Ready to collect mo data on 6.5 creedmoor

[Lonewatie]

Reading the wind is a more important skill than understanding rpm, especially when you know your bullet is being stabilized at "X" distances. (Without using an rpm calculator). Sometimes we get away from the true skill of marksmanship/handloading because of things like "calculators". Its just like teenagers now days are 100% clueless as to the operation of a typewriter.

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[dennishoddy]

Reading the wind is a more important skill than understanding rpm, especially when you know your bullet is being stabilized at "X" distances. (Without using an rpm calculator). Sometimes we get away from the true skill of marksmanship/handloading because of things like "calculators". Its just like teenagers now days are 100% clueless as to the operation of a typewriter.

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Welcome to OSA! We appreciate your input.

 

[Cowcatcher]

Welcome @Lonewatie !

 

[D. Hargrove]

A few days ago I saw some 6.5cm brass for sale that was specifically marked small primer. I just kinda shrugged it off. Now since Jcann assumed I was loading small primer brass, it's got me wondering if I should add one more "variable" to my "process" by buying some. Opinions?

Personally I think you are right on course and need not convolute the waters with more variables.

 

[Jcann]

Reading the wind is a more important skill than understanding rpm, especially when you know your bullet is being stabilized at "X" distances. (Without using an rpm calculator). Sometimes we get away from the true skill of marksmanship/handloading because of things like "calculators". Its just like teenagers now days are 100% clueless as to the operation of a typewriter.

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Welcome to the forum.

I believe all relevant knowledge completes the total portrait from the chosen caliber, chamber dimension, twist, bullet weight/type, barrel length, etc on to the handloading bench and eventually to the range. After all, when you choose to build a rifle, caliber, bullet weight/type, barrel twist/length and reamer print should be your first thoughts. And there is certainly nothing wrong with technology. I’m sure the old buffalo hunters would die for what the modern day hunters have at their disposal.

Once you boil all the fat out of it, true marksmanship is hitting what you’re aiming at, the means and by what methods are irrelevant.

 

[Lonewatie]

It does, and only one variable needs changed at once. You cant change bullets, velocity, and seating depth at one time trying to focus on something as irrelevant as rpm. Build a load, typically starting with a ladder test knowing already that the manufacturers have already given you baseline for their testing of that bullet/powder/primer combination. Hornady, nosler, sierra, berger, etc etc etc, are NOT going to release load data that doesnt function with their bullets properly. All a shooter needs to be concerned with while selecting a bullet is the twist rate of his barrel. That is knowledge that was around before computers, its a given, and it will never change. Theres no reason to introduce something such as "rpm" to a newer/lesser experienced reloader when the bullet manufacturer already has covered that for them. Not all bullets of the proper weight range will function in all weapons of a given cartridge, much less caliber. The entire purpose of custom loading is so you have ammunition that "fits" that particular rifle.

Having someone take 5 steps back when developing a load that is obviously stabile at a closer distance isnt a good thing.

Learning what certain things do and why they change thingstheway they do is much more educational than not understanding why a computer told them something wouldnt work.

So many people have figured this out on their own its not even funny.

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[dennishoddy]

It does, and only one variable needs changed at once. You cant change bullets, velocity, and seating depth at one time trying to focus on something as irrelevant as rpm. Build a load, typically starting with a ladder test knowing already that the manufacturers have already given you baseline for their testing of that bullet/powder/primer combination. Hornady, nosler, sierra, berger, etc etc etc, are NOT going to release load data that doesnt function with their bullets properly. All a shooter needs to be concerned with while selecting a bullet is the twist rate of his barrel. That is knowledge that was around before computers, its a given, and it will never change. Theres no reason to introduce something such as "rpm" to a newer/lesser experienced reloader when the bullet manufacturer already has covered that for them. Not all bullets of the proper weight range will function in all weapons of a given cartridge, much less caliber. The entire purpose of custom loading is so you have ammunition that "fits" that particular rifle.

Having someone take 5 steps back when developing a load that is obviously stabile at a closer distance isn't a good thing.

Learning what certain things do and why they change things the way they do is much more educational than not understanding why a computer told them something wouldn't work.

So many people have figured this out on their own it's not even funny.

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RPM is just a measure of twist vs velocity, and your correct, This stuff has been figured out long ago. I went to the Camp Perry matches back in the 80's as part of a support unit of the Army Reserve.
I volunteered to work nights so I could watch the 1000 yard matches. They would fire one round, remeasure the humidity, and other variables then load one more round right on site. Shoot again, rinse and repeat. It was a laborious process they used.
Now technology has improved long range shooting with Kestrels to measure wind speed (which can certainly change over the course of 1000 yards in different directions) and other innovations in technology.
In the 60's and early 70's the 30-06 was still the king of the 1000 yard range. My how things have progressed with the new bullets with incredible BC's, and the use of ultra high speed photography to actually watch the bullet in flight and improve the design.

