Standard FL Die vs. Bushing FL Die

[brshtr]

I've always used full-length dies that use a bushing to size the neck, but occasionally I hear people say that using a standard die, i.e., one that doesn't use bushings, is preferable. Assuming you can choose between (1) a bushing FL die that's a good match to your fired cases or (2) a standard die that's an equally good match, which would you choose and why? I'm trying to figure out why the latter is better. Thank you.

Dave Rabin

 

[fguffey]

Years ago I was told seating and crimping at the same time was not a good ideal, I said I was not starting over by replacing my dies. And then there was that problem with having presses with 4 position tool heads.


And then competition dies came with bushings; I purchased a few Gold Medal/Competition seating dies, I like the way the bushing aligns the bullet with the case mouth. I am not starting over with sizing dies. All of my dies have threads; threads make my dies adjustable to the shell holder.


And then before the bushing dies I sized cases without sizing the neck, the one thing I have not been able to do is ‘BUMP!” I find it impossible to move the shoulder back with case body support. And when I move the shoulder back without case body support I crush the case, it starts out a fild at the shoulder/case body juncture and then turns into something that looks like a bellows/accordion.


F. Guffey

 

[ireload2]

This assumes that the standard FL die has a neck and body that were both reamed on the same centerline.
If the standard FL die has the right neck ID it is probably superior since it will force the neck and the body to be concentric.

The floating bushing can float off center and it cannot move an off center neck back into alignment with the case body.

 

[LHSmith]

If you turn necks for a cartridge, you are pretty much relegated to using the bushing style die- it will allow you have more control over neck tension.....a third parameter in which to further tweak the tune after finding the powder charge and seat depth sweet spot......virtually mandatory for Competition Benchrest. For hunting rifles and no-turn brass a properly matched non-bushing die will give as good performance as a bushing die set up with the proper size bushing. However, the bushing design also has merits when using multiple calibers of the same cartridge family by sharing the same die body and only require a simple bushing change....... .243, .260, 7mm-08, .308 etc.

 

[Shynloco]

If you turn necks for a cartridge, the bushing die will allow you have more control over neck tension.....a third parameter in which to further tweak the tune after finding the powder charge and seat depth sweet spot......virtually mandatory for Competition Benchrest. For hunting rifles and no-turn brass a properly matched non-bushing die will give as good performance as a bushing die set up with the proper size bushing. However, the bushing design also has merits when using multiple calibers of the same cartridge family by sharing the same die body and only require a simple bushing change....... .243, .260, 7mm-08, .308 etc.

+1. If you are serious about precision reloading, buy the Bushing Die and cry once. I started out buying non bushing dies and have had to virtually re-buy every FL die once I got into precision reloading, primarily because once you start turning necks and want to regulate neck tension, you can't do that without using bushings, especially in a dedicated/custom chamber where a custom reamer is used as opposed to the standard SAMMI spec chamber on an across the counter rifle.

Alex

 

[jepp2]

Assuming you can choose between (1) a bushing FL die that's a good match to your fired cases or (2) a standard die that's an equally good match, which would you choose and why? I'm trying to figure out why the latter is better.

I consistently get much straighter necks by using FL sizing dies than using bushing dies.

I have Redding S bushing dies and Redding FL sizing dies for many calibers I load for. I set the dies up similarly. The runout typically runs: Redding S bushing dies 0.003-0.004" TIR. Redding FL sizing dies 0.001" TIR.

Boring background in case you are interested.

1. I set my dies up with an O-ring under the die lock ring. This helps the die center in the press threads and makes it much easier for me to make minor adjustments to the die to adjust shoulder setback.
2. I set my expander high so it exits the case neck as the case just starts to retract from the die. This way the case is much better supported in the die to reduce the possibility of pulling the neck off center.
3. I run carbide expanders on my dies and lube the inside of the case neck.
   
