300 Norma Mag barrel extremely hot

[topcat265]

Two weeks ago I received a new rifle I had built for shooting the mile target at our range.
The barrel is a Brux 1200 straight. Thick and very heavy.
I am shooting it suppressed with a RAD buttstock.
My load is lapua brass, and 83 grains of h-1000 powder. Berger 230 gr hybrid target bullets averaging 2,955 fps.
My challenge is that the barrel becomes incredibly hot and takes forever to cool down.
After realizing this on my first outing, I created the blowgun in the photo. It still is not hugely effective.
Someone mentioned wet towels?
Taking 3 or 4 shots and waiting 5 to 10 minutes seems to take the fun out of a morning on the range.
Any thoughts?
T

 

[Shane Lindsey]

No help here. I have the same issue with them heating up and mirage coming off the barrel/can so much I can only shoot about three rounds before the reticle becomes too blurry on the target to shoot.

Carbon fiber barrels are even worse. I think taking the can off would help alot.

Shooting on lower power? I can't say I ever remember seeing it on a fixed 10x scope with barrels so hot they were not comfortable to the touch.

 

[wasskeet]

A cooler with ice water and a microfiber cloth will cool a hot barrel faster than any other reasonable method. Only thing is you will then need to let barrel warm back up depending upon how long you leave it on.
Cheap and effective.

 

[hydehunter]

also, when you are done cooling the barrel make sure you do not have water condensation in the barrel . I have a small shop vac that I blow cool air down the barrel , and just for grins looked down the barrel when finished before shooting the next round and saw water so I run a couple dry patches before shooting again

 

[topcat265]

Thank you.

 

[7.62 Gunner]

Two weeks ago I received a new rifle I had built for shooting the mile target at our range.
The barrel is a Brux 1200 straight. Thick and very heavy.
I am shooting it suppressed with a RAD buttstock.
My load is lapua brass, and 83 grains of h-1000 powder. Berger 230 gr hybrid target bullets averaging 2,955 fps.
My challenge is that the barrel becomes incredibly hot and takes forever to cool down.
After realizing this on my first outing, I created the blowgun in the photo. It still is not hugely effective.
Someone mentioned wet towels?
Taking 3 or 4 shots and waiting 5 to 10 minutes seems to take the fun out of a morning on the range.
Any thoughts?
T

You're burning 2x the powder as a 6.5 creedmoor so yeah it's going to get hot to the touch.

Considering I shoot 10 round strings at matches in 2 minutes with a creed you're going to be fine shooting 1-2 rounds per minute.

FWIW I have no trouble shooting 6 round strings in my #5 300NMI with 245s and 81 grains H1000

 

[FEENIX]

Two weeks ago I received a new rifle I had built for shooting the mile target at our range.
The barrel is a Brux 1200 straight. Thick and very heavy.
I am shooting it suppressed with a RAD buttstock.
My load is lapua brass, and 83 grains of h-1000 powder. Berger 230 gr hybrid target bullets averaging 2,955 fps.
My challenge is that the barrel becomes incredibly hot and takes forever to cool down.
After realizing this on my first outing, I created the blowgun in the photo. It still is not hugely effective.
Someone mentioned wet towels?
Taking 3 or 4 shots and waiting 5 to 10 minutes seems to take the fun out of a morning on the range.
Any thoughts?
T

Have you tried shooting unsuppressed and see if you are generating the same barrel heat?

 

[BALLISTICJESUS]

Welcome to magnums and increased case capacity. Just part of the game.

 

[southpa]

Somethings gotta give hahah.

 

[Phil Rizzo]

You are shooting a "cooler" burning powder.
But a pile of it!

 

[topcat265]

Guess I'm used to a 6creed that can shoot all day.
I'll try the fan and a cool towel this weekend
Thx

T

 

[huntinfool18]

Get the barrel fluted. You'll lose a little weight but it shouldn't affect the way the gun shoots. The increased surface area will help the barrel shed heat faster.

 

[tim_w]

Completely to be expected. 80-90 gr of powder 70k psi with the backpressure of a suppressor to top it off. Personally I would keep plenty of time between each shot and then more time between groups. As a hunting setup it should last for yrs in that format. But banging steel you could cook it in no time or make it last 1200 rds. Nothing you likely don't already know.

 

[AZShooter]

I have used towels and even running water. At one point I remember reading about a small CO2 tank that was featured in an ad in Precision Shooting. A friend had purchased the system and said it didn't have the expanding volume to release cool air.

I had a welding shop closeby and they were nice enough to let me try regulators till I found one with enough flow and cooling when attached to a 20 lb CO2 tank. Later on Dave Miller (gunsmith) made one. He took a regulator he had and drilled out an interior orfice till he got the correct flow. Then another guy who copied the idea made it simple for all of us. He used a ball valve!


A 3/8" OD rubber hose is attached to the ball valve or regulator. The tip is tapered with a knife so it can wedge into the neck area of any chamber. I use mine from 6mm BR to 375 Taylor.

As for using the CO2. Hold hose in place while you open up tank valve then rotate then get a mild flow coming out of the end of the barrel. (if you don't hold the hose it will whip your face repeatedly before you can grab it or turn it off! I know because I did it) It only takes seconds to cool it down a warm barrel to ambient. Dave Miller and I did performance tests and inspections and could find no harmful effects and good accuracy.

I only use this system if I am working up a load or sighting in for a hunt. I like to keep the barrel at ambient to duplicate hunt conditions of the first cold barrel shot.

It does cost some money to set up. The welding shop will sell you the tank or in my case two tanks. Then they will exchange the empty tanks for full ones. Naturally the cost of CO2 has gone up but IMO it is worth it to me.