Load development technique

[Canhunter35]

I start with longest coal, either lands or mag length depending on gun. Then perform ladder test with single shots, identifying "nodes" in the harmonics then I tweak with five shot groups around the node in .2 gr increments over my chronograph, often they will group, but there always seems to be a sweet spot where es is tight. Depending on results I can then turn seating die in by 1/4 turns, finding the right jump if I'm not satisfied with results. Only push the bullet further in, this way you will not create higher pressure. Vld's through wby usually need seating depth adjustments.

 

[Magnum72576]

Rckymtnshooter, just so I'm clear my only variable to begin with is powder weight. Load 1 round at each increment. Shot them all at 300 yds. Then look for groups that are close in verticle separation. Then pick a group and fine tune from there with seating depth for example. I never heard of this method but it sounds interesting. When I move on to my next variable say seating depth do I use the same 1 shot method or do I use 3 shot groups. Thanks tony

 

[dok7mm]

I start with a one shot ladder test and .3 or .5 increments in charge weight, dependent on case capacity, at 300 yds. W/ chronograph. This gives me a rough idea on nodes, velocity and pressure limit. I then fine tune at 400-600 yds, depending on conditions, with smaller increments. I try to load in middle of chosen node and refine seating depth when I decide on final load.

 

[coyotezapper]

http://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

 

[Greyfox]

The Berger 215 has worked well for me when seated .020" off the lands. It does not appear very sensitive to seating depth. Work up from 75 gr of H1000, or 77 gr of Retumbo in .5 gr increments. Fed 215's have worked best for me. I'm partial to Norma brass. It has 1-2gr greater capacity over the Winchester brass. I get an additional 75 FPS at 2880 with 77.8 gr Retumbo with ES under 10 FPS in my current 24" barreled 300WM compared to H1000.

 

[Litehiker]

Exactly what JoeFrazell sez, change only one thing about your load at a time, whether it is primer brand, bullet type or brand, cartridge OAL or powder charge. Then you will know if that particular change works or not.

Eric B.

 

[bpcrshooter]

I do the ladder test like talked about above, and when i find the sweet spot I take the lowest charge in that "sweet spot" and increase the charge by .1gr and ladder test those with 3rds each to find best group. I start by finding coal then back of 20-30k depending what bullet im using, most mag charges will use mag primers, my dads 300win does not. after the ladder test change primers an see if groups change. Also if you use H1000 (and this is what ive seen so far in my short life ) is that loads close too or over max work well, not saying yours will. Just pay close attention to your cases as you fire and your gun will tell you when its had enough. good luck have fun!!!!

 

[old_heli_logger]

http://www.accurateshooter.com/technical-articles/long-range-load-development/

Good luck!

 

[lancetkenyon]

I perform a ladder test also. ALWAYS with the bullets seated into the lands. That will always give you the most pressure, so you will know what your max charge weight would safely be no matter what else you change.

1 round of each charge weight, starting usually midway up the book scale, in .5 grain increments, to a couple grains over book max.

Shoot at 300 minimum over a chrono, 400 or more preferred. Starting lowest, and moving up, looking for signs of pressure, and stopping at the first sign.

Once I find my low and high nodes, I look at chrono data to find the best set of speeds.

Then load up charge weight testing at .3 grain increments and 3 shot groups. Look for best group, least vertical spread, and best RD.

Then do the same testing procedures with seating depth testing in .0400" increments.

Then, load up 15 or so and go test at distance. Usually 600, 700, 800 yard 5 shot groups.

I might fine tune a touch after that with .1 grain, or .0100" seating depth changes, but only if I am not satisfied after the initial seating depth tests or they don't quite meet my standards.

Then go and shoot....a bunch, to validate drops and accuracy way out.

It has worked phenomenally well for me in a LOT of different rifles.

 

[Zerk]

Is a .3 grain charge weight difference really going to show in the bigger cased magnums? mtmuley

First I have never shot 1000 yards. But was reading Lymann 47 and how a grain is small percentage of the load, and bullets were more important.

Again not a success, I have been doing .5, cause I read it in bunch of places. But I quit doing it for the first few grains. Unless I really want to use the powder, I more interested in the higher speeds.

 

[Albatross]

.020 off the lands or into the lands only works if you are going to shoot single shot, otherwise wasted time and powder. If you are shooting thru a magazine, to to max COAL for that mag as starting point.

Broz already has several good loads to start from with the 300 win and 215s so that makes it easier.

Agreed, although I still think its worth developing that best single shot load close to the lands as the first shot is critical and can be loaded directly into the chamber without seeing a magazine.

 

[Joefrazell]

This is only true in some guns. I've got a 300 win that I can seat .050 into the lands if I wanted to with about any bullet. It's got a huge floorplate

 

[lancetkenyon]

My R700 LA BDL with factory mag box can fit rounds in 7 Rem Mag seating 180 Hybrids and 183 SMKs into the lands in my long throated Bartlein.

And my .300RUM has a Wyatt's extended box to seat 230s way out, with a .010" jump.

So seating bullets put for a ladder test DOES make sense of you have the room or plan ahead.

 

[coyotezapper]

This is only true in some guns. I've got a 300 win that I can seat .050 into the lands if I wanted to with about any bullet. It's got a huge floorplate

Huge floorplate or huge magazine?