4. I SS wet tumble my brass after firing, so there is no carbon inside the case neck.
5. I hone my case necks on my FL sizing dies so they only undersize the case neck by about 0.001".
6. I also polish my the interior of my dies (which significantly reduces the effort to size).
7. I use Bootleg case lube and for me it makes sizing the easiest of any lube I have tried.
8. I've tried the bushing number up, numbers down, and other things to improve the runout of the S bushing dies.
9. There are times I use bushings - like for the intermediate steps in forming 20 Practical brass or sizing the necks on military pull down brass with tar sealant present, but the just don't produce as straight of case neck.

 

[LHSmith]

I consistently get much straighter necks by using FL sizing dies than using bushing dies.

I have Redding S bushing dies and Redding FL sizing dies for many calibers I load for. I set the dies up similarly. The runout typically runs: Redding S bushing dies 0.003-0.004" TIR. Redding FL sizing dies 0.001" TIR.

Boring background in case you are interested.

1. I set my dies up with an O-ring under the die lock ring. This helps the die center in the press threads and makes it much easier for me to make minor adjustments to the die to adjust shoulder setback.
2. I set my expander high so it exits the case neck as the case just starts to retract from the die. This way the case is much better supported in the die to reduce the possibility of pulling the neck off center.
3. I run carbide expanders on my dies and lube the inside of the case neck.
   
4. I SS wet tumble my brass after firing, so there is no carbon inside the case neck.
5. I hone my case necks on my FL sizing dies so they only undersize the case neck by about 0.001".
6. I also polish my the interior of my dies (which significantly reduces the effort to size).
7. I use Bootleg case lube and for me it makes sizing the easiest of any lube I have tried.
8. I've tried the bushing number up, numbers down, and other things to improve the runout of the S bushing dies.
9. There are times I use bushings - like for the intermediate steps in forming 20 Practical brass or sizing the necks on military pull down brass with tar sealant present, but the just don't produce as straight of case neck.

Do you let the bushing float? Have you tried carbide bushings?

 

[jepp2]

Do you let the bushing float? Have you tried carbide bushings?

I set the bushings up exactly the way Redding say, and yes that does allow the bushing to float. Not aware of carbide bushings, but mostly I use Titanium Nitride coated instead of the standard polished steel.

 

[Wirelessguy2005]

To be fair there are a couple of explanations for the runout that you are experiencing with Redding bushings. First off they chamfer the edge where the brass enters the bushing, second they stamp the Information onto the face of the bushing. Both of these features distort and stress your brass. You might test a different brand of neck bushing. I highly recommend the CRT neck bushings that Whidden Gunworks sell. They have a radius instead of a chamfer which creates much less stress on the brass as it enters the bushing, they also CNC engrave the data on to the face of the bushing so it doesn't become distorted. While these may sound like little things they can have a big impact on the finished brass.

 

[LHSmith]

I set the bushings up exactly the way Redding say, and yes that does allow the bushing to float. Not aware of carbide bushings, but mostly I use Titanium Nitride coated instead of the standard polished steel.

I had lousy results with TiN bushings, much better with Wilson and excellent results with carbide--although not readily available in many sizes.
FWIW, true custom competition bushing dies like Harrells do not use an expander.

 

[Shynloco]

Do you let the bushing float? Have you tried carbide bushings?

Respectfully, in addition to LH's question, are you comparing Mil Brass to Lapua Brass in your comments? I've done extensive testing and comparing LC Match Brass to Lapua and the mil brass has some extremely poor concentricity to begin with (when manufactured) as compared to Lapua. If you are getting .003 - .004 runout after resizing in a Bushing Die (plus all the steps you listed-many of which I employ), something is wrong. That kind of runout is acceptable for hunting ammo, not competition casings ammo.

Alex

 

[jepp2]

are you comparing Mil Brass to Lapua Brass in your comments?

My tests have always used brass from the same groupings (might not be same lot, but definitely manufacturer). So it might be all LC once fired brass tried in both dies. And I do not run an expander with bushings, I do normally with the FL sizing dies. I have done similar tests using Lapua in both S and FL sizing dies.

I haven't found the difference of running an expander or not, to make any change in runout.

