DO I really need a bushing die set if...

[Cameron SS]

I've already bought the dies, so this is more of an academic discussion based on a bit of buyers remorse.
After reading alot of the threads, and measuring more things on my cases then I ever thought I'd need to, I've learned the following things.

1. There is still alot about reloading that I need to learn.
2. The SAAMI SPEC for .300 WSM is an outside neck diameter of .344
3. My fired, unsized cases measure .343, which accounting for spring back tells me that my rifle neck diameter is at the max.
4. My loaded rounds measure between .336 and .337 which tells me that I would probably benefit from neck turning to make them more uniform.
5. My brass neck thickness averages .014, as confirmed by measuring, and deduction of loaded rounds. .336 - .308 divided by 2 = .014

based on what I've read, I would want a neck bushing of .335 or .334.

Heres the thing, my $40 rcbs dies resize brass to .3345, which should be perfect, no?

If my brass is expanding .008 to fit my rifle neck each time it is fired, am I really benefiting from decreased working of my brass? Not sure if there is something that I am not considering here.

I know from lot to lot I may get different neck neck thickness, so the ability to move up or down .001 would be a bonus, but is that it?

 

[whiskey08]

I would use the rcbs die as long as you could, I think that after awhile of stretching and trimming the brass might grow thinner at the neck. Using bushings are nice tho, you have the ability to control how much of the neck you size, and how much you size it which can increase accuracy. I have my target rounds, and my hunting rounds. I put a little more neck tension on my hunting rounds just so the bullet doesnt slide around.

What brass are you using, my loaded norma brass with berger bullets measure .340? I would think that everything you can do to minimize how hard you work your cases will improve the life of them. That doesnt matter so much when you've got a jillion .308 cases but now that a box of .300wsm costs $125, im doing everything I can to make them last. To include anealing which i did for the first time this week. gl

 

[Larryh128]

For Hunting loads, I turn my necks to .013 on the WSM, basically just to uniform them. As stated, anneal after a few loading or the necks will split.

 

[watercam]

While neck turning to 70-80% will help center up the bullet with the bore and incrementally increase accuracy, my experience with my 325 WSM with most brass has shown me that the primer pockets give out after about 8 loadings. Never lost any brass due to cracking. If any thing, remove your expanding ball and see how tight the dies make the neck - if more than .004" tighter than a loaded round one can have the neck portion of the die polished larger until it is right. Not sure if this is more or less expensive than a bushing sizing die alone or not. Frankly, unless you are trying to keep your brass for more than 8-10 loadings, I'd just load and shoot if accuracy is what you like.

 

[Cameron SS]

I just read this German Salazar article
http://riflemansjournal.blogspot.com/2009/10/reloading-neck-tension.html

It answered alot of questions.

I am using winchester brass right now. Its the only brass I've worked with so far. I am new to reloading, only reloaded about 800 rounds total, all for the .300 short mag. I wanted to refine my techniques and set up before I moved up to the more expensive brass. Living in Canada, the good stuff is proving elusive to find in any quantity as well.

How much of a hassle is annealing?

Most bushing dies that I've seen don't have an expander ball, which is the number one factor in reducing excessive working of brass, as I expand it. Most people at my range tell me that the bushing dies pretty much double case life, which, even with the modestly priced winchester brass, will add up quite a bit over a life time.

Some of my necks started to crack after about the 4th firing. Maybe 1 in a hundred cases. I think my loads might be a little hotter than I think they are. I usually end up within half a grain or so of loading manual published limits, without seeing any real signs of excess pressure, but stop anyways just cause everyone says to.

How much can excessive bullet grip affect pressure?

 

[zcrackshot]

I use bushing dies to keep things straight and uniform. My past experience with standard RCBS dies is that if the expander ball isn't precisely centered in the sizing die (which it typically isn't) then every case that gets pulled over the expander ball is getting pulled out of uniformity and left crooked. I used to pull the expander balls out of standard dies so that I could minimize runnout.

 

[RonAKA]

Your big issue is the large neck in your chamber. Nothing you can do about that. Neck turning will make it worse. If anything you may want to look for thicker brass as another poster suggested. If you size your necks down to .3345, then between the bullet seating and firing you expand them back about 10 thou on each firing minimum. With a standard sizing die you are getting to that final 0.3345 with the expander ball. So after sizing and not expanding the neck will be smaller still. Possibly 0.002". You can easily check by removing your expander ball, and size a few cases to see what you get for a neck. Subtract 0.001" that and you will know what it was sized to in the die before spring back. Subtract that from the .344 and that is the total expansion cycle.

Your necks are about right as they come out of the standard die, and should give you 0.002" tension. So you will not save anything there with a bushing die. However, you can avoid the over sizing and expanding back up. That might save you in the order of 0.003", so perhaps a 30% reduction in working.

For sure you will gain more by annealing every 4 loads.

 

[BoydAllen]

To get a better handle on the amount of work that your brass is experiencing with your current setup, pull the expander ball, size a case, and compare its diameter to one that was sized with the expander.

Redding S type FL dies (bushing) come with a decapping pin retainer, as well as an expander ball. For situations where there is likely to be no improvement in accuracy by turning (large chamber neck like yours) I like to use a bushing that gives me a very slight feel of the expander ball being pulled through the sized neck. This small amount of work is no going to cause concentricity issues, and it will tend to make neck tension more uniform with unturned necks.

In order to fully appreciate what your dies are doing to your brass, you need to have someone check the sized brass for neck runout, on a concentricty gauge. With a typical die, the pull of the expander ball is so great that it cocks the neck. This is because the ID of the neck portion of the die is so small. Some die manufacturers will lap out the necks of their FL dies for a modest fee. Forster is one that comes to mind.