All,
Building an 8mm something and thought that this config may be a worthy round. Let me know what you think the velocity potential would be. If you know of any other 8mm rounds with 8mm Rem Mag potential and fit into a 300 Win Mag length action easily I would love to know about them.

Cheers,
Jason

Haven't seen it done, but you could expand a .300 Ultra Mag to 8mm, push the shoulder back, and trim the case to a length of 2.50". In doing so, you'd have no problem equalling 8mm Rem Mag velocities. Also, I've worked with the 8mm Remington for years and have found it to be highly underrated. For one, Remington uses too short of a barrel to get the most out of the round (ie, 24"). I built an 8mm Mag on a stainless Model 70 and with a 26" barrel, I could get slightly over 3,000 fps with a 220 grain bullet. With powders such as Retumbo, RL 25, AA8700, etc., you can easily surpass factory loads.

Lee Martin
www.singleactions.com

What's wrong with the 8 Rem Mag? The only reason you'd go to 8mm WSM is to use a shorter action and to lighten the rifle. Other than that it would seem to be a complete waste of potential and time. Also, you're close enough to 338 where you have a significantly better choice of bullets in that caliber.

I have one 338WSM on a M70 action and am in process of building another on a short Montana Rifles action. I'm doing it for weight. Hope to end up at about 7 pounds as opposed to 7 lbs 14 oz on the current one. The short cases will NEVER equal the potential of the longer cases. Your idea would seem to be an exercise in futility and a waste of a good long action which could be used for a long cartridge with more potential.

Not so. Just got my 325 Montana (WSM necked up to 8mm) reamer back from Pacific Precision. with the 220gr Hornady seated just .050 deeper than the base of the neck, the COAL is 3.094, perfect for the M1999 SA coming in a couple of months.

The case holds 77gr of V550 (uncompressed), which just might get close to the 8mm REM (89gr of RE25), but if not, what will know on the receiving end?

8x68 is sexy, but the brass is a bit tough to come by over here.

QUOTE]You're dreamin'.[/QB][/QUOTE]

Exceedingly well said, Jon.

Factories can underload the standard magnums and overload the short magnums then hype that the shorts are the equal of the standards, but it ain't the case and never will be.

It appears that jrswick is wanting the highest performance possible in an 8mm from a magazine box limited to about 3.35 inches. If that is the case, a "Dakota"-style 8mm cartridge as suggested by Lee, an 8mm/300WIN, or an 8mm/.338 would all provide more velocity than an 8mmWSM. The most practical would be an 8mm/.338, but since the same action would accomodate the excellent 8mm Rem by only lengthening the magazine, what would be the point?

Rod's suggestion that the 8mmWSM will fit like a glove in the new Montana action is certainly attractive to someone who wishes to use this action for a higher-powered rifle, but to suggest that it will somehow equal an 8mm Rem is unrealistic. While I would agree that the 200 fps slower bullet would not fail to dispatch the same game animal, that hardly makes the ballistic potential of the two cartridges identical.