ELDx seating depth. 7mm Mag

[Jake Suttles]

If you are looking for a load with ELDX the best way to find your load is to find your lands and measure to the ogive. Seat your bullet .01 in the lands and .01 out of the lands. This .02 between the two is your no go zone. Find your powder you wish to try and check your reloading manual for charge data. Choose the middle of where you want to be and load 1 bullet at each charge moving charge in half grain increments up and down 3 charges each. For example chart reads 45gr is a good moderate charge, so load 1 rd at 45gr 1rnd at 44.5 gr 1 rnd at 44gr 1 rnd at 43.5gr then 1rnd at 45.5gr 1 rnd at 46gr 1 rnd at 46.5gr. Then shoot all 7 rnds at 100yds. You will see consistency in the group. Then look at your group note where each charge landed on the paper before taking the next shot. After shooting this ladder test with .01 in the lands repeat the process .01 out of the lands. Document each rnd. When completed choose which length is best then load 3 rds of each charge that shot similar. Fire these 3 loads at 400yds you will know at that point which load is yours. If for some reason no load shines through choose another powder and repeat process. I have never had to choose an alternate powder. This is by far the best way to test loads. Your checking consistency at 100yds and rpms at 400yds. Good luck,and have fun.

Is there a sweet spot for loading these? I loaded a few different lengths and they didn't shoot well. I started .050" off the lands and went from there. Do they prefer to be seated closer to the lands?

 

[Blackhawk]

Is there a sweet spot for loading these? I loaded a few different lengths and they didn't shoot well. I started .050" off the lands and went from there. Do they prefer to be seated closer to the lands?

As with any rifle there are what is known as stacked tolerances.
Let me explain and you will understand.
Every part of your rifle that has been machined, has been machined to a given plus or minus set of tolerances. Even though a part can be machined to factory specifications lets say with a plus or minus .005" tolerance, a part can be machined to lets say a +.004" and still be used as the specs allow for a + - '005".
Follow me ?
Now lets say that those dimensions were for the chamber.
Now lets say for simplification that your barrel's fit to chamber using a headspace gage is + .003" again using your head space gage. your barrel and chamber now are showing a stacked dimension tolerance of +.007".
This is the tolerance which is still within allowable specifications.
Now carrying this on further , lets say that the bolt itself is +.003".
Well now you have a stacked tolerance of + .010"
Every component has established dimensions you can see how they become stacked towards either the high side or the low side.
As each rifle part is manufactured it is made to a set of tolerances whether they are to the + side or - side and are still within these hypothetical manufacturing specifications , therefore are useable (as long as they meet said specifications)
So what I am trying to say is that you will have to work up your jump factor incrementally until your ES and SD numbers are as small as possible.
Please stay with me !
I have one rifle that has an - .008" jump factor using Horandy ELDX Bullets (ACTION IS BLUEPRINTED),while another rifle of the same manufacturer and caliber, again with a blueprinted action has a jump factor of - .040". using the horandy ELDX bullets.( Caliber doesn't matter, as the result is will be the same for any caliber and any bullet, in any one given rifle)
So I recommend the following.
Here your Chronograph is your best friend ,however with that being said you must only (unless you want to go crazy) change one item at a time.
Start with a powder and grain recepie that will get you on paper and temporarily leave it be.
Now establish where your bullet makes contact with your rifles lands.
Without changing anything else, what I do when starting load development is to set a jump of -.003' and load five rounds.
The next five rounds are loaded with a -.010 "jump.
The next five rounds are loaded with a -.015"' jump.
I do this is .005" increments ( you can use -.010" if you prefer) until I have loaded 25 rounds.
Now to to the range and get some trigger time.
Carefully note your MV = ES and SD form your 5 shot groups again using your chronograph as your guide.
Keep up this procedure by loading at -.005' jump in increments of five completed rounds and shoot until you find your "Node" (your Chronograph will speak here)
Now you can refine your bullet's jump incrementally until your ES & SD numbers are as small as possible.
You will then either increase or decrease your powder charge in leys say = .005" without changing your already established jump length until your MV = (ES) and SD are at least below 20 fps ( for hunting and tighter for accuracy shooting) and your shots are as closely grouped as possible.
Document everything and just be patient.
Soon everything will fall in place for that particular rifle, that particular bullet, that particular brass case, that particular powder and grain weight, and particular primer for a complete satisfactory recipe.
I hope that you don't feel that I have digressed from your original question?
However, IMHO it is all relevant regarding your quandary. Is It Not?
I really hope that you will benefit from this rather long text.
best of luck !!

