New 7mm Wildcat idea - thoughts???

Do you like this idea for a new cartridge?

  • Yes

    Votes: 11 44.0%

  • No

    Votes: 14 56.0%
  • Total voters
    25
gabrielguitars

gabrielguitars

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OK, so I have this idea for a new super-fast 7mm, made to work through a standard-length action. I have an older Sako M658 in 7 Rem., but I am wanting more jam to reach 500-600 yards with enough energy for a quick kill. The Sako has a detachable mag, so I have length requirements that are strict. My plan is to take the .338 RUM (which is a little shorter than the .300 RUM) and neck it to 7mm, shorten the neck to normal 7 Rem Mag length, and possibly increase the shoulder angle to about 35 degrees. That should allow the cartridge to fit (just!) in the mag, yet provide performance in the 7 STW - 7 RUM realm. I am also toying with moving the shoulder back a slight amount for longer neck, but am afraid of trying that due to buckling cases during forming. I was thinking of calling it the 7mm NNUTS, which stands for Nothing New Under The Sun. I would love some feedback, so give me your best shot, thanks!
 
Does you Sako bolt have enough meat for a .590" boltface?? If so, you could just go with the 338 Lapua parent case that fits a standard action and has a massive case capacity. One variation of this is the 7mm Allen Mag, basically as 7mm/338LM with a 44 degree shoulder. I think it is hard on barrels, I'm told it does 160 Accubonds over 3700 FPS. A bit excessive, but that will get you out to 700m no problem.

JT
 
Check out the fairly new wildcat designed here in Edmonton called the 6.5 Extreme, done by the same guy that did the 20 Extreme. Not 7mm but next best thing. FS
 
Isn't that what the 7 RUM is?
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No,the 7 RUM is full-length, like the .300 RUM,and has a less acute shoulder angle.

Jtoews80, the body of the Lapua won't fit or feed from the mag, so that idea is out. I think that I could probably have opened the boltface, but the RUM brass just fits perfectly, plus I'm not sure I need any more capacity than the RUM will provide.

Fassteel, how do I find out about the Extreme series of cartridges? In this case, it would't matter, as I want to just do a simple re-chambering job, with no other work, though I love 6.5 cal.
 
Assuming you want it to feed from the mag, if you use 338 RUM brass, and are restricted to a max OAL of 3.400" or so, you might find that the heavy bullets have to be seated so deep that the neck is not gripping the flat of the bullet. You might want to shorten it to 300 Win Mag length (2.620"). Either way, you'll likely have some neck turning to do. Neck size a 338 RUM case with a 7mm SAUM die, seat your bullet of choice where you'd like it, and see what OAL you'll need.

A 416 Rigby (or 338 Lapua) case, shortened to 2.620" ("Lazzeroni" style) and with the rim diameter reduced to 0.535" would likely max out available capacity for a round that would feed from the mag (but you said it wouldn't), and allow for solid gripping of the heavy bullets.

If you are happy with a single shot, you can ignore mag length restrictions and just go all the way up to and including a 7mm RUM.
 
Sounds a lot like the 7mm Imperial Magnum that used to be kicking around. I would go for it and have fun.
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The 7mmImperial Magnum was virtually the same as the 7mmRUM.

The 7mmDakota is a shortened version that has performance just below the 7mmSTW,but it fits in a shorter action.Personally,I don't see the point of a new cartridge,with the 7mmDakota,7mmSTW and 7MMRUM available.
 
The 7 Imperial is too long, even a little longer than the .300 RUM. The 7 Dakota I looked at, but the shoulder is too far back so that it won't clean-up the 7 RM chamber, so that is a no-go. I had originally looked at making the cartridge .300 Win length, and that's likely what I will do. As far as not needing a new cartridge like this, I only partially agree. First of all, "need" has nothing to do with guns, otherwise one gun would be good enough, right? LOL! However, I am trying to fill the niche of re-chambering factory 7 RemMag guns into a real boomer that feeds from the mag and pretty well maxes out performance, all without any other changes. I do believe there can be some 'need' there, for those that want more power with minimal change and minimal cost.
 
I am trying to fill the niche of re-chambering factory 7 RemMag guns into a real boomer that feeds from the mag and pretty well maxes out performance, all without any other changes.
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That requires not only rechambering,but modifying the feed rails to feed the larger diameter cartridges on some actions,the 700 being one.
Most people that are going to that effort will install a higher quality barrel and true the action at the same time.
 
So this is trying to reinvent the wheel.
If you really want to try something different that I have not heard of before why not neckdown a .50 BMG? Overbore but there are lots of other overbores to chose from
 
That requires not only rechambering,but modifying the feed rails to feed the larger diameter cartridges on some actions,the 700 being one.
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I am mostly looking at guns that have a removable, single-stack mag, such as the Tikka, Savage, etc. BTW, I mistakenly said I was working on an older Sako, it is a Tikka! Whoops!
 
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