What size neck bushing for .308 Lapua brass?

[ReaperDriver]

I recently got my batch of new Lapua brass and I'm ready to run them through the neck sizer. But since I don't have any loaded rounds with Lapua brass - I don't know which bushing to use to get the recommended .001 to .003 under the loaded size. What are you guys using?

Thanks in advance.

 

[CanPopper]

Re: What size neck bushing for .308 Lapua brass?

.332 and .331

 

[McCrazy]

Re: What size neck bushing for .308 Lapua brass?

I'm currently running a .335 bushing on my .308 Lapua brass.

.015" x 2 (average neck thickness times 2 sides) + .308" = .338"

Take .338" and subtract for whatever neck tension you desire.

 

[Sig685]

Re: What size neck bushing for .308 Lapua brass?

Wow, do you seat with a hammer?

I use .335, I'm looking for about .002 neck tension.

 

[ReaperDriver]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Wow, do you seat with a hammer?

I use .335, I'm looking for about .002 neck tension. </div></div>

I assume that was directed at can popper?

 

[308sako]

Re: What size neck bushing for .308 Lapua brass?

.

 

[ReaperDriver]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 308sako</div><div class="ubbcode-body">J,

Why size virgins? Load first go round and measure the loaded diameter, apply proper bushing next time.

D </div></div>

I wondered if I could do that. My only issue is a few of the case mouths are not in round, so I thought running them through the neck bushing would even them all out.

Plus I measured several of the batch and the neck diameters are varying about .003 or so - so I thought I'd get them all back to a common starting point for consistancy's sake.

 

[mattmcg]

Re: What size neck bushing for .308 Lapua brass?

Yeah, I prefer to one unfired brass through a FL sizer die to ensure all brass is identical in size. Some say its not necessary, I say its a healthy precaution.

As far as bushings go.

+.308 bullet
+.015 brass side 1
+.015 brass side 2
=.338
-.002 neck tension
-.001 brass spring back
=.335 bushing

I would also buy the .336 bushing as well for the Lapua brass. I've seen Lapua 308 virgin brass actually range from .015 to .016 depending upon the lot.

 

[Wild_Bill]

Re: What size neck bushing for .308 Lapua brass?

hi i use LApua brass in my 308 and use a Redding Type S bushing full length die with a .334 die it gives me good tension and helps ignition. a .335 is also OK but i like to keep a bit more neck tension.

 

[AugeredIn]

Re: What size neck bushing for .308 Lapua brass?

336 works just fine for me. I have previously used a 335 but see no difference on new or very used Lapua brass.

 

[427Cobra]

Re: What size neck bushing for .308 Lapua brass?

I use a .339 then a .336, my fired cases measure .342

 

[ReaperDriver]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">I use a .339 then a .336, my fired cases measure .342 </div></div>

That brings up a good question that's been bugging me..... how does sising the neck in two steps like you do "work the brass less" than going right to .336? Its ends you in the same place - how does stepping it help? I've heard that you don't want to go more than .009 to .010 at once, but you're only going .006, so why the extra step?

 

[427Cobra]

Re: What size neck bushing for .308 Lapua brass?

IDK, I read somewhere that you shouldn't go down more than .005 at a time, so I do .003 at time, i will say that run out is a lot better doing it this way.

 

[johngfoster]

Re: What size neck bushing for .308 Lapua brass?

I use a 0.336" bushing. This gives 0.002" neck tension. However, I think I need to get a 0.334 or 0.333 for my BHA/Win brass as they are constantly thinner (0.012-0.013").

 

[mattmcg]

Re: What size neck bushing for .308 Lapua brass?

I'm not a metallurgy expert but the sizing in steps has to do with the malleability of certain metals. If you go too far in one step, rather than metal fluidly expanding and settling, you will tear as the malleability of each metal has its limit. Once you have stretched metal, it will settle and allow another round of stretching (but not to the same extreme as the first stretching).

Again I'm not a metallurgy expert but this seems to hold true from my experience with die forming brass (and necks in particular).

