24hourcampfire.com
24hourcampfire.com
-->
Previous Thread
Next Thread
Print Thread
Hop To
Joined: Jul 2001
Posts: 2,202
Likes: 2
R
rufous Online Content OP
Campfire Regular
OP Online Content
Campfire Regular
R
Joined: Jul 2001
Posts: 2,202
Likes: 2
Ken Howell said this in answer to a recent question about barrel length and powder burn rate, "Also check the "difference" in down-range performance. There virtually isn't any practical difference that you can tell. Both the velocity loss and the increase in drop are infinitesimal at close range, minuscule at even several hundred yards. Often, the difference is less than one scope click, less than the spread of the ten-shot group. OTOH, the shorter barrel is generally stiffer, more likely to print smaller groups."

I checked the difference in trajectory for my 300 Winchester Magnum load (200 grain Partition at 3035 fps) versus what it would be if the velocity was 2980 (estimated velocity with a 24" barrel). At 500 yards (with a zero at 250 yards) the present drop is 31.7" whereas at the slower velocity of 2980 the drop would be 33.1". One click up on my scope at 500 yards would account for the difference. Velocity at 500 with a starting velocity of 2980 would still be 2100 fps. The difference in wind drift would only be 0.5" at 500 yards between those two velocities.

So here is my question: What real world difference are we going to see in accuracy between a 24 versus a 26" barrel assuming the same countour? I can see that my 26" barrel is not achieving anything significant for me and I realize that it is heavier and more likely to get hung up in the brush so the next time I rebarrel it I will likely go with a 24" barrel. I am just wondering if there will be any significant accuracy improvement. I seriously doubt that there will be any significant improvement. If the 26" barrel will give me 0.7" groups with the 200 Partition (which it will) would a 24" barrel give me 0.6" groups or 0.5" groups or 0.65" groups? Rufous.


GB1

Joined: Dec 2002
Posts: 131
Campfire Member
Offline
Campfire Member
Joined: Dec 2002
Posts: 131
You cannot be sure one way or another until you do it. See "Hey Charlie, what are your guidelines for barrel contours, length ..." in the archives. Every barrel is different. That is a great rig as is.

Last edited by boss; 03/30/03.
Joined: Dec 2000
Posts: 29,348
Campfire Ranger
Offline
Campfire Ranger
Joined: Dec 2000
Posts: 29,348
Somewhere in my *&^%$#@! clutter, there's a two-inch piece of muzzle from a .257 rifle that a friend cut from 26 to 24 inches. That muzzle stub weighs no more than a couple of ounces. Less than two ounces, IIRC. So the weight "gain" of a barrel only two inches shorter is too small to worry much about -- especially for the shooter who uses a "cobra" type of sling made of sandwiched harness leather, a huge overly powerful variable scope, etc. It wasn't either a bull barrel or a feather-weight -- just typical sporter-weight. Two inches of a .300 barrel with the same outside dimensions would be even lighter.

I have a bunch of rifles with 26-inch barrels and haven't ever had one "hang up in the brush" more readily, or be any harder to handle, in some of the thickest brush a hunter can expect to find himself in -- as I've heard so pessimistically predicted so often through the last fifty years or so. In brush that's thick-enough to snag a 26-inch barrel, a 24-, a 22-, or even a 20-inch barrel gets snagged often enough to make it impossible to judge whether a 26-inch barrel would snag on brush any quicker or worse. I've had my hat knocked off by brush -- and my face scratched -- and my glasses "stolen" off my face -- but haven't noticed that the length of my barrel had any bearing on how hard it was to negotiate that brush.

Careful how you accept dire predictions at face value or as "facts." Keep in mind that an awful lot of what you "know" came from the often-repeated, often-copied surmises of desk-bound writers who've had no experience with the problems (or advantages, for that matter) that they've predicted or copied from their reading. A great deal of my shooting fun for half a century has come directly from discovering that an awful lot of the "common knowledge" and universally "accepted facts" about shooting simply aren't true.


"Good enough" isn't.

Always take your responsibilities seriously but never yourself.



















Joined: Jan 2002
Posts: 1,200
Campfire Regular
Offline
Campfire Regular
Joined: Jan 2002
Posts: 1,200
I just happen to have a (nearly) one inch long piece of a stainless barrel that was cut off a factory .300 Weatherby. I threw it on the E-scale and the .933 inch long stub weighed 386 grains. If anyone wants to do the conversion to ounces ....a full 2 inches of this barrel would have weighed approximately 778 grains.
The barrel was a #2 and .600" at the original muzzle (26").

S.B.

Joined: Dec 2000
Posts: 29,348
Campfire Ranger
Offline
Campfire Ranger
Joined: Dec 2000
Posts: 29,348
1 oz = 437.5 gr


"Good enough" isn't.

Always take your responsibilities seriously but never yourself.



















