OzFclass

For arguments sake if I were to look at setting up a 7mm barrel what would be the current chamber of choice? Reason Im asking now is with the brass issues of 284, is it worth considering the 7SAUM, 280AI, 7/300WSM paths?

I dont think I would be willing to co operate with the continual boot of 7mm 180gr bullets belting out at magnum speeds, so staying at the 2820-2950fps range in a 10kg gun would be about it.

What about the 7x57ai should offer similar powder capacity to the .284 without the problems of the rebated rim.
Not sure if the 7x57ai or the 280ai would have the same accuracy potential as the .284 but someone needs to be the crash test dummy!

Locally, Paul Moynahan seems to shoot some nice 1000 yard light gun groups with a .280 AI.

I think the 280 or 280 AI would be the way to go, I dragged out some 6.5 x 57AI cases and measured for capacity, 6.5 x 284 holds 65.2 grn of H20 and 6.5 x 57 AI holds 61.2 grns of H20, the neck on 57 case is very long so you could move the shoulder forward I guess. The big plus is RWS brass it's bullet proof, I wore out 3-4 barrels on 50 cases and the primer pockets are tighter than new 284 Lapua cases.

Matt

Matt,

I never had any problems with primer pockets with 6.5-284, or with 168s and 175s in 284 Shehane. Its just the 180s that are the problem. In your 280AI, did you ever push the 180s hard?

Alan

Alan
I didn't really do to much with the 280ai before I sold it, so I can't really comment but the capacity would be more than the 284 so I would hope that you could run @2800-2850 with less pressure which is what I'm after.
Matt P

Matt,

In the 7 Shehane I can run at those velocities without head expansion even with the sus Lapua brass. I think the reason is that moly coating combined with a slower powder (N165) means I'm getting more even pressure right up the barrel. With 2209 and uncoated, there is probably more of a pressure spike in the first half of the barrel. I guess its a choice between the two lows : the lower velocity spread of 2209 and the lower pressure of slower powders.

Alan

I think it's been mentioned already that the 1000BR shooters are looking at RWS 8x68mm brass. Apprently very heavy contruction, even compared to the 6.5x68mm. Maybe neck down some 8x68mm to 7mm and try some 168gr at full-tilt?

Is the 8x68, necked down to 7mm (and improved), a 7mm BooBoo? If so, it is a pretty big sort of cartridge, but Paul Janzo has a reamer for sale in the For Sale section.

im running a 7saum and find it very flexible with several nodes between 2950 and 3080.

just because you have a magnum doesn't mean you have to run it flat out! id rather be sitting at 2950 on a node with long brass of knowing i can go up even more than rum a .284 at MAX and ruin cases to get the same results.

i think the .280ai has very similar case capacity to the 7saum so just because it isn't a "magnum" doesn't make it kick any less.

Something I have been thinking about lately is that since I love my 6.5 WSSM so much, I would like a 7mm version. Only problem is a WSSM case is a bit too small to get a 180gn pill up to the 2830 fps area, while an RSAUM is too much.
I have just found out that a company http://spencertoolandgrind.com/ makes dies to shorten 7mm RSAUM cases by .200". (or use 270 or 300 WSM brass)This would be perfect to get a 180gn bullet to 2830 fps with less powder than a 284 Shehane, in a tough case.

Looks like Gertrude might be getting a bigger sister.

if you don't want to have visible throat loss after 2 x 10 to count, don't get a 7 mm stw.
great hunting cartridge though it is, it can be hard on barrels when string shooting.
don't ask me how i know this.
the 7mm boo boo would be as bad or worse.
keep safe,
bruce.

RDavies wrote:Something I have been thinking about lately is that since I love my 6.5 WSSM so much, I would like a 7mm version. Only problem is a WSSM case is a bit too small to get a 180gn pill up to the 2830 fps area, while an RSAUM is too much.
I have just found out that a company http://spencertoolandgrind.com/ makes dies to shorten 7mm RSAUM cases by .200". (or use 270 or 300 WSM brass)This would be perfect to get a 180gn bullet to 2830 fps with less powder than a 284 Shehane, in a tough case.

Looks like Gertrude might be getting a bigger sister.

Rod 2209 Davies,

I think you're a victim of the "design a case around a powder" syndrome.

Alan

While I would likely use 2209 in my 7mm WFSM (Winchester fairly short magnum), I am going to start playing with 2213sc in my new 284.

I wouldn't mind running my 6.5 Gertrude (WSSM) reamer into a 7mm barrel if I can get someone with a neck reamer to cut that section of the chamber for me. It might not have the capacity to get the bullets up to the 2800 fps area, but would be something fun to try.

Well Rod it looks like i bet you to the punch i called it a 7 Ratshot (ofcourse) its a 25 wssm case necked up to 7mm bit less body taper and a 40 deg shoulder . it should match a 284 . i ve cut a seating die next is a neck die and a body die . cases are necked up and turned, now to find the time to cut the chamber. i was keeping this little wildcat under my hat until i got it up and running. i ve been dickin around with it for the last 18 months , getting close now.cant wait to see the first fire formed case.
cheers Paul...