ES static or dynamic?

[ScottPriestley]

Yes, this might be a theoretical question and maybe I think too much but Im learning and thinking. The obvious response is "test it yourself" and I likely will, but wanted to see if anyone has any immediate feedback?

Assuming all variables are similar in loading (Brass, Brass prep, neck tension, primer, powder, bullet, depth) would the ES when shot from 1 rifle be similar to the ES when shot from another? Within reason - meaning an ES of 12fps on one rifle wouldnt be expected to produce ES=26fps from another rifle would it? Rifle differences would produce velocity differences but I would think that if all loaded the same, the ES would be similar from rifle to rifle. Not to say the accuracy performance would be the same of course due to differences in chamber, barrel length, etc

 

[straightshooter1]

Yes, this might be a theoretical question and maybe I think too much but Im learning and thinking. The obvious response is "test it yourself" and I likely will, but wanted to see if anyone has any immediate feedback?

Assuming all variables are similar in loading (Brass, Brass prep, neck tension, primer, powder, bullet, depth) would the ES when shot from 1 rifle be similar to the ES when shot from another? Within reason - meaning an ES of 12fps on one rifle wouldnt be expected to produce ES=26fps from another rifle would it? Rifle differences would produce velocity differences but I would think that if all loaded the same, the ES would be similar from rifle to rifle. Not to say the accuracy performance would be the same of course due to differences in chamber, barrel length, etc

I would only expect the ES's to be the same if the different rifles have exactly the same chamber specs, like tight chamber vs a loose one that can change the ignition and pressure dynamics.

 

[ScottPriestley]

I would only expect the ES's to be the same if the different rifles have exactly the same chamber specs

Ok, that may be the gap in my knowledge. But... this may increase or decrease velocity but it should do so uniformly so would the ES also vary uniformly?

 

[straightshooter1]

Ok, that may be the gap in my knowledge. But... this may increase or decrease velocity but it should do so uniformly so would the ES also vary uniformly?

I've got a spreadsheet with 1,333 lines of 22 lr data comprising of over 24,000 recorded rounds fired with various ammo and rifles and pistols, much of it from my own shooting. And though rim fire ammo doesn't even compare to what we can get out of hand loaded center fire, I can see that ES is quite uniform whether fired from a 3" barreled pistol or an 18" rifle barrel; MV's are obviously different, but ES's (and SD's) are virtually the same from different guns no matter who's ammo is being used. When I have Lapua Midas+ giving me ES's of ~25 in one gun, I can pretty much expect that same lot of ammo to do the same in a different gun just as a bulk box Winchester Super-X giving me ES's of ~ 80 does the same in various guns.

Though this data and conclusion is from rimfire, I feel sure it holds true for center fire.

This data, in large part, is what's convinced me that when handloading my ammo, my chrono numbers (the ES's and SD's) tell me nothing more than how well my cartridges are being reloaded. Other variations on paper are the results of other issues.

 

[ScottPriestley]

I've got a spreadsheet with 1,333 lines of 22 lr data comprising of over 24,000 recorded rounds fired with various ammo

Thank you! That's some great information and insight. Uniformity in firing comes from uniformity in loading.