.260 Remington reloading questions

[scudzuki]

I'll be rebarreling my Remmy 700 action in .260 Remington soon.
I have an ample supply of .308 brass.
How difficult is it to make .260 cases from .308?
Is it just a matter of FL resizing them in a .260 die, turning the neck and trimming the length?

If buying .260 brass is the way to go, is there any to stay away from?

Where can I get .260 dies?

Anybody ever used IMR 4895 in .260 Remington cartridges? Powder is tough to come by these days, at least the popular powders, but I have 12 pounds or more of I4895 and a bunch of bullets on the way (some 139 scenars, 140 SMKs, Nosler competitions, etc.) so I hope I can at least get started with what I have.
Thanks in advance.

Joe

 

[bcrich]

I'm in the same boat but I'm not even gonna try to make 260 brass from 308 too much work and nobody I know has been successful doing it to get advice from! So far I have the dies (lee) 140g Amaxs and Winchester brass 7mm-8 converted but no powder so far..gonna try my luck with H4831sc. Until I get the powder Ill just keep shooting the current 22-250 barrel.

 

[bjay]

I was curious too.but i decided to go 243 and 7mm 08 much closer on mouth size.. and besides 7mm 08 and 308 brass are about the price.243 is much cheaper but its muss less on brass life from expanding case mouth from 243 to 264.i think 7mm 08 is d best way to go

 

[Clark]

From my experiments and years of reading about this question over and over...

The factory 260 Rem chambers are typically .299" neck.
The factory 260 Rem full length sizer dies are typically .284" neck.
The factory 260 Rem brass with a 6.5mm bullet are typically .292" neck.
The military 308 LC97 brass with a 6.5mm bullet are typically .299" neck.

SEE THE PROBLEM?

The brass used for 260 is 7mm-08, 260, 243, and 308. Which brass is going to be used drives what diameter to have the sizer neck honed.
The stock Forster full length sizing die has a neck that will go with a .284" pin gauge.
---------------------------------
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


I have used 308 brass, 243 brass, and 260 brass in my 260.
My experiences are consistent, but not a complete verification of the synopsis I offer here of internet folklore mythology I have read about the 260:
1) 7mm-08 brass is the best, good fit between chamber neck and ammo neck
2) 260 brass is second best
3) 243 brass is third best. It gets a donut formed at the base of the neck
4) 308 brass is 4th best. Commercial brass will work. 10% of the time there will be a nasty pressure spike from a pinched bullet. These misfits can be sorted out, turned, or reamed.
5) Lapua 308 Palma brass will not fit at all.
http://www.saami.org/PubResources/CC_Drawings/Rifle/260 Remington.pdf

https://www.youtube.com/watch?feature=player_embedded&v=UgM727o387U
Here is a 1 minute video of my turning the neck of a 308 Lapua Palma case necked down to 260.

 

[427Cobra]

308 brass is too short for 260Rem

 

[Shoots 700's]

I have a friend of mine that made his 260 brass from 308. He got 2 loadings and had a head separate.

 

[scudzuki]

Thanks for the responses.

I picked up some 7mm-08 cases a while back and set them aside, thinking that I would probably use them to make .260 cases out of (I've been planning a move to .260 for a while). There's not much of it, though.

7mm-08 brass is just as hard to come by as .260 these days.
I just bought some Remington .243 brass from Natchez since it's the only thing I can find.

I have a bunch of different .308 cases so I figure I'm gonna try some of each anyway; should be interesting.

Joe

 

[kyshootnman]

I have ran both .243 and 7mm-08 brass in my 260 without an issue. Both were Winchester brass. I haven't had the issue with the donut on the 243 brass but it may eventually happen. I have around 4 firings on my current lot of brass ~100 pieces.

 

[scudzuki]

500 nickel plated Remington brand .243 cases just showed up, along with some dies.
I wiped a little of the Lee paste case lube on the inside of the neck, and a little on the outside of the neck and the shoulder.
A little shove through the press later and I have some mighty fine looking brass.

For $hits 'n giggles I shoved a .308 case through the .260 die.
Took a little doing.
Never seen the press flex so much!
That turned out a little uglier, but there are no strange artifacts on the outside of the case, although it is more obvious it has suffered a serious trauma.

The neck O.D. of the resized .308 case is .002" larger than the resized .243 case. While the resized .243 case drops right in my chamber. the resized .308 case won't go all the way in.

I think I'd better check the chamber neck. Fortunately I have pin gages.

I would think that if the chamber neck is a little tight, starting with .243 cases would be an advantage as the case wall thins when the neck is expanded.
I'd hate to have to turn the necks on these cases, the nickel plating is very nice to work with IME.

