I am researching as much info as possible before I invest my money on a silhouette rifle. I really like a 257 roberts kimber, but I also really like a Remington 700bdl in 7-08. I think the 708 might be a better gun, but the brass seems to be scarce right now. Do any of you form your 708 brass from 308?

That is what it was origanaly made from along with the 243 and 260. Aneal the neck before you neck them down and check the outside neck diameter. You may have to turn them down just a little.

Lube the necks and run them through a 308 die without the expander, next re-lube and resize with a 7-08 die, usually they need a light turning to make them concentric. If you can find Lake City match brass the necks are thick enough for a full turning facilitating fitted cases, if you have a good barrel your gun will really group well with them assuming everything else is done properly.

Take new or once, twice or more fired factory .308 brass properly lubed and run them up a full length 7-08 die. No need to anneal or even turn necks concentric as not much reduction in size. Generally, they will be .015 to .018 short as .308 is 2.005 standard length and 7-08 is 2.035 standard length. They will grow longer after a couple of firings with little harm to the end of the chamber. This is a common practice I use all the time. Just this weekend I fired 200 shots on once fired range pick up Hornady match .308 brass that had been fired seven times each as reformed 7-08.

I would have to agree with Bob, that was the benchrester in me thinking you should turn the necks, doubt you'll ever be able to see any difference in an offhand game such as silhouette.
Then again that advice your getting is from the "Guru", known around these parts as "black neck Bob" because he never even bothers to clean the carbon off the necks of his 7-08"s! I have never understood how a guy who is so meticulous, neat and clean in ever other aspect of his life doesn't bother to clean cases! So it shouldn't surprise anyone that he doesn't ever turn them, he can make just about anything on a lathe but probably doesn't own a concentricity gauge.
BIG disconnect here Bob, we want a logical explanation. ;)

Kevin, remember seeing that multi function case measuring tool I have? The one made by GCP Inc. I also have a ball micrometer for measuring neck wall thickness, too. The black necks are not really carbon issues, more stained by the chemical reaction of burning powder.

Bob, Remember this is what brass is SUPPOSED to look like

Military 308 brass is quite thick at the neck. necking down to 7mm thickens the necks more and NOT uniformly. Thus you will get an uneven bullet release. Turn the necks for a factory chamber to .014 then neck down and then turn again at.014. All military brass is annealed and fire formed into 7-08 it should last for years. I assume neck sizing with a button .002 smaller than the brass thickness times two plus.284. So with a factory chamber and .014 brass then its .028 + .284=.312 minus .002 or a .310 button (even .309)

Just got home 30 minutes ago. Arrrrgg...long ride.

Hey 259, real men don't give a crap about shiny brass. A selected sample of those Hornady match 7-08 cases fired seven times each. Do you like my Kansas sunflower design?







Never mind about the brass, 259. Focus on the shiny bullets, focus.

Bob Mc Alice wrote:Just got home 30 minutes ago. Arrrrgg...long ride.

Hey 259, real men don't give a crap about shiny brass. A selected sample of those Hornady match 7-08 cases fired seven times each. Do you like my Kansas sunflower design?

Send me the crappy looking dirty brass and I'll return it to you looking like new.... If anything it will surprise and blind Bonner when you open your box and give you a chance

Snake wrote:Military 308 brass is quite thick at the neck. necking down to 7mm thickens the necks more and NOT uniformly. Thus you will get an uneven bullet release. Turn the necks for a factory chamber to .014 then neck down and then turn again at.014. All military brass is annealed and fire formed into 7-08 it should last for years. I assume neck sizing with a button .002 smaller than the brass thickness times two plus.284. So with a factory chamber and .014 brass then its .028 + .284=.312 minus .002 or a .310 button (even .309)

I made 300 6.5x308's {pre-260 Rem} from Lake City Match 62 308's in 1987, the gun wore out before the brass did, the necks were thick enough to fit them .003 under, had to slightly bump the shoulder every other firing.

I went through the process (hassle) of creating 7mm-08 brass from .308 Lapua. Completely unnecessary. In my safe are 3 standard and 2 hunter silhouette rifles, all 7-08, all using Winchester 7mm-08 brass. Settling on K-I-S-S has worked well for my purposes. Good shooting.

The only reason I would do it at this point would be that 7-08 doesn't seem to be easily available, I saw two bags of it at Sportsmans Warehouse a couple of weeks ago and by the time Bonner and the Guru decided they wanted it.......gone in about an hour. That was the first I had actually touched NIB brass in over a year and I am able to look every day up and down the front range. I have a good supply of both military and lapua 308 brass, I refuse to sell it to hoarders, if someone getting into the game needed components that would be a different story.
Kb

Bob Mc Alice wrote:Just got home 30 minutes ago. Arrrrgg...long ride.

Hey 259, real men don't give a crap about shiny brass. A selected sample of those Hornady match 7-08 cases fired seven times each. Do you like my Kansas sunflower design?

Inexplicable.....

Keep up the sunflower stuff Bob. On day you will turn left at the I-70 ramp comming back from CRC and in just a short time you will be home. Soon you will be looking for some red slippers to ad to your sunflower picture.