Forming 260Rem from 308Win

#4
Re: Forming 260Rem from 308Win

I fail to understand your intended plan...

308 is shorter than 260. 2.005" vs 2.035"

Running 308 into a 260 die is going to give you a fat, thick neck. The brass will chamber, but a loaded cartridge probably won't unless you've got a LOOSE chamber.

The trim die wilk trim, but trimming isn't the challenge - thick necks and donuts are.
 
#5
Re: Forming 260Rem from 308Win

My brother and I both have a Medesha .260 upper and we use LC .308 brass necked down. The reamer scott uses is a 6.5mm-08 reamer so the shorter necks aren't an issue, nor would they be with a .260 reamer. The only issue you will have will be you will need to neck turn your brass as the necks will be thick. For me while this takes time it is still a better option. Remington .260 brass the pockets don't last in a gas gun as I got about 2 or 3 (if lucky) loads out of them, and Lapua brass well it's just to expensive.

Your other option is to neck up Wincester .243 brass. I did this for my 142's for my .260 upper.
 
#6
Re: Forming 260Rem from 308Win

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Heman</div><div class="ubbcode-body">My brother and I both have a Medesha .260 upper and we use LC .308 brass necked down. The reamer scott uses is a 6.5mm-08 reamer so the shorter necks aren't an issue, nor would they be with a .260 reamer. The only issue you will have will be you will need to neck turn your brass as the necks will be thick. For me while this takes time it is still a better option. Remington .260 brass the pockets don't last in a gas gun as I got about 2 or 3 (if lucky) loads out of them, and Lapua brass well it's just to expensive.

Your other option is to neck up Wincester .243 brass. I did this for my 142's for my .260 upper. </div></div>

308-->6.5-08 just fine

308-->260 is not just fine
 
#8
Re: Forming 260Rem from 308Win

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body">I have formed hundreds if not thousands of pieces of 260 brass from 308 brass, it is a bit of work but if you are looking to save on cash it is the cheap way out, <span style="font-weight: bold">fyi-neck turning is required.</span> Your best bet is take 7-08 and neck it down. </div></div>

This
 
#9
Re: Forming 260Rem from 308Win

Well beg to differ the 0.02" won't make a difference. I basically do the same thing with .30-06 brass necking down and blowing shoulder out for .280. It is shorter than what it should be but it works.
 
#11
Re: Forming 260Rem from 308Win

I have been necking down LC .308 brass to .260 for my bolt gun and I have not had any issues what so ever. Is this primarily a problem for Gas Guns?

I understand that the neck is thicker, but I still have to trim the brass down to 2.035" to get the brass to spec! Even though the .308 brass is normally shorter. LC Brass being once fired makes it come out long from the press.
 
#12
Re: Forming 260Rem from 308Win

The 260 SAAMI drawing tolerances for the chamber neck are:
a) .299 - .301" at the rear of the neck
b) .298 - .300" at the front of the neck


As best I can measure with pin gauges, my 260 [long chambered at Douglas] is:
a) .299" at the rear of the neck
b) .298" at the front of the neck

Necking down LC or WIN 308 brass in 260 sizer die and then seating a 140 gr at 2.925", there is some lands engagement.
The loaded neck measures .297" with the LC97 brass.

There should be .001" clearance in my chamber, right?

I can get away with it, too, 90% of the time.

That one time in 10 that the bullet gets pinched, I am lucky if the extra pressure just wrecks the brass, and does not jam the gun. If I have to hit the bolt handle with a stick to get it open, others will notice at the range. Unsafe ammo is against the rules.
_________________________
 
#14
Re: Forming 260Rem from 308Win

Yeah I agree with you on that, and as I originally said why I neck turn it after I neck it down.

I have never checked to see if around would chamber without neck turning it may, I just turned them to be safe and LC brass isn't always the most uniform so turning makes sure I have consistant neck tension.
 
#15
Re: Forming 260Rem from 308Win

I checked my rounds yesterday and they are all right there with in the Spec, and none where over anyways... I probly need to look into neck turning tho for consistency, but this is good info...

Thanks alot guys...
 
#17
Re: Forming 260Rem from 308Win

1. Primer pockets last the longest on LC brass vs. Remington or Winchester (never tried the Lapua .260).

2. I already have a lot of LC .308 brass sitting around.

3. The brass is cheaper than Remington or especially Lapua

4. LC brass shoots good for me regardless what cartridge. My LC LR .308 brass shoots just as well at 1000yd in my Palma as my Lapua so goes back to #3,2, and 1.
 
