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Which big 30 to build???

Ranger007 said:
Thank you. I am going to read up allot more on 300 Norma Imp vs straight 300 Norma.

So Imp must be fireformed?
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Yes, but you can shoot it with mid pressure loads while fireforming brass. My rifle shoots great with virgin unformed brass. Just can’t run loads anywhere near max when fireforming. And like Alex said, a barrel really doesn’t calm down and come into its prime until after the first hundred rounds or so.

The difference between the 300 Norma and 300 NMI is pretty significant as well. The standard 300 Norma isn’t going to perform much better than a 300 PRC or the Nosler cases. If I had to choose between the PRC and standard Norma, I’d keep it simple and use the PRC because I wouldn’t be losing much.

But when you add 7gr of increased capacity by going NMI and fill it full of Vihtavouri N570, now you’ve got one hell of a mean animal on your hands ;)

The standard Norma with Lapua brass has about 102-102.5gr of H20 capacity. My NMI with straightened body and 35 deg shoulder in Lapua brass has 109-109.5gr of capacity. That’s a pretty significant increase of around 7gr.

Standard Norma on the left, Fireformed 300 NMI w/35 deg shoulder on the right.

A51DDADD-7437-4962-A9BB-AD9DF82FDF38.jpeg
 
Ledd Slinger said:
Yes, but you can shoot it with mid pressure loads while fireforming brass. My rifle shoots great with virgin unformed brass. Just can’t run loads anywhere near max when fireforming. And like Alex said, a barrel really doesn’t calm down and come into its prime until after the first hundred rounds or so.

The difference between the 300 Norma and 300 NMI is pretty significant as well. The standard 300 Norma isn’t going to perform much better than a 300 PRC or the Nosler cases. If I had to choose between the PRC and standard Norma, I’d keep it simple and use the PRC because I wouldn’t be losing much.

But when you add 7gr of increased capacity by going NMI and fill it full of Vihtavouri N570, now you’ve got one hell of a mean animal on your hands ;)

The standard Norma with Lapua brass has about 102-102.5gr of H20 capacity. My NMI with straightened body and 35 deg shoulder in Lapua brass has 109-109.5gr of capacity. That’s a pretty significant increase of around 7gr.

Standard Norma on the left, Fireformed 300 NMI on the right.

View attachment 1224518
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EXCELLENT and TY!!!!!!! This helps. I am tracking. This helps
 
Alex Wheeler said:
The Norma imp is quite a big difference. A much better case design over the standard case. You just shoot them once then use the right dies as you normally would. No brass prep needed.
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Alex, for shooting the heavies do you have a preference of the 30-338 NMI or 30-338 Lap Imp? They both have top notch brass available for them and use the same action/s the biggest difference I can see is the shorter NMI may work better as a repeater while giving up less due to OAL restraints. We all like what we like so no wrong answer just curious if you preferred one over the other and why.
 
taylorw said:
View attachment 1224522
Here’s a before & after fire formed 300NMI 35degree shoulder. It’s Alex Wheeler’s reamer design. There’s other variants as well...
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TY very much to you as well. Greatly appreciate it.
Now is that ADG or Lapua brass?
So a very mild fire forming load like Ledd Slinger pointed out will blow the shoulder out for 35 degrees NMI?

I know Mr. Wheeler mentioned his dies. Anything wrong with getting a blank Whidden Micrometer and say a LE Wilson micrometer blank seater and having them reamed when the builder is chambering the barrel?

Sorry for so many questions.
 
Ranger007 said:
TY very much to you as well. Greatly appreciate it.
Now is that ADG or Lapua brass?
So a very mild fire forming load like Ledd Slinger pointed out will blow the shoulder out for 35 degrees NMI?

I know Mr. Wheeler mentioned his dies. Anything wrong with getting a blank Whidden Micrometer and say a LE Wilson micrometer blank seater and having them reamed when the builder is chambering the barrel?

Sorry for so many questions.
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It’s lapua brass. I used 82 grains of H1000 with 215 hybrids. Alex sets head space so that when chambering a case, it will have a crush fit. That’s important for holding the case against the bolt face for a good consistent fire form. I went with a LE Wilson/Sinclair micrometer seating die and Alex altered it to work with his reamer specs.
 
taylorw said:
It’s lapua brass. I used 82 grains of H1000 with 215 hybrids. Alex sets head space so that when chambering a case, it will have a crush fit. That’s important for holding the case against the bolt face for a good consistent fire form. I went with a LE Wilson/Sinclair micrometer seating die and Alex altered it to work with his reamer specs.
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Tracking and again thank you.
 
B23 said:
Alex, for shooting the heavies do you have a preference of the 30-338 NMI or 30-338 Lap Imp? They both have top notch brass available for them and use the same action/s the biggest difference I can see is the shorter NMI may work better as a repeater while giving up less due to OAL restraints. We all like what we like so no wrong answer just curious if you preferred one over the other and why.
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The 30-338 Lap imp has my interest. More so for the 2000yd match. I have a 338 lap imp chambering thats working well so necking it down is simple. I have not built one yet, but its on my list of ones to try. It should just fit a cfe 9 box.
 
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Ranger007 said:
Roger that. Excellent food for thought.
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Alex, I fireformed alot of 22-250 AI brass and lost alot of barrel life doing it. I used bullets not the other method. I simply came to realize it's just part of this game we play. Barrels are one of the cheapest components to replace so getting over it wasn't hard. What many don't realize is fireforming isn't any different than shooting formed brass. Accuracy is nearly the same. Load it, hunt with it or shoot targets with it. It's loaded ammo.
 
Pretty much what I did with my 338. Gave me the chance to form brass and break in the barrel. I still used standard brass for hunting while forming it.
 
Alex Wheeler said:
The 30-338 Lap imp has my interest. More so for the 2000yd match. I have a 338 lap imp chambering thats working well so necking it down is simple. I have not built one yet, but its on my list of ones to try. It should just fit a cfe 9 box.
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I have one of each, 338 Lap Imp is on a BAT HR single shot and has a pretty long OAL over 4.000 w/300's the 30-338 Lap Imp feeds through a older Seekins det mag I think I'm 3.865 touching with 230 Bergers.

I've always been a fan of the big 30's so even though the 338 built on the BAT HR is a masterful piece, I actually prefer its ugly little brother better.
 
Good to know. I have the reamer ordered. I think we can achieve our goals with the Norma, but I will run the Lapua and if the accuracy is there, more speed will help. I think the case would already be more popular if guys would figure out the dies.
 
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