How does measuring powder accurately translate to distance accuracy?

[Bart B.]

“Neck tension” is a term used in the hand loading community for the diametral fit between the bullet OD and case neck ID. Control is usually via sizing the case neck OD. Many would say that a round comprised of a case having a neck ID that is .001” less than the bullet OD has .001” of “neck tension.”

Neck tension in units of diameter difference between die neck diameter and loaded round case neck outside, or sized case mouth and bullet diameters, is easier to comprehend by most people than the industry standard of bullet pull or extraction force in pounds is needed to overcome the case neck grip and friction on the bullet to push it out of the case neck.

Depending on the amount of friction between bullet and case neck, plus how hard or soft the case neck brass is, a given dimension of neck tension will require different amounts of force to push the bullet out.

That said, "neck tension" dimensions works good enough for most people.

 

[Dusty Stevens]

Neck tension in units of diameter difference between die neck diameter and loaded round case neck outside, or sized case mouth and bullet diameters, is easier to comprehend by most people than the industry standard of bullet pull or extraction force in pounds is needed to overcome the case neck grip and friction on the bullet to push it out of the case neck.

Depending on the amount of friction between bullet and case neck, plus how hard or soft the case neck brass is, a given dimension of neck tension will require different amounts of force to push the bullet out.

That said, "neck tension" dimensions works good enough for most people.

Or plain old “tensions” as your mentor guffey says

 

[Bart B.]

Or plain old “tensions” as your mentor guffey says

He does have several.

He ain't my mentor, he has too many tensions for me to put up with.

He may be one of your mentors for all I know. You get to decide that; I won't assume either way.

 

[dmoran]

Neck tension in units of diameter difference between die neck diameter and loaded round case neck outside, or sized case mouth and bullet diameters, is easier to comprehend by most people than the industry standard of bullet pull or extraction force in pounds is needed to overcome the case neck grip and friction on the bullet to push it out of the case neck.

Depending on the amount of friction between bullet and case neck, plus how hard or soft the case neck brass is, a given dimension of neck tension will require different amounts of force to push the bullet out.

That said, "neck tension" dimensions works good enough for most people.

Your repeatedly misconstruing neck tension with bullet pull, and they are 2 totally separate aspects. Neck tension is plain and simply a measurement of how much the necks are sized. It is a sizing aspect and measurement of it.

Bullet pull, just like seating force, is effected by the amount of neck tension (as well as other effecting aspects) but are both separate aspects that come after neck tension is set. Why you and your 2nd, fguffey, keep misconstruing it, does nothing but add confusion to new comers.

 

[T-shooter]

Pretty much the same process I’m loading by. I resize on a Forster fl die. Bump the shoulder about .0015 and then use a Sinclair mandrel to set neck tension. I turn my necks to about 90% clean up, which results in about a 13.5 neck thickness. I’m running alpha brass for 6.5 creedmoor.
There are a few other variables you can look at such as trying a different primer or powder. I’m runnging H4350 with 210m’s. Also look at your full ratio. Supposedly best sd and Es for a given loan can be achieved at 95% fill.
I’m very new to precision reloading but have done 300 blk ammo for years now. I read everything I can get my hands on. I’m always looking for a new approach to something to bring down sd and Es. My latest venture is sorting primers to .001 grams. I’m taking those loads out tomorrow to see if they actually shoot any better. Sorted about 400 primers and found a Es of .014 grams. I have a Labradar so it makes data collection much easier and quite fun.

A couple of other things you may try. Cut all your primer pockets to the same depth (unless they happen to be deeper). I use the same tool to cut and clean them later on. And deburr the inside end of the primer hole in the cases.

Also try measuring the internal case capacity. I changed lots on some Hornady .308 brass and found an average of 7% decrease in case volume (after all case prep). The velocity fell off substantially and it took about 3/4 grain of Varget to get the velocity back to where it was. 21st Century makes a nice 0-ring plug to use for the primer pockets. Weigh the case dry with the plug and then fill with water and weigh again.

 

[sremmell]

A couple of other things you may try. Cut all your primer pockets to the same depth (unless they happen to be deeper). I use the same tool to cut and clean them later on. And deburr the inside end of the primer hole in the cases.
View attachment 1052935
Also try measuring the internal case capacity. I changed lots on some Hornady .308 brass and found an average of 7% decrease in case volume (after all case prep). The velocity fell off substantially and it took about 3/4 grain of Varget to get the velocity back to where it was. 21st Century makes a nice 0-ring plug to use for the primer pockets. Weigh the case dry with the plug and then fill with water and weigh again.

View attachment 1052937

Thanks for the info. I’m try cutting the primer pockets. I’m trying to change one thing at a time to see what gives me the best bang for the buck.

 

[Hoosier]

I have a DVD that features David Tubb. He tells us that most standard quality powder measures provide adequate
powder charges. The variance in powder is the least important part of reloading for accuracy. It doesn't mean
that we should be careless in setting the charge in a powder measure or not checking the powder output at
different intervals for possible large changes. You still need to try and find the powder charge that is the most accurate in your particular rifle, but very minor changes are not that important. If I remember correctly, one of the most important is neck turning.
Mr Tubb, I am confident has forgotten more about accuracy than I know.

 

[Bart B.]

I have a DVD that features David Tubb. He tells us that most standard quality powder measures provide adequate powder charges.

Military 'smiths rebuilt M14NM and Garands shooting 7.62 ammo that tested about MOA at 1000 yards shooting M118 match ammo rebulleted with 180 grain Sierra HPMK bullets. The 3/10ths grain spread in IMR4895 in those rounds didn't seem to make much difference with new arsenal primed cases.

 

[Dusty Stevens]

I have a DVD that features David Tubb. He tells us that most standard quality powder measures provide adequate
powder charges. The variance in powder is the least important part of reloading for accuracy. It doesn't mean
that we should be careless in setting the charge in a powder measure or not checking the powder output at
different intervals for possible large changes. You still need to try and find the powder charge that is the most accurate in your particular rifle, but very minor changes are not that important. If I remember correctly, one of the most important is neck turning.
Mr Tubb, I am confident has forgotten more about accuracy than I know.

In mr tubb’s game it may not matter more than the other external elements that they have to deal with- i cant imagine a slung rifle with iron sights ever being able to see things like sorted primers or sorted bullets or a tenth of a grain powder charge variance like a benchrest rifle can having much less human error

 

[mikegaiz]

i do not use a "weapon" for target shooting, i use a TARGET RIFLE.
in 50 plus years of TARGET shooting, i have never been attacked by a target.

Well You have obviously never shot at some of the 1000 Yd. ranges where I shoot. They are sneaky little Sons of B____hs.

 

[newbieshooter]

Here is a similar thread.

 

[seymour fish]

There are a lot of things out there that you read that are just ideas. Similar to .1" group at 100 equals 1" at 1k. Well thats math, but it doenst work that way in real life. In this case its so easy to see a .1 powder change at 1k that its becomes very obvious that you want to weigh to the kernel. To comment on the .1gn eqauls 1" at 1k... that only tells me they have not tested it, only did the math. .1 may move the group nothing or it may move it 6" or more depending on where its at in the node.

Exactly