What bushing to start with in .223 rem!

[jonbearman]

A friend has a 5R remington in 223 and has bought a set of bushing dies. In order to get about 2 to 3 thou undersize to squeeze the bullet without it being excessive, where would be a good place to start. The case fired is .237 and .012 wall thickness and we want .002 thou undersize and taking into that the case springs back about .001 thou I am thinking .246? .237 is inside diameter, .254 is fired outside diameter and I keep getting .243 bushing but it seems small or maybe I was off on my first calculation.

 

[gdbleb]

.246 bushing sounds about right.
You sure about that .237 ? Assuming that is fired case neck OD? Mine come out .252 - .253.
I use .247 for Lapua. .245 for Lake City.

 

[Charlie-NY]

Measure the outside neck diameter of a loaded case and subtract .002". Done!

BTW - it never hurts to have a bushing on either side of the calculated size. Brass thickness varies from mfg-to-mfg. Occasionally, case lots vary too.

 

[DocDoc]

.224 + 2(.012) = 0.248 If thickness is really .012 then 0.246 its about right. It is good to have something a little tighter and a little looser.

 

[urbanrifleman]

245-246.

 

[jonbearman]

.246 bushing sounds about right.
You sure about that .237 ? Assuming that is fired case neck OD? Mine come out .252 - .253.
I use .247 for Lapua. .245 for Lake City.

That was the ID and I wrote the wrong number ,it should have been .234

 

[jonbearman]

Thank you everyone for the help.

 

[JimSC]

Measure the outside neck diameter of a loaded case and subtract .002". Done!

I like .003 but like others have said having one on both sides is not a bad idea

 

[Charlie-NY]

I like .003 but like others have said having one on both sides is not a bad idea

IME - measuring a loaded case neck rarely falls exactly on the .001". So I select a bushing that will reduce the neck somewhere between .002" and .003". With a little spring back, the neck tension on a loaded round should be just about right. However, as stated earlier, things change and various bushings are needed.

I've got a Ti .286" & .288" bushing for my Creed. The .286" works well with Berger bullets but is too tight for Hornady bullets. The .288" is a bit too loose for the Bergers. So ........ I just ordered a .287" and we'll see how that works. Sooner or later, you'll have a selection of (rather expensive) bushings in inventory.

 

[Coyotefurharvester]

What will you do if the neck brass is thicker/thinner? Brand/lot/ number of load cycles all can cause brass thickness variation.

 

[JimSC]

What will you do if the neck brass is thicker/thinner? Brand/lot/ number of load cycles all can cause brass thickness variation.

well that is why I got over bushing dies, I really should list all my bushings and bushing dies in the classifieds. These days I just FL size without the expansion ball and use a mandrel .003 smaller than whatever caliber I am sizing. I figure with springback I get a squeeze of .0025 - .003 consistently no matter what.

 

[Charlie-NY]

well that is why I got over bushing dies, I really should list all my bushings and bushing dies in the classifieds. These days I just FL size without the expansion ball and use a mandrel .003 smaller than whatever caliber I am sizing. I figure with springback I get a squeeze of .0025 - .003 consistently no matter what.

If you use a bushing die and then your expander mandrel, you could minimize work hardening of the neck.

 

[Ned Ludd]

If 0.254" is the OD of a fired case, loaded rounds having a neck diameter of 0.250" will give ~.002" clearance per side, which is plenty. Brass prepped with a final neck OD of 0.247" to 0.248" should end up very close to 0.250" after seating bullets. Of course, different brands of brass have different neck wall thickness, and although most bushings will yield an actual neck diameter within .0005" to .001" of the stated diameter, none of this is written in stone. You need to buy two or three bushings and see exactly what neck OD they yield before seating bullets, then seat a bullet and re-measure. It's the only way to know with certainty. I used a 0.248" bushing for years with various Lots of Lapua .223 Rem brass, which yielded a consistent neck OD of 0.248" and very close to .002" neck tension (interference fit). I would suggest that having bushings of 0.246", 0.247", and 0.248" ought to cover most of the commonly-used brands of .223 Rem brass.

Further, if your friend ever decides to add in a mandrel step as the final neck sizing operation, it is a good idea to use a bushing of at least .001" smaller than would be used if it were the sole neck sizing step. This is so that the mandrel will actually do some work opening up all of the necks slightly, thereby achieving more consistent results. A mandrel seems less effective, potentially producing less consistent results, if the necks are very close in diameter after the bushing die step to what they will be after the mandrel. Having a 0.246", 0.247", and 0.248" bushing will likely also cover this scenario in the future.

 

[JimSC]

If you use a bushing die and then your expander mandrel, you could minimize work hardening of the neck.

I have never split a neck in 12 years of doing this stuff. Primer pockets always are always the first to go south. Oldest brass I have some old Lapua Palma with over 25 firings. I have always annealed after every firing, used the plumbers torch for years then a year or so back I switched to a AMP. Neck hardness is the least of my problems

 

[Charlie-NY]

I have never split a neck in 12 years of doing this stuff. Primer pockets always are always the first to go south. Oldest brass I have some old Lapua Palma with over 25 firings. I have always annealed after every firing, used the plumbers torch for years then a year or so back I switched to a AMP. Neck hardness is the least of my problems

Sounds like everything is working well for you.

 

[Bocephus]

A friend has a 5R remington in 223 and has bought a set of bushing dies. In order to get about 2 to 3 thou undersize to squeeze the bullet without it being excessive, where would be a good place to start. The case fired is .237 and .012 wall thickness and we want .002 thou undersize and taking into that the case springs back about .001 thou I am thinking .246? .237 is inside diameter, .254 is fired outside diameter and I keep getting .243 bushing but it seems small or maybe I was off on my first calculation.

Have some really good(older) WW brass but the necks are +/-.011” so I use a .244 on those. My Lapua brass seems to work best with a .247”.
On my yote rifles where I’m feeding exclusively out of the mag, I like things a bit tighter, just in case.
All the advice here has been solid.

 

[Rob01]

On my Hornady brass I use a .245 bushing to give me .002" of neck tension. Starline uses a .248 for .002". I load a dummy and measure the neck and subtract .002 and get the bushing. Have used this way for decades in multiple calibers and it works just fine. No need to over complicate an easy process.