Using lapua .308 brass for .260Rem

[Caughtshort]

Does anyone use resized .308 lapua brass for .260rem here? I am concerned that the inside neck dimension will be too tight and will nick the base of projectiles.

Does reaming help?

The rifle in question has .260 match chamber.

Daz

 

[RobertB]

Re: Using lapua .308 brass for .260Rem

If you turn the necks and ream them shouldn't have a problem I wouldn't think. Don't know for sure though. I use win 7-08 and they work great. Got some norma .260 as well that I like.

 

[deadeye]

Re: Using lapua .308 brass for .260Rem

I've done over a thousand from Federal 308 down to 260 and never had a neck problem. Never reamed or turned the outside.

Always chamfer the necks on everything I load which would eliminate any catching of the bullet.

 

[Buckoman]

Re: Using lapua .308 brass for .260Rem

I have such a tight chamber that even 243's opened up won't fit. I have to use factory 260 brass or bench rest brass.

 

[Short Round]

Re: Using lapua .308 brass for .260Rem

I dabbled with the project but haven't put a lot of time.

The adivice I got here was to use the RP brass and run with it, or use winchester 7mm-08. Alternatively my smith suggested necking down from .308 to custom fit the brass to my chamber. I took 50 Lapua .308 cases and lubed them with my redding standard FL 7mm-08 die, then followed up with my .260 S die. The necks will be thick.

Originally I turned them from near 17 thousandths to 15. I did run them on a sinclair expander matched to the sinclair turning mandrel. The fit was tight and they would heat up while turning.
The ID was too tight on the turning mandrel. Back to this point later.

I fire formed them and found the necks retracted back to .004 neck tension. So much for my expectation that they'd stay chamber sized. I figured the resizing work hardened them and the turning on a tight mandrel was an additional concern.

I annealed at that point and re-turned them and found donuts already formed. I'm not that experienced with turning and probably should have done things differently.

I've been working on other gun projects and haven't got back to the lapua brass project. I'm still using the black hills/Rem .260 brass for my normal .260 use.

 

[ChadTRG42]

Re: Using lapua .308 brass for .260Rem

I also wondered this, so I sized down a Lapua 308 case. I FL sized it in a 7-08 die, then 260 die. The case necks went to just over .017" thickness. This puts the outside diameter to just over .298. Most 260 chambers would require this to be reduced to chamber. So, I don't think it will work without trimming the necks.

 

[bohem]

Re: Using lapua .308 brass for .260Rem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadTRG42</div><div class="ubbcode-body">I also wondered this, so I sized down a Lapua 308 case. I FL sized it in a 7-08 die, then 260 die. The case necks went to just over .017" thickness. This puts the outside diameter to just over .298. Most 260 chambers would require this to be reduced to chamber. So, I don't think it will work without trimming the necks. </div></div>

I have to turn anything over .296 and I've found out that result the hard way. My chambers is a factory DPMS 260 upper.

 

[bohem]

Re: Using lapua .308 brass for .260Rem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RJ Hunter</div><div class="ubbcode-body">What do you get necking up from 243? </div></div>

295-296 using Win brass, I haven't tried Lapua 243 brass though.

 

[Caughtshort]

Re: Using lapua .308 brass for .260Rem

Thanks guys, looks like I may have to spend the extra dollars on lapua .243 brass and save myself some hassle.

Thanks again.