300 Norma Magnum Build – Solid Setup or Would You Do It Differently?

[ShowMe QTR MOA]

Hey Hide members,

I’m putting together a dedicated 300 Norma for ELR and long-range steel work — mostly prone shooting, with the goal of pushing consistent impacts past a mile. Weight isn’t a concern; I’m prioritizing stability, precision, and long-term performance.

Here’s the build so far:

Build Specs:

• Action: Kelbly Prometheus Magnum Long Action
• Barrel: 32” Bartlein MODBB, 1.25” straight contour, 5R rifling, hand-lapped, 1:8 twist (non-fluted)
• Muzzle Brake: EC Tuner Brake Gen 2
• Trigger: TriggerTech Diamond Pro
• Optic: ZCO 5-40x56
• Mount: Area 419 One-Piece 36mm, 20 MOA built-in
• Chassis: Undecided — leaning toward MPA Matrix Pro II or Vision chassis or MDT ACC Elite (need weight tuning options, balance, and recoil control)
• Intended Use: ELR steel, occasional comps — not for hunting or field carry
• Looking at the black & acid red color by MPA or the Patriot color by Paramount Tactical for the MPA Matrix Pro II

Looking for your feedback:

1. Would you stick with the 32” barrel for 300 Norma or go shorter?
2. Thoughts on the MODBB contour vs MTU or other?
3. MPA vs MDT chassis — which has worked better for you at distance?
4. Any regrets with this action, brake, or optic choice?

Hoping to build something that stays tight past 1,500 yards and doesn’t fall apart after 500+ rounds. Appreciate any insight — especially from folks who’ve already walked this path.

Thanks ,

ShowMe-QTR-MOA

 

[Mike Tackleberry]

Remember, you have to make weight in the ELR Light class (26LBS) if you want to shoot in competitions. My 300 PRC with 28" MTU contour is 25.9lbs for reference. You also need a 36mm mount, not a 34mm for the ZCO.

 

[Shoots 700's]

I went 300 Norma with a 27” barrel. Not sure how much speed you would pick up going that long.

 

[Kopfjager1]

A 28" MTU contour is only going to be around 6.9 lbs, the 32" 30 cal, 1.250" straight will weigh 10.0 lbs, depending on the breach and muzzle threads. 28" straight cylinder will weigh around 8.7 lbs.

And its only going to yield approximately 100 fps over a 28" with the same cartridge components. Is 100-150 fps worth the extra $100-200 for each barrel? Just something you should ask yourself. If its occasional matches, I would forego anything longer than 28", until you reach the point where you're trying to find any advantage, slightly perceived or not, to get ahead.

 

[Schw15]

Hey Hide members,

I’m putting together a dedicated 300 Norma for ELR and long-range steel work — mostly prone shooting, with the goal of pushing consistent impacts past a mile. Weight isn’t a concern; I’m prioritizing stability, precision, and long-term performance.

Here’s the build so far:

Build Specs:

• Action: Kelbly Prometheus Magnum Long Action
• Barrel: 32” Bartlein MODBB, 1.25” straight contour, 5R rifling, hand-lapped, 1:8 twist (non-fluted)
• Muzzle Brake: EC Tuner Brake Gen 2
• Trigger: TriggerTech Diamond Pro
• Optic: ZCO 5-40x56
• Mount: Area 419 One-Piece 34mm, 20 MOA built-in
• Chassis: Undecided — leaning toward MPA Matrix Pro II or Vision chassis or MDT ACC Elite (need weight tuning options, balance, and recoil control)
• Intended Use: ELR steel, occasional comps — not for hunting or field carry
• Looking at the black & acid red color by MPA or the Patriot color by Paramount Tactical for the MPA Matrix Pro II

Looking for your feedback:

1. Would you stick with the 32” barrel for 300 Norma or go shorter?
2. Thoughts on the MODBB contour vs MTU or other?
3. MPA vs MDT chassis — which has worked better for you at distance?
4. Any regrets with this action, brake, or optic choice?

Hoping to build something that stays tight past 1,500 yards and doesn’t fall apart after 500+ rounds. Appreciate any insight — especially from folks who’ve already walked this path.

Thanks ,

ShowMe-QTR-MOA

I run a 300 norma improved 32 inch barrels i believe the vcc contour with a samson foundation long action Bat action with brass weights but the arca was non brass. With one set of back weights out im 25.9 or so...... I run a razor gen 3 area 419 mounts sent it level. I think bats are go to for the lapua cases and I'm a huge fan of stocks now since I went foundation

 

[BurtG]

Make sure you order a 36mm mount obviously

 

[Long Range 338]

300 Norma is all about performance and performance comes with a cost. The longer barrel length will certainly provide the best chance for best performance. Your specified rifle fills the bill well in my opinion and Its all personal preference anyways...

 

[demarpaint]

I like it, I might consider a 30" barrel as a compromise.

 

[ggmanning]

I just ordered a 28" 1:9 barrel. Medium Palma/DTA contour. I couldn't find enough benefit to go longer, unless a lot longer than 28", which I didn't want to do.

 

[Mike Tackleberry]

I just ordered a 28" 1:9 barrel. Medium Palma/DTA contour. I couldn't find enough benefit to go longer, unless a lot longer than 28", which I didn't want to do.

That should work well, mine is a 9T MTU 28" and I shoot the Berger 245 LRHTs, and it shoots very well.