Switching from standard to bushing dies - questions

[Roach]

So I had this happen today on 3x fired Hornady brass and it's unsettling. Most of my rifle reloading has been for .308 where I used standard dies RCBS dies. I never turned necks, used an expander ball, and FL sized only bumping the shoulder back .002. I had 500 pieces of LC LR brass that was primed and never fired. All that brass has 5x on it and I only have a few loose primer pockets. It shot a legit .5 MOA consistently although everyone shoots that on the internet these days.


The Old Ghost Thomas Lovell Beddoes

I'm using basically the same standard FL sizing die on the 6.5 creedmoor along with a Redding competition seating die because the micrometer makes this simple. I'm still only bumping shoulders back .002 but apparently I'm overworking the brass so I was thinking about switching to FL bushing dies. Lately it seems like the expander ball requires more force to be pulled out of the case. I can only assume that the neck is getting sized down too much.

So with bushing dies I'm figuring the best practice is to decap the brass separate and use a bushing .002 smaller than a loaded round. The question is if the bushing sizes the neck with the right tension why are some people using a mandrel to expand the neck?

::

 

[243winxb]

The question is if the bushing sizes the neck with the right tension why are some people using a mandrel to expand the neck?

Unturned neck that are sized with a bushing have the uneven neck wall thickness pushed to the inside. The mandrel pushes it back to the outside.

 

[Roach]

Unturned neck that are sized with a bushing have the uneven neck wall thickness pushed to the inside. The mandrel pushes it back to the outside.

Simple enough, thanks.

 

[Dusty Stevens]

You think you may have set up to bump .002 on once fired brass then after it was formed you bumped it way way back? If you set up for 2 on the first firing you may be bumping 8-10 after it forms. Thats what i see but could be wrong. You gotta check those bumps every firing

 

[Roach]

You think you may have set up to bump .002 on once fired brass then after it was formed you bumped it way way back? If you set up for 2 on the first firing you may be bumping 8-10 after it forms. Thats what i see but could be wrong. You gotta check those bumps every firing

i check every firing. I know sometimes the brass won't fully form to the chamber after the first firing but my measurements (shoulder) always come back 1.556 using the Hornady kit, forget what it's called comparator? They didn't have the RCBS precision mic when I got the gun, but that's what I use in other calibers. First, second, third firing all the same.

I just took a bunch of measurements on the neck, base, and body of the brass to see how much the die was sizing down. I first removed the expander ball and the body that measured .464 only went down to .465.

The neck sizing however went from fired- .295 / resized (no xpander ball) to .280 and the expander ball opened it up to .286

 

[Dusty Stevens]

i check every firing. I know sometimes the brass won't fully form to the chamber after the first firing but my measurements (shoulder) always come back 1.556 using the Hornady kit, forget what it's called comparator? They didn't have the RCBS precision mic when I got the gun, but that's what I use in other calibers. First, second, third firing all the same.

I just took a bunch of measurements on the neck, base, and body of the brass to see how much the die was sizing down. I first removed the expander ball and the body that measured .464 only went down to .465.

The neck sizing however went from fired- .295 / resized (no xpander ball) to .280 and the expander ball opened it up to .286

Well my theory is shot then. Let us know when you find out!

 

[08glide]

Have you checked to see how much your die is sizing the body? I would be measuring a fired case before and after sizing in the area where the separation happened. Hope you get it figured out.

 

[Roach]

Have you checked to see how much your die is sizing the body? I would be measuring a fired case before and after sizing in the area where the separation happened. Hope you get it figured out.

About .001 from .465 to .464.

 

[Dusty Stevens]

You may just have gotten a bad batch of brass. It sucks.

 

[Roach]

You may just have gotten a bad batch of brass. It sucks.

At least it's Hornady and not Lapua. I have no problem tossing all couple hundred fired pieces I have. I have 300 more, new, in the box. I just want to minimize it happening again.

 

[Clancy]

Hornady 6.5 Creedmoor cases with case head separations are about as common as photoshopped ladies on the Internet. I literally see someone post about it very regularly. The solution is to buy better brass...

It might seem like it costs more, but when you can fire it 20 or 30 times it starts to make sense....

I’m sure you knew that, just a friendly reminder.

 

[7887mm08]

i check every firing. I know sometimes the brass won't fully form to the chamber after the first firing but my measurements (shoulder) always come back 1.556 using the Hornady kit, forget what it's called comparator? They didn't have the RCBS precision mic when I got the gun, but that's what I use in other calibers. First, second, third firing all the same.

I just took a bunch of measurements on the neck, base, and body of the brass to see how much the die was sizing down. I first removed the expander ball and the body that measured .464 only went down to .465.

The neck sizing however went from fired- .295 / resized (no xpander ball) to .280 and the expander ball opened it up to .286

Am I missing something? ( .464 only went down to .465) That's going up not down.

 

[243winxb]

The neck sizing however went from fired- .295 / resized (no xpander ball) to .280 and the expander ball opened it up to .286

Classic over working of the neck.

The Redding type S fl sizing die can be used with or without the expander. http://www.redding-reloading.com/tech-line-a-tips-faqs

It has come to our attention through customer calls and our own use of the bushing style sizing dies that in certain instances, a given neck sizing bushing will produce a case neck diameter that can be several thousandths of an inch smaller than the actual diameter of the bushing. This idiosyncrasy occurs when the neck diameter of the fired case is a great deal larger than the diameter of the neck sizing bushing, such as occurs when factory chambers are on the large side of the tolerance range and the brass is on the thin side. NOTE> Typically, we have not noticed any problems until the case neck is reduced more than 0.008-0.010".

