Help me decide caliber for new build

[MudRunner2005]

My Sendero STW will shoot 1 ragged hole groups at 100 yards with factory loaded ammo (Federal Premium 160gr Accubonds), and they will fit in the magazine.

When I shoot at the range, I shoot all mine as single-shot rifles, loading only 1 round in at a time. And if you are wanting to push the Berger 180 VLD's out anywhere near your lands you will have to shoot them as a single-shot style.

My Sendero 7STW with 180gr Berger VLD Hunting Match bullets a couple thousandths off the lands, is still in the 3.858" range, which will definitely not fit in the magazine. I have not experimented with how far down you could pack them in there to make them fit in your magazine well. When I get a chance (probably this evening), I will measure the OAL of my 700 mag well.

I'm sure other people can give better advice on the 180 Bergers, since I haven't had a chance to test-fire mine yet...

 

[MontanaRifleman]

That was a good read. I've got some more reading to do before I make a decision. I still think that it will take something in a magnum case to do what I want. I don't think a 284 pushing a 180 at 2650 will cut it. I'm thinking the 7/300 the 7 dakota maybe an STW or a lazzeroni. Which ones will I run out of room in a Remington 700 mag action with a detachable bottom metal? I don't want to get something built and have to run it as a single shot to make it shoot.
Thanks for the advice so far and keep it coming.

7/300 WM capacity, 91.3 gr: case length 2.825

7 Dakota capacity, 90.7 gr: case length 2.500

7 STW capacity, 92.7 gr: case length 2.850

All very close in capacity and performance. The Dakota will give you more flexibility in seating long high BC bullets to fit the mag box.

And I'll probably ruffle a few feathers here, the Dakota doesn't have that nasty scabby belt thing around the base

 

[Dhughes]

7/300 WM capacity, 91.3 gr: case length 2.825

7 Dakota capacity, 90.7 gr: case length 2.500

7 STW capacity, 92.7 gr: case length 2.850

All very close in capacity and performance. The Dakota will give you more flexibility in seating long high BC bullets to fit the mag box.

And I'll probably ruffle a few feathers here, the Dakota doesn't have that nasty scabby belt thing around the base

Thanks for that. The Dakota is looking better and better the more I read about it.

 

[north of 53]

The 284 shehane has been getting some good results with the F class crowd. It might be worth a look.

 

[hhack]

I have a 7/300 win mag and I am running the 168gr at 3150 out of a 25" barrel. It shoots great so far but I haven't had it that long, bout 100 rounds down the tube. My only regret is that I built on a standard 300 win mag length action. I feel to really utilized this cartridge you need to run a magnum length action. I got my best performance when I loaded to a COL of 3.60" and single loaded, but my magazine only allows a COL of 3.34."

There is a guy from New Zealand that has a web site that has done a lot of research on a very similar cartridge he called it the 7mm practical which is a 7/300 win mag with a 30 or 35* shoulder and the neck was a little longer. Here is his website

The 7mm Practical. A Practical Magnum.

I would go with one of the big 7mm's if I were you. You won't regret it.

 

[Dhughes]

I'm still reading up on it, but the 7 dakota is looking pretty good. It is short enough to running a Remington mag action, you can buy brass and dies for it and it will run a 180 over 3000 fps.
Does anybody have anymore info on these? Pros and cons of the dakota over the 7/300 or 7LRM?

 

[MontanaRifleman]

The difference in performance between the 7 Dakota and the 7/300 will be negligible. As far as I know there is no brass or dies available for the 7/300. If that's the case you have to get custom dies. I would recommend sending a reamer drawing to Hornady. It will take about 14 weeks give or take. Then neck down 300 WM brass to 7mm.

The Dakota has brass and dies availble. If you get Dakota brass call Dakota and order from them in 100 pc lots. Cheaper that way.

Other than that, the Dakota will fit the mag box easier than the 7/300 with a long bullet.

 

[MontanaRifleman]

The 7LRM is proprietary. Last I heard, you had to order a rifle to get the brass. maybe that's changed? Necking down 375 Ruger brass would involve sizing dies and a fairly involved process including neck turning.

If you could get 7LRM brass it would be something to think about but not a lot of advantage over the Dakota. The LRM would probably be more costly overall?

Maybe someone can chime in

 

[Dhughes]

Will I have to have an ultra mag action/bolt face for the dakota? Or will a magnum action work?

 

[MontanaRifleman]

Std magnum action will work

 

[fmajor]

For brass on the 7mm/300, I'm planning on using 300 WM brass and simply necking it down - not a complex operation. There is plenty of 300 WM brass on the market and likely less expensive than Dakota (Norma?) brass. I think for the foreseeable future, 300WM is going to be around so brass will also be readily available. I don't know about the Dakota...

Admittedly, sizing dies are another matter. However, any of the larger manufacturers (Hornady, et al) would make one without a problem and probably not too expensively. Otherwise, collet seating dies are the way to go and they're caliber specific so no problems there.

Neck sizing, once the cases are properly full-length sized requires nothing custom or special, so the 7mm/300 in this regard is standard.

Also, for a reamer, it would be worth a call around to some of the more notable 'smiths. Certainly one of them has a 7mm/300 reamer...

 

[hhack]

I use a 7mm neck sizing die and a 300 win mag body die for sizing and a 7mm rem mag die for seating bullets. These dies are cheap compared to any custom die. 4-d reamer rentals has a 7/300 win mag reamer. If you want to buy a reamer PTG has them, just give them a call.

 

[MontanaRifleman]

Will I have to have an ultra mag action/bolt face for the dakota? Or will a magnum action work?

The Rem 700 UM action is the same as any other Rem LA. Same thing. And the bolt face is the same as any std (non Lapua) mag action.

 

[Dhughes]

Thanks for the help guys. I'm still trying to decide between the 7/300 and the 7 dakota. I'm leaning towards the dakota though. With good off the shelf brass and dies, it looks like a good way to go. I can then save my 300 win brass for a 300 win build and then re barrel my 30/378 to 338/378 so that I have a caliber for everything! So many guns to get so little time to shoot them...