Determining a load

[Lonewolf74]

Having a chronograph for load development is vital.

Not busting on you but this is like saying a Kestrel is vital to shooting long range and figuring out shooting solutions, both are simply not true.

A chronograph can be a handy tool for some guidance but shouldn't be used as hard fact without verification.

 

[MagnumManiac]

My seating depth testing is done first with a middle load that is untuned, this guarantees that results are seating and not powder.
I start at touching, then go in .010" increments away from touching for 5 loads, then, if a test shows really good promise, I fine tune by .005" changes up and down. If none of the tests prove worthwhile, I will try Bergers seating test. I have had some great results from this at .100" away and further, so I don't dismiss this.
Once a seating depth is found, it rarely ever changes with powder, so I then do my powder testing at that length. This shows powder only, then if I feel a gain can be made, I will try different primers.
All of my testing is done at 200 initially, then I move out to 600 to confirm results, and I can tell you that sometimes, it falls in a heap…

Cheers.

 

[FireFlyFishing]

Not busting on you but this is like saying a Kestrel is vital to shooting long range and figuring out shooting solutions, both are simply not true.

A chronograph can be a handy tool for some guidance but shouldn't be used as hard fact without verification.

You're right. You don't NEED one to do load development. I would argue if you want to get things done quicker, less hassle, I'd say a Chrono is vital. Saves time…time is money.

Since I like to shoot farther than 100 yards, I like having the avg. muzzle velocity to plug into a calculator. I can also calculate effective range of my hunting projectile. For me to do this a chronograph is vital.

I'll rephrase…they're vital to me and my process of load development. I'm guessing many others are in the same line of thinking.

 

[Lonewolf74]

My seating depth testing is done first with a middle load that is untuned, this guarantees that results are seating and not powder.
I start at touching, then go in .010" increments away from touching for 5 loads, then, if a test shows really good promise, I fine tune by .005" changes up and down. If none of the tests prove worthwhile, I will try Bergers seating test. I have had some great results from this at .100" away and further, so I don't dismiss this.
Once a seating depth is found, it rarely ever changes with powder, so I then do my powder testing at that length. This shows powder only, then if I feel a gain can be made, I will try different primers.
All of my testing is done at 200 initially, then I move out to 600 to confirm results, and I can tell you that sometimes, it falls in a heap…

Cheers.

Magnum; what do you generally do when it falls apart at 600?

 

[Lonewolf74]

You're right. You don't NEED one to do load development. I would argue if you want to get things done quicker, less hassle, I'd say a Chrono is vital. Saves time…time is money.

Since I like to shoot farther than 100 yards, I like having the avg. muzzle velocity to plug into a calculator. I can also calculate effective range of my hunting projectile. For me to do this a chronograph is vital.

I'll rephrase…they're vital to me and my process of load development. I'm guessing many others are in the same line of thinking.

Fair enough. I just cringe when I read statements like "I find a velocity flat spot and work around there". People would be better off working up until they see pressure signs then simply picking a charge 10% or so below that because that "velocity flat spot" they think they see would disappear with more shots fired.

 

[MagnumManiac]

Magnum; what do you generally do when it falls apart at 600?

I try a new load, I find it is rarely the bullets fault because I choose my bullets to be optimum for the twist rate. If a load falls apart at 600 and I have exhausted all primers available, then I will resort to a new powder. It doesn't happen often, but my 22-250AI started out awesome at 300, but when I went to 600 with those 77g bullets it would produce fliers, changed bullets in the end, went heavier and everything settled. I feel the 7" twist was the issue.

Cheers.

 

[the big greasy]

I try a new load, I find it is rarely the bullets fault because I choose my bullets to be optimum for the twist rate. If a load falls apart at 600 and I have exhausted all primers available, then I will resort to a new powder. It doesn't happen often, but my 22-250AI started out awesome at 300, but when I went to 600 with those 77g bullets it would produce fliers, changed bullets in the end, went heavier and everything settled. I feel the 7" twist was the issue.

Cheers.

So a 1-8 twist should be perfect for the 77 smk?

 

[Lonewolf74]

So to fix things your making a major change such as powder or possibly bullets as a last resort, your not tweaking your charge weight or seating depth to bring it in?

 

[FireFlyFishing]

Fair enough. I just cringe when I read statements like "I find a velocity flat spot and work around there". People would be better off working up until they see pressure signs then simply picking a charge 10% or so below that because that "velocity flat spot" they think they see would disappear with more shots fired.

In total agreement with you there. I don't use my Chrono for that purpose…although I have seen it in some of my test results.

 

[Mikecr]

@Mikecr; would you expand on how exactly you do your seating depth test, then your ladder afterwards?

Do you shoot groups (similar to OCW) for seating or something different?

Do you find that your ladder test always produce different results then an OCW (barrel vs powder tune)?

I've nearly given up on ladder test because they almost never repeat and seems it's just a snapshot of statistical noise.

My seating test mirrors that described by MagnumManiac.
It is group shooting, 3sht for this normally tells me enough (for just this much).
The thing about seating is it's VERY coarse to results. Huge.
So at a mid charge I can be throwing out 1/2 to 1.5" 3sht groups with seating changes, and that's ok. It's easy with that to spot optimum coarse seating.

For me it has been rare that my barrel tune, providing ladder flat spots, has been within reach of an optimum powder tune.
OCW started out as a search for a forgiving load, based on ES/SD. That's not what I have been doing, except when I shot a Browning Boss barrel.
With a barrel tuner I could just shoot an MV ladder (in a sense), and from a flat velocity, adjust the tuner to put barrel tune on top of it.
Without that, I initially focus on barrel tune (ladder), and only mind load density and pressure with powder.
I could picture a balance needed at great distances, and I would want a barrel tuner for that. In my view, that's >600yds.
The last barrel I developed with ended up barrel tuned with an ES of 8fps -without a tuner. That is just luck.

The abstracts in this will never be predictable with math, so statistics are useless for ballistics.
To reduce noise you have to take everything to baseline standards. Remove variables.

 

[Big Trouble]

I went through the same thing with the 75gr. eldm. I ended up dropping to the 73gr. eldm and all was good. I am jumping them around .050. The 73 is only slightly shorter obviously, but it made a huge difference in my 223AI. Also an 8 twist.

 

[the big greasy]

I went through the same thing with the 75gr. eldm. I ended up dropping to the 73gr. eldm and all was good. I am jumping them around .050. The 73 is only slightly shorter obviously, but it made a huge difference in my 223AI.

Will try then if my smks don't shoot. I've had it with the 75 eldms. I've wasted hundreds of dollars trying everything to ge them to shoot. The a maxes shot awesome, but of course discontinued. Maybe it's because hornady recommends 1-7 twist on the eldm box and my gun is a 1-8.

 

[Big Trouble]

Gentleman I bought mine from was shooting the 75's out of it. He was pushing them much harder and liked them. I am much happier with the 73's at around 3025. While many folks have good luck with the 75's, I believe the 1:8 was borderline for me. Hope the 77's work for you Big G. If not, 73 may be another option.
Best wishes!

 

[the big greasy]

Gentleman I bought mine from was shooting the 75's out of it. He was pushing them much harder and liked them. I am much happier with the 73's at around 3025. While many folks have good luck with the 75's, I believe the 1:8 was borderline for me. Hope the 77's work for you Big G. If not, 73 may be another option.
Best wishes!

I am too! If not I will try the 73s you suggested. Thank you.