205 Bergers Powder Testing Advice 300PRC

[LocalJW]

I have the following spread sheet from Berger on 205 EH.

Seekins Element
22" Barrell
Lapua Brass
CCI250s probably

How would you decide what powders to shoot? 300PRC. Is there a quicker and more efficient way to find a powder node without shooting 3-5 shots every .4 grains? per a powder? That is close to 35-50 loads per powder range. Any advice would be great.

I thought about shooting 1 bullet for each node, and Chrono and looking for 2-4 bullets where there is less than 15fps spread between the powder jumps. Not sure if that's accurate.

My goal is obviosly get the fastest most accurate node possible.

 

[ARlife4me]

I've done the same with only 1 per. When I do that, it came down to shooting more at the same time because of multiple guns in the same cartridge with different barrel lengths and twist. Gives more time too cool down between shots. I have 3 300wm's and 3 264wm's, so I load'm all up and head out. Less driving back and forth.

 

[ridge86]

I had good luck with retumbo and h1000

 

[whatnext]

this. And N570.

 

[just_jon]

I look for a powder that gives me the highest velocity with a fill rate around 95% at max load. I then run a 10 shot velocity test up to the max load looking for pressure signs and noting velocity nodes.

 

[QuietTexan]

If the brass is new and the barrel is under ~150 rounds, don't even bother looking at velocity stats. Either pick a mid-range velocity from a known load, or run a mini-ladder up to a mid-range load and shoot all the brass a couple times and get a good number of rounds on the barrel.

And no, there are no shortcuts if you want to find the best place to be. You can SWAG based on experience and averages and the results of others, but there's no replacement for taking shots.

35-50 shots is not a lot to shoot in any rifle.

 

[LocalJW]

I look for a powder that gives me the highest velocity with a fill rate around 95% at max load. I then run a 10 shot velocity test up to the max load looking for pressure signs and noting velocity nodes.

So then if you run a 10 shot velocity

How do you pick where you going to load at or investigate more?

 

[LocalJW]

I look for a powder that gives me the highest velocity with a fill rate around 95% at max load. I then run a 10 shot velocity test up to the max load looking for pressure signs and noting velocity nodes.

Also, how far apart do you do you loads?

 

[Jud96]

First, find what powders on that list that you can actually get or that you have in hand. Of the powders on that list, H1000 and H4831sc are about the only ones I have seen for sale locally and online recently that are temperature stable and good choices.

As far as load development, I'd do as @QuietTexan recommended. I shoot at least 100 rounds through a barrel before I really start trying to narrow down a load. After that, I'll start doing some load development. In those first 100 rounds I'll get an idea of where to start with seating depth and get an idea where pressure might be. I don't rely on a single shot per charge weight to tell me anything about velocity "nodes". I have done this in the past and it's led me on wild goose chases. If you shoot 3-5 shots per charge you'll see that there's rarely a "flat spot" and most of the time every increasing charge bumps the velocity up.

I will do a pressure test beforehand with one shot each looking for pressure and seeing where the velocities are over the chronograph. I do a modified version of OCW at 100 or 200 yards and look for 2-3+ consecutive charge weights with the same point of impact. Depending on case capacity, I'll do 0.2-0.4gr increments in charge weight. I will load 10-12 loads from my safe maximum load down. This covers around 2-4gr of powder and will find you 1-2 loads. If there's large variations in points of impact between charges or no consecutive loads with the same point of impact, then that could be a sign to test a different powder or bullet. You can also shoot a ladder at long range, ideally 500+ yards. It's the same concept as an OCW test but you can do it with less shots and it's typically easier to read and is usually believed to be a more conclusive test. I don't have a reliable place to shoot long distance whenever I want, so I stick to 100 yards for most testing then I'll test my rifle and load at long range when I have the opportunity too.

 

[just_jon]

So then if you run a 10 shot velocity

How do you pick where you going to load at or investigate more?

