Neck Turning -> Bushing Size Question

[Stangs55]

I've finally started to dive into neck turning.

I'm starting with my 300 WSM and picked up a K&M tuner, mitutoyo micrometer, and a Redding Type S neck sizer.

Before beginning, I measured my minimum Nosler neck thickness to be about 0.014 (most around 0.015). I then decided to turn everything down to 0.013. Doubling that and adding .308 means that I should have a neck diameter of 0.334....take that down 0.002 and I should start with a 0.332 (+/- 0.001) bushing).

Is that correct?

My concern is that I stumbled upon this chart from Redding that list the bushing range for a 300 WSM to be .335-.343....clearly below where I'm at.

So am I trimming these necks too thin? Or should I just go ahead with the above bushing...?

Thanks in advance

 

[HOGWILD]

I would suspect it depends on what manufacturers brass you are using and how they did manufacturing it? But I would give Redding a buzz as they have some great techs that enjoy giving wonderful CS !! (607)753-3331

 

[DAVETOOLEY]

Assuming you do turn your necks to your desired thickness you need a bushing -.004" under a loaded round. Remember they will spring back about a .001" after sizing

 

[knockemdown]

Your math is correct.
Don't fret the standardized chart.
What you want is a bushing that is a couple thou. smaller than your loaded rd. neck dia. I generally shoot for the bushing that will net -.002-3" smaller than loaded nk. dia. Let your rifle tell you what amount of neck tension it prefers, In a mag fed rifle, I don't mind a bit of extra 'grab' on the bullet...

Questions.
Are you turning necks, just for the heck of it?
To 'clean up' a shitty lot of brass?
Or, to fit a tight neck chamber?

On my 'no turn' chambered rifles, I only skim off as much material, so as to true the necks all the way around. Point is, I'm not picking an arbitrary thickness to turn to, only going so far as to remove any eccentricity from the outside, after expanding to trued ID. If your rifle is NOT a tight neck chamber, I'd recommend doing the same...

If you're turning necks to fit a specific, tight neck chamber, then you want to make sure that your loaded rd. nk. dia. is at least .002" SMALLER than the chamber's dimensions. That is to allow adequate room for necks to expand & release the bullet.
Same rules apply for bushing selection. Determine loaded rd. nk. dia, and subtract the desired neck tension. That is the bushing to run. If using Redding dies, drop the bushing in, number side, down...

Good luck & have fun!

 

[Stangs55]

Your math is correct.
Don't fret the standardized chart.
What you want is a bushing that is a couple thou. smaller than your loaded rd. neck dia. I generally shoot for the bushing that will net -.002-3" smaller than loaded nk. dia. Let your rifle tell you what amount of neck tension it prefers, In a mag fed rifle, I don't mind a bit of extra 'grab' on the bullet...

Questions.
Are you turning necks, just for the heck of it?
To 'clean up' a shitty lot of brass?
Or, to fit a tight neck chamber?

On my 'no turn' chambered rifles, I only skim off as much material, so as to true the necks all the way around. Point is, I'm not picking an arbitrary thickness to turn to, only going so far as to remove any eccentricity from the outside, after expanding to trued ID. If your rifle is NOT a tight neck chamber, I'd recommend doing the same...

If you're turning necks to fit a specific, tight neck chamber, then you want to make sure that your loaded rd. nk. dia. is at least .002" SMALLER than the chamber's dimensions. That is to allow adequate room for necks to expand & release the bullet.
Same rules apply for bushing selection. Determine loaded rd. nk. dia, and subtract the desired neck tension. That is the bushing to run. If using Redding dies, drop the bushing in, number side, down...

Good luck & have fun!

Thanks for the reply.

My GAP 300 WSM doesn't have a particularly tight chamber...and I typically only buy Norma or Lapua brass....I'm really just trying out neck turning because I enjoy reloading. I like to learn new stuff...so this is my current endeavor

Question...since none of my rifles have custom right chambers...could I also select a neck thickness for all my 30 cals (300 WSM, 308, 300 RUM, 300 WM) and just leave my turner set at this thickness and use the same bushing in each neck sizing die? Or is this a bad idea....

 

[Assault116]

Thanks for the reply.

My GAP 300 WSM doesn't have a particularly tight chamber...and I typically only buy Norma or Lapua brass....I'm really just trying out neck turning because I enjoy reloading. I like to learn new stuff...so this is my current endeavor

Question...since none of my rifles have custom right chambers...could I also select a neck thickness for all my 30 cals (300 WSM, 308, 300 RUM, 300 WM) and just leave my turner set at this thickness and use the same bushing in each neck sizing die? Or is this a bad idea....

I've tried that and it works fine, however you have to keep your eyes peeled for doughnuts more critically on some of the thicker stuff. Meaning one brand of brass or cartridge may be more susceptible to it than another and the ones that aren't may lead to a false sense of security. If that one with the thicker brass or more growth, happens to also be a load that's on the high end of the pressure scale, you can end up with doughnuts causing high pressure. It's more just something to be aware of and keep in mind than anything.

The other downside, is that if you have a certain chamber that's on the big side, and you're turning the brass down more than needed to just clean it up, you're going to decrease the life of that brass both by making it thinner, and overworking it.

I'd recommend finding the thickness that yields a clean even thickness across the brass you're running for each cartridge, and keep notes on it. Turn all that cartridge's brass to the same and then you can run the same bushing for all of your brass of that cartridge, so you're not sacrificing durability of one cartridge's brass for another's chamber or brass. For instance, with the brass dimensions you mentioned on the WSM, I'd turn them all to .014" since that's the minimum thickness on them now. There's no reason to take an extra .001" out of it, just uniform it all to the thinnest, or even go to .015" and cull the .014's if it's only 1 or two of them.

Doing them all the same across the board for all your 30 cals is only really going to save you $25 max per cartridge (cost of the TiN coated bushings) by using the same bushing for all of them vs one for each, assuming you don't buy one bushing for each die anyway. When you're talking about Lapua and Norma brass, getting the max life out of it is going to be a better place to save that money.

 

[knockemdown]

Agree with above.
As I stated before, for a standard chamber, only turn as much material off as you must, in order to true the neck thickness, all around. Assault made good points as to why that's a good idea...

And yes, I actually have two K&M turners. One in particular, is set to cut to .015" @ .284 caliber. My GAP 7WSM is a 'no turn' chamber, so I'm only wanting to clean up the crappy necks of the Winny brass, which .015" does nicely without gettin' too thin & stressing the necks out when firing in that chamber. Also, when I make 6.5 SAUM brass, I step Norma 300SAUM brass down to .284, then turn necks to .015", with the same K&M tool. Makes for easy turning chores...

One more thing. Trim all brass to uniform length before turning, so that the cutter will run to the same depth for every case!

 

[HOGWILD]

Redding Neck Bushing Tips - YouTube
Redding tech talking about same issue!