7 mag /300 win mag wildcat

[scpaul]

Hope I Do this right. New to web & forums. I'm thinking about necking 300 win. down to 7mm. I would welcome any advice or help. Because of cost and ease of rebarreling and changing the boltface of a Savage that I already own. Thanks again!

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[coop44]

why not get a 7mm magnum?

 

[scpaul]

The 300 case has approx 10% more volume & it shouldn't be a barrel burner

 

[Jamie6.5]

The 300 case has approx 10% more volume & it shouldn't be a barrel burner

Good luck with that.
Remington's "Big 7" is based on the .338WM case, and barrel life is considered rather short.
Certainly shorter than the 300WM, the .308, or the '06.

You'd be better off going the other way.
the .30-.338 is a helluva round for accuracy.

 

[jluck]

Isn't that known as a 7mm "practical"? If you just have to have a 7mm, look in to the 7 RUM.

 

[Velzey]

So your pretty much making a 7mm STW. My all time favorite, elk, deer, bear, coyote, cougar round!!

 

[coop44]

if you really want the additional case capacity go Ackley improved. straighter case walls and steeper shoulder.

 

[clambo]

Seems like a lot of work to make something that 7 or 8 or 15 rounds dont already do. However, if you decide to do this it sounds pretty straightforward to me with the rebarrel. Im not even positive the bolt face will need changing, have to do some measuring. Beyond that, get some dies, make some brass and have at it. It probably wont be an absolute barrel killer but probably not good either. I managed to wash out the barrel on my plain old 7mm Rem. Mag. in 800 rounds. How you load it will make a big difference. Balls out expect less than 1000.

 

[2506]

Good luck with that.
Remington's "Big 7" is based on the .338WM case, and barrel life is considered rather short.
Certainly shorter than the 300WM, the .308, or the '06.

You'd be better off going the other way.
the .30-.338 is a helluva round for accuracy.

Actually, the 375 H&H is the parent case for both rounds. It would be as if the OP wanted to use 270 brass to make a 25-06 rather than 30-06 (the parent case for both). Not seeing the point, frankly.

 

[Jamie6.5]

Actually, the 375 H&H is the parent case for both rounds. It would be as if the OP wanted to use 270 brass to make a 25-06 rather than 30-06 (the parent case for both). Not seeing the point, frankly.

Not really.
The .270 case is slightly longer (+.046)than the '06, whereas the .338 case is quite a bit shorter (-.120) than the .300WM.
I'm told the case was reduced due to the length of the overall cartridge with larger/longer bullets.
Remington supposedly chose the .338 over the .300 case to ensure that they could use a standard long action M700 and keep the bullet from intruding on the case volume, from having to be seated that much deeper, and still fit the mag dimensions. Same with the .264WM.
That's why the .338WM, the 7RM, and the .264WM all share the same 2.5" case length, whereas the .300 is at 2.62".

To the OP, you can use the .300WM length case, and if you have an extra long mag-length action, you may see some gains.
But in a standard length(long) action you'll probably end up with the bullet buried so far in the case (to fit them in the magazine) that the gains will be minimized.
And if you already have the extra long action, why not just get a 7STW?

 

[scpaul]

It would be rem. 7mm mag. plus about 10% case volume and still less than a 7 stw casevolume and expensewise and should be more powder efficient due to higher load density. Later if needed , I could give it the Ackley treatment .I already have 2 Savage long magnum receivers so long bullets don't need to be seated deep enough to reduce powder volume. I'm also thinking about a 26 in. or longer bbl. and increasing twist 1/2 to 1 in. for long range stability with longer bullets. Here in SC , We have lots of fields , power and gas line right of ways that if you have rights on both sides you can hunt. Offseason some friends and I have some informal 500 plus yd. matchs. Oh and to give credit to the man in these parts......Kenny Jarrett !

 

[Spitpatch]

And I thought those of us that lay awake at night staring at the ceiling dreaming up such stuff were almost all dead.

I think this is one of those threads where the guy asking the question already has determined his answer.

If the Ackley ideas are appealing, go with what ol' P.O. LEARNED: His .276 Ackley Magnum (a 7mm), was shorter than any mentioned here (including the Remington), and was at the absolute wall he discovered for efficiency and performance. Anything beyond was throwing bad after good.

A fine Mauser built by P.O. himself, chambered in the "sensibly efficient" .276 Ackley Magnum:

 

[scpaul]

Now you dunn it! Gave me even more to think about. Beautiful weapon,I'm interested in more info on both rifle & ctg. specs. I looked in most of my manuals,don't see any info on .276 Ackley. Guess I'm going to the book store. Thanks in advance for the suggestion & the info.



ore to think about. BEAUTIFUL weapon,I'm interested in more info on both rifle ctg. specs.

 

[scpaul]

Did some research . Hadn't heard of 7 Practical, really thought it was a play on words. I was Wrong. Thanks for the aqdvice.

Paul

 

[Daniel1989]

need some info on a gun I was thinking about picking up tomorrow its a 405-300win mag shoots a 325 and a 350 grain bullet has anyone herd of this round and or is it any good its built on a savage Acton with a custom barrel I guess comes with the dies and brass and has muzzle brake

 

[Swedish K]

I don't know how 7mm mag brass is in comparison, but iirc there is a 14 gr + variance in case capacity between various brass manufacturers in 300 win mag. iirc Remington brass is the second or third smallest capacity and Lapua brass had the most capacity (again, in 300 WM). You might look into 7 mag case capacity variations and get brass that has the higher capacity - seems much easier than going wildcat or custom rifle. (unless you are looking for a reason to build a custom )

 

[scpaul]

Never heard of any thing like it .Sounds interesting. Bet it's a real thumper. If you get it tell me more after you try it. Paul