Which neck bushing for no turn 6br?

[zanemoseley]

I'm trying to get up and running for my new Savage 12 Benchrest in 6BR. I ordered 200 pieces of Lapua brass and have a Redding competition die set.

Should I load the Lapua brass as is or run it through the FL die before loading the first time?

Also should I go ahead and buy bushings or wait to see what the fired brass measures. I intend to go with a no turn method.

 

[RonAKA]

Should I load the Lapua brass as is or run it through the FL die before loading the first time?
Also should I go ahead and buy bushings or wait to see what the fired brass measures. I intend to go with a no turn method.

I would open the neck up with an expander ball as I would expect the new brass may be too small in the neck, and you will get excessive neck tension, unless that is what you want for the first firing.

To calculate your bushing size, you need to measure several loaded rounds. If you want for example 0.002" neck tension you would get a neck bushing that is 0.003" smaller than the loaded round necks. The extra 0.001" is to allow for springback. That said, I have a vague recollection that Redding may try to compensate for springback for you and their bushing sizes are not the actual sizes. You should wait to hear from a Redding bushing die user. I use Forster and they work with actual sizes of their bushings.

 

[jepp2]

You may find this useful: http://www.redding-reloading.com/tech-line-a-tips-faqs/140-bushing-selection

I find I always just need one more bushing. You need to be interested in the size of your loaded case necks, not the fired case necks. Do you plan on annealing? How often? The bushing size you need after annealing will probably be different than the bushing size you need after several firings.

Up to you, but I find on new Lapua brass I just chamfer the inside of the case neck to break the sharp edge. The necks tend to be very round. Everything else I at least run an expander through. Sometimes I full size. Depends on the length of the datum to the case head and what my rifles need.

 

[Mozella]

...... snip....... The necks tend to be very round. ..... snip........

My experience is just the opposite with Lapua brass, both .223 and 6mm BR Norma. A batch of 100 will normally have two or three with the necks smashed well out of round; obvious from 10 feet away.

My routine is to resize new brass along with chamfering, primer pocket normalizing, flash hole deburring (caution, the Lapua flash hole might be smaller than expected). I also anneal new brass and I run a turning mandrel down the neck to round out the ones which came bent from the factory.

To the OP, the idea of "turn" vs "no-turn" has to do with your chamber neck diameter vs the neck thickness of the brass you use. Unless you ordered a tight chamber, chances are you have a "no turn" standard chamber and you won't have to turn your brass. However, some people turn their brass anyway just to clean up any differences in thickness from one side to the other. This, like many tiny tweaks we make, may or may not make a difference on paper and it's not normally a procedure you would copy when you're first starting out, especially if you don't already own a neck lathe.

Your bushing size choice will be based on how much neck tension you want. No matter how small a bushing you use, once you seat the bullet the neck diameter will equal the diameter of the bullet plus twice the case neck thickness. Assuming that's a couple of thou smaller than your chamber neck diameter, you're good to go. The advice you got earlier in this thread is a good starting place for selecting your first bushing size.

 

[zanemoseley]

Well I'm trying to wrap my brain around the function of all 3 dies in the Redding Competition set and there is no expander ball like with a cheap RCBS FL die. So do I need to buy a piece to go in one of my existing dies or buy a separate die? Probably doesn't help I bought these dies second hand and there are no instructions.

Also I have an annealer which I plan to use every 2-3 firings.

 

[RonAKA]

Well I'm trying to wrap my brain around the function of all 3 dies in the Redding Competition set and there is no expander ball like with a cheap RCBS FL die. So do I need to buy a piece to go in one of my existing dies or buy a separate die? Probably doesn't help I bought these dies second hand and there are no instructions.

I found some brief instructions for the bushing die and seater die here.

The Forster Bushing Bump Die allows you to use an expander ball. There are varying sizes of the ball to give you the final ID that you want. Not sure the Redding does that... If you have a basic die for another 6mm cartridge you may be able to stroke it to just go over the ball and come back out again.

 

[zanemoseley]

One of my buddies recommended the Sinclair neck expanding mandrel, not bad at $25 plus $10 each for the expanded.

So if I get this and run the mandrel through the new brass will I have to neck size right away or after the first firing?

 

[ericskennard]

The answer is 0.266" +/- .001

 

[zanemoseley]

Well right now I have the .266, .267 and .268 bushing in my cart at Sinclair along with their mandrel die and a 6mm mandrel. Anything else I should grab while I'm ordering.

 

[Webster]

I would open the neck up with an expander ball as I would expect the new brass may be too small in the neck, and you will get excessive neck tension, unless that is what you want for the first firing.

To calculate your bushing size, you need to measure several loaded rounds. If you want for example 0.002" neck tension you would get a neck bushing that is 0.003" smaller than the loaded round necks. The extra 0.001" is to allow for springback. That said, I have a vague recollection that Redding may try to compensate for springback for you and their bushing sizes are not the actual sizes. You should wait to hear from a Redding bushing die user. I use Forster and they work with actual sizes of their bushings.

Running an expander ball thru the neck doesn't reduce neck tension. Every time you expand up or size down you are cold working the brass. It works both ways. I would just shoot each piece of brass once then make decisions based on the after shooting dimensions.

 

[ericskennard]

Well right now I have the .266, .267 and .268 bushing in my cart at Sinclair along with their mandrel die and a 6mm mandrel. Anything else I should grab while I'm ordering.

Good choice. I always use the Sinclair expander. I remove the expander ball from the die and throw it in a box. I have loaded 6mmBr for 14 years and one of those sizes will work with blue box Lapua brass assuming no turn necks.

 

[RonAKA]

Well right now I have the .266, .267 and .268 bushing in my cart

I use a 0.267 bushing in my Forster die, and have not needed to change it over 5 reloadings of the brass. I follow the bushing downsize with an expander ball with a diameter of 0.2425". This is with gold box Lapua. I suspect you have blue box Lapua which will I believe has thinner brass in the neck?

 

[Hntndad]

Once you've fired your brass in your no-turn chamber. Measure outside neck dia. of the fired case. When I size with a bushing die in a no-turn neck I don't like sizing anymore then 4 thou. at a time. If your fired case neck measures .277 for example, use a .273 or .272 bushing first then your final bushing. This has eliminated all the concentricity issues I've had.

 

[mikecr]

So if I get this and run the mandrel through the new brass will I have to neck size right away or after the first firing?

You won't have to down size new brass/necks. Just run the Sinclair expander through, and necks will be right to seat bullets.
I think your on the right path with your bushings & expander choice.

 

[zanemoseley]

Well I got everything ordered as well as a 6br modified case and a Hornady OAL gauge, now I can stop borrowing my buddy's.