Joe

 

[Unknown]

I bought 7mm-08 cases took the decaping pin out of my 260 dies and sized them down without a hitch. If I had the decamping pin in the dies the cases got crushed.

I read through the threads about 260 ammo, and went with H4350 as more people seemed to get good results with it. It worked so well I haven't tried another powder. I load 123 scenar or 140, 142, 144 grain bullets. Lapua makes a 144 grainer that is wonderful, but you have to look for someone who carries that bullet.

 

[turbo54]

It seems like we might benefit from a sticky thread dedicated to this question; it is asked about twice a week. Or maybe members need to do a better job searching.

[MENTION=1548]Clark[/MENTION] - excellent and informative post

[MENTION=6522]427Cobra[/MENTION] - you say the same thing every time...that it's too short...I feel like I reply every time that while this is *technically* true, in the real world it doesn't matter a lick. Most people trim 308 brass back to 2.005" (SAAMI "trim length") or so, meanwhile most folks' chambers will accomodate 2.045" (or so). The reloading/accuracy success of these people proves unquestionably the .040" gap between casemouth and the end of the chamber is NOT A PROBLEM. Furthermore, if you form 260 brass (or 708 for that matter) from 308, you can simply skip trimming it for a firing or two and it will lengthen to "true" 260/708 length, which is only .025" longer than 308 anyway.

[MENTION=17566]Shoots 700's[/MENTION] - Your buddy's casehead seperation was not caused by forming 308-->260, but rather, him oversizing the brass. This would have happened to him anyway if he had even been simply reloading correct headstamp brass.

The simple answer here is good 260/708 brass can be formed from 308, but whether or not it's worthwhile depends on your chamber and how much work you want to go through.

Fire a few rounds of legimate 260 head stamp cartridges in your rifle and then measure the OD of the fired necks, then add .001" to that measurement. This is the diameter of your CHAMBER'S NECK.

Neck down a couple pieces of yoor 308 brass and seat some 6.5mm bullets. Measure the OD of the casenecks of these. This is your loaded round CASENECK DIAMETER.

If your CHAMBER'S NECK is at least .004" bigger than your CASENECK DIAMETER, you're good to go.

If your CHAMBER'S NECK is .003" bigger than your CASENECK DIAMETER, you're probably ok but should be careful because you may come across some pieces of brass with thicker neck walls, eating up your clearance.

If your CHAMBER'S NECK is .002" bigger than your CASENECK DIAMETER, you should probably neckturn.

If your CHAMBER's NECK is .001" (or less) bigger than your CASENECK DIAMETER, you MUST neckturn.

 

[jcfd2201]

I started out with Remington brass before switching to 7mm-08 Winchester brass. I didn't have any issues with the Rem brass but the Win was less expensive and from everything I could find it held up better. I opted for the Win based simply on case life since my 260 is an AI. I have had great luck with H4895 with 123's, 129's, and even 140's. I tried Varget, H4064, and H4831 with the Varget running a close 2nd.

 

[scudzuki]

https://www.youtube.com/watch?feature=player_embedded&v=UgM727o387U
Here is a 1 minute video of my turning the neck of a 308 Lapua Palma case necked down to 260.

Just watched your video.
That's how I figured I'd do it, except I'm going to chuck up the holder from my Hornady brass trimmer to hold the case by the rim, if I can get it to run true enough that way.

Joe

 

[turbo54]

When forced to turn necks, I use a Forster neck turning tool, but I chuck the case in my cordless drill. While the case rarely runs nice and true in the drill, I've found it doesn't affect how the brass comes out.

Its actually a fairly fast way to neck turn, but I still avoid it like the plague.

 

[LRRPF52]

I started out with Winchester 7mm-08 brass, full-length sized it and have had excellent results with it. Then I got a bunch of Lapua brass and learned that I need to size it before loading. I'm shooting a gas gun.

Best powders have been H4350 and RL17 for me. I started with N540, and have also used H4831. Accuracy was great with H4831, but couldn't get enough of it into the case.

I asked Janne Pohjoispää of Lapua about using the Palma brass with Small Rifle Primers for .260 Rem, and he said in extreme cold conditions, it doesn't ignite the powder column in the .260 Rem well, hence the 6.5x47 Lapua.

Sierra has book data for .260 Rem with IMR-4895, but it is more ideal for lighter bullets like the 85gr Sierra HP, 100gr, and even the 107gr SMK. It starts to become a non-efficient (too fast) powder once you go to the 120gr weight class, so you have to limit charge weights with 140gr class. Start load for 142gr SMK's is 32.6gr, max is 37.5gr using Remington brass, Remington 9 1/2 primer, 2.765" COAL, 24" Savage. Velocity was 2600fps. Sierra listed 6 other powders that produced a safe 2700fps in that spread, not including RL-17 or H4350.