Should I or Should I Not cut down the 7 Mag rifle barrel?

[Rog]

I've got a 26" 7mag barrrel that's been shot about 20 times or less.

It's pretty accurate with the two loads shot thru it so far.  One load shoots in thes 0.6's.  150's chrono'd at 3144 fps with an absolute max charge of H1000.

Last few days I've had a near uncontrollable urge to cut the thing down and make it a short barrel version.

I've owned, in the past, 7-30 Waters, 30-30 AI, 308 Win, and currently a 30-06 JDJ, all in 14-15" barrels.  Seems like that 7 mag barrel is just begging to be shortened to about 16" or so.

Somebody talk some sense into me.

Besides, I think I've spotted a 280JDJ that needs a home.  You know how those stray barrels are.  Just need a kind, warm, loving home...

Regards,

Rog

[PJ]

Cut it off Rog....I had a 300mag 26" heavy barrel now it's a 16.5" and I love it!!!! I chrono'ed it with factory 180's before and after.I only lost 361 fps.The 26" tube went 3081 fps the 16.5" tube goes 2720 fps with the same factory load.150's go 2886 fps not bad for a handgun Plus if you want down the road to use it as a rifle all you need is a rifle scope and stock.I had my barrel drilled and taped, so I could you the pistol or rifle forend.Let me know what you do a 7mm mag or .223 will be my next barrel to cut.

[Dalton]

I don't own a 7mm Rem Mag but in looking at the loading data, it appears to use between 50 and 70 grains of slow burning powder.  Cutting it down to 16.5" will make it easier to carry, but your going to be burning a lot of powder outside the barrel.  I may just be a powder miser, but I like using all the powder I load to effectively accelerate the bullet.  A big flame is need to see, but doesn't help performance.  I would look at trading or selling it to get a caliber that would be more powder efficient in that length of barrel.  I don't know what to recommend as a replacement without knowing what your using it for.

[jamie]

Rog, when you cut it, it won't be as fast as your 06 JDJ.  I don;t mind spending money, but I am not going to spend it to make my bullets 300 fps slower.

[PJ]

My 300mag is faster than an '06jdj

[PJ]

Oh ya my 300mag burns the slow powder.........How do I know this the barrel is clean after the shot and I know it's burning it all too....How do you ask....Well I put a 4x8 slab of ply-wood down painted white in front of the barrel and shot over it there was NO POWDER on the board.Cut it down if you don't like it sale it to me :grin:

[Rog]

The cutdown 7 mag should be faster than the 30-06 JDJ with caliber-typical bullet weights (ie - bullets of the same or similar sectional density).

Just as a side note, if bigger cartridges didn't work in short barrels, then we'd never see an increase in velocity when going from 30-30, 7-30, 30 Herret (the list goes on...) to bigger rounds such as the 30-06 JDJ and other such cartridges.  My 30-06 JDJ will generate more velocity than the std 30-06 and the 308 Win as well as the other smaller rounds typically chambered for the Contender.  And do so with great accuracy.  Consistantly.  The '06 JDJ uses 60+ graims of powder with some load combinations.  No problems with unburnt powder.

Yes, I know that there is some deminshed return, and at some point the increase in ballistics is not worth the added muzzle blast and recoil.  But for me, at least, I haven't gotten there yet.

JD Jones has the 280 JDJ which should be similar ballistically to the 7 Mag in short barrels, and I would expect a slight edge to go to the 7 Mag interms of ballistics.  JD informed me in an email today, that I could expect 8-10% reduction in velocity with the same load when going from a 24" barrel to a 15" barrel.  I would expect about a 12% reduction in velocity for a 26" to a 15-16" tube, which is right in the ballpark for what PJ's resulted in.  That being the case, what the 280 JDJ does with a 140 grain bullet, I would expect the 7 Mag to do with a 150 grain bullet.

However, until I actually do it, I won't know for sure.

The point in making a 'handgun' barrel out of the rifle barrel isn't to make the bullets go 300 fps slower (would probably be more like 350 fps anyway...), but rather to make it faster than nearly any other 7mm 'handgun' round currently available in the Encore.

Besides, my passion is in handguns, not rifles.  I have owned two other Remington 7 mag rifles and both have been sold.  I only have the current 7 mag rifle barrel for those hunts which (in my state) require a rifle.

I stopped by a gun shop today, and they have a used 7 mag barrel that I may have to use instead of my existing barrel.  Kinda hate to mess up that barrel anyway.

Well, enough of my soap box.

