.300 Norma Magnum

[Moorlander]

On paper it looks very interesting and I understand the US Military have taken it on , what actions could it be built on?  anyone here have experience of the .300 NM?

[Catch-22]

Not the .300NM but I am having its original big brother .338 Norma Mag built for me. It'll be a 6.5x47L & .338 Norma Mag switch barrel tube gun. 

From what I gather about the .300NM, it's very accurate, easy to tune and spits those heavy .30cal bullets very fast. Norma brass (and that also produced by Jaimeson in the US) is supposed to be very good.

Jimmy Sloan, the designer of the original .338 Norma Mag case, designed it around the standard Rem700 long action with a Lapua Mag bolt face, though some prefer using larger dedicated large Magnum actions. The case is also optimised to be able to seat the bullets out to their longest length and still easily fit within an AICS magazine.

I believe the major issue with the .300NM is barrel life. In its .30cal form its very over bore. I've heard reports of around 1000 rounds and the tube is toast. But as we know, if you're a velocity whore (which I guess you would be shooting the calibre) and use high energy powders, then yes it's gonna be short. Who knows, by using better single base powders, you may eek out some more barrel life.

Stepping up to .338 Norma Mag and using a cooler burning powder, like VV N165 or possibly a lower energy double based(e.g. Ramshot Magnum) rather than the higher energy stuff (e.g. Rel 33/ RS80 or VV N560), I'd expect to get 2800-3200 rounds from my barrel.

[terryh]

Dave,

also inteested in you progress/thoughts on this round?

currentky looking at the 230g Berger OTM’s over RS80 or a bit slower N170.

barrel life might be short but realistically 1200 rounds is a couple of years shooting of this rifle amongst others, you’d not bother using it below 800-1000 yards (I’ve a 6.5x 47 and 45-90 for that).

Think it is a better bet than a 338 personally?

Tis a bit of a brute thou, here it is next to the 47:

 

Brgds T

[The Gun Pimp]

The 300 Norma Magnum Imp. was my first 'custom' rifle - built by MacMillan - about 25 years ago. 

I bought it as a 1000 yd benchgun - which we were just getting going in the UK.  On a good day, it would shoot sub MOA but, as a 10lb rifle, it wasn't nice to shoot!

I didn't use a double-base powder but, when you're burning that much powder and shoving it through a 30 cal hole the barrel didn't last long.

In the intervening years, we've learned a lot - i.e a 6mm will do the job at 1000 yds with a lot less fuss!

[terryh]

Vince concur,

Smaller calibres are more pleasant to shoot, but not many folks choose a 6mm for say F Class ( but stand to be corrected) or personally the magic mile?

I’m not looking bench so weight of the rifle and a good muzzle break will sort the recoil unpleasantness. 

T

 

[The Gun Pimp]

Terry - I do shoot a 'six' in F Class but I wouldn't if I wanted to win!  The 'sevens' still rule of course.

But what are you hoping to use the 300 Norma Magnum for?

[Moorlander]

2 hours ago, The Gun Pimp said:

The 300 Norma Magnum Imp. was my first 'custom' rifle - built by MacMillan - about 25 years ago. 

I bought it as a 1000 yd benchgun - which we were just getting going in the UK.  On a good day, it would shoot sub MOA but, as a 10lb rifle, it wasn't nice to shoot!

I didn't use a double-base powder but, when you're burning that much powder and shoving it through a 30 cal hole the barrel didn't last long.

In the intervening years, we've learned a lot - i.e a 6mm will do the job at 1000 yds with a lot less fuss!

According to wiki the 300 Norma Magnum wasnt designed until 2012 where as the 308 Norma Magnum came about in 1960?

https://en.wikipedia.org/wiki/.300_Norma_Magnum

[The Gun Pimp]

Mine used the 30 cal bullet certainly - 200gn Sierras if I remember correctly.  Very similar case to the 300 Win.Mag but with a slightly longer neck - I think.  There was some case-forming required but I can't remember the details.

Once the barrel was shot-out, I broke it up, sold the stock and 'sleeved' the action with a glue-on Davidson sleeve and used it for 1000 yd benchrest for many years.  Callum Ferguson 'blueprinted' the action (properly - re-cutting the tenon threads, sleeving-down the bolt-face and sleeving the bolt-body). It was then re-barrelled in 6-284 - a great 1000 yd round that shot many half MOA groups but the barrel only lasted for 400 rounds!

[brown dog]

5 hours ago, terryh said:

 

Tis a bit of a brute thou, here it is next to the 47:

 

Brgds T

What sort of charge weight does that thing have?!

[terryh]

3 hours ago, The Gun Pimp said:

Terry - I do shoot a 'six' in F Class but I wouldn't if I wanted to win!  The 'sevens' still rule of course.

But what are you hoping to use the 300 Norma Magnum for?

Vince

shooting steel targets out as far as possible as I’m now less than 20 minutes drive from the ranges on Salisbury plain as two clubs I have access to use them. 

So basically for fun as I do not have the time to be ‘a competitor’ any more along with various BPCR’s

T

[terryh]

BD

North of 80grain under the 230g bullets, looking for velocities 2800++ from a sensible length barrel.

T

[Ronin]

I have a 300 NM reamer, planning to put a F class profile barrel on the Surgeon XL for F class as an experiment 

 

I already have the XL in 338 form

so it’s only really a Rebarrel and die  machining job for me

 

I don’t expect to be competitive with it (being as the rifle is a repeater and i'll be using a bipod) but as I haven’t a magnum bolt for the Rimrock (or another action) it’s the cost effective method to try a 30 cal in f open 

 

 

 

 

[Scotch_egg]

No more off topic post gents. 

[Shuggy]

Have a look at Longrange blog on YouTube (THLR.NO and ‘Roe’ on here). He has been shooting a Blaser in 300 NM. Lots of relevant info, starting from video 204.

I reckon almost everyone on here would enjoy Thomas’ channel!

[SRGNXL]

What about the 7/300Norma with 180grn bergers, would they hold up to the velocity generated by the cartridge? Being a light bullet, it shouldnt kick like the heavier 200+grain bullets. I would estimate 800 rounds would get you through a season of shooting.

[ezmobile]

On 12/29/2017 at 12:23 PM, Moorlander said:

On paper it looks very interesting and I understand the US Military have taken it on , what actions could it be built on?  anyone here have experience of the .300 NM?

Not too sure about actions etc, but I have fired one round in this cartridge from a friends rifle and it was absolutely spot on at 1100 yards! It does boom a bit, mainly due to its very effective muzzle brake which made it feel more like a .308, but in his hands there was no problem scoring successive V's at this distance!!  A hell of a cartridge from my experience.