.260 Rem case forming?

[jet_lagged]

Starting to do some thinking about a .260 Remington build somewhere down the road. But before I get too committed, I want to know if I can use my tons of once fired .308 brass to form cases, and how much work and expense is really involved.

Can I just anneal the necks to soften them up, then form using a full length .260 Rem die in one step?

Use some type of 7mm die as an intermediary step?

Spend the $100 and get the RCBS 2 die case forming set?
(Anyone using this, how well does it work and what percent do you reject or trash?)

Thanks.

Or is too much trouble, and just buy new brass?

 

[ChadTRG42]

Re: .260 Rem case forming?

Yes, you can use 308 brass, but the necks will be thicker than standard. You will need a 260 FL sizing die with correct neck size bushing. I would use a 7mm-08 FL size between the 308 and 260. Watch for donuts after a few reloads.
But, I would just buy new Remington 260 brass. Much easier.

 

[Fuzzball]

Re: .260 Rem case forming?

"Can I just anneal the necks to soften them up, then form using a full length .260 Rem die in one step?"

Yes. But don't go crazy with a torch. Just heat the necks enough to make a blue blush on the shoulder, NOT RED HOT!


"Use some type of 7mm die as an intermediary step?

Not absoultely necessary but, yeah, it will help.


"Spend the $100 and get the RCBS 2 die case forming set?"

By no means. All that would give you would be 7-08 sizer and a 260 file trim die. You can do without them, or even buy a new set of 7-08 dies for much less.


The case necks will get a little thicker but not much. Form a few cases, load a bullet in one and see if it's thicker in the neck than your chamber. Not likely to be but, if it is, turn the necks a few thou and your reformed cases will have better necks than factory new cases.

Would it be "easier" to buy new brass? Sure. (But not by much.) It would be easier/quicker to buy factory ammo than to reload too. But that isn't the point,is it?

 

[jet_lagged]

Re: .260 Rem case forming?

Thanks for the replies.

I'll watch for a (relatively) cheap 7-08 die on eBay or somewhere along the way to help give it a try when the time comes.

 

[shoots100]

Re: .260 Rem case forming?

I've formed alot of brass for my .260 from .308 brass.Lube them well and run them through a .260 FL die at a slow pace.I don't anneal them.I usually half stroke,back off and then size it all the way to get them sized without the doughnut appearing at the base of the neck.With a few tries,you'll get nice brass.Don't spend the money on new brass or 7-08 size dies , buy alot of 6.5 bullets instead.Once you shoot your .260 , you might just leave your 30 cals in the safe for awhile.
STEVE

 

[polish handgunner]

Re: .260 Rem case forming?

When i could not obtain 260 rem brass i made some from 243 win brass. That way i did not have to worry about thick necks.

 

[Short Round]

Re: .260 Rem case forming?

I normally use .260 rem brass for simplicity but I did run an experiment with .308 Lapua brass.

I ran the .308 Lapua through my 7mm-08 Redding FL sizer with the expander ball removed with Imperial wax for lube. Then I sized with my .260 FL bushing die.

Trimmed, sinclair neck expander then neck turned. Neck turning was a bitch due to excessive tightness on the turning mandrel. I think I got some work hardening and the brass was springing back to too small of an inner diameter. I figured I'd load and shoot to fireform and all would be hunky dory. Nope even after firing the brass would spring back to excessive neck tension.

I annealed since then but haven't played with them since that.

If I was to do it again I'd neck turn at 308 or 7mm before sizing down to 6.5mm. Then clean up with another neck turn. Then anneal before firing.

I was warned on SH that it was more work than it's worth but my smith suggested to try it so as to get a closer fit to the chamber. I tend to think they're right; buy RP or Norma and go shoot.

If you want winchester buy 7mm-08 or .243 for an easier start. I fooled around with some oddball winchester .243 brass when setting up my neck turner but never shot them.

 

[ChadTRG42]

Re: .260 Rem case forming?

by chance did you measure the neck thickness on the Lapua case when it was sized to 260 before you neck trimmed? I am curious on this. I want to take a new Lapua case and size it down for S&G. Thanks!

Chad

 

[Short Round]

Re: .260 Rem case forming?

I did. Now if I can find my notes. I'm thinking 17 thousands which is in the ridculous range.

OK, consulted my notes which as usual aren't as complete as I'd like.

They were at 17 thousandths at high spots sized, unreamed or turned. I didn't write down the 4th place in my notes, I was just quick calculating clearance for my 0.297 chamber neck.

I cleaned them up to 16 thousandths on the sinclair 4000 I have. Reading this thread last night got me back to the bench and I checked for the expected donuts after they were once fired. I had annealed them a few weeks ago and last night I returned to get rid of the donuts. Current neck wall is 0.0156" with my mitotoyo ball mic.

The 2nd turning certainly did yeild donuts. (I FL resized after annealing, retrimmed, run them through the sinclair expander die, then turned)

The 2nd turning cuts were also much cleaner/smoother than the first.

I'm convinced that the annealing step is needed. After the first firing the neck did not blow out to the chamber wall as expeced. It retracted back to 0.003-.004" neck tension. I ran them through the sinclair expander and they still were contracted.


I hope this helps.

Tom

ETA- Chad, the lapua had 1.6 grains less of water volume than my RP fired brass.

 

[bkster]

Re: .260 Rem case forming?

when you have the barrel done just have it done with a larger neck...
mine is .297 i run lap 308 brass through an rcbs series a die
leaves a ring on the shoulder but still works fine
ist loading is tight necked of course but fairly accurate
and mine run .295...
then i necksize only and i went with a .293 bushing
after a couple of firings youo will need to set back the shoulder
this will need an overly large neck diameter to not reset the neck too tight

it is a pain in the ass and im not convinced it is wworth it
better brass has not netted better groups for me
some of my best have been with the crappy rem stuff

 

[nashlaw]

Re: .260 Rem case forming?

I necked up, not down. Used some .243 brass and had no donuts. This worked for me, anyway.

 

[Fuzzball]

Re: .260 Rem case forming?

We can easily calculate and predict the end neck thickness of any such caliber change quite closely. Calculate the percentage of change beween the diameter of the two necks and mulitiply that times the original neck thickness for a very close approximation to the final thickness.

For this caliber change it's .308"/.264" = 1.1666% X .013" for a typical original factory neck. Meaning the necks will size down quite close to .0156". Book max loaded neck diameter is .297", so the finished/loaded necks should be close to .2952", a thou or so under book cartridge max. Most chambers are at least a couple thou larger than book max cartrige necks so Mr Jet Lagged will have a safe but much better than normal cartridge fit. The down sized necks should be fine but it's still prudent to mic them to be sure.

I make chamber casts of my rifles so I don't have to guess if I have sufficent clearance but adding .0015" to the diameter of a fired case will be quite close.

The main reason to anneal reformed necks afterwards is to reduce premature splits.

 

[Frank]

Re: .260 Rem case forming?

Just remove the expander stem from your 308 die and run the brass thru it. it will leave the neck a little smaller, then run it thru your 260 sizer. As mentioned be sure to check brass neck OD against your chamber ID.

 

[RobertB]

Re: .260 Rem case forming?

If you need to buy brass due to that way not being to your liking. I recommend WIN 7mm-08 brass. I first run it through my redding bushing die with out a bushing and then run it with the bushing. Works great. Just saying cuz I got the freedom of speech. God bless America.