.260 vs .308 brass

[huntinfool87]

I've never used .308 brass for my .260 but I have no .260 brass and a ton of .308 brass. My book says 308 max case length is 2.015 and for the .260 its 2.035. So my question is this. Is it possible to use .308 brass for my .260? Or would I be better off selling my .308 brass and buying .260 brass?

 

[Legionnaire]

Yes, you can use .308 brass. The .260 Rem, like the .243 Win and 7mm-08, is a necked-down .308 case. Should be easy to neck down. You’ll just need to watch for thick necks, so turning or reaming might be necessary.

 

[Blue68f100]

As said, Yes you can. I would anneal the brass prior to the sizing. I've taken 308W to 6.5 CM, without any problems except thick necks which needed turning.

 

[ArchAngelCD]

IMO it is always better to use the correct head stamp when possible.

Go to the "Buy, Sell and Trade: Reloading Components and Gear" forum and offer to sell or trade your 308 brass for 260 brass. I'm sure you can make a deal with someone.

If you do neck down I see no reason why it won't work but usually when necking up or down the brass is work hardened and becomes likely to crack without annealing.

 

[jmr40]

I like to use the correct brass if practical. Especially if you own both 308 and 260 rifles. It can lead to confusion and increases the possibility of trying to load the wrong ammo in one of your guns. But 260 brass is getting harder to find and 308 is everywhere. I used 30-06 brass to load 338-06. It wasn't ideal, but finding 338-06 stamped brass was a chore and expensive.

 

[huntinfool87]

I like to use the correct brass if practical. Especially if you own both 308 and 260 rifles. It can lead to confusion and increases the possibility of trying to load the wrong ammo in one of your guns. But 260 brass is getting harder to find and 308 is everywhere. I used 30-06 brass to load 338-06. It wasn't ideal, but finding 338-06 stamped brass was a chore and expensive.

I agree with you. Fortunately I no longer own a 308 so there will be no risk of confusion.

 

[huntinfool87]

Yes, you can use .308 brass. The .260 Rem, like the .243 Win and 7mm-08, is a necked-down .308 case. Should be easy to neck down. You’ll just need to watch for thick necks, so turning or reaming might be necessary.

That's the part I'm struggling with my book says the 308 brass should be shorter than the 260. So I'm not sure if that could cause accuracy issues.

 

[Legionnaire]

Necking down will also lengthen it a bit. It will be fine.

 

[huntinfool87]

Necking down will also lengthen it a bit. It will be fine.

Oh good to know thank you. I've never done this so I really appreciate the information

 

[Legionnaire]

Look at the trim-to length rather than the max length: 2.025. A bit shorter than that won't hurt, and if your resized brass is shorter than that, a couple of firings and you'll be where you want to be. But when you neck down, the brass has to go somewhere; the neck will lengthen a bit as well as thicken.

If you're going to be reloading .260, you'll need a set of dies anyway. Try resizing a couple of .308 cases and see if you like the results. If not, you can always sell the .308 and buy .260.

 

[huntinfool87]

Look at the trim-to length rather than the max length: 2.025. A bit shorter than that won't hurt, and if your resized brass is shorter than that, a couple of firings and you'll be where you want to be. But when you neck down, the brass has to go somewhere; the neck will lengthen a bit as well as thicken.

Only if

If you're going to be reloading .260, you'll need a set of dies anyway. Try resizing a couple of .308 cases and see if you like the results. If not, you can always sell the .308 and buy .260.

Look at the trim-to length rather than the max length: 2.025. A bit shorter than that won't hurt, and if your resized brass is shorter than that, a couple of firings and you'll be where you want to be. But when you neck down, the brass has to go somewhere; the neck will lengthen a bit as well as thicken.

If you're going to be reloading .260, you'll need a set of dies anyway. Try resizing a couple of .308 cases and see if you like the results. If not, you can always sell the .308 and buy .260.

That is if I can find .260 brass lol. I already have dies for .260 so I'm all set there. What kind of leeway would you say I have for thickness?

 

[Legionnaire]

Hard to say, as it depends on your chamber; some chambers are tight, others are pretty loose. I'd simply resize a case, trim if necessary, seat a bullet, and see if it chambers easily. If it does, you're good to go. If not, you'll need to turn or ream. Easier to ream, but turning is more flexible if you want a specific thickness.

I am far from an expert on resizing to a different caliber; most of my reforming has been blowing standard cases out to Ackley Improved dimensions. I've not had to do neck turning although I have the tools to do so.

