7 TCU build advice

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bluetopper

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I want to build a 7mm TCU rifle out of a Savage Axis action but I don't know whether to buy a 223 rifle or a 308 and change the bolt head to a 223. I'm afraid if I get a 223, I'm about 99% sure the 7TCU cartridges won't fit down in the magazine.
 
Well a .223 based cartridge won't work in a .308 magazine. It'll be easier to make your cartridge fit in a .223 mag, than to modify a .308 mag to work. So I don't see how a .308 mag is going to help?
 
I found some data for 7 TCU using from 120gr up to 168gr and was shot in Thompson Contender and OAL ran from 2.535" up to 2.675".
 
old roper said:
OAL ran from 2.535" up to 2.675".
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The Savage factory magazine for .223 is going to allow around a 2.30" COAL. There is a spacer at the back of the factory magazine that can be altered to allow longer COAL lengths, as long as the barrel is throated properly the OP could probably work with the COAL listed in your data.
 
Neither will work perfect.
I had a 7Tcu. It is a neat handgun cartridge but nothing about it appeals to me for a rifle cartridge. 7-08 IMO.
 
Years ago I built a 7mm TCU bolt action rifle for a customer. He chose a Howa action because of the bullet length issue. Apparently the Howa's magazine is longer than needed for the 223. Savage actions in 223 have a short magazine, I'm not sure if it's long enough for a 7mm TCU.
 
I want to be able to use any 7mm bullet.
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I don't have all your answers but here is a good question for you.

Given you will be in the lower velocity range , what twist rate will stabilize your heavier bullets?

My intent is not to rain on your parade. Twist just a good thing for you to have worked out ahead of time.
 
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Have you considered the Remington Bench Rest cartridges? Shortened 308's with small primers?
One of my little pipe dreams I will probably never build is a 6.5 or 7mm BR.

.308 bolt face and mag stack.

And there is the 6.5 Grendel. You can get that in a built Howa barreled action.

I have no idea what you want to do with it....but those are options.
 
What is it to be FOR?
Do you NEED a magazine? So many rifles are just shot hunkered down on a bench and just as well be single shots.
 
I'm thinking of scratching this whole idea.
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What kind of an attitude is that for a project gun? I have built dozens of rifles in odd calibers because the customer wanted one. Bolt action rifles in 7.62X39, bolt action rifles in 444 Marlin, bolt action 30-30s, you name it. 7mm TCU wouldn't be that bad of a build. The one I built for the guy in NV turned out really good, and he thought it was better than his 30-30 with similar weight bullets. Quick, accurate, and very little recoil. If you see your project through, you will have a unique piece chambered for what you wanted.
Have you considered the Remington Bench Rest cartridges?
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I built a 7mm BR on an Interarms Mini-Mauser for my son's first deer rifle. Now that he's outgrown it and wants my 308, I may take it back and turn it into a 22 BR or just restock it and use it myself.
 
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