7mm - 338 Norma mag AI

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sandytye

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I am thinking of building a long range hunting gun and have settled on AI'ing the 338 Norma Mag and then necking it down to 7mm.
Barrell burner I know! but this will be a gun that only gets 10-20 rounds a year after I build a load. Therefore it should last for quite a few years.

My question is if anyone knows if there is already a cartridge design that fits this description or would I have to draw it up in order to get a reamer made?

Thanks
 
I had planned to get the reamer from Pacific tool. I have just never ordered a reamer based on my own drawing / dimensions. i am not sure of that process.
maybe it is an easier process than I think and I should just call them and give them the dimensions. is that the best way to go?
 
Most cases have been necked every which way to cover most calibers, including this one. So it would not be an original. The 300wm, 7RM 7RUM & all the "new short FAT cases" will push a bullet at approx the same speed as the one you're considering. Build a custom with a good barrel correct twist, it will be accurate. Start with a good foundation, Remington 700 action.
Bill
 
i just had a reamer made from them although I had sent them a couple dummy rounds to make it from. I'm sure you could figure it out over the phone though. They were great to deal with.
 
this will be approx 6% less case capacity but will allow long bullets (180 to 200's) to be seated at proper length while still using a standard long action.

That is the goal at least.
 
sandytye said:
I am thinking of building a long range hunting gun and have settled on AI'ing the 338 Norma Mag and then necking it down to 7mm.
Barrell burner I know! but this will be a gun that only gets 10-20 rounds a year after I build a load. Therefore it should last for quite a few years.

My question is if anyone knows if there is already a cartridge design that fits this description or would I have to draw it up in order to get a reamer made?

Thanks
Click to expand...

An over bore case that size should probably have a 28 inch barrel to get optimum velocities. Very costly project... reamer, go gauge, special dies, forming brass - you may want to have two barrels fitted... with identical chambers... one a used barrel to fire form a whack of brass... and then the new barrel to just work a load up and use lightly...

My preference would be a smaller case...
 
Guntech Thanks.
that is a great ideal to fit 2 barrels and have the used one to fire-form. I never thought of that.

Planning to have a 30" barrel. the plan / goal is 180 gr bullets going 3300+ fps
 
sandytye said:
Guntech Thanks.
that is a great ideal to fit 2 barrels and have the used one to fire-form. I never thought of that.

Planning to have a 30" barrel. the plan / goal is 180 gr bullets going 3300+ fps
Click to expand...

Well, be prepared for experimantation because the 180 VLDs tend to not like going that fast, and make sure you have the right twist so they stay together when yu try,
 
The new 195gr Hybrids should prove interesting out of this case as well, might have to look into it. ;)

sandytye said:
Guntech Thanks.
that is a great ideal to fit 2 barrels and have the used one to fire-form. I never thought of that.

Planning to have a 30" barrel. the plan / goal is 180 gr bullets going 3300+ fps
Click to expand...
 
The 7mm Ultra Magnum boasts the largest case of any commercial 7mm cartridge.
Go with it with a 28 to 30" barrel and you will get close to the 3300fps
Buy a Rem Sendero, change barrel to a custom premium grade stainless, buy dies off the shelf save a lot of coin this way.
No fireforming brass, expensive custom dies, reamers and when you get tired of recoil you will have a much better chance of selling rifle as ammunition is available.
manitou
 
manitou210 said:
The 7mm Ultra Magnum boasts the largest case of any commercial 7mm cartridge.
Go with it with a 28 to 30" barrel and you will get close to the 3300fps
Buy a Rem Sendero, change barrel to a custom premium grade stainless, buy dies off the shelf save a lot of coin this way.
No fireforming brass, expensive custom dies, reamers and when you get tired of recoil you will have a much better chance of selling rifle as ammunition is available.
manitou
Click to expand...

Very good advice as it will be virtually the same ballistics and as mentioned you will save a lot of coin.
 
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