Regards,

Rog

[jamie]

Well, if you expect a 12% decrease in velocity then it would be 377.28 fps slower, but 300 was just a ballpark figure.  Yes I know lager cartridges work in short barrels, they figured that out along time ago  ie....38 Special to .357 Mag.  Yeah nothing new, but the point I was making is that if you cut it down you will have 2766 fps with a 150 bullet versus 2850 with a 140 in 280 JDJ.  So will the JDJ lose 84 fps going to a 150, I don't know.  Now if you are doing it for something different or because you don't like rifle barrels then by all means saw it off.  If you are doing to have the baddest 7 out there, well you could be wasting time and money.
But do whatever you like it is your barrel and your choice.  I would not cut on a .5 MOA barrel.

[PaulS]

Ok, All you guys who are cutting your barrels besure to save the cut off sections and mail em to me Rev. Paul Stephens at

Rev. Paul Stephens
C/O Church of life
P.O.Box 18574
Seattle, WA. 98118

I'll make handguns out of them!

PaulS

[Rog]

Well, I decided not to cut down my existing 7 Mag barrel.  Hated to mess up that particular barrel since it shoots good.  Instead, today, I put a 7 Mag barrel on layaway at a local shop.  The barrel is used, in good shape.

When the barrel is paid for and no longer in layaway, it will be cut down and turned into a 'handgun' barrel.

I have thought about sending the cut off section to SSK and see if they can turn it into a 7mm Whisper.  Depending on the final cutoff length, I could wind up with a ~10" stub.

Regards,

Rog

[DLH]

:roll:   Don't cut it!!!     I did and now my 7mm-08  is faster!!!   I cut it to 15",
  When shot at dusk it is impressive!!!   still accurate, but slow.!!!

[Rog]

DLH,

Could you elaborate on the 7 mag bbl you shortened?

I'd like to hear the chrono'd velocity from each barrel (you mentioned the 7-08 was faster...) and their respective bullet weights.

What powder did you use in the 7-08 and what did you use in the 7 mag (assuming they were handloads)?

I would expect that the 7 mag would be the virtual ballistic twin to the 280 JDJ, so I'm suprised at the results you had.  Not doubting your word, just suprised.

Regards,

Rog

[DLH]

:-D   I took a Encore rifle bbl. and cut it off at 15" in a lathe, and recrowned it.  Accuracy was there, but the fastest that I could get a 139 Hornady to go was Ave. 2350fps.  I was using Win 760.  The 7-08 same bullet comes out at 2460fps with  41 g IMR 4064.  
   The crony was set 15' in fron of the bench.

[Smiley]

Trying to figure this out. If you cut off a barrel it gets slower. The idea behind the longer barrels is to let the bullet keep picking up speed all the way out and burn all the powder. If you were to cut one off it would seem logical unless you can increase the velocity in the short barrel, ie different powder, then when the bullet leaves the barrel it is slowing down, it doesn't get any faster. So If you have a large flame that is powder burning. If you bought a 15 inch barrel it won't be any different than the one you cut off. Whats the point??? Please explain this to me.. Trying to learn.. <

[DLH]

They don't make a 15" 7mm Rem mag.  Because  it will not burn the powder compleatly.  A 280 Mabey but not a Mag.  I also have a 30/06 and a 35 Whelen in 15"  both ported by BLACK MESA.  Heavy bullets  with 4064 and I get good resulst. and a lot of looks from the range officer.

[Rog]

T/C's custom shop (Fox Ridge Outfitters) offers the 7 mag barrel in a pistol version.

I am having a hard time understanding why some of you don't get the idea of a shortened barrel.  The idea isn't to 'loose' velocity (of course if you cut a rifle barrel it will be slower than it was prior to cutting it....), but rather to have a 'fast' pistol barrel.

I don't plan on using the shortened barrel in a rifle configuration.  Just as a 'pistol.'

Same reason I own a 30-06 JDJ.  Ballistically, it will out perform a  std. 30-06 Spr., a 308 Win, a 309 JDJ, and 300 Sav., and a 30-30 WCF, and other similar rounds, in the same length barrel.  Mine started out as a 308 Win., and now, as a 30-06 JDJ, it beats the 308 Win by a considerable margin with the same or better accuracy.

The reason I plan on cutting mine is due to the fact that I've got two 7 mag barrels and don't really need but one rifle length barrel.  So the second will probably get cut down.  That way, I don't have to spend money on another barrel that is already at the length I want.  Besides, I am curious as to what a 7 mag will do in a 16" barrel.  My hope is that it will be the ballistic twin of the 280 JDJ with out the hassel of case forming.  My 30-06 JDJ is a pain to form, and case loss during forming is more than I'd like, plus, with high end loads, case life is very short.  I hope to avoid this with the 7 mag.

DLH, have you tried any other powder in the 7 mag 15" barrel?  That powder is not an ideal 7 mag powder.  I'd be curious to see if you've tried H4831, or RL22 or similar powder.

Regards,

Rog :wink:

[DLH]

I did  not try any other powder yet.  Right now I am playing with a 6.5 X50 Bellm.