#18
Re: Forming 260Rem from 308Win

all good points but the LC brass is much thicker than commercial so you will reach max pressures before you can reach the speeds commercial can. If that is not a concern disregard but try 50 pieces of winchester 243, you can get those for around 40 bucks load them with 44 gr of H4350 with a 142 SMK test accuracy and speed and try to duplicate with LC brass.
cheers.
 
#19
Re: Forming 260Rem from 308Win

That also makes it to where you can usually use a little less powder to reach the speed you want... The LC Brass is also everywhere... Remmington and those don't always have .260 brass...

And besides I am a Cheap Ass!!! The less I spend on quality Brass the more bullets I can buy... Like I tell everyone who starts reloading the biggest expense is More Components...

They never believe me until they start!!!

Good Luck Guys!!!
 
#21
Re: Forming 260Rem from 308Win

You definately need to turn your necks if you are necking down from .308 to .260. It does take time and there is a learning curve, but it can be done to make quality sub moa ammo.

I have had great luck with Winchester 7mm-08 brass. No neck turning required and seems to be consistant brass.

I haven't used the Lapua brass but being Lapua brass I expect it works great. But it is expensive.
 
#22
Re: Forming 260Rem from 308Win

yeah Ild say go with some new brass, if you want to save a little neck 7mmo8 brass down. but remember if you do neck fired 308 brass down you will want to anneal them first.
 
#23
Re: Forming 260Rem from 308Win

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rick 324</div><div class="ubbcode-body">That also makes it to where you can usually use a little less powder to reach the speed you want...</div></div>

I believe you're trying to make the point that because the LC brass has less capacity than others, less powder will generate equal pressure and speed...

Equal pressure, yes.

Equal speed, no.

Ask yourself why 300WM can launch a given bullet faster than a 308 - with equal pressure, and you'll have your answer.

Case efficiency factors aside (which are small, anyway), more case capacity will always provide higher velocity with equal pressure.

Can LC brass match Winchester brass velocity? No. Not with equal pressure, anyway.
 
#24
Re: Forming 260Rem from 308Win

Also, you'd better be VERY time-rich and money-poor if starting with 308 brass, forming, then turning necks is going to be a worthwhile method of getting 260 brass.
 
#25
Re: Forming 260Rem from 308Win

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Joe A.</div><div class="ubbcode-body">I tried searching but I didn't have any luck.

Is anyone using the CH4D size/trim die to form 260Rem from 308Win?

I am wanting to build an AR-10 and I already have a bolt gun in .308. I want to try something new.

TIA
</div></div>

Joe, I know you ask for information on how to make 260 cases from 308. Do you have any experience with these procedures? Is this a strictly cost effective situation? Unless you do have vast experience, I think it is foolish to reform cases when commercial 260 brass is very available.

My opinion, You have two choices, cases that may last only a few reloads or more expensive cases that will probably last longer. Gee, Dude. I have done a lot of this stuff when no other option exists but not being a gluten for punishment, (really) the smart move is to buy the better quality brass and forget the project.

And, just because somebody did it does not make it (what's the word?) smart. You plan on building an AR10. The cases are a small expense, compared to the gun. Look at the big picture. Now, lay down until the urge goes away. BB
 
#27
Re: Forming 260Rem from 308Win

I appreciate all of the information.

No, I dont have any experience forming 260 brass but I do have experience forming 300BLK and I figured it would be about the same. Plus I am not afraid of learning.

The main reason I wanted to form the brass was because I wanted to be able to consider it throw away brass. If I had to pay $.50-$1 per case I would be obsessed with picking up the brass after a match rather than focusing on the match. 308LC runs around $.10-$.20 (not factoring in cost/time)so I wouldn't mind leaving them behind.

I don't shoot many action matches with a heavy caliber so maybe I put all this on the back burner or just build a .308.

Thanks everyone.
 
#28
Re: Forming 260Rem from 308Win

the 6.5-.308 A-Square is not the exact same as the SAAMI spec'd .260 Rem. The differences are minor as readin the specs will show. If you've been forming 300 Whisper out of .223 or .221 Fireball and aren't losing many brass, resizing .308 to .260 will be baby shit to you.
 
#29
Re: Forming 260Rem from 308Win

So far I have sized over 250 pieces of LC 7.62 brass to .260 with out neck turning. I have taken the advice above and measured almost every single piece and I have not seen even 1 out of Spec. All the loads that I have produced chamber in my rifle with no issues and the consistency has been great.

I am going out tomorrow to shoot my second batch of LC re-sized brass, and I will report my findings.

Thanks for all the info...
 
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