260 small primers

[dar1246]

Would necking down 308 palma brass to get a small primer solve the primer pocket issue???
I would think that will let you get more firings on the brass. The large primers if loaded hot will stretch out. The small primer should give better results and solve the pocket stretching out.
Any thoughts.

 

[coldboremiracle]

Re: 260 small primers

Dont know if it will work or not, but this is not the first time I've heard it.

 

[ChrisGarrett]

Re: 260 small primers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dar</div><div class="ubbcode-body">Would necking down 308 palma brass to get a small primer solve the primer pocket issue???
I would think that will let you get more firings on the brass. The large primers if loaded hot will stretch out. The small primer should give better results and solve the pocket stretching out.
Any thoughts. </div></div>

What's the issue bud? Primer pockets will tend to loosen up more, the hotter the load. I'm pretty much sure that smaller pockets will stretch out as well.

I know Lapua makes small pocket 308 brass and Remington made some special batches, but how many cycles are you getting out of your 260 brass, what loads are you using and what brand of brass is it?

You can always experiment with a box of the Lapua small PP stuff, nothing wrong with that.

I loaded up about 650 260 Rem rounds using RP brass for a buddy of mine, running a 200 ct batch. Loads were moderate--40.8-41.8 of AA-4350/H-4350, 140Amax/142SMK. Never had a primer pocket loosen up after 3 cycles.

Brass wears out...much like barrels.

Chris

 

[dar1246]

Re: 260 small primers

On hotter loads I normally get around 3 to 4 reloads on pockets. If you load moderate loads. You will not have an issue.

 

[ChrisGarrett]

Re: 260 small primers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dar</div><div class="ubbcode-body">On hotter loads I normally get around 3 to 4 reloads on pockets. If you load moderate loads. You will not have an issue. </div></div>

What leads you to believe that smaller pockets will handle the same pressure, better?

I ran this by a buddy/reloader of mine a few minutes back and while he's no engineer, he thought that the larger surface area of the larger pocket, would be better at resisting the force pushing the pocket wall outwards.

There are just more molecules of metal there, to help mitigate stretching, given the fact that both are subjected to equal pressures.

Chris

 

[Clark]

Re: 260 small primers

I have necked down 100 pieces of <span style="font-weight: bold">Lapua 308 Palma brass to 260 small primer brass</span> and turned the necks.

I just have a standard SAAMI 260 reamer.
With most 308 brass, 90% will fit necked down into a 260.
It is usually right on the hairy edge.
Not the Lapua, none of it will fit.
It is all just barely over the edge.
I had to turn all of it.

I broke in a new 260 I built last month with CFE223 ball powder. The CCI450 magnum small rifle primer can only set off 40 gr, no more. AND the velocity is erratic with 120 gr Nos Bal Tip.

I also had a plan last month to neck down and turn 7x57mmRimmed to 257RIA and get away with really high pressure. But the Norma case heads are soft as butter.

So I am not doing that well with some of my plans, but CFE223 is a great way to break in a barrel.

 

[427Cobra]

Re: 260 small primers

How will/did you make 308 brass longer, its .020 too short? Also the firing pin will\should be changed out to a .060 diameter one with the bolt face bushed.

I use Win 7-08 brass in my 260, I guess 44.9 of H4350 or 49.0 of H4831sc is not a hot load pushing 142smk, primer pockets seem to last forever, some of my brass has 25+ loads thru them, and the pockets are still tight.

 

[dar1246]

Re: 260 small primers

I ran it by a friend of mine that shoots bench rest but that is an opinion. Thought it would work great. Does someone really know the difference?


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dar</div><div class="ubbcode-body">On hotter loads I normally get around 3 to 4 reloads on pockets. If you load moderate loads. You will not have an issue. </div></div>

What leads you to believe that smaller pockets will handle the same pressure, better?

I ran this by a buddy/reloader of mine a few minutes back and while he's no engineer, he thought that the larger surface area of the larger pocket, would be better at resisting the force pushing the pocket wall outwards.

There are just more molecules of metal there, to help mitigate stretching, given the fact that both are subjected to equal pressures.

Chris</div></div>