22" 7mm Mag Barrel

[superwolf]

I am building a lightweight mountain rifle and I have decided to go with the 7mm Mag cartridge. Since low weight is a main concern I wanted to go with a 22" barrel.

Has anyone noticed a difference (major drop in velocity) in shooting the 7 Mag with a 22" vs a 24-26"?

I found an article that stated the 300 Win Mag suffered no changes in velocity after being cut down from 26" to 22" and I wanted to know if this would also be true with the 7 Mag. http://www.tacticaloperations.com/SWATbarrel/

Thanks.

 

[CSS]

Re: 22" 7mm Mag Barrel

I've got a friend with a couple 7RM's, he says the 24 is about 300fps slower than his 26" with the same ammo. If I were building a 7mm LW and wanted a long action, I'd look at a 280 rem. YMMV

 

[Gray]

Re: 22" 7mm Mag Barrel

I run a 24" barrel on my 7mm mag. There is a slight velocity difference between the 24" and my old 26". Not enough to matter really. But i will say that venturing to 22" or shorter will put you in the same velocity range as a 7mm-08 but with a lot more powder. Long range hunters can still be light if you stay with a smaller contour barrel, personally i would lean towards the 24"-26". Just my opinion, hope this helps.

 

[superwolf]

Re: 22" 7mm Mag Barrel

Thanks a lot for the help guys. I have always been interested in the 280 Rem but ammo seems a little hard to come by compared to the 7 mag. I guess I would have to stay with a 24" barrel to keep any "magnum" performance.

I see that Lilja barrels has a .525" final muzzle diameter contour barrels. Would that barrel be to thin to flute?

 

[VKC]

Re: 22" 7mm Mag Barrel

I personally won't go shorter than a 26" barrel for a 7mm mag. 24" is a compromise but still acceptable, depending on what is important to you. But at 22", I would go with a 280AI or 7mm-08 instead.

 

[BoilerUP]

Re: 22" 7mm Mag Barrel

My father has a Japanese-made Weatherby Vanguard VGL in 7mmRM that has a 20" pencil barrel and (I believe) a very light McMillan stock. I dunno the exact weight, but its a very light and handy rifle; it also kicks like a damn mule even with the thick recoil pad. I'm sure the short, skinny barrel was a great idea for a backcountry/mountain rifle but it really handicaps the 7Mag.

A family friend hunted with it for a few years, then gave it back and bought a 270 because it was "too much gun" for him.

 

[7mmRM]

Re: 22" 7mm Mag Barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vkc</div><div class="ubbcode-body">I personally won't go shorter than a 26" barrel for a 7mm mag. 24" is a compromise but still acceptable, depending on what is important to you. But at 22", I would go with a 280AI or 7mm-08 instead. </div></div>


Same here.

 

[superwolf]

Re: 22" 7mm Mag Barrel

All I have for my build so far is a stainless steel rem 700 long action with a mag bolt. Since I have not bought the barrel yet, I guess there is still an option to change the cartridge. If I were to get a 280 barrel, could I still use my mag bolt? Or would I have to get a 30-06 size bolt?

 

[BoilerUP]

Re: 22" 7mm Mag Barrel

30-06 (.473) bolt face for the 284...

 

[RobG]

Re: 22" 7mm Mag Barrel

I'd go a 24" barrel. The weight savings between 22" and 24" is going to be virtually unnoticeable on a lightweight hunting barrel. You should be able to push a 180 at 2800 pretty easily which should do the trick on most critters.

 

[Top Cat]

Re: 22" 7mm Mag Barrel

I wouldn't lose any sleep about minor velocity loss from a 22" bbl...

Although 7RM loses a tiny bit more velocity than some other rounds, in my experience it is still negligible and will make absolutely no difference at all on game...none whatsoever!

Bullet choice will have more of an impact...(yeah funny)

If I were doing this, I'd pre-order a Win Extreme Weather in 7WSM and shorten the bbl when it gets there, or just get a 22" 270 EW...again...little difference on game.

The 270 is a 7mm magnum in disguise.

TC

 

[jsthntn247]

Re: 22" 7mm Mag Barrel

If you go 22" you wont be able to utilize some of the better powders like H-1000 or Retumbo. In my 24" barrel, I use h-1000 and 162's and get no more velocity past 68 grains (71 grains max) which is right at 2900. You might want to look at H-4350,4831 or Re22 if you go 22". I wished I would have gon 26" for shure.

 

[rogers0311]

Re: 22" 7mm Mag Barrel

Jared, I've been trying to reach you, shoot me a text or pm when you get this.

 

[tictar]

Re: 22" 7mm Mag Barrel

I just read that Swat article on the 300 Win Mag whos barrel was cut down an inch at a time to see what the velocity change was. The article said that there was no velocity difference between 26" to 22".

Why would the Rem 7mm Mag be any different if it were cut down to 22"?

 

[Top Cat]

Re: 22" 7mm Mag Barrel

The SWAT article sez they didn't see any losses with the 190 Match bullet Fed GMM load...ok...

Even if one believes that statement, I guarantee that if you load up the 300Win with a case full of slow powder and a heavy bullet it will be slower out of a 22" bbl...and faster than a 308/30-06.

I like the feel of a shorter barrel, and I have had a few 22" Win Mags. That's about as short as I would go in that round.

A 22" 7RM will lose a little more, but still be a lot faster than a 7-08 or 280, and not enough to matter at normal hunting ranges. For LR Hunting at extreme ranges a short barrel in any caliber is counter productive.

Otherwise, I'd be more concerned about bullet choice...so you have to hold-off a half inch higher...so what?

TC

 

[VKC]

Re: 22" 7mm Mag Barrel

It really depends on powder selection, eg burn rate, and powder charge. You can only burn so much powder at a certain rate before pressure is too high. Thus slower burning powders in longer barrels to get more velocity.

 

[ZLBubba]

Re: 22" 7mm Mag Barrel

I've got a 22" 7WSM that shoots very well. Long barrel lengths are overrated, IMHO.

 

[tictar]

Re: 22" 7mm Mag Barrel

I guess 20" Lapua Mags do pretty good. Cant imagine why a 7mm Mag wont do good.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2897994#Post2897994

 

[Gray]

Re: 22" 7mm Mag Barrel

The reason why you see these short barreled magnums such as a .338 Lapua is because they are on guns running a suppressor the size of a pringles can. A 26"-30" 338L would blow the doors of a shorty at long distances which these guns were made to perform. There is no way 90 gr. of powder can burn in 20 inches. Probably looks like a flamethrower and kicks like a battering ram to the noggin.