Cutting down barrel to 18 myth?

[bvmoney]

So ive been reading more and more about GPS Defense cutting down their 308 rifles to 18. So my ques is: what other calibers can you cut the barrel down to 18 without considerable lose in accuracy or FPS. Also are they cutting down factory barrels or aftermarket?

Also i found a website the other day that started at 24 and ended at 10 barrel length. It also showed the FPS table for every inch cut off. But i dont rem the caliber.

 

[browningguy]

Shoter barrels will be stiffer and potentially more accurate, but you will lose velocity. How much velocity you need is up to you, but I like the most for certain rifles, so I use a 24" barrel on my 7x57, and a 28" on my .243. I also have 30-06's with 18" barrels and a .308 with a 18.5", just depends on the rifle and its main use.

28" barrelled .243



18" barrelled 30-06

 

[Zak Smith]

Although it may be true with some ammunition, there is incremental advantage in longer barrel lengths. If you go to a long-range match - where pride or money is on the line - how many 18" barrels do you see?

 

[danweasel]

You will lose a fair amount of FPS but I am still going to cut my Stevens 200 to 18". I am willing to bet I get a tad more accuracy (maybe shave off .1-.2 MOA?) and lose about 200 FPS. Mostly just doing it for fun though. That and I like the look of short barrels, they look mean.

 

[P.B.Walsh]

You will lose a fair amount of FPS but I am still going to cut my Stevens 200 to 18". I am willing to bet I get a tad more accuracy (maybe shave off .1-.2 MOA?) and lose about 200 FPS. Mostly just doing it for fun though. That and I like the look of short barrels, they look mean.

+1 on the mean looking part

 

[essayons21]

What is that 30-06?

 

[isthatajoke?]

What is that 30-06?

ditto

 

[bvmoney]

Thats exactly what i plan to do. Get a Stevens 200 in either 7mm08 or 308 and cut it down to 18 to hunt with. I love the look of it.

 

[browningguy]

It's an HK SLB2000 K, the carbine model of the HK SLB2000. They came with 2,5 and 10 round detachable mags, which are now unbelievably expensive (the norm with HK, because we suck and they hate us).

 

[rangerruck]

fat slower bullets; actually a 762.39 suffers very little in speed, and even less in terminal performance , with a shorter bbl. 3030 is good, 338's and 325's work well as well

 

[Maverick223]

It is not a myth...the stiffness is increased, thereby allowing a greater potential for accuracy. The best way that I can explain this phenomena is through the use of a ordinary wood pencil, a long pencil is much easier to flex than a short stub, this flexure can (but not always, as there are many more factors in play WRT barrel harmonics) deteriorate the accuracy of a barrel. The change is likely small, and may not be worth the loss of velocity and increase in muzzle blast.

 

[Bailey Boat]

In addition to all of the above there are some rifles that are just "out of balance" with longer barrels.

 

[Wes Janson]

Although it may be true with some ammunition, there is incremental advantage in longer barrel lengths. If you go to a long-range match - where pride or money is on the line - how many 18" barrels do you see?

But is that really due to accuracy loss, velocity loss, or simply "not done that way"-ism?

 

[kanook]

huh. Most of my barrels are 16 1/8". I hunt in brushy areas where my shots are no longer than 200 yds.

 

[browningguy]

But is that really due to accuracy loss, velocity loss, or simply "not done that way"-ism?

Velocity is the key. When you start shooting at 600 yards and longer you want to maximize velocity for several different reasons, all having to do with getting the bullet to the target faster. Wind drift, drop, etc., not to mention being able to run the heaviest bullet you can to get maximum BC.

 

[P.B.Walsh]

Well with .308's isn't the 155 Lapua Senar the best BC, going by that, shouldn't a 18-20" barrel be ok.

 

[Maverick223]

If you have the velocity and a twist that can stabilize it, the 240gr. SMK is the best BC .30cal that I know of...it has a BC of 0.771 (the 155 Scenar is 0.508 in comparison). That said, I wouldn't try it in your .308Win., I don't even think my .300WM (1 in11") will stabilize something that long.

The traditional reason for a long barrel is to maximize the sight radius...with optics that is no longer necessary.

 

[USSR]

Velocity is the key. When you start shooting at 600 yards and longer you want to maximize velocity for several different reasons, all having to do with getting the bullet to the target faster. Wind drift, drop, etc., not to mention being able to run the heaviest bullet you can to get maximum BC.

+1. I know a few guys who are running the 208gr Amax and 210gr HPBT bullets with BC's of about .650 in their .308's. While the internet chatter says that their 1-12" twist barrels won't stabilize them, the fact that they actually do trumps that. Long barrels and slower burning powders are the key. Personally, I shoot 190SMK's at 2700fps out of my 1-12" twist FN SPR quite often.

Don

 

[P.B.Walsh]

If not .300WM, what would you use that 240 grain .30 cal. bullet with?

 

[Maverick223]

If not .300WM, what would you use that 240 grain .30 cal. bullet with?

A .300RUM or a faster twist .300WM...a 1 in 11" may stabilize it...but I don't know for sure and doubt it, and am not willing to give it a shot (at least right now) if it won't.

 

[rcmodel]

In addition to all of the above there are some rifles that are just "out of balance" with longer barrels.

I'd say there are a heck of a lot more rifles that would be "out-of-balance" with an 18" barrel.

Ever held a 26" Winchester lever-gun or a Kentucky long rifle?

You can shoot them standing on your hind legs better than a really short rifle you can't hold steady on the target setting down.

From a bench-rest short barrels might be more accurate, but in the real world standing up, they sure ain't.

rc

 

[Maverick223]

rcmodel, that is true, but I think a shorter OAL (not necessarily bbl length) has merit for a precision rifle. I really believe that the bullpup configuration is the answer...but I do like the feel of my 1885 High Wall with it's 28in. barrel also. There is no way I'd cut it, heck I'd lengthen it if I could find a good barrel stretcher.

 

[atblis]

6.5 Grendel does well with an 18" barrel. Doesn't really have enough powder capacity to take advantage of anything longer.

IIRC, 17 HMR actually gets slower with anything over an 18"

The Remington Ultra Mags can benefit from 28" barrels.

 

[P.B.Walsh]

How can a rimfire LOSE velocity, such as the .22lr?

 

[Maverick223]

Friction...at some point the powder will be fully expanded and at that moment the only accelerating force (in this case it is in the negative direction) is friction between the projectile and the barrel wall.