I actually went through the same evaluation a while ago when I got out of .308 and ended up selling mine. I've bought Lapua .260 when I find it on sale. With regular annealing, I'm hoping it lasts a good long while.

Edit: Here's a good article on the subject of neck turning.

 

[Legionnaire]

A couple of additional thoughts:
1. Good idea to anneal your .308 brass before sizing if you have the means to do so.
2. You might also consider going from .308 to 7mm-08 as an intermediate step, then from 7mm-08 to .260.

You have me curious now. I don't have any .308 brass left, but will have to scrounge a couple pieces so I can try downsizing them with and without the intermediate step.

 

[Blue68f100]

I had no problem doing the 6.5CM without the intermediate step. I did anneal before I did it though. The 6.5 CM moves the shoulder way pack compared to a 260. If you don't have a annealing machine, use a socket on a cordless drill to spin and a propane torch. Soon as you see the flame start to change colors stop, you have it hot enough. If your glowing bright you over cooked it.

 

[BigBore45]

I do it for my 260 rem. With 308 and 243. No need to anneal or do it in steps as one step works fine. The 308 is hard to do so lube is your friend. The 243 sizes just like 260. Works fine. Dont mix it up and put it in the wrong gun.

 

[Bfh_auto]

I agree with you. Fortunately I no longer own a 308 so there will be no risk of confusion.

I used 308 brass and was forced to start neck turning. You will have tight necks if you don't.
Annealing was also necessary. 7-08 was perfect. Tighter than 260, but didn't pinch.

 

[FLIGHT762]

I've formed 308 brass into 260 brass. What I found was thinner necked brass like older Hornady and Winchester cases that weighed under 165 grains (with no primer) worked fine. Gave necks that didn't need turning. Thicker brass such as Federal, Military 7.62X51 and heavier cases in the 170+ weight range produced necks too thick.

 

[MrMagumba]

I have two pages of detailed notes from my work reforming 308 class brass into 260. Conclusion: I have settled on 243 brass to use in my 260. I ordered a tapered 260 expander to go in my Redding 260 die and it makes the reforming easier. I also use Imperial sizing wax when reforming and save the Hornady One Shot oil for regular resizing. No intermediate steps are needed.

The point of the following samples is to prove that it works. This might be a little boring and long winded, but again it's to show it works. Your results will vary depending on the dies you have and your technique.

Note samples: (308) 308 to 260 too short overall length (I shoot short bullets and my throat is growing so I can't afford to use short brass) , headspace on resized 308 within 1-2 thou measured at 4 different datums on shoulder
(30-06) I did it by sizing in a 308 then a 260 then trimming. Fun but too many issues.
(243) Fired Federal case had neck wall thickness of .018 and .015 after reforming into 260. My Remington 260 rem cases have a neck wall thickness of .014, Remington 243 is .017. Winchester is .016. PRVI is .014. All end up within 1 thou of the .014 Remington factory 260 after reforming. None of these brands had a headspace more than 1 thou longer than the Remington brass measured at 6 different datums. There were a couple that were 4-5 thou shorter so those would get blown out.
Case capacities: Remington 260 - 55.2, Fed 243 reformed - 53.9, Rem 243 reformed -55.4, Win 243 reformed -55.7, PRVI 243 reformed -53.8
These are weights of table salt filled to the top of the neck. I didn't feel like filling with water and trying to dry things out or manage measurng water. I can't remember what I did with the primer hole. I probably put a spent primer in to plug it. So brand matters, but they will all work.

(7-08 notes) I didn't do much here because 7-08 brass was not exactly cheap or easy to get when I did this. PRVI 7-08 brass reformed to length 2.034 when run through my dies which is in the zone for 260. Neck wall thickness was the same as PRVI 243 brass so it is probably safe to assume that any 7-08 brass will yield acceptable neck wall thickness. Headspace was within 1 thou measured only at the .350 datum.
I also didn't do anymore work with 7-08 because I actually have a 243 and I can just buy 243 brass and decide where it gets used later. My 260 brass will not chamber in my 243 and if I shoot a 243 in my 260 I'll probably survive (I am very careful and all reforms are labeled with yellow warning labels on the boxes). I also liked the idea of expanding to get the caliber I wanted rather than necking down. The tapered expander was the best thing I did in the process.

I just bought a Savage 110 260 and have over 500 reforms shot through it. On 3rd firing of PRVI 243 cases. No problems except struggling to find super accurate load for 120-130 grain hunting bullets.