Did I get the right bushing for redding sizer?

[Tomekeuro85]

My Remington brass measures .014" neck wall per side.

I bought the .333 bushing and have been using that.

I also bought the .335 bushing.

Is .333 the one to use?

 

[858]

Re: Did I get the right bushing for redding sizer?

Size down from fired case necks in .005-.007 increments. Finish .001-.002 under loaded diameter. Account for .001 of brass spring back so if you need .333 final unloaded neck diameter get .332.

It would be helpful to know your fired case neck OD and your loaded neck OD in addition to your already listed brass thickness.

 

[shadow4]

Re: Did I get the right bushing for redding sizer?

.014 + .014 + .308 = .336 (subtact) .002 for neck tension that gives you .334"

So if you use the .333 bushing you'll have .003 neck tension and if you use the .335 you'll have .001 neck tension. I personally use a bushing that gives .002 NT BUT, to be honest with you I seem to get the same accuracy whether I use my bushing die or my FL small base sizer die. I use the bushing die more often b/c it works the brass less.

FWIW, I think most full length sizer dies give about .003 Neck tension, and I believe most virgin brass gives anywhere from .003 to .005 neck tension.

You shouldn't go wrong with either...

 

[Tomekeuro85]

Re: Did I get the right bushing for redding sizer?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shadow4</div><div class="ubbcode-body">.014 + .014 + .308 = .336 (subtact) .002 for neck tension that gives you .334"

So if you use the .333 bushing you'll have .003 neck tension and if you use the .335 you'll have .001 neck tension. I personally use a bushing that gives .002 NT BUT, to be honest with you I seem to get the same accuracy whether I use my bushing die or my FL small base sizer die. I use the bushing die more often b/c it works the brass less.

FWIW, I think most full length sizer dies give about .003 Neck tension, and I believe most virgin brass gives anywhere from .003 to .005 neck tension.

You shouldn't go wrong with either...

</div></div>

Yup thats how i calculated it. Just was making sure cuz most people say they buy .336... I bought a .335 in case future brass is thicker.

Would .001 tension be to little? Does more tension cause a higher pressure buildup before the bullet releases, therefore increasing veolcity?

 

[MitchAlsup]

Re: Did I get the right bushing for redding sizer?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomekeuro85</div><div class="ubbcode-body">Yup thats how i calculated it. Just was making sure cuz most people say they buy .336... I bought a .335 in case future brass is thicker.

Would .001 tension be to little? Does more tension cause a higher pressure buildup before the bullet releases, therefore increasing veolcity? </div></div>

More tension leads to higher pressure before the case lets go (around 10K PSI) but has minimal effect on pressure after release if the bullet has any reasonable jump.

0.001 tension is OK for bullets that suffer no discomfort between the reloading station and the final firing position (think benchrest).
0.002 is find for bullets that suffer a little stress but are not abused in any serious maner and used in bolt guns (tactical)
0.003 is fine for bullets that suffer the semi-auto loading sequences of modern gas guns (AR15, AR10, M14, M1)

 

[Tomekeuro85]

Re: Did I get the right bushing for redding sizer?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MitchAlsup</div><div class="ubbcode-body">

More tension leads to higher pressure before the case lets go (around 10K PSI) but has minimal effect on pressure after release if the bullet has any reasonable jump.

0.001 tension is OK for bullets that suffer no discomfort between the reloading station and the final firing position (think benchrest).
0.002 is find for bullets that suffer a little stress but are not abused in any serious maner and used in bolt guns (tactical)
0.003 is fine for bullets that suffer the semi-auto loading sequences of modern gas guns (AR15, AR10, M14, M1)</div></div>

So is there any advantage in my case to using .335 as opposed to .333? My bullets dont go thru any stresses so they would stay seated how they were. Just wondering if theres anything better about .001 neck tension as opposed to .003.

 

[shadow4]

Re: Did I get the right bushing for redding sizer?

Just my opinion, but, I "personally" think .001 is too little for tactical. What if you drop a bullet on the ground? It might get seated deeper that you want it to be OR it could make the run-out in your load worse.......... If I were single loading them for a bench rest gun I probably would not mind .001 NT

By stresses MitchAlsup "might" have meant.... A bumpy road (ammo box bouncing around in the back of a truck on the way to the range), accidentally dropping the box of ammo, it doesn't take much to put it through some stress. Heck you put a little stress on a bullet just loading from a magazine (not much).

I'd rather go with just a little more than too little...... That being said, I am sure their are people on here that use .001 NT with no problems.

 

[mattmcg]

Re: Did I get the right bushing for redding sizer?

So I typically account for some amount of "spring back" in the brass when neck sizing. I've found this to be the case on any brass with less than about 3 firings on it. I usually budget .001" for this depending upon the case so in your case, here is how I calculate my desired bushing.

+.014" 1st neck
+.014" 2nd neck
+.308" diameter of bullet
-.002" desired neck tension
-.001" brass spring back budget
=
.333" bushing

So use the .333" bushing and you should be good to go. Save your money and return the .335" bushing unless you begin using Lapua (I turn to .0165") or military brass (.016"-.018" from my experience) with a thicker neck.

 

[MitchAlsup]

Re: Did I get the right bushing for redding sizer?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shadow4</div><div class="ubbcode-body">By stresses MitchAlsup "might" have meant.... A bumpy road (ammo box bouncing around in the back of a truck on the way to the range), accidentally dropping the box of ammo, it doesn't take much to put it through some stress. Heck you put a little stress on a bullet just loading from a magazine (not much).</div></div>

Bumpy road--depends on how ammo is stored while on the road
Dropped box--definately stressful
Running over a field and jumping into a ditch--definately stressful if ammo is in magazine.
Semi-Auto (or auto) loading cycle--definately stressful
Slamming the bolt home in a bolt gun--definately stressful