I have not tried bushings made by others, but would be willing to. I consider the 0.003-0.004" TIR to be unacceptable to me for most of my brass.

 

[brshtr]

Thank you for your responses.

I've always used bushing dies for exactly the reason given above -- they enable me to experiment with and control the amount of neck tension. If I'm understanding this correctly, it sounds like the main potential advantage of a non-bushing die is that it may produce more concentric cases.

If I use use a Harrell's bushing FL die, typically my "go-to," am I giving up anything in the concentricity department?

 

[mikecr]

I have no problem with bushing dies (Wilson) and runout.
I would not ever FL size necks, as this brings excess tension (including donut area binding), which brings excess variance in tension.
It's surprising though to read concerns of runout, with all the touting lately that runout doesn't matter..

 

[K22]

I have used standard RCBS full length resizing dies for over 40 years except for a brief period when I used neck sizing dies. I stop neck sizing years ago (won't go into it here why I stopped).

I've never found the standard full length sizing dies lacking in any way if they are adjusted properly meaning a .001 to .002" shoulder bump for my bolt rifles. I've been able to develop loads in the .2's with these dies in my varmint grade rifles with match barrels.

 

[RonAKA]

I've always used full-length dies that use a bushing to size the neck, but occasionally I hear people say that using a standard die, i.e., one that doesn't use bushings, is preferable. Assuming you can choose between (1) a bushing FL die that's a good match to your fired cases or (2) a standard die that's an equally good match, which would you choose and why? I'm trying to figure out why the latter is better. Thank you.

I wouldn't choose either. I like the Forster Bushing Bump Die which does not size the body. It sizes the neck only, and you can control how much of the neck to resize. Independently you can control how much to bump the shoulder.

The big advantage of a bushing die is that you can change bushing to accomodate different cases with different neck brass thicknesses. If all your brass is the same thickness, that advantage starts to go away. However, you will probably have to get a custom sized neck in your fixed neck die to get the same degree of control. And you are stuck with a die that only works on one thickness of brass.

 

[500Stroker]

To be fair there are a couple of explanations for the runout that you are experiencing with Redding bushings. First off they chamfer the edge where the brass enters the bushing, second they stamp the Information onto the face of the bushing. Both of these features distort and stress your brass. You might test a different brand of neck bushing. I highly recommend the CRT neck bushings that Whidden Gunworks sell. They have a radius instead of a chamfer which creates much less stress on the brass as it enters the bushing, they also CNC engrave the data on to the face of the bushing so it doesn't become distorted. While these may sound like little things they can have a big impact on the finished brass.

I am with Wirelessguy, I use a Whidden FL bushing die with CRT bushings and maintain <.001 concentrically.

 

[noload]

I have good success with both bushing type, and custom honed neck size FL dies. I get less than .001 runout either way I go, with an RCBS press.. The bushing type gives you more options IMO.

 

[Ned Ludd]

I consistently get much straighter necks by using FL sizing dies than using bushing dies.

Not sure why you're having so much trouble. I use a number of different Redding Type S bushing dies with no runout issues whatsoever. So do a lot of other people. Either you have a bad die, or else some part of your process is likely the culprit, rather than the die.

 

[mikecr]

Folks, bushing neck sizing is more than just picking the right bushing. The bushings are not about reducing runout.
What they do, that benefits those understanding this, is provide for actual neck tension adjustment(which is length of neck sizing, not interference fit).

I stop neck sizing years ago (won't go into it here why I stopped).

You really don't size necks anymore?
Your standard, but apparently perfect off the shelf FL dies (wow),, size the necks, right?
They size FL of necks right?

As far as body sizing, this is different and separate from bushings. Different subject & thread.
The sizing attribute that is neck sizing, is not about runout, or clearances, it's about load development. Tune.
It really seems like reloaders don't understand this. Like we auto-associate 'bushings' with a conflict neck sizing only -vs- FL sizing (including way more than neck sizing).
If we slow down and consider separately each attribute in our sizing, it could lead to far better understandings of what's going on, which could lead to better sizing plans.