300 Norma Build Help

[Jackie_Daytona]

Alright fellas, need help on 2 fronts, barrel shank and contour.

I’m planning on building a 300 Norma, I know there are bigger (arguably more suitable) actions thank can accept 1.35” shank barrels, but bear with me as I’m limited to a 1.25” shank and chassis system.

I’m aiming for a heavy target focused build. With that in mind, I’m trying to decide between a NBRSA HV or an MTU contour finished to 30”. Supposedly, the MTU will be marginally heavier, but I like the NBRSA breech length is 5” vs the 2.75” on the MTU. Any guidance here or am I splitting hairs?

The outlier here, I could get a heavier “match” contour, but it’s a 1.20” shank. Heavier barrel at 30”, but I’m worried about the joint at the action for the higher pressured 300 Norma.

Any suggestions or guidance?

 

[DeathBeforeDismount]

ST 1.25 or a HV.

You could order one the new giessele cut rifle barrels and have it in less than a month in any twist or contour you want.

 

[Long Range 338]

What are your priorities? Are you pushing for more weight or velocity? Or possibly both. Getting any contour you like shouldn't be much of a problem but typically barrels over 26-28 inches are a custom order with longer lead times. Many smiths are pushing to use the larger shanks on the 338LM/300NM boldface actions because of the pressures and the extra shank will certainly give you more rigidity at the action/tenon joint. I've got a buddy that has a heavy Bartlett 28 inch barrel running 3185 fps with 220 gr Bergers and VV570. He's already seeing throat erosion within 300 rounds....

I'm only giving you the round about because the performance can come with a heavy price depending on what are trying to accomplish.

 

[Jackie_Daytona]

ST 1.25 or a HV.

You could order one the new giessele cut rifle barrels and have it in less than a month in any twist or contour you want.

I seriously considered a ST 1.25”, I was afraid at 30”, that’d be a lot of weight free floated.

Or is that not a problem?

 

[Jackie_Daytona]

What are your priorities? Are you pushing for more weight or velocity? Or possibly both. Getting any contour you like shouldn't be much of a problem but typically barrels over 26-28 inches are a custom order with longer lead times. Many smiths are pushing to use the larger shanks on the 338LM/300NM boldface actions because of the pressures and the extra shank will certainly give you more rigidity at the action/tenon joint. I've got a buddy that has a heavy Bartlett 28 inch barrel running 3185 fps with 220 gr Bergers and VV570. He's already seeing throat erosion within 300 rounds....

I'm only giving you the round about because the performance can come with a heavy price depending on what are trying to accomplish.

I know I’ll get crucified here, but I don’t plan on reloading (i.e pushing velocity), just shooting factory Berger…maybe mild reloads.

I have a 23lbs 300 PRC which is a pleasure to shoot so I’m mainly trying to match the weight for that reason (different chassis system than the PRC).

I’ve basically limited myself to the shank (impact action) and the chassis that can accept that barrel (MPA Matrix Pro).

 

[Long Range 338]

ST 1.25 or a HV.

You could order one the new giessele cut rifle barrels and have it in less than a month in any twist or contour you want.

Where are you ordering them? I don't see anything but AR barrels on their website

 

[Taylorbok]

I seriously considered a ST 1.25”, I was afraid at 30”, that’d be a lot of weight free floated.

Or is that not a problem?

Not a problem at all.
Just buy this thing. It absolutely hammers

Firearms - Terminus Zeus 300 Norma Foundation ELR Rifle

Selling a lightly used, tack-driving ELR rifle. Traded for the rifle recently with a Hide member and have since then acquired another .300NM. A total of 60 rounds fired (Berger factory 215g ammo). Specs: Terminus Zeus LA with two bolt knobs (original Terminus knob and one pictured) Bartlein...

www.snipershide.com

 

[DeathBeforeDismount]

Where are you ordering them? I don't see anything but AR barrels on their website

Call them up. They have a ton up for sale and said they will be full production in 2 weeks, with more machines coming online after that.

 

[Ebar48]

I do a custom contour that is similar to the MTU. I run 1.25 straight for 5” then a straight taper to finish at 1” diameter at a finished length of 32”. Easy to communicate when ordering. About to have 2 spun up in 300NMI.

