300wm load help please

[muddy216]

Load data as follows
Twice fired norma brass
Primer pockets uniformed
Wilson bushing die sized
5thou bump on shoulder
Remington mag primers
75.2 grains of rs70 after ladder test of 15 rounds same speed node across 3 rounds went bang in the middle node no other noticeable node.

Loaded 15 rounds as per above after load test using above load with eldx 178gr now getting a sd of 24 and es of 79.9
Speed is average of 3035fps
Powder measured on very high precision lab scale.

Load developed using Gordon’s reloading all within pressure parameters and showing no signs of pressure when fired

Need to get the ES and SD down

Any pointers or advice for improvement please

 

[muddy216]

Bullets seated 15 though off jam

 

[NP435]

Not that this will help you, I am curious about the group size you are getting. Unless you are shooting extreme long range I would not worry about what you are getting now.

 

[muddy216]

Bout 1.5 inch at 100 at the minute but not tried tuning it yet. Trying to he the es where it should be.

Factory ammo going into an inch

 

[muddy216]

Not that this will help you, I am curious about the group size you are getting. Unless you are shooting extreme long range I would not worry about what you are getting now.

Unfortunately I’m down the rabbit hole

 

[.25-06]

Redo ladder test at a least 300m that would give a better start point.

 

[muddy216]

Redo ladder test at a least 300m that would give a better start point.

Why would doing the ladder at 300m improve anything? My chrono will still give me the same speed surely

 

[HandB]

I have found bad chrono numbers indicate I am using the wrong powder for my rifle/cartridge/bullet combo and, usually it turns out to be too slow. Try a ladder test with a slightly faster powder. If that doesn't improve things try a heavier bullet.

 

[Eric the Red]

Ensure you are sizing all the neck. (I'd anneal if you can). Are you sure you're using the right sized bushing? Make sure the body is sized all the way down as well - remember it's headspaced off the belt.
What OAL are you using - make sure the whole neck is gripping the bullet. What barrel length? Personally I'd focus on getting the brass as consistent as possible on length, and then forget chasing the lands; use what neck you have to grip the bullet - you've probably not got enough consistency sat too far out.

 

[Outback]

I used to load all different powders as there were shortages but always could get Vht165 shooting 190 SMK or 180 Nosler , aimed for 2900/2950 loaded to mag length .
Case prep is very important as mentioned , why 15 thou shoulder bump ? Larry Willis makes a die for the shoulder bump .
Measure case base to ogive seat the bullets just under mag length and you should be good .

 

[Outback]

Sorry the Larry Willis die should have read case bulge .

 

[Edinburgh Rifles]

Load data as follows
Twice fired norma brass
Primer pockets uniformed
Wilson bushing die sized
5thou bump on shoulder
Remington mag primers
75.2 grains of rs70 after ladder test of 15 rounds same speed node across 3 rounds went bang in the middle node no other noticeable node.

Loaded 15 rounds as per above after load test using above load with eldx 178gr now getting a sd of 24 and es of 79.9
Speed is average of 3035fps
Powder measured on very high precision lab scale.

Load developed using Gordon’s reloading all within pressure parameters and showing no signs of pressure when fired

Need to get the ES and SD down

Any pointers or advice for improvement please

Understand the "Rabbit Hole" effect but why the NEED to get ES down?
Have you actually tried these at range?
ES is a niggle that does not always impact group size or accuracy at range

My 300Norma Mag loads are significantly bigger ES and proven 0.5MOA at 1000m

Given everything you have listed I would personally be looking at Neck tension
Anneal.
Run an Expander Mandrel through them all
Outside neck turn to standardise neck wall thickness. Your Outside neck bushing is very precise but not if the neck is variable thickness or not concentric

 

[markyw]

Out of interest, what weight bullet and speed for the factory rounds and have you tried the OBT button in GRT to see how that differs from your current load? I'd have done it but no barrel length given.

Regards

Mark

 

[muddy216]

Understand the "Rabbit Hole" effect but why the NEED to get ES down?
Have you actually tried these at range?
ES is a niggle that does not always impact group size or accuracy at range

My 300Norma Mag loads are significantly bigger ES and proven 0.5MOA at 1000m

Given everything you have listed I would personally be looking at Neck tension
Anneal.
Run an Expander Mandrel through them all
Outside neck turn to standardise neck wall thickness. Your Outside neck bushing is very precise but not if the neck is variable thickness or not concentric

In all honesty Ed I’ve not done any more than take a rough gauge at 1.5” at 100 as I was looking to get the ES down prior to throwing more ammo down range. I’ll revisit the group size and see what it is when not concentrating on ES alone. I’ll anneal and run through the expander mandrel aswell see where I end up.

 

[muddy216]

Out of interest, what weight bullet and speed for the factory rounds and have you tried the OBT button in GRT to see how that differs from your current load? I'd have done it but no barrel length given.

Regards

Mark

150gr at 3129 fps. 24” barrel

My daughter has smashed the screen last week on my laptop so no grt at present new screen getting fitted

 

[muddy216]

I used to load all different powders as there were shortages but always could get Vht165 shooting 190 SMK or 180 Nosler , aimed for 2900/2950 loaded to mag length .
Case prep is very important as mentioned , why 15 thou shoulder bump ? Larry Willis makes a die for the shoulder bump .
Measure case base to ogive seat the bullets just under mag length and you should be good .

5thou shoulder bump 15 thou for bullet seating from jam

 

[ejg]

One hears normal primers can often improve accuracy and ES on the 300wm.
edi

 

[markyw]

150gr at 3129 fps. 24” barrel

My daughter has smashed the screen last week on my laptop so no grt at present new screen getting fitted

Sent you some details on the first safe OBT node values.

Regards

Mark

 

[Outback]

5thou shoulder bump 15 thou for bullet seating from jam

Sorry my mistake (multitasking )
Your cases If new possible haven't finished expanding to your chamber spec according to die makers they generally need three firings on virgin brass to let them fully seat in .
The general shoulder bump is 2 thou for target shooting (you are possible setting back to beyond virgin brass dimensions ) which is were I'm at and I load to mag spec .
I would sort out neck tension consistency and load to a mag length spec which would give you a fast second shot if needed .

 

[.25-06]

Why would doing the ladder at 300m improve anything? My chrono will still give me the same speed surely

ILDM Load Testing (aka “Ladder Test”) – Coyote Stuff

coyotestuff.com

At 100m your powder will still be fizzling out.
With 243 I have found some loads at 100 had bullets sideways at 300. Those loads weren't tweaked but binned. A good load combination tends to shoot well and get better with a tweak