300nm or 338lm

[mattman215]

Hello all I am going to be building a custom large caliber rifle and I am torn between a 300nm and 338lm. This will be a heavy rifle for shooting steel and a few long range hunting spots I have for elk and bear. I originally wanted a 338lm but my smith recommended a 300nm with the new 250atips or 245 bergers.

338 i would use the 300gr otm.

What are your thoughts ?

Weight does not matter
It will be suppressed, I already have a 338 can in jail.

Gonna be built on a defiance action.

I would like a solid 2k yard rifle on steel and 1k rifle for animals, 1k would be a stretch but I would like the energy if I felt comfortable that day.

I already have a full custom 300wm so I do not want a 7prc or 300prc etc.

Thoughts?

 

[Dogtown]

300NM fits the bill in your case and is a bit more pleasant to shoot.

 

[mattman215]

Also if anyone has experience in barrel twist I would love to hear. I was thinking a 26in 8.5twist brux

 

[kthomas]

.300NM would fit that bill nicely.

Excellent ballistics, better then .338lm in most cases. Can feed the heavy for caliber projectiles from a mag no problem, unlike the .338lm. Softer recoil.

Barrel life will be worse, but that's the only trade-off I can think of. 8.5 twist should be just fine.

 

[mattman215]

Thank you
I am not worried about barrel life as I will prob shoot 400-500 rounds a year max and I can get a new barrel spun up pretty easy every 3 or so years

 

[kthomas]

Thank you
I am not worried about barrel life as I will prob shoot 400-500 rounds a year max and I can get a new barrel spun up pretty easy every 3 or so years

Just don't try and chase the speeds you see posted here on SH in the reloading section - a lot of people are running well into pressure to get 3000+ fps out of their normas.

 

[Dogtown]

Also if anyone has experience in barrel twist I would love to hear. I was thinking a 26in 8.5twist brux

1:8 is pretty standard for the cartridge. In fact, I think that’s all I’ve ever shot with it, and I’ve done 190s to 250s

 

[kthomas]

1:8 is pretty standard for the cartridge. In fact, I think that’s all I’ve ever shot with it, and I’ve done 190s to 250s

Anything from 1:8 to 1:10 should be adequate for the .300NM, but for heavies 1:8-1:9 is probably the sweet spot on twist

 

[mattman215]

I don’t play with hot loads, I had a bad experience years ago it will probably be a pretty mild load as long as it’s accurate.

I was thinking 1:8 may be too fast if I ever need to shoot 220-230s if I can’t find heavy bullets ets so I figured 1:8.5 would be a good middle ground.

 

[kthomas]

I don’t play with hot loads, I had a bad experience years ago it will probably be a pretty mild load as long as it’s accurate.

I was thinking 1:8 may be too fast if I ever need to shoot 220-230s if I can’t find heavy bullets ets so I figured 1:8.5 would be a good middle ground.

You're good with 1:8. I use a 1:8 twist barrel to shoot 220's and 230's, as do many others. Especially if you don't go crazy on speed.

That said, a 8.5 twist will work just fine as well.

 

[ShootnFool8]

I don’t play with hot loads, I had a bad experience years ago it will probably be a pretty mild load as long as it’s accurate.

I was thinking 1:8 may be too fast if I ever need to shoot 220-230s if I can’t find heavy bullets ets so I figured 1:8.5 would be a good middle ground.

1/9 if you're going 300NM. Research some more, and you will see that's what everyone likes. Also, a barrel longer than 26" would be beneficial. Just my opinion though. My next barrel is going to be 30".

 

[Chickentoast]

300 Norma Improved, and a 9 twist up through 250 a-tips with that speed. If going Badlands or other long solids, 8 twist is better. Juice is definitely worth the squeeze improving the Norma. Fireforming loads just as accurate as well. Second the longer barrel.

 

[ACard]

1:8 is pretty standard for the cartridge. In fact, I think that’s all I’ve ever shot with it, and I’ve done 190s to 250s

Same. Though I like a 30" tube

 

[kthomas]

I'm guessing he doesn't want the longer tube for hunting applications, which makes sense.

 

[Dogtown]

I’ve had .300NM barrels from 26-34 inches, and for target shooting the 30” is the sweet spot. The 26” can do heavy bullets, but mine liked 212gr solids and 215gr Hybrids much better than 230s & 250s.

 

[mattman215]

Yes I could do 28 but wanted shorter for hunting

I also wanted heavier bullets like 245/250 not 215 or I may as well just stick with my 300wm or do a 300prc. Barrel length of 26 plus my 12 inch can that’s a beast as it is in the field I guess I could do 28 or so idk.

 

[Dogtown]

Here's some ballpark numbers for a hunting barrel - 24" with 245 EOLs

 

[Ty21]

300 nm… although don’t they make a 338 Norma? Idk what the ballistics are but that would probably split the 300mn and 338 lapua. Of the two you chose I would go 300 nm.

 

[Aftermath]

338 Lapua Ackley Improved

 

[mattman215]

Sounds like my gun smith and the consensus here all agree 300nm for the win Lol prob go 300nm as it sounds it’s my best bet.