Separation- Seem to be a Hornady 6.5 brass problem from a google search?? http://forum.accurateshooter.com/threads/hornady-brass.3934813/ and http://www.65creedmoor.com/index.php?topic=9426.0

Or its operator error when sizing?

http://www.65creedmoor.com/index.php?topic=3500.0

 

[Roach]

Classic over working of the neck.

The Redding

Or its operator error when sizing?

The million dollar question right there...

http://www.65creedmoor.com/index.php?topic=3500.0

Am I missing something? ( .464 only went down to .465) That's going up not down.

Fired, unsized brass measures .465. Sizing it brings it down to .464 a reduction of .001.

Now I'm reading that people are getting smaller neck OD than the bushing size. Redding says this happens when you're attempting to size over .008 going from a fired .295 to .286/.287 tells me I'll probably experience the same problem.

 

[6milphil]

I had this exact same problem with hornady 6.5 creedmoor brass. I switched to starline brass and the problem disappeared.

 

[MikeMcCasland]

Unturned neck that are sized with a bushing have the uneven neck wall thickness pushed to the inside. The mandrel pushes it back to the outside.

Do you have a link to the mandrel you're talking about? Does it replace the expander in a Redding bushing die, or is it it's own separate thing?

 

[Roach]

Do you have a link to the mandrel you're talking about? Does it replace the expander in a Redding bushing die, or is it it's own separate thing?

While you're waiting for your answer - by everything I've seen - it's a seperate step. Guys are NOT using the expander ball and instead using the mandrel expander. Sinclair has the dies and mandrels.

https://www.sinclairintl.com/reload...ls/generation-ii-expander-dies-prod38807.aspx

 

[Dusty Stevens]

http://www.portersprecisionproducts.com/porter/

Call kenny porter. Its the only expander die to have. Way better than trying to get a neck turning mandrel in the right size. For under $5 on ebay i can have any size i want and can adjust tension in very few lbs at a time

 

[243winxb]

I use this.

 

[Roach]

That is so above my pay grade, I'm going to have to read it a couple times. Thanks.

Some of us know that, of the 3 components of the Holy Trinity of precision ammo (powder, seating depth and neck tension), neck tension is the most difficult to control.

I know that everyone likes to control neck tension with bushings but to me that doesn't seem like a very good way. From my way of thinking bushings transfer any variance in neck thickness to the inside of the neck where they have a direct impact on neck tension. That is not a good thing, because no matter how careful you are turning necks there will be variances, and those variances will impact neck tension.

I believe that the outside of the neck has minimal importance, as long as there is a minimum .003 neck clearance for bullet release. The only important thing is how thick the necks are because that has an influence on spring-back. IMO the part of the neck everyone should be focusing on is the inside of the neck, or more appropriately inside diameter. The inside diameter is what influences neck tension, if one can transfer neck wall variances to the outside of the case it is that much better.

So the question is: How do we control neck tension from the inside of the neck? What if instead of honing die necks (an irreversible and often problematic process because dies are hardened, not to mention that you have to be twice as accurate with a die then with a mandrel, an impossible taskfor most small machine shops) we were to use a mandrel to expand the necks to provide the desired neck tension? What would a mandrel do?

Well, ... a mandrel would control the inside diameter of a case neck much more precisely than any bushing ever can. It could also transfer neck thickness variances to the outside of the neck where it doesn't interfere with neck tension and bullet release. That's good isn't it?

I have been using mandrels for thousands of cases. The problem is that just when I have a mandrel that gives ideal neck tension (down to .0001 precision) it starts to wear, and after a couple of thousand cases it is done. Making another mandrel to .0001 precision is very difficult/not possible for most machine shops and grinding shops. So I set out to look for a solution. I eventually focused on the Hornady bullet puller collet, because that's what I had. I started using the bullet puller to hold pin gages to expand the necks to match the turner mandrel.

However, the bullet puller did not hold the pin gages as co-axially straight as I wanted, so I approached Kenny Porter ( kennethp@portersprecisionproducts.com ), who makes all kinds of things including parts for pacemakers (can you think of anything more critical?). I told him I wanted him to make a die for me that would hold a pin gage, actually a range of pin gages ie .305, .306, .307, .308 and .309. Once I showed him what I had in mind he made a leap to a collet that is ideally suited for what I wanted. The collet holds the cutting bit for a CNC machine. It has real holding power. Here’ the mandrel die that Kenny Porter made for me.

Pin gages are small tubes 2" long and can be bought for a few dollars and they are available in dimensions as exact as .0001 (+/- .00002). They generally have a 60 to 62 Rockwell hardness, like tool steel. They are ideal for this purpose, all you have to do is bevel the tip. To bevel the tip all I do is chuck the mandrel in a drill and spin it against a grinding stone until I get the tip that I desire. Takes less than 5 minutes.


Now, when I need a new mandrel I buy a Vermont Gage pin gauge. If you’re looking for +/- .0002 precision they are round $3 each. If you really want to get precise and have a mandrel to .0001 (+/- .00002) precision then the price jumps to around $18 and you’ll have to order directly from Vermont Gage. For $18 you get a mandrel and a certificate of accuracy and the name of the guy that inspected and when.

This mandrel die makes all other mandrel dies I have seen or bought look primitive.

Joe