMC, with factory barrel and 175SMKs, my personal records have been done with 43gr Varget.
When i was loading hornady match 178gr, my sweet spot was 42.1gr

6MT, what are the 3 seating depths you usually try for?
 
6MT said:
I just can't agree with your statement that you would be back at square one in development if it's done this way.
Click to expand...

square one would be an exaggeration, sorry. If simplicity and efficiency is the goal of load development, start .020"ish off the lands (assuming it functions in magazine) and tune powder charges to find the node
 
todbartell said:
square one would be an exaggeration, sorry. If simplicity and efficiency is the goal of load development, start .020"ish off the lands (assuming it functions in magazine) and tune powder charges to find the node
Click to expand...

Once you have found the node, you don't try a few seating depths within that node to see what could result of it?
 
Long range load development at 100 yards.
Erik Cortina Team Lapua USA
http://forum.accurateshooter.com/members/erik-cortina.1217825/
4. Load a known powder/primer/bullet combination. I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020".
Update: 9/17/14
Some of you have asked for more detailed instructions on how I do this. Here they are:
1. Find Jam by seating a bullet long on a dummy piece of brass (no primer nor powder) and apply die wax to the bullet ogive and record it's base to ogive length.
2. Chamber the round and close the bolt.
3. Snap the bolt open and measure the base to ogive measurement. If it is shorter than previous measurement, this is your jam. Do it a few times with different cases to make sure.
4. Load a known powder/primer/bullet combination. I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020". I use one shot of each to get barrel fouled up and also keep an eye for max pressure at the same time. You can also use these rounds to break in a barrel if you are inclined to. If I encounter pressure on the hotter rounds, I will not shoot groups with the other loaded rounds and will pull bullets when I get back home. Do not shoot in round robin style because position and natural point of aim will be compromised.
5. Shoot 3 shot groups starting from lowest to highest. All groups are shot over a chronograph.
6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.
7. Load to the middle of the powder node and do a seating depth test.
8. Load 3 shot groups starting from Jam - 0.005" all the way out to Jam - .040" in .003" increments.
9. When you find the seating depth test that shoots the best, load towards the longest side of the node to allow more room for throat erosion.
10. Final step is to load the new seating depth and load 5 shot groups in 0.1 gr. increments 0.5 gr. on each side of node (if pressure limits are not reached). This will cover an entire grain of powder and you will be able to pinpoint where the powder node starts and ends. In the summer, load towards the low end of the node, and do the opposite in the winter.

HAPPY SHOOTING!
 
MartyK2500 said:
10-4, you know something i had not even considered.
Having a match barrel come in (cdn made ibi barrels), and just figured my 'ol 175SMK that had me regularly shoot 0.6moa (and sometimes better) in a factory savage pipe was the go to bullet.

If my match barrel is somewhat hard to find nodes or hard to shoot well, i will try something else.
Just can't afford shooting 1$ pills called Berger, 175SMK is pretty much my max budget considering other components.
Click to expand...

Try some 155gr or 168 amax’s, they are cheap and have been consistent for me.
 
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