How tight is too tight when seating a bullet?

stuey

Well-Known Member
Just Getting into reloading my tikka t3 in 6.5 x 55 calibre.

Have been cleaning brass and practicing with the tools for case prep.

Had a go at seating a bullet in the case and the case appeared to shave a bit of copper from the bullet. Does this mean that I need to adjust my full length resizing die to make the case neck a bit more open or is what I have experienced normal??

Cheers

Stu
 
Assuming your resizing die is doing what it should and correctly sizing the neck, did you try deburring the inside of the neck (adds a tiny chamfer to stop the neck of the case cutting in)?

Alex
 
Just Getting into reloading my tikka t3 in 6.5 x 55 calibre.

Have been cleaning brass and practicing with the tools for case prep.

Had a go at seating a bullet in the case and the case appeared to shave a bit of copper from the bullet. Does this mean that I need to adjust my full length resizing die to make the case neck a bit more open or is what I have experienced normal??




Cheers

Stu


Have you trimmed case to length?
Have you deburred the case neck inside and out?

Sounds like deburr problem, deburr removes or 'chamfers' the case neck... you do not need to go wild with deburr tool just enough to see the sharp edge is 'broken'.
One other thing which will shave a little from bullet is how concentric your die and press are. if there is misalignment it will tend to shave a little too!!!

FYI bottleneck cases rarely have a die to 'bell' the case mouth, pistol dies for instance have this for seating a bullet.
 
Last edited:
Just Getting into reloading my tikka t3 in 6.5 x 55 calibre.

Have been cleaning brass and practicing with the tools for case prep.

Had a go at seating a bullet in the case and the case appeared to shave a bit of copper from the bullet. Does this mean that I need to adjust my full length resizing die to make the case neck a bit more open or is what I have experienced normal??

Cheers

Stu

I have only been reloading 6 months but I have taken the time to study the subject in some depth and have achieved some really good results.

My 2p's worth.

1. Are the bullets boat tailed or flat base, if they are flat base you certainly need to give the inside neck a good sized chamfer. I use one of these >>>http://www.kmshooting.com/catalog/c...rolled-depth-tapered-reamer_small_17-6mm.html
They give a good lead for the bullet into the neck of the case. You could get an RCBS chamfer tool which will chamfer the inside and outside of the neck but the K&M tool is better for the inside neck case for certain. Boat tailed bullets still need a chamfer to the inside neck case but the shape of the bullet helps to give a nice lead.

2. If you want good long range accuracy (over 300yds) case neck tension consistency is absolutely essential. If you check the ES and SD of your bullets over a chrono I suspect you will see some very high figures (Over 100) which is probably caused by tight neck tension and will give poor long range groupings.

3. If you shoot upto 200yds and are happy with 3" groups then I am sure you will be alright.

4. If the bullets are throwing up a burr when they are seated the bullet will no longer be round, symmetrical or balanced which will again affect the accuracy. They will leave the barrel and will struggle to stabilize and will not give good groups.

My advice to anyone reloading is to buy the very best dies you can afford. I have Redding competition dies which allow you to set an exact neck size which helps to give consistent bullet release.

The reason most of us reload isn't to save money, I would have to reload .243 bullets till I am 93 to cover the costs I have already shelled out. I reload for accuracy, when I started shooting center-fire rifles I used factory ammo and struggled to get 1" groups at 100yds, with home-loads I have ammo that produces sub 1" groups at 200yds. To get the good results you have to be really fussy. You are doing the right thing asking questions, I made a real nuisance of myself asking questions when I first started.
 
Last edited:
I have seen this many times. Sometimes it is the bullet and what it is made of, sometimes is it a tight neck. My 7x57 with Speer bullets will do this and show no reduction in accuracy. A neck that is too tight will show a reduced diameter below the bullet base.

I now use a Lee Universal Expander Die to gently flare the case mouth to just bullet diameter. I haven't yet seen how it will affect the aforementioned 7x57 but the "problem" is gone now from all other chamberings I load for.~Muir
 
This is a subject I was thinking about recently, but don't know much about.

Can any one give an overview of neck tension, ie: what is too much, what is too little, how do we measure and/or control it using standard dies such as RCBS?
 
This is a very contentious issue, If you talk to F-Class shooters they load their bullets with such a light fit that if they try and take a loaded bullet from the chamber and it was loaded into the lands, the bullet will detach from the case. F-Class shooters find that the lightest bullet hold gives the best consistency.

This would be no good for your average stalker though would it. Each time you had to unload your weapon you would get a chamber full of powder.

I have a set of Redding competition dies and when I asked Norman Clarke at Rugby about neck tension he referred me to the packet of the bush for the bushing dies and it tells you to measure the outside of the neck of a loaded bullet and get a bush for the dies which is .001" smaller in diameter.

I do this and get sub 25ES and 13SD and I also get sub 1" groups from my .243 at 200yds.

Most hunters use .003-.004" neck tension.

Its very much a case of suck it and see. Some cases are made from quite hard brass, some are made from soft brass, some people take time to prep cases well, other aint got a clue.

I use .001" tension but the norm is 3-4.

Good luck mate.
 
So 1 to 2 thou less on the inside neck diameter than the bullet being fired?

ie, a 6.5mm / .264 bullet should have an inside neck measurement of .262"?

Let's be very basic here, if i measure my expander ball and find it is .263" diameter, can I chuck it up in a drill and take a thou off with a bit of very fine wet and dry paper?


I ask all this because I get a regular odd bod velocity measurement with my 260rem. Lets say three shots out of four have an ES of 15-20 FPS, one might be out by 60-80FPS, usually, but not always on the low side. My reading suggests this might be attributable to neck tension?
 
Last edited:
Just Getting into reloading my tikka t3 in 6.5 x 55 calibre.

Have been cleaning brass and practicing with the tools for case prep.

Had a go at seating a bullet in the case and the case appeared to shave a bit of copper from the bullet. Does this mean that I need to adjust my full length resizing die to make the case neck a bit more open or is what I have experienced normal??

Cheers

Stu

Is it virgin Brass Stu? I had a issue similar when loading some lapua brass, I just ran it through a neck die to expand it slightly then deburred and it solved the problem.
 
Get some of your completed ammo.

Measure the OD (Outside Diameter) of the neck with bullet in situ.

eg.
The case neck measures .273" in a round of .243 ammo with bullet in place.

You want the neck case to measure .273" minus 3 thou before you seat the bullet.

Then when the bullet is seated the OD measures 3 thou bigger, .273".

With Redding competition dies you buy the relevant bushes to give the required neck tension.


With your dies what is the OD of the neck cases before you seat the bullets and what is the OD after you seat the bullets ???

With some dies you have no control over the neck tension, all you can do really is chamfer the inside of the neck case and only size part of the neck depth. This will have the effect of reducing neck tension.

If you want P.M me and I will send you my phone number.
 
Last edited:
CD: Too bad you ditched the Collet dies. When properly used they will allow for adjustable neck tension.

As to the question, the amount of neck tension is called "pull weight": the amount of effort needed to pull a bullet from the case neck. As replies have indicated, the exact amount varies. A clever fellow could rig a gage to measure this in conjunction with a collet-style bullet puller.~Muir
 
Back
Top