 

[thaught]

As with any rifle there are what is known as stacked tolerances.
Let me explain and you will understand.
Every part of your rifle that has been machined, has been machined to a given plus or minus set of tolerances. Even though a part can be machined to factory specifications lets say with a plus or minus .005" tolerance, a part can be machined to lets say a +.004" and still be used as the specs allow for a + - '005".
Follow me ?
Now lets say that those dimensions were for the chamber.
Now lets say for simplification that your barrel's fit to chamber using a headspace gage is + .003" again using your head space gage. your barrel and chamber now are showing a stacked dimension tolerance of +.007".
This is the tolerance which is still within allowable specifications.
Now carrying this on further , lets say that the bolt itself is +.003".
Well now you have a stacked tolerance of + .010"
Every component has established dimensions you can see how the become stacked towards either the high side or the low side.
As each rifle part is manufactured it is made to a set of tolerances whether they are to the + side or - side and are still within these hypothetical manufacturing specifications , therefore are useable (as long as they meet said specifications)
So what I am trying to say is that you will have to work up your jump factor incrementally until your ES and SD numbers are as small as possible.
Please stay with me !
I have one rifle that has an - .008" jump factor using Horandy ELDX Bullets (ACTION IS BLUEPRINTED),while another rifle of the same manufacturer and caliber, again with a blueprinted action has a jump factor of - .040". using the horandy ELDX bullets.( Caliber doesn't matter, as the result is will be the same for any caliber and any bullet, in any one given rifle)
So I recommend the following.
Here your Chronograph is your best friend ,however with that being said you must only (unless you want to go crazy) change one item at a time.
Start with a powder and grain that will get you on paper and temporarily leave it be.
Now establish where your bullet makes contact with your rifles lands.
Without changing anything else, what I do when starting load development is to set a jump of -.003' and load five rounds.
The next five rounds are loaded with a -.010 "jump.
The next five rounds are loaded with a -.015"' jump.
I do this is .005" increments ( you can use -.010" if you prefer) until I have loaded 25 rounds.
Now to to the range and get some trigger time.
Carefully note your MV = ES and SD form your 5 shot groups again using your chronograph as your guide.
Keep up this procedure by loading at -.005' jump in increments of five completed rounds and shoot until you find your "Node" (your Chronograph will speak here)
You will then either increase or decrease your powder charge without changing your already established jump length until your MV = (ES) and SD are at least below 20 fps ( for hunting ) and your shots are as closely grouped as possible.
Document everything and just be patient.
Soon everything will fall in place for that particular rifle, that particular bullet, that particular brass case, that particular powder and grain weight, and particular primer for a complete satisfactory recipe.
I hope that you don't feel that I have digressed from your original question?
However, IMHO it is all relevant regarding your quandary. Is It Not?
I really hope that you will benefit from this rather long text.
best of luck !!

Thanks. I'll give it a whirl

 

[dougduey]

I've found them to be all over the place with seating depth. I load them in 5 different cartridges. Some like jump, others like to be closer to the lands. What has worked best for me lately is I seat the boat tail/base of the bullet junction to the neck/shoulder junction of the brass. This gives a very concentric round of ammo. I'll work up the load and find my best and most consistent velocity node. Then I see how it groups. Usually it's excellent, but I've had to play with a couple. It only took me adjusting the seating depth 0.005" to snug things up.