What 7mm to build - 280AI or 284 Shehane

[Quick]

Brad, I'm going to wait until after the Teams and Tassie Queens to decide. Need to see how the rifle we use go against the bigger stuff.

[DenisA]

Another positive to the .284 band wagon is the apparent introduction of Lapua straight .284 cases.......................... if it evers happens.

[IanP]

Brad, I'm going to wait until after the Teams and Tassie Queens to decide. Need to see how the rifle we use go against the bigger stuff.

Good idea, especially if you can talk one of the shooters to let you shoot a few rounds for yourself. There are a couple of FO shooters in SA that I know shooting the 280AI and one in my club who is a new shooter and is doing very well with it.

Using 280AI Nosler brass the member at my club is launching at just over 2900 fps with a conservative and accurate load. The info I have is that the 280AI can launch at higher velocities and accuracy nodes than the 284W without case damage.

I'm putting my money where my mouth is and have a JGS 280AI custom reamer on its way to me now. I also have for experimenting with re-chambering 7mm (Shehane) barrels, a 7mm-300WM reamer on its way. The 300WM should launch the 7mm, 180-195gr hybrids out to 3200 fps and finish off the shortened barrels nicely inside 1000 rounds. Look forward to playing with the 7-300WM but the 280AI is a serious 7mm, F-Open contender with reasonable barrel life and a replacement for my Shehane.

Ian

PS The other shooter who I mentioned above initially loaded his brass (not sure what make) to launch 180 grainers at 3000 fps and got 10 firings from it before he changed to new cases. He now loads more conservatively for longer case life but if I loaded my Shehane to launch at 3000 fps with lapua brass, I'm pretty sure one firing would be all it was good for with 180gr bullets.

[AlanF]

Ian,

With where you're going have you considered the new Norma 7mm Blaser Magnum case? http://www.norma.cc/en/Products/Hunting/7-mm-Blaser-Magnum/

Alan

[IanP]

Ian,

With where you're going have you considered the new Norma 7mm Blaser Magnum case? http://www.norma.cc/en/Products/Hunting/7-mm-Blaser-Magnum/

Alan

Alan, its a 7mm-300WSM clone or at least very close to being a clone performance wise. Dont know much about it except its based on 0.404 Jeffery, (RUM) case approx 2.5" long with a 30 degree shoulder. A little less capacity than the 300WSM? I already have plenty of 300WM cases to experiment with and my American friends tell me the 7mm wildcat is supremely accurate. I will have fun recycling my older 7mm barrels.

Ian

[AlanF]

Ian,

Yes, on closer inspection the Blaser is much closer to the WSM than the WM in capacity. I make it about 5% more than the WSM and about 11% less than the WM. Are you going to shoot the WM in F-Open? If you are able to get the 7mm 180s to 3200, I reckon it'll be a handful in terms of behaviour on the bags. Don't forget the extra powder adds to the recoil too.

Alan

[IanP]

Ian,

Yes, on closer inspection the Blaser is much closer to the WSM than the WM in capacity. I make it about 5% more than the WSM and about 11% less than the WM. Are you going to shoot the WM in F-Open? If you are able to get the 7mm 180s to 3200, I reckon it'll be a handful in terms of behaviour on the bags. Don't forget the extra powder adds to the recoil too.

Alan

The 7-300WM is an experiment and I dont have any desire to run the 180s at 3200 fps. I get the equivalent ballistics running the 300WM with 230gr hybrids at 2870 fps. If and when the 195 grainers become available then I would probably run them conservatively at 3000 fps in FO.

Having said that, I would still experiment with the 180s to see where the accuracy nodes are and just how much recoil is generated. Remember I can run slower burning powder in the 300WM (2217 or 2225) so recoil is not as bad as you might think. Wont really know till I put one together next year and see how it goes. If it shoots like stink at 3200 fps then I would certainly use it.

Main FO rifles of choice at present are both 30 cals with my 300WM launching 230gr hybrids and my 30-06AI launching 200gr hybrids. I plan on taking these to the Vic Queens in April. My youngest son, (15yo) Michael will also be attending and competing in FO with his new 6.5x47L. Which reminds me that I had better look at booking accomodation after xmas. Any recommendations?

Ian

[AlanF]

...Which reminds me that I had better look at booking accomodation after xmas. Any recommendations?...

Ian,

Will be good to see some more 30 cals in the Vic Queens field. Richie Neil went very close last year with a 300 WSM.

The McIvor Motor Inn is reasonably close to the Range, and Park Lane Holiday Park has cabins and is also within a few minutes.

Alan

[IanP]

...Which reminds me that I had better look at booking accomodation after xmas. Any recommendations?...

Ian,

Will be good to see some more 30 cals in the Vic Queens field. Richie Neil went very close last year with a 300 WSM.

The McIvor Motor Inn is reasonably close to the Range, and Park Lane Holiday Park has cabins and is also within a few minutes.

Alan

Thanks Alan, I will try both those places and see if I can get in!

Ian

[bsouthernau]

Main FO rifles of choice at present are both 30 cals with my 300WM launching 230gr hybrids and my 30-06AI launching 200gr hybrids. I plan on taking these to the Vic Queens in April.

I hope so. I'd be interested to discus that 30-06AI with you - assuming I make it there of course.

Barry

[macguru]

Ian, have you tried 230gr hybrids in the 30-06 AI ? Wouldn't you get about 2750fps ? ; i was thinking thats all you would need .......

andrew

[IanP]

Ian, have you tried 230gr hybrids in the 30-06 AI ? Wouldn't you get about 2750fps ? ; i was thinking thats all you would need .......

andrew

I think the 230s are a little heavy for the 30-06AI, (haven't tried loading with them) and I have a 300WM that launches them just fine at 2850 fps for the long ranges of a competition. I have the 30-06AI running on a nice accuracy node at around 2900 fps with the 200s for the short to mid ranges. It seems the 215 hybrids would be easier to load for but the BC gain is not that much better than the 200s so I haven't tried them either. I think I have all ends covered pretty well with the combination of both calibres and projectiles.

You raise a good point though and its worth exploring, but I have two accurate loads now and really cant be bothered wearing the barrel to find out. Maybe sometime in the future I will give it ago and see if the lapua 30-06 case is upto the Big Berther of 30 cal projectiles for f-class.

Both the 300WM and the 30-06AI are running at conservative loads and should give long barrel life. I have scoped the 300WM barrel at 600 rounds and it looks very good, no real signs of throat erosion and without any fire-cracking present. I have not needed to adjust the seating depth of the 230s and it looks very much like this barrel likes the load of 2225 its running. Touch wood, I hope it stays this way for the Vic Queens. I can see no reason to date not to expect decent barrel life from this combination. Its a new cartridge for me as is the 30-06AI so I dont know if the 300WM throat will suddenly just start eroding. Time will tell on the barrel wear question with the medium velocity loads I'm shooting the 230s at.

Ian

[IanP]

Main FO rifles of choice at present are both 30 cals with my 300WM launching 230gr hybrids and my 30-06AI launching 200gr hybrids. I plan on taking these to the Vic Queens in April.

I hope so. I'd be interested to discus that 30-06AI with you - assuming I make it there of course.

Barry

Barry, if its possible I would be happy to let have a shoot with it and get a real feel for how it performs!

Ian

[bsouthernau]

That's very generous - we'll see. And seasons greetings to you Ian.