Question about neck tension on rifle bullets


PDA






SASS#23149
April 21, 2008, 05:32 PM
I have loaded many thousands of pistol rounds,going to do some rifle now.

neck sized some once fired 30-30 brass,and the .308 bullets are extremely loose in the neck.The ball is only maybe .002 smaller than the bullet diamter.
Leaving the expander ball out still gave the same reading.hmmm.

switched over to a fl die,without the ball,and the necks sized with that one are about .295. Much better,but is this 'too tight' do you think?
I'll be using the fl die for .308 jacketed and .311 cast bullets so dont want to remove any material from the expander ball.

upshot is?
should a .30 caliber necksize die resize to below the .306 reading?
AND
Is the .295 neck diamter that I get with the fl die so tight that pressures might spike,or is that good enough to use.It would give good neck tension.

sorry for the long possibly confusing post.

If you enjoyed reading about "Question about neck tension on rifle bullets" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Grandpa Shooter
April 21, 2008, 05:45 PM
You are right about the rambling and confusing part.

If you are reloading for 30-30 you are not trying to get the neck to hold the bullet, you are going to want a solid crimp on the bullet. A Lee Factory crimp die is useful for this purpose. Neck tension is fine for ammo fed from a box magazine, but not for a tubular magazine rifle like a 30-30. I assume you know not to use pointed bullets?

As for lead, it is common to use a bullet which is .001-.002 over the nominal caliber size. This it would be a cast .309 or .310. Too big and I fear you will have serious leading issues, depending on how fast you are trying to push the lead bullet.

I think this answers your question?

SASS#23149
April 21, 2008, 06:14 PM
sorry about the confusion.
we're shooting them in a box magezine rifle,cases were once-fired in this rifle.
I guess I have read where just neck tension is good enough for some types of rifles,but these werw LOOSE.Touch it wth a finger and they slide in...loose.

As I say,the main question is,do most sizers only size the neck a couple of thousandtsh smaller than the bullet? Mine do that and it's too danged loose.

thanks for the help,I need it. !:confused:

Walkalong
April 21, 2008, 06:16 PM
I'll have to disagree with Grandpa Shooter here, and I usually agree with him. Yes, you want good neck tension for any rifle bullets short of specialty situations.

Get a second expander plug. It's cheap & will solve your problem. No amount of crimp, no matter how good, will make up for poor, or in your situation, non existant, neck tension.

mallc
April 21, 2008, 06:21 PM
My neck sizing requires a bushing for the particular thickness of the brass being sized. Thinner brass would make for a loose fit.

Scott

Ol` Joe
April 21, 2008, 06:54 PM
0.002"-0,003" under bullet diameter is the normal mouth ID reduction for a resized bottle neck rifle case. This should be enought tension to hold the bullet, although a tube type magazine with cartridges under spring pressure working on each other during recoil will need some crimp. If the bullet is loose in the neck, the die isn`t sizeing it properly or the expander is oversize. Does the neck die size the case enough to hold the bullet without the expander in it? If so the ball may be the wrong size.

As a aside I often run my brass in a FL sizer with out the expander then follow up with a tapered one to open the mouths up to the proper size. This helps reduce run out in some instances for me. If the FL die is leaving you with a ID of 0.295" I`d reinstall the expander and just run it in the die enough to open the mouths.

243winxb
April 21, 2008, 11:01 PM
Your expander button should measure .002" to .003" under bullet diameter (.308"), the brass will spring back some after the button is removed. This is fine for a jacket bullet loading. Now for the .311" diameter cast bullet, you want to buy a Lyman "M" type die to open the neck to seat the cast bullet. If you are using a neck sizing die and its not taking the neck diameter down enought, you may have a faulty neck sizing die. Most all dies will size the neck down .010" or more. Then the expander opens the neck up to the correct inside diameter. Are you trying to use a full length sizing die to only neck size?? .

If you enjoyed reading about "Question about neck tension on rifle bullets" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!