IC B2

Joined: Jan 2001
Posts: 5,781
Campfire Tracker
Offline
Campfire Tracker
Joined: Jan 2001
Posts: 5,781
I'm with you Ken, regarding the "hanging on the brush" characteristics of long vs. short rifles. I just can't tell the difference. My two most used rifles have 26" and 22" barrels and brush is just NOT a consideration of which to take along. Barrels just tend to slip on past. Slings, on the other hand .... &*^%%&&*!!!!!

Joined: Jul 2001
Posts: 2,202
Likes: 2
R
rufous Online Content OP
Campfire Regular
OP Online Content
Campfire Regular
R
Joined: Jul 2001
Posts: 2,202
Likes: 2
Ken, thanks for the reply. I had a 26" barrel installed because I figured that the extra 50 fps velocity was more of an advantage than the supposed disadvantage of extra weight and more likelihood of tangling in brush from 2" more barrel. My 7mm Rem Mag has a 27" barrel and a muzzle brake (inherited from my dad) and I have hunted quite a bit with it with no real problems. But you raised the point that a shorter barrel would likely be more accurate. That issue has not been addressed further. I would gladly take greater accuracy over greater velocity (I would even more gladly take greater velocity along with greater accuracy). I guess I am wondering where the balance point is. Any thoughts? Thanks, Rufous.

Joined: Dec 2000
Posts: 29,348
Campfire Ranger
Offline
Campfire Ranger
Joined: Dec 2000
Posts: 29,348
To get some idea of the effect of barrel length on velocity, study the velocity curve below as it relates to velocity (right scale) and barrel length (bottom scale). Accuracy can not be predicted. The shorter the barrel is, the stiffer it is, and the more likely it is to be accurate. But you can't be sure before you cut and try, and any improvement in the accuracy of an already accurate barrel is foredoomed to be too slight to brag about.

This graph is for the 180-grain .308 Partition at about 3,035 ft/sec from a 26-inch .300 Winchester Magnum barrel.. I don't have a graph -- or the data to make one -- for the 200-grain Partition. Sorry. (It wouldn't be much different from this one, anyway.)

[Linked Image]


"Good enough" isn't.

Always take your responsibilities seriously but never yourself.



















Joined: Apr 2002
Posts: 569
N
Campfire Regular
Offline
Campfire Regular
N
Joined: Apr 2002
Posts: 569
There is a small correction needed here regarding the graph and it's information.

- It is not for the Nosler Partition it is for the Ballistic Tip as is noted at the bottom of the graph.

- The 180 grain Partition graph would read 3021 fps. @ 58,149 psi. when run in a true length 26" barrel but using 73.65 grains of IMR-4831. Not much of a difference but still...

- Using your pressure parameter, the corrected graph for the 200 grain Partition would read 2870 fps. @ 58,140 psi. in a true length 26" barrel and the bullet traveling 24".

I edited this when I discovered that my graph was in "barrel travel" not "barrel length". My apologies. The above shows corrected information.

Best.

Last edited by nononsense; 03/31/03.

The greatest mystery in life is who we really are.
Joined: Dec 2000
Posts: 29,348
Campfire Ranger
Offline
Campfire Ranger
Joined: Dec 2000
Posts: 29,348
All right, so I goofed. Neither my first nor my last -- and in this case (fortunately) completely harmless. How does any of the resulting "confusion" alter the point that this graph is a close-enough approximation that illustrates -- generally -- about how much less velocity to expect from two inches less barrel length, bullet travel, or whatever? What difference does the inner construction or the type of tip make in the shape of the building velocity curve?

You got me -- but it's just a flesh wound, Pard. <img src="/ubbthreads/images/graemlins/smirk.gif" alt="" />


"Good enough" isn't.

Always take your responsibilities seriously but never yourself.



















IC B3

Joined: Apr 2002
Posts: 569
N
Campfire Regular
Offline
Campfire Regular
N
Joined: Apr 2002
Posts: 569
As I said in my edit statement, I had set my graph differently for my original response then had to edit and I apologized, but forgot to take out the "confused" term.

Best.

There, now I've changed the wording.

Last edited by nononsense; 03/31/03.

The greatest mystery in life is who we really are.

Moderated by  RickBin 

Link Copied to Clipboard
AX24



595 members (1234, 10Glocks, 163bc, 10gaugemag, 1936M71, 65 invisible), 13,934 guests, and 1,178 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums81
Topics1,197,989
Posts18,599,605
Members74,134
Most Online21,066
May 26th, 2024


 


Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2024 24hourcampfire.com, Inc. All Rights Reserved.



Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.33 Page Time: 0.308s Queries: 35 (0.033s) Memory: 0.8468 MB (Peak: 0.9101 MB) Data Comp: Zlib Server Time: 2024-06-22 01:05:48 UTC
Valid HTML 5 and Valid CSS