Correlating seating force with... anything?

[memilanuk]

Could it be because I am not resizing the full length of the neck? More like 3/16" only.

Nah, thats fairly normal with bushing dies.

I did email 21st Century. John suggested trying the .287 bushing. He said it sounds like I'm not actually getting the .002 tension like I think I am.

On the one hand, if it shoots the way you want, don't go changing too much because someone on the Internet doesn't like it

On the other hand... you can get a rough idea of what the ID is using the tips on the back side of your calipers. Just have to be careful to be sure the bevels don't interfere with the contact. Or if you want to be more confident, you can get some pin gages off Amazon for pretty cheap, in 0.0005" increments. Basically you'd use them like go/no-go gauges - if the .2875 one fits, but the .2880 doesn't... well you have a pretty good idea what the hole size is, more accurately than you can generally measure with calipers.

 

[Bart B.]

Could it be because I am not resizing the full length of the neck? More like 3/16" only.

Yes, so thinks me.

The unsized part of the neck has a larger inside diameter. As bullet heels are usually bigger in diameter than their shanks, less force is needed to seat them once their heel goes past that step inside the neck. A few to several ten-thousandths inch difference.

 

[mikecr]

Bullet extraction force does contribute to muzzle velocity.

Only a truth passes all tests, so the first time your notion fails a test, it is not a truth.

Now, clean a neck ID, and a bullet both to squeaky clean. Note the greatly increased seating or pull force.
Fire it with other cases of same sizing, and you will not see a change in MV.
Now coat both a neck ID and bullet with Tungsten Disulphide(incredibly slippery). Seat the bullet and notice you might be able to pull the bullet here with your fingers alone. Fire with the others -zero change in MV.
Bullet extraction force does not contribute to muzzle velocity.

ACTUAL neck tension does contribute to muzzle velocity.
Partial length size a few necks to .xxx of interference fit.
FL size a few necks to same interference.
Seat all bullets short of bearing into neck-shoulder junction.
Measurement of seating forces -vs- pull forces between these would show higher pull forces than seating forces.
This time we have no frictional difference. It's a tension difference.
MV will shoot higher with the FL sized necks.
Yes, this is apparently higher pull force equals higher muzzle velocity. But prior evidence(frictional testing) eliminates that notion.

It's important to understand the difference.

 

[Dusty Stevens]

I am the fan of bullet hold, all of my gages are calibrated in pounds.

F. Guffey

show us these gages?

 

[Immike]

Only a truth passes all tests, so the first time your notion fails a test, it is not a truth.

Now, clean a neck ID, and a bullet both to squeaky clean. Note the greatly increased seating or pull force.
Fire it with other cases of same sizing, and you will not see a change in MV.
Now coat both a neck ID and bullet with Tungsten Disulphide(incredibly slippery). Seat the bullet and notice you might be able to pull the bullet here with your fingers alone. Fire with the others -zero change in MV.
Bullet extraction force does not contribute to muzzle velocity.

ACTUAL neck tension does contribute to muzzle velocity.
Partial length size a few necks to .xxx of interference fit.
FL size a few necks to same interference.
Seat all bullets short of bearing into neck-shoulder junction.
Measurement of seating forces -vs- pull forces between these would show higher pull forces than seating forces.
This time we have no frictional difference. It's a tension difference.
MV will shoot higher with the FL sized necks.
Yes, this is apparently higher pull force equals higher muzzle velocity. But prior evidence(frictional testing) eliminates that notion.

It's important to understand the difference.

Just jumped in here without reading but everything you said seems true. I recently tried solid neck 40# tension instead of soft seating a jammed Bullet. Conducted a jam test and found improvement with just less than jam and it shot well for a long match.

 

[Bart B.]

Would crimping case mouths into bullet cannelures cause velocity change compared to not crimped?

 

[CT10ring]

Gents, I have been following this conversation...not sure what theses presses are.
Here's a photo of mine. No brainer when the bullet is fully seated. Can you post a pic w your presses, dials etc.

 

[Dusty Stevens]

Gents, I have been following this conversation...not sure what theses presses are.
Here's a photo of mine. No brainer when the bullet is fully seated. Can you post a pic w your presses, dials etc.
View attachment 1039941

 

[CT10ring]

OK thx, so this tool/dial is measuring/ the force necessary to : do what exactly?
If the preferred C/OAL is known (jump to lands), and presumably should be the same for all rounds, and the neck tension is/has been set by the die/brass dimensions/bushing already chosen, all bullets are same diameter, say.224", what variable is this measuring and...why?

