Load development technique

[Magnum72576]

I've scoured the internet regarding this topic. However I feel more confused than ever. Can you guys direct me towards what you feel is the best approach for hunting load development for my custom 300 win mag. I hope to practice out to 1000yds. Many have had great success with h1000 and the 215 burger hybrids, which I have. I have done some shooting a few years ago with it but I want to start over with a systematic approach. Hoping BROZ might chime in here.

Thanks Tony

 

[Joefrazell]

Try to make it as simple as possible and only change one thing at a time. I'd start .020" off the lands and start at a min charge weight. Load 5 rds. Then go up .3 gr. In powder and do this all the way to maximum charge weight.

Be sure your weighing your powder accurately. Make sure you've got good brass and be sure your bullets consentricity is good on all loaded rds.

Once you find a bullet that shoots good do an ocw test so your impacts won't change dramatically with small variations in temp, Pressure ect.

 

[Dosh]

Mag, with your experience using 215 Berger and H1000 you'll perhaps need only a few test loads to find accuracy. The Broz thread "Comparing Berger 210 VLD to 215 Hybrid" is a benchmark for the 300's. We saw the 215 very quickly found accuracy with just three loads. Start with premium brass and fresh powder. Good luck

 

[Rich Coyle]

Tag

 

[Rckymtnshooter]

I have become a firm believer in ladder tests. It requires a minimal number of rounds to complete. The last ladder I did was with a 300wm. I wanted performance and accuracy so I skipped the bottom third beginning charge weights. Loaded one round each and increased the charge weight by .3 grains.

You should see accuracy nodes develop within the charge ranges where rounds start start to group together. Go back and work within these accuracy nodes. Start shooting at at least 300 yards and as you narrow down your accuracy nodes increase your distance. I did the last test at 500 yards with my final 3 loads and could have picked any one of the three but settled on the lowest charge for hopefully a little more brass life and a very minimal velocity loss. Once you have settled on the charge weight do the Berger bullet seating test and you should be done.

Guys will get lucky and have a rifle barrel combo that will shoot any load well. This last 300wm was kind of like that. I hopped around at first with random charges and finally decided to do the ladder. At the end I am confident I found the best load my riflen will shoot with.

From now in for me, new load development will always be done with a ladder test. Lots of info to read on it and also a good way to establish the max pressure load in your rifle.

 

[mtmuley]

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

 

[BountyHunter]

.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.

 

[Rckymtnshooter]

On the initial start of the ladder the .3 grain difference was very noticeable. I started at 300 yards and had 12 rounds to test. The extreme vertical spread was probably close to 10 to 12 inches with all rounds fired. Within that spread were two very distinct clusters of sequential charge weights clustered together. It is neater than hell to see how this comes together. Once you start working in those accuracy nodes you need the longer distance to start creating separation for the most accuracy. On my final three loads tested at 500 yards,that were only .2 grains different in charge weight, I could have picked any of the 3 for accuracy as there was just right at an inch difference from best to worst 3 shot group. My shooter error could account for that difference alone.

 

[Rckymtnshooter]

I saved the targets from this last test. attached is a picture of the first 300 yard test. There are actually 3 accuracy nodes you can see and the total vertical spread is 8.5 inches. I used freezer paper with the glossy side showing so the powder charges are hard to see but they are written next to each bullet hole. It gives you a good idea of the separation you will see with just a small change in powder charges.

 

[Rckymtnshooter]

My error, I got to looking at my notes. My initial 300 yard test was with .5 grain increases in charge weight.

 

[Magnum72576]

Thanks for all the great info guys.

 

[Joefrazell]

.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.

Some rifle can be loaded to the lands or even into and still fit in the mag though

 

[Alex Wheeler]

I found for 1000yd Benchrest the most efficient and best way to tune was the ladder test format at 1000 yards. In a hunting rifle I will do it at 600, even sometimes at 300. Combine it with chony data. If you find a node in the ladder AND it also happens to be in a spot where velocity stabilizes, that load will work. Just be aware, you can find the best 100 yard load with great es and it may be all vertical at 1k. You do need to test at longer range to be sure.

 

[coop2564]

.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.

This is not always true. I have a TC venture .025 off and fits fine in mag.