260 Rem, Lapua Brass, neck up or down?

[AKDaddy]

Hey all,

I posted this in the "6.5mm and up" forum, and then realized this is more of a general reloading question and might more useful to others here.

I just ordered a 260 Rem Match reamer with a .294 neck for a new build. I'd like to give Lapua brass a try, and was wondering whether it would be better to neck up Lapua 243 brass or neck down 308 brass?

I'd really like to use 308 brass, for two reasons. First of all, I was thinking I'd like to experiment with the new 308 Palma brass (small primer pocket) when it comes out, to see if it will work for a 260 Rem using small rifle magnum primers and RL 17 or H4350. Second, after forming the brass to 260 Rem, I plan on turning the necks just enough to even them out. My thought was that necking down would provide a little thicker neck wall to work with.

However, since I'll be necking down using Redding bushing dies I am worried about having to deal with a bad donut of brass right above the shoulder when I'm done.

On the other hand, if I neck up from 243 brass I wouldn't have a donut to deal with but the neck wall would be thinner, thus leaving me less to work with for neck turning.

Anybody have any thoughts or experience with this? Would it help eliminate a donut if I neck down in two or three steps, then run the brass over an expander mandrel before neck turning?

Thanks!

 

[Laurie]

You get a 'doughnut' after necking Lapua .243W brass up too as I know to my cost. As my rifle is throated long to suit 140s seated right out, it's not a problem as the rear end of the bullet bearing section is just above the ring.

I don't know if it would be worse necking .308W brass down mind you, as I've never tried that. From what I've read recently, the favourite method in the USA nowadays is to neck Winchester 7mm-08R cases down.

Laurie,
York, England

 

[jr600yd]

Save yourself a lot of time, worry and work. Neck up

 

[AKDaddy]

Wow, very mixed responses, from some very experienced shooters. It sounds like it doesn't really matter, as far as avoiding donuts is concerned. From the responses (here and in the "6.5mm and up" forum), some get donuts necking up and others necking down, and there seem to be about an equal number of really bad experiences both ways.

Hmmm... Looks like it's six of one and half dozen of the other, and another half dozen that say not to bother with Lapua brass altogether. So much for a simple answer! Thanks for all the input. Looks like I'll have to flip a coin!

 

[Dans40X]

The necked down Rem URBR brass w/ small primer pocket/.080" flash hole works well in the 6.5-'08/260 chambering.

I won't speculate how the Lapua small pocket 308 brass will perform.

I'll continue to run the Remington URBR brass in numerous chamberings.

 

[AKDaddy]

Good info Dans40X. I'm definitely going to give the Lapua .308 Palma brass a try once it becomes available. I just updated my post concerning this same subject (with the same subject line too) in the 6.5mm and up forum. Anyone interested can read about it there. Basically, I experimented with necking down Winchester 7-08 brass. Since I had one very big jump when necking down, it required several extra steps but the necking down seemed to work out quite well in the end. The problem was that the case mouths were very uneven, and trimming them until they were square lost me any neck length I had gained from starting with 7-08 brass.