 

[Dusty Stevens]

OK thx, so this tool/dial is measuring/ the force necessary to : do what exactly?
If the preferred C/OAL is known (jump to lands), and presumably should be the same for all rounds, and the neck tension is/has been set by the die/brass dimensions/bushing already chosen, all bullets are same diameter, say.224", what variable is this measuring and...why?

no matter how much you try to be consistent neck tension is never the same every time. sometimes you gotta change bushings, anneal, scrap pieces, etc.

 

[CT10ring]

no matter how much you try to be consistent neck tension is never the same every time. sometimes you gotta change bushings, anneal, scrap pieces, etc.

OK, so the hydro press gives a quantifiable number to the force required to seat bullet vs a "feel". I'd like to know if the fellow in the video
has better results on paper shooting with the information gleaned from the hydro.

hand reloading - art + science + technique + aptitude + personal choices + voodoo. Then there is the actual shooting

 

[Dusty Stevens]

Everybody i know that uses one can see it on paper. All it takes is one reloading session finding one of your lower tensions and shooting it with the other ones to see. If youre running 40-50psi then get a 30 its hard to feel on a regular arbor but you can see it on the hydro and that 10-20psi makes a huge difference

 

[Richard Coody]

Everybody i know that uses one can see it on paper. All it takes is one reloading session finding one of your lower tensions and shooting it with the other ones to see. If youre running 40-50psi then get a 30 its hard to feel on a regular arbor but you can see it on the hydro and that 10-20psi makes a huge difference

for me using the 21st century shooting hydro press was a very enlightening experience. i thought my very carefully prepared brass had consistent neck tension. the gauge will quickly let you know if that is so. went through several different ways of preparing necks after that. what i learned. take care of that carbon in the necks. turned necks annealed every firing. i clean the outside of the cases with a rag soaked in ballistol and just lightly brushed out the necks with a nylon brush. after trying several different sizing dies i wound oup with a harrell simi-custom bushing die and used a k&m custom mandrel for final sizing. even then there would be some cases with either high or low seat force. by sorting by seating force i could definitely see the difference on the target. now this is a rifle that consistently shoots in the 1's and 2's. with a less accurate rifle you probably wouldn't see the difference.

 

[Bart B.]

by sorting by seating force i could definitely see the difference on the target. now this is a rifle that consistently shoots in the 1's and 2's.

That's about what the groups had that hold the NBRSA 100-yard aggregate records. No doubt a few were in the 0's.

Kudos to those who do all the right stuff to get such results.

 

[Dusty Stevens]

That's about what the groups had that hold the NBRSA 100-yard aggregate records. No doubt a few were in the 0's.

Kudos to those who do all the right stuff to get such results.

These days the aggs are commonly .15xx to .17xx at most matches

 

[Bart B.]

I used the NBRSA January 2018 posted records for 100 yard agg's. Its amazing they're commonly equalled for all practical purposes.

 

[Dusty Stevens]

I used the NBRSA January 2018 posted records for 100 yard agg's. Its amazing they're commonly equalled for all practical purposes.

View attachment 1040140

hey I own one of those record holding rifles.

 

[oldroper]

I used the NBRSA January 2018 posted records for 100 yard agg's. Its amazing they're commonly equalled for all practical purposes.

View attachment 1040140

I bet your jealous Bart since you never shot BR

 

[JBO]

show us these gages?

Yes please, I'd like to see what kind of gauge you used for that test too?

 

[CT10ring]

for me using the 21st century shooting hydro press was a very enlightening experience. i thought my very carefully prepared brass had consistent neck tension. the gauge will quickly let you know if that is so. went through several different ways of preparing necks after that. what i learned. take care of that carbon in the necks. turned necks annealed every firing. i clean the outside of the cases with a rag soaked in ballistol and just lightly brushed out the necks with a nylon brush. after trying several different sizing dies i wound oup with a harrell simi-custom bushing die and used a k&m custom mandrel for final sizing. even then there would be some cases with either high or low seat force. by sorting by seating force i could definitely see the difference on the target. now this is a rifle that consistently shoots in the 1's and 2's. with a less accurate rifle you probably wouldn't see the difference.

great info, thanks for posting.