I'm thinking of building a 257 or 264 wildcat to shoot 115-120g bullets for Deer out to 500m with minimal recoil.

I want it to fit in a Rem 700 short action, and the 257/284 or 6.5/284 looks pretty good, but there is some roumours that they dont fit in the 2.8" mag on the 700's.

The other options would be something based on the WSM, WSSM or SUAM short fat cartridges.

Are there any web sites that list these cartridge capacities and lengths so I can get a better idear of which suits me best.

Or should I just stick to a 260 Rem?

Cheers

Grant

Well, deal is, with a wildcat you can have it throated to seat whatever COL you like. Even to the particular bullet you plan to use (though you aren't really limited that way, but say you have a 100g NP you like; have it throated to fit that at 2.8" COL.)
The base measurement for the 284, SAUM and WSM parent cases are on the order of .500", .550 and .555" resp. The 6.5-284 does about what the 6.5-06 does except for longer bullets sitting deep in the case; the WSM case will do close to the 2.5" Win Mag cases, again excepting the longer bullets.
Any of those guys would give you lots of room for a little .257" bullet. The 284 rim is rebated, so that might be a consideration.
Hope that helps!

Having traveled the road yopu are considering when I settled on the 257DGR, I used a variety of sources. The problem I found was almost nobody measures case capacity ion the same way. I made most of the brass for the options I was considering and filled them with the same powder, I had an engineer friend do CAD drawings of the cases, use nominal dimensions and we could use calculated volumes (which aren't accurate because not all brass cases are constructed the same) but it gave a comparison. One thing you always have to consider is how much of the powder space is the bullet going to "waste"- something that does happen in a sa mag box. I think think you will find that a 308 case, with a 30-40 degree shoulder, a 455-460 shoulder diameter, and if looking for max capacity with only 110-120 in 257 or 140 in the 6.5, go with a one caliber neck. The 257 DGR has almost a 1.25 caliber neck to allow for the 75 gr bullet to touch.
Anyway designed as above the 308 case is within about 1.5-2 grs of usable powder spacee of the 284 case in a rem sa- use a long action and the 284 case can flex its muscles.
So to make a long action short if you want a 6.5 go with the 260 or a 260AI.

DuaneinND

Thanks for the input. I read the article in SCN about your 257DGR and got quite keen about one. I even emailed you to ask about having a barrel chambered and sent over to me in New Zealand, but it must have got lost in cyberspace.

I'm still deciding whether its 257 or 264 so if I go with 264, is ther any reason to go with a 260DGR rather than standard 260 Rem or AI?(have you done a 260DGR?) You have pushed the shoulder back a bit so it will seat longer bullets better in the Rem 700 action wont it.?

Cheers

Grant

My isp providers excellent spam blocker must have thought you were out to infect me! I have not done a 260 version, The benifit would be in the neck length and the supposed cleaner/efficient burn of the 30 degree shoulder. I did push the shoulder back just a tad for the 700 sa box and so that the base of a 100 gr bullet would be just at the shoulder/neck junction when it was about .010-.015 from touching. Supposedly better accuracy and less standard deviation. Now the question does it work? I can't say for certain, but all the 257DGR I have built to date have been excellent shooters, and in chronographing velocities do seem to have low extreme spreads and standard deviations. I think that the whole 308 family would benifit from the 1.25 caliber neck and the 30 degree shoulder, it sure works for the BR cases.