Yes. I then plot the velocity data and investigate any flat spots. If none present themselves, I drop 1/2 to 1 grain from where I found pressure and shoot groups.

Also, how far apart do you do you loads?

Depends on the powder charge. For a 300 PRC, I would load in 1/2 or 1 grain increments. My goal is to find both a velocity node and the load where my rifle begins to exhibit pressure signs.

 

[LocalJW]

I look for a powder that gives me the highest velocity with a fill rate around 95% at max load. I then run a 10 shot velocity test up to the max load looking for pressure signs and noting velocity nodes.

Why 95%?

 

[LocalJW]

First, find what powders on that list that you can actually get or that you have in hand. Of the powders on that list, H1000 and H4831sc are about the only ones I have seen for sale locally and online recently that are temperature stable and good choices.

As far as load development, I'd do as @QuietTexan recommended. I shoot at least 100 rounds through a barrel before I really start trying to narrow down a load. After that, I'll start doing some load development. In those first 100 rounds I'll get an idea of where to start with seating depth and get an idea where pressure might be. I don't rely on a single shot per charge weight to tell me anything about velocity "nodes". I have done this in the past and it's led me on wild goose chases. If you shoot 3-5 shots per charge you'll see that there's rarely a "flat spot" and most of the time every increasing charge bumps the velocity up.

I will do a pressure test beforehand with one shot each looking for pressure and seeing where the velocities are over the chronograph. I do a modified version of OCW at 100 or 200 yards and look for 2-3+ consecutive charge weights with the same point of impact. Depending on case capacity, I'll do 0.2-0.4gr increments in charge weight. I will load 10-12 loads from my safe maximum load down. This covers around 2-4gr of powder and will find you 1-2 loads. If there's large variations in points of impact between charges or no consecutive loads with the same point of impact, then that could be a sign to test a different powder or bullet. You can also shoot a ladder at long range, ideally 500+ yards. It's the same concept as an OCW test but you can do it with less shots and it's typically easier to read and is usually believed to be a more conclusive test. I don't have a reliable place to shoot long distance whenever I want, so I stick to 100 yards for most testing then I'll test my rifle and load at long range when I have the opportunity too.

So if I wanted to load up 4-5 different powder types.

I could probably load the top 3-4gr off bergers data of each powder.

Load 3-5 bullet of each powder Grain. Maybe .5gr apart since is a 300PRC large case volume

Shoot those over chronograph. Compare that with the ES/SD and POI.

My range is hour away so I try to do most I can in 1 trip if possible.

If one powder isn't having consistent POI then maybe try the next powder?

I have RL26, 4350, N570, and N565

 

[Jud96]

I would start with N565 or RL26 with the bullet weight you have. I'd load up 10 loads of each from 1.5gr over Berger's max to 3.0gr below Berger max in 0.5gr steps. This will let you test a wide range of loads and going beyond book max will hopefully let you find max in your particular rifle. It's important to know where max is in your rifle so you know how high you can go without problems when testing.

I do 2 shots each when doing the powder test. This is enough to show where bullets are impacting and how wide the "groups" are. When you find something that looks good, then you can refine and retest with 3-5 shot groups. If you want, load up 3 of each load when you go to the range. Shoot 2 on paper without the chrono, unless it's a LabRadar, then shoot one of each charge over the chrono. Don't fall in love with a "flat spot" in velocity. That flat spot will most likely disappear if you do 3-5 shots at the same charge weights. I just use the chrono to see what my speeds are and how much change is occurring as I go up in powder each step. Big swings up and down in velocity can be a sign that the powder or primer combination isn't working. Big swings in point of impact is also a sign your load combination isn't happy like I mentioned before. I would bring loads with both powders to the range and choose whichever one looks best on paper and with the velocity data.

 

[LocalJW]

I've got a labradar. Just got one this past week but never used it.

So then when you refine, you look for 2-3 loads in congression that all have POI similar to target. Then choose middle? Do you then work seating depth? My plan was to go .002 of lands for load developement.