 

[CaseFinder]

Wonder if Geissele will be doing any 1.350" size barrels for the.actions that have larger breech tenon diameters. Need to call them up...

 

[kthomas]

I know I’ll get crucified here, but I don’t plan on reloading (i.e pushing velocity), just shooting factory Berger…maybe mild reloads.

I have a 23lbs 300 PRC which is a pleasure to shoot so I’m mainly trying to match the weight for that reason (different chassis system than the PRC).

I’ve basically limited myself to the shank (impact action) and the chassis that can accept that barrel (MPA Matrix Pro).

Asking this out of curiosity.

If you already have a 300 PRC, what are you planning on gaining with a .300NM?

The ballistic differences between the two cartridges are not enough to warrant a whole new rifle, IMO. A 300 PRC can essentially do anything that a .300NM can.

 

[CaseFinder]

Asking this out of curiosity.

If you already have a 300 PRC, what are you planning on gaining with a .300NM?

The ballistic differences between the two cartridges are not enough to warrant a whole new rifle, IMO. A 300 PRC can essentially do anything that a .300NM can.

I wonder the same given Cal Zant's 2020 research; seems shooter success is driving the interest?

NF ELR Calibers & Cartridges – What The Pros Use

Over the past few weeks, I surveyed over 100 shooters who competed in this year’s Nightforce Extend...

precisionrifleblog.com

 

[Taylorbok]

I wonder the same given Cal Zant's 2020 research; seems shooter success is driving the interest?

Could be the reason but at that point it's the shooter and how well they know their gear. If you'd have those top Norma shooters use 300 PRC I'd bet they'd finish in the same spot.

 

[CaseFinder]

Could be the reason but at that point it's the shooter and how well they know their gear. If you'd have those top Norma shooters use 300 PRC I'd bet they'd finish in the same spot.

True, and the fact that the United States Special Operations Command (USSOCOM) adopted the 300NM cartridge for its Mk22 Mod 0 Advanced Sniper Rifle in 2017. A fact which historically drives buying trends and greater availability (thus lower prices over time) of a cartridge that ostensibly will become more commercially available. (References: https://www.americanrifleman.org/content/the-300-norma-magnum-history-performance/ and https://web.archive.org/web/20220527102654/https://www.defense.gov/News/Contracts/Contract/Article/1782108/ and https://web.archive.org/web/20220404193558/https://www.tactical-life.com/firearms/barrett-mrad-mk22-review/)

 

[JWSmith]

I do a custom contour that is similar to the MTU. I run 1.25 straight for 5” then a straight taper to finish at 1” diameter at a finished length of 32”. Easy to communicate when ordering. About to have 2 spun up in 300NMI.

What is your contact information?

 

[45-90]

I run a 30" heavy palma and a 28" M24 both .900" at the muzzle both 1.25" barrels no problem. I even ran 80,000 + psi hybrid cases through the 30", so their should be no problem.
But do what you're comfortable with. But if I build a 300 NM probably not the improved, it will be on the 1.25" dia barrel heavy palma 8 twist.

 

[Newbie2020]

Could be the reason but at that point it's the shooter and how well they know their gear. If you'd have those top Norma shooters use 300 PRC I'd bet they'd finish in the same spot.

I agree. Most of the targets in the Nightforce Steel Challenge are 700-1,500 yds which reduces the need for a more potent cartridge than the 300 PRC, except maybe extra for mv to counter wind drift? And the extra recoil would work against spotting impacts on the closer targets?

 

[Hawk in WY]

Asking this out of curiosity.

If you already have a 300 PRC, what are you planning on gaining with a .300NM?

The ballistic differences between the two cartridges are not enough to warrant a whole new rifle, IMO. A 300 PRC can essentially do anything that a .300NM can.

This has been my experience as well.

In theory, the 300 NM should outrun the 300 PRC.

My experience has been shooting loads optimized for accuracy, the differences are not what I expected.

In theory, theory and practice are the same thing.
In practice, they often are not.

Good luck.