Question about a load development method ....

[nksmfamjp]

Personally, with a highly desirable bullet, on a new loading project, I start with the upper 25% of listed loads, on its lower end. After full-length sizing and loading to standard specs, I find best node by 3-shot groups, increasing 1 gn at a time until pressure max appears.

Interesting for 300 WSM, with h4350, the range Hodgkin provides is 59.0-63.7gr.
5gr range.
So, start at 62.4 and work up in 1 gr increments to 63.7?

How well does that work for you? Am I just reading your post wrong somehow?

 

[Veteran]

Over on Snipers Hide forum a recommended load development approach is to first chose a velocity and then adjust seating depth to tune the load. From your experience, does this a actually work?

I suppose if you were using compatible powder for the cartridge and bullet, and chose an appropriate velocity, it could work.

I believe that velocity is important in load development. That's why you hear about velocity nodes, and everything you do to vary powder charge, and bullet seating, etc. all correlate to velocity. I think velocity is important because of system and barrel harmonics. It all correlates to harmonics and the way some authors and scientists have approached this is using bullet exit time in milli seconds from the barrel.

The goal in finding a perfect load is to find the combination of bullet seating, powder charge, neck tension etc. that produces a velocity at which the harmonics of the system result in the muzzle of the barrel at time of bullet exit pointing in an identical direction. That results in small groups.

The way I approach this is using the Chris Long white paper, estimate for a given load the bullet exit time or range of times.

Then, using Quickload, calculate bullet exit time for a number of seating, and powder charge combos.

Then back into the velocity range that gives that same bullet exit time range in Quickload,

That gets you into the ballpark without wasting a lot of components. Then do the actual shooting using bullet seating, powder charge, primer selection,
shoot ladders, or OCW, or plot velocity nodes from Satterlee,
to home in on your tight groups.

But I do believe its velocity related due to harmonics and finding the combination of factors that result in consistent muzzle pointing positionat the time of bullet exit
which is by proxy a function of bullet exit timing, however you get there.

 

[Veteran]

By the way, I see a lot of folks saying bullet seating depth is the coarsest adustment you can make.

That makes some sense to me because within some defined range of differing powder charges the seating depth likely has the biggest impact on bullet exit time at the muzzle.

Bullet Exit timing ( a proxy fir velocity) and harmonics have a lot to do with accuracy and group size.

I think because the bullet seating depth may have a big impact on bullet exit timing, this is precisely why its important and noted as a more major or "coarse adjustment."

There probably is an increasing charge weight that at some point which will if still at a safe and case capacity threshold will overcome the effect of seating the bullet deeper, until it exits the muzzle at the same time it did when the bullet was seated more shallow.
You could model this in Quickload to see if this is right. I have not tried it, but it seems to make sense.

Just another thought in explaining why bullet seating is a big factor, at least over some defined range of charge weights.

 

[asd9055]

By the way, I see a lot of folks saying bullet seating depth is the coarsest adustment you can make.

That makes some sense to me because within some defined range of differing powder charges the seating depth likely has the biggest impact on bullet exit time at the muzzle.

Bullet Exit timing ( a proxy fir velocity) and harmonics have a lot to do with accuracy and group size.

I think because the bullet seating depth may have a big impact on bullet exit timing, this is precisely why its important and noted as a more major or "coarse adjustment."

There probably is an increasing charge weight that at some point which will if still at a safe and case capacity threshold will overcome the effect of seating the bullet deeper, until it exits the muzzle at the same time it did when the bullet was seated more shallow.
You could model this in Quickload to see if this is right. I have not tried it, but it seems to make sense.

Just another thought in explaining why bullet seating is a big factor, at least over some defined range of charge weights.

Veteran, have you tried GRT? Measuring velocity of at least five rounds, then GRT can help you optimize with the data!

 

[Veteran]

Veteran, have you tried GRT? Measuring velocity of at least five rounds, then GRT can help you optimize with the data!

GRT is very similar to Quickload.
You can likely use either program.
I have Qiickload.

 

[asd9055]

GRT is very similar to Quickload.
You can likely use either program.
I have Qiickload.