 

[Cowcatcher]

BC is a yuge factor it seems to me. I was playing with the "stability calculator" linked above and noticed that BC number can be the difference between one bullet requiring 1875fps to be "comfortably stable" while another bullet of the same weight only requires 1080fps. Now, I realize nobody is gonna load a 6.5cm to 1080 or even 1875 but there is a little info on what Improved BC can be responsible for.

 

[Jcann]

It does, and only one variable needs changed at once. You cant change bullets, velocity, and seating depth at one time trying to focus on something as irrelevant as rpm. Build a load, typically starting with a ladder test knowing already that the manufacturers have already given you baseline for their testing of that bullet/powder/primer combination. Hornady, nosler, sierra, berger, etc etc etc, are NOT going to release load data that doesnt function with their bullets properly. All a shooter needs to be concerned with while selecting a bullet is the twist rate of his barrel. That is knowledge that was around before computers, its a given, and it will never change. Theres no reason to introduce something such as "rpm" to a newer/lesser experienced reloader when the bullet manufacturer already has covered that for them. Not all bullets of the proper weight range will function in all weapons of a given cartridge, much less caliber. The entire purpose of custom loading is so you have ammunition that "fits" that particular rifle.

Having someone take 5 steps back when developing a load that is obviously stabile at a closer distance isnt a good thing.

Learning what certain things do and why they change thingstheway they do is much more educational than not understanding why a computer told them something wouldnt work.

So many people have figured this out on their own its not even funny.

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I don’t believe anyone is focusing on RPM and no one is asking anyone to take 5 steps back. An 8 twist barrel (which his probably is) will stabilize 140 grain bullets just fine in a Creedmoor. The question of stability was asked without a clear meaning or understanding by a different poster.

Your comment, “All a shooter needs to be concerned with while selecting a bullet is the twist rate of his barrel” may be true for the most part but it’s not necessarily true for the long range shooter. Say a company comes out with a new bullet with extremely high BC but needs an 8 twist to fully stabilize it and your barrel has an 8.7 twist. Can you shoot this bullet and fully stabilize it while taking full advantage of its BC? You can if you shoot it fast enough. How fast? If you use a calculator you can determine a starting point or baseline.

How does the typical handloader know what twist will stabilize a bullet? You are correct in saying it’s from the manufacturer’s web site or reloading manuals. When Berger first came out with their 195gr 7mm EOL Elite Hunter it had a stated twist of 8. They have since changed it to a 9 twist but through conversations with Berger’s technical staff through emails they said it is not fully stabilized in a 9 twist barrel for all 7mm chamberings. The only reason I see to this change was because most factory 7mm barrels are 1:9 twist. Those of us who may want to use this bullet to its fullest potential know we need a 1:8/1:8.5 twist. Also, if you are shooting a 7wsm with a 1:8.5 twist you may not get the muzzle velocity to take full advantage of the high BC unless you have a lot of free bore allowing you to seat the bullets long for more case capacity for powder. Doing this may exceed magazine length causing it to become a single shot. Now I could go out and spend $50 on a box of bullets and give them a try but I choose not to based on information gleaned from the manufacturer and knowledge in the relationship between bullet weight, twist, and muzzle velocity with regards to BC. Bergers twist rate calculator also gives the shooter a starting point for adjusted BC if twist and MV do not achieve manufacturer stated BC. Granted, these are usually tweaked based on field data, but it is a starting point. Kind of like your comment, “manufacturers have already given you baseline for their testing of that bullet/powder/primer combination”.

If you shoot extended long range, how well does a bullet transition through transonic flight? They are not all equal in this regard and manufactures such as Sierra, Hornady, and Berger have test data that proves this.

Will this information help cowcatcher in his reloading pursuit with the creed? No, but it may aid him in future endeavors. Keeping his reloading simple, choosing the correct bullet, powder, primer, case prep, and changing one thing at a time while gathering data will help the most. Personally I believe with the proven track record of H4350 in short action 6.5mm that’s the powder he should be trying first but I understand the issues of finding it. Your suggestion of ladder testing is a great idea if he understands what that is and how to do it. Maybe in your next post you can be a mentor by explaining this bringing value to the discussion and stop complaining about computers, calculators and teenagers who are clueless of typewriters. I’m sure this forum was set up for like minded people to ask question and share information to those who enjoy the shooting sports and those who are trying to broaden their knowledge.

 

[Jcann]

BC is a yuge factor it seems to me. I was playing with the "stability calculator" linked above and noticed that BC number can be the difference between one bullet requiring 1875fps to be "comfortably stable" while another bullet of the same weight only requires 1080fps. Now, I realize nobody is gonna load a 6.5cm to 1080 or even 1875 but there is a little info on what Improved BC can be responsible for.

That program is only for Berger bullets of which you are not using. BC's give the shooter an idea of how well the bullet slips through the air and doesn't matter to a greater degree until you're shooting longer distances. The average rifle hunter could care less about BC and that's probably the reason you don't see it on a box of manufactured ammo.