 

[Sig685]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">IDK, I read somewhere that you shouldn't go down more than .005 at a time, so I do .003 at time, i will say that run out is a lot better doing it this way. </div></div>

Yeah that makes sense... to somebody else. You resize in two steps, but you do not worry that the neck will go from .336 to .342 at firing. Also, it's usualy when it is expanded that brass will split, not when it's squeezed back down.

I think you are wasting your time, but that's just me.

 

[Cigarcop]

Re: What size neck bushing for .308 Lapua brass?

I've been using .334 Bushing w/good results.

 

[427Cobra]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">IDK, I read somewhere that you shouldn't go down more than .005 at a time, so I do .003 at time, i will say that run out is a lot better doing it this way. </div></div>

Yeah that makes sense... to somebody else. You resize in two steps, but you do not worry that the neck will go from .336 to .342 at firing. Also, it's usualy when it is expanded that brass will split, not when it's squeezed back down.

I think you are wasting your time, but that's just me. </div></div>

My runout gauge tells me I'm not wasting my time

 

[Sig685]

Re: What size neck bushing for .308 Lapua brass?

Ok, if you say so. My guage showed me runout in the .002 range or less. I will say that runout is much more a function of bullet seating than it is of resizing the neck down in increments of .003. But if it works for you, then by all means...

 

[dreever]

Re: What size neck bushing for .308 Lapua brass?

Using a 175 Sierra Match King my loaded Lapua brass Mic's at .33820
so that would mean a .335 bushing.

My Black Hills brass however Mic's at .33310-.33420 which would require a .330 bushing. Big difference.

I also have some Federal and Winchester that I haven't Mic'd but feel it can't be any different than that.

So whatever brass you go with buy the proper bushing. You asked about Lapua so that would indicate a .335, but if you have other brass it could be much different as in my case since a .335 bushing with the Black Hills would not size much of anything at all.

Danny

 

[lal357]

Re: What size neck bushing for .308 Lapua brass?

on my new brass i load and shoot since its not formed to my chamber yet both measure .338 new and resized after still .338 i use a .334 bushing

 

[Leaddog]

Re: What size neck bushing for .308 Lapua brass?

.337 works great with Lapua Brass fired from a Remington 700 5R.

 

[johngfoster]

Re: What size neck bushing for .308 Lapua brass?

My Lapua brass neck thickness runs around 0.015". Multiply by 2 for both sides, and you get 0.338" (0.308 + 0.015 + 0.015). However, my BHA brass necks mic around 0.012 - 0.013" for a total of 0.332 - 0.334". When sized with my 0.336 bushing, the bullets drop right out. I think general consensus us to have around 0.002" neck tension to hold them in place, maybe more with a semi- auto like an AR-10.

 

[minnesotadan]

Re: What size neck bushing for .308 Lapua brass?

Reaper Driver wrote "I wondered if I could do that. My only issue is a few of the case mouths are not in round, so I thought running them through the neck bushing would even them all out."

I just finished loading 100 plus rounds on new Laupa brass as well and notice the same issue even after neck sizing, I run all of them thru the Sinclar mandrel and it seems to give me the 002 to 003 stretch that I like

Dan

 

[minnesotadan]

Re: What size neck bushing for .308 Lapua brass?

Sacrifice a round and put in your selected bullet and measure the diameter. Try a sizing bushing about .003 less and see if it comes our aroung a .002 then you are good to go. This is assuming you are doing a bolt gun, if AR platform try .003 to .004 for the neck strech.

Dan

 

[mavrick10_2000]

Re: What size neck bushing for .308 Lapua brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Wow, do you seat with a hammer?

I use .335, I'm looking for about .002 neck tension. </div></div>

I use .331 for Win brass hardly feels like there is any tension during seating with Nosler 155 gr CC's.

 

[Nunu]

Re: What size neck bushing for .308 Lapua brass?

on my new brass i load and shoot since its not formed to my chamber yet both measure .338 new and resized after still .338 i use a .334 bushing

If roundness is the problem why not run an appropriate mandrel to iron out the neck. I think a more uniform inside diameter will benefit more than the outside.

 

[TheOE800]