I have both! GRT can optimize OBT given the actually data from your rifle

 

[Phil Rizzo]

But but but, nodes don't exist some say.
You can call it anything you want but there is a "zone" that says STOP and look close, like .1 grain increments.
And the wider the better to get in the middle!

 

[asd9055]

But but but, nodes don't exist some say.
You can call it anything you want but there is a "zone" that says STOP and look close, like .1 grain increments.
And the wider the better to get in the middle!

This is for those who believe they do. Those who don't can just ignore me

 

[Phil Rizzo]

I'm with ya..

 

[Phil Rizzo]

Another tidbit to add..not my original idea by any means but a close friend's advice.

If at all possible do ladder testing beyond 100 yards if possible.
200-300 is great, 400-500 even better, as long as wind isn't too bad.
Give each shot room to disperse if that's what it wants to do.
And when interesting results appear, go to 3 shot groups.

 

[asd9055]

Another tidbit to add..not my original idea by any means but a close friend's advice.

If at all possible do ladder testing beyond 100 yards if possible.
200-300 is great, 400-500 even better, as long as wind isn't too bad.
Give each shot room to disperse if that's what it wants to do.
And when interesting results appear, go to 3 shot groups.

You are on the rght track in my opinion, and its only an opinion. I talked with a few competivie shooter champions, those who are humble enought to still share.
If you want to do ladder test, try no less than 300 yards, no more than 600. Do a 10 load 30 shot round robin. Color code the projectiles, measure velocity. You look at both the elevation change and the velocity nodes.
Find the flat spots and develop your load.

 

[asd9055]

I'm with ya..

My next try will be part modelling, part measuring, repeat.
I loaded 10 rounds. I will measure velocity, model with GRT for OBT optimum charge for my rifel and conditions. Load those, repeat.
If it works, this will be the quickest, least consumable use of any method. I don't mind trying. I dont pay attention to those will will say I am nuts.
I do what I believe in, you do what works for you. The "YOU" is for all those who have other ideas. "All roads lead to Rome" Choose the one you like

 

[Mike Matteson]

With a precision built rifle, good optics AND mounting system, I think it's pretty simple to get 1/2 MOA fairly quickly.
Just personal experience with MY rifle and 7 different bullets I developed loads for. Basically just for fun and boredom during the off season.
All bullets easily shot 1/2 MOA with 20 ES 10SD or better.

195 EOL berger
180 Hybrid berger
180 VLD Hunt berger
180 VLD Target berger
177 Hammer Hunter
169 Hammer Hunter
143 Hammer Hunter

All with N570 and 215M in either Peterson or ADG

Do a charge weight ladder. 1g. at a time. Hit pressure signs. Ejector marks, but mostly bolt lift. Back off 1g. or even 1/2g. sometimes depending on sign.

Seating depth test. Start at lands. Seat deeper 10 thou at a time until best group is reached. Normally close to the lands. Hammers needed zero adjustment. Berger's were more finicky but didn't take long to stack them on top of each other.

My charge weights were all in whole or 1/2 numbers. It really is simple, if you keep it simple. I watch all Ryan Furman's videos also. Super good info. But if I have a bullet/load that goes to **** with .2gr powder difference or .01 seating depth change, I'm going to try and find something else. I stuck with the hammers because they don't go out of tune even remotely as fast as the bergers do in my 28NOS.

Depending on case sizes. If the case is a mag size, then .5gr increase until hit chamber pressure signs. In smaller cases only .025 gr increases. You do need to learn to watch and read your cases or how your rifle is acting. It tell you that you getting into high pressures. Do some or a lot of reading on reading pressure signs. I work with a chronograph to read what going on at the same time. If you are going to use MLRP then reduce you load by about 5%. I generally don't use Mag Primers, but my case max out at about 75grs. Above that yes MLRP or shorter barrels.
Hard lift bolts, ejector marks on the case base is telling you are to hot. I stop at flatten primers. No ejector marks. Lot of people don't seem to worry about creator primers, because of firing pin bolt face opening. I don and stop there and back off a .5gr or so. Several of my reloads are 5+ grains about reloading manual max loads.
Powders are the other thing. Some powders change greatly with temp changes. This can change your chamber pressure greatly. I have attached a temp chart on some powder which has increase as the temp changests.
There no luck, just stay safe.