What is "neck" on a rifle spec?

[foggybottombob]

I notice that these rifle builders always put a specification for "neck" on the barrel of the rifles they build. What does that mean exactly?

Accurate Custom Hunting Rifles by Quarter Minute Magnums

 

[SavageShtr]

That just let's you as the shooter/reloader know what the neck of the chamber dia is. Those rifles have a custom chamber not a SAAMI spec chamber. Lets you know if the neck on your brass needs turned or not. A lot of your bench guns have tight neck chambers requiring that they need to be turned to a certain diameter. What you would need to do is measure a loaded round to see what the diameter is and based on the rifles specs determine if it will work unturned or not. It will also let you know what bushing to use for your resizing die. Hope this helps.

 

[Talkyn]

I believe it refers to the actual diameter of the chamber where the neck of the cartridge will sit.

My understanding is that best accuracy is often from a tight chamber, but "tight" doesn't really mean anything without a reference. Specing a neck size in your rifle allows you to run a desired neck size on your brass and ensure a close fit.

I just know the theory a bit you'll have to wait for more knowledgeable folk with real experience if you want practical advice on actually choosing a neck size.

 

[foggybottombob]

That just let's you as the shooter/reloader know what the neck of the chamber dia is. Those rifles have a custom chamber not a SAAMI spec chamber. Lets you know if the neck on your brass needs turned or not. A lot of your bench guns have tight neck chambers requiring that they need to be turned to a certain diameter. What you would need to do is measure a loaded round to see what the diameter is and based on the rifles specs determine if it will work unturned or not. It will also let you know what bushing to use for your resizing die. Hope this helps.

What resizing die uses bushings? I did notice someone mentioned using different sized Sinclair expander balls.

 

[dragman]

example:
30 caliber standard .341 - .343 (usually)
If you take new unturned brass and size it down in a REGULAR die it will come out around .336 and then when you seat a bullt it should bring it out around .339. These numbers float and can be different from gun to gun and die to die. thats why many bench guys get tight necks because then they can control everything.
Example:
make a 30 cal a .338 tight neck (exact)
then you have to turn your brass down making it perfect. then you buy a redding type bushing die and size it down to .333 (what I would prefer) then when you seat your bullet it expands the neck back too .335 and gives you .002 bullet grip and .003 for the expansion. Some people like more or less bullet grip more or less expansion room but the idea is that you can completely control what your loads are doing giving you the ability to make a gun do what you need it to do for any and all distances.

 

[SavageShtr]

What resizing die uses bushings? I did notice someone mentioned using different sized Sinclair expander balls.

I use redding type S bushing dies. They are really nice dies, they give you the flexability to choose the neck tension that you want.

 

[foggybottombob]

Just to kind of complete this discussion, do you use an expander ball when running precision neck sizing dies? If so what is the typical difference in size between the "sized" neck and that same neck after it is expanded. I read somewhere that an expander was typically .025" under size of the caliber. I have no idea if that is correct since I have never checked it.

 

[SavageShtr]

Just to kind of complete this discussion, do you use an expander ball when running precision neck sizing dies? If so what is the typical difference in size between the "sized" neck and that same neck after it is expanded. I read somewhere that an expander was typically .025" under size of the caliber. I have no idea if that is correct since I have never checked it.

I personally don't use an expander ball on any of my dies. You will get many different opinions on this as well. I have gotten better and more consistent accuracy since I switched.

 

[foggybottombob]

I personally don't use an expander ball on any of my dies. You will get many different opinions on this as well. I have gotten better and more consistent accuracy since I switched.

This is all stuff I did not know. So thanks for the posts everyone.