Load Development via pressures?

[TimberHunter]

Hello All,

Do any of you follow the pressure sign style of load development?

1. Start by choosing a powder and bullet
2. Load 1 round starting at low powder charge and work up in .5 or 1.0 grains until you hit max or just over max. (One round at each different powder charge)
3. Go to range and shoot, starting with lowest powder charge and continue up until pressures signs are seen (ejector mark, hard bolt lift, flattened primer)
4. Chronograph the above shots to make sure you’re in line with book values and pressures are ok.
5. Back off a grain or so from max and load 3-5 rounds.
6. Shoot those rounds. If those don’t group well, adjust the seating depth until desired group size is met?

I’m asking because I’m trying to safely get as much velocity out of a short barreled 308 as possible. An accurate load that has low velocity doesn’t do me much good for hunting at longer ranges

I believe hammer bullets used this style of load devleopememt


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[brisket]

Kinda...
1) I load 3 of each at 0.3gr apart starting at 10% below book max.
2) Shoot them all over a chrono looking for pressure signs.
3) Also shoot around 500yds all on the same sheet of paper.
4) look for flat spot in velocity using chrono data and impacts on paper being clustered together around different charges
5) using acceptable flat spot in charge weight, load 5 at 0.2 gr increments
6) shoot at 100 for group size and lowest es
7) load best charge weight from step 6 using bergers method to find optimal length

If velocity is not acceptable, ill change powders, primers, or brass and start over

 

[TimberHunter]

Kinda...
1) I load 3 of each at 0.3gr apart starting at 10% below book max.
2) Shoot them all over a chrono looking for pressure signs.
3) Also shoot around 500yds all on the same sheet of paper.
4) look for flat spot in velocity using chrono data and impacts on paper being clustered together around different charges
5) using acceptable flat spot in charge weight, load 5 at 0.2 gr increments
6) shoot at 100 for group size and lowest es
7) load best charge weight from step 6 using bergers method to find optimal length

If velocity is not acceptable, ill change powders, primers, or brass and start over

I’ve been doing something similar but at 100 yards. 3 rounds of each powder charge starting at low box and working up to book max in .5 increments.

Hoping to learn a quicker/more efficient way to get to an accurate and fast load


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[cooperjd]

i"ve bee doing what you're doing except i load to fairly well over book max to test, with 'normal' bullets. I'm working on absolute hammers which i'm going way way over book max to play with. i'm just shooting one at each powder and watching velocity and pressure to see what my rifles will do. From there i will back off a grain or so and play with seating depth to see if i can get good groups. idk, saw a neat article recently posted on here dealing with seating depth. lots of ways to skin a cat.

 

[TimberHunter]

i"ve bee doing what you're doing except i load to fairly well over book max to test, with 'normal' bullets. I'm working on absolute hammers which i'm going way way over book max to play with. i'm just shooting one at each powder and watching velocity and pressure to see what my rifles will do. From there i will back off a grain or so and play with seating depth to see if i can get good groups. idk, saw a neat article recently posted on here dealing with seating depth. lots of ways to skin a cat.

That’s where I got the idea from was hammer bullets but wondered if the same works for other bullets?

If you find that seating depth article, can you post it on here?


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[cooperjd]

Bullet Jump Research: Executive Summary & Load Development Tips

This is the last post in a series of articles focused on bullet jump research that has been conduct...

precisionrifleblog.com

 

[TimberHunter]

Following up on this...

I loaded benchmark 39 grains to 43.5 in .5 grain increments. 1 round at each powder charge. Used nosler brass. Book max is 43 grains

I didn’t not see any pressure signs with the nosler brass. I saw predictable velocities between the powder charges and the bullets grouped in 2 distinct groups.

Charges 39.39.5 and 40 in the yellow circle. Charges 41,41.5,42,42.5,43.0 and 43.2 grain all fell within the red circle within approx 1” group. Very happy about that! Shot 9, 43.5 grains hit the target as it fell so it hit high but I’d think it would’ve impacted within the red circle.

I then shot 3 rounds of 42 grains and got about .5” group which is very good for me.

I think this style of load development can provide valuable data in regards to if a load will have predictable vs sporadic velocities, powder charge ranges that group together and can lead to less component usage to find an accurate load

Targets are at 100 yards

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