# Thread: Velocity in a 338 WM 18.5" barrel

1. ## Velocity in a 338 WM 18.5" barrel

I thought I saw info on this somewhere here. Tried to search for it to no avail.

Does anyone have data for velocity of a 250 grain (and/or 225) from a carbine 338 WM.

Say a Sako Battue? Murphy, we now know you had one..........?

2. As a rule of thumb you loose 1% of any given velocity for every inch you shorten the barrel.

In other words a rifle shooting 4000 fps will loose roughly 40 fps for every inch cut off the barrel!

At a velocity of 3000 fps you will loose 30 fps for every inch shortened! etc.etc.

My Barnes manual (338mag load) shows a 250 grain bullet behind a healthy dose of RL19 plodding along at 2669 fps out of a 24 inch barrel. So its going to loose 26.69 fps for every inch shortened. Going from 24 inches to 18.5 you loose 5.5 inches x 26.69= a loss of 146.79 fps. for a final velocity of 2521 fps from the 18.5 inch barrel.

The top load for the 225 grainer is running 2936 fps out of a 24 inch barrel. Applying the same rule of thumb would give the same bullet a velocity of 2774 out of an 18.5 inch tube.

I have used this rule of thumb for years and when put to the chronograph it is usually quite close.

I can't remember for sure which old time gun writer I picked this up from all them years ago but I'm thinking it was Jack O'Connor

3. Generally speaking you do loose a set amount per inch..... However,,,, there is a point for certain cartirdges when the velocity drop becomes severe.

For instance when I did some chrony test on my various 6.5x55mm Swede rifles. A 29 inch, a 23.5 inch and an 17.5 inch. (Around there because they are meteric lengths)

17.5 = 2,300 fps
23.5 = 2,500 fps
29.0 = 2,580 fps

So you can see that 5.5 inches can either make 200 fps difference or only 80 fps difference depending on where it happens.

If I ever own another short 338 Wm carbine, which I doubt, I would work up handloads using a chronograph and various powders until I found the best combo. Factory ammo is more than likey loaded for a 24 inch barrel.

4. You may want to think about a 338 06 if the 18.5 inch barrel is a must have. The 338 06 would be much more efficient and the actual velocity will probably be pretty close to the 338 WM in this length barrel. Recoil and specifically muzzle blast will be much more tolerable in the smaller case.

5. ## Battue

If your planning to have a 338 WM in the 18.5" Tika Battue, you might as well order it in the 338 Federal. The Federal will performe more effeciently in a short barrel, giving decent velocity; without the excess muzzle blast and recoil. The short 308 case in the long action would allow the bullets to be seated out close to the lands, and accuracy should be very good. Reloading components will be available for a LONG time.Most Tika firearms are accurate out of the box, 1 MOA or better.

6. Or have a 30-06 carbine rebarreled to 35 Whelen. A short barreled 35 Whelen is a nice shooting rifle. Short barreled 350 Remington Mags leave something to be desired, even though the powder charge is about the same as the Whelen... Just something about that 30-06 case that works out so well. Plus more rounds in the magazine.

7. I appreciate everyones replies.

I have a 338 fed in a Kimber 84 that I really like. However, I am eyeballing a Sako Battue with an 18.5" barrel in 338 WM.

If elmerkeithclone's formula is accurate I think I could live with 2500 fps for a 250 gr bullet out of a fast handling carbine. The best a 338 fed would do is approx. 2300 fps (I think), maybe not a huge difference but, significant.

Of course as brav01 states, with a long action the 338 fed could squeeze out a little more if seated longer. However, the Kimber is not only a short action, it is rather short overall because its a "match" chamber (lands are closer yet).

I do agree with dorm that if looking at a new build or an existing rifle of choice a 338-06 may be the most efficient with a short barrel with a 250 gr. I have a Ruger 77 30-06 Tang safety that I often contemplate rebarreling to a 338-06.

thanks all,

Eastwoods

8. Originally Posted by Float Pilot
Generally speaking you do loose a set amount per inch..... However,,,, there is a point for certain cartirdges when the velocity drop becomes severe.

For instance when I did some chrony test on my various 6.5x55mm Swede rifles. A 29 inch, a 23.5 inch and an 17.5 inch. (Around there because they are meteric lengths)

17.5 = 2,300 fps
23.5 = 2,500 fps
29.0 = 2,580 fps

So you can see that 5.5 inches can either make 200 fps difference or only 80 fps difference depending on where it happens.

If I ever own another short 338 Wm carbine, which I doubt, I would work up handloads using a chronograph and various powders until I found the best combo. Factory ammo is more than likely loaded for a 24 inch barrel.
I hear what your saying. However you are comparing three different rifles with different barrel lengths. That really won't cut it with the 1%/1 inch rule of thumb. Case in point , I have two 243's that are almost identical. They both have 22 inch barrels yet one shoots 75 fps second faster with the same load. One shoots a 70 grain Hornady SP 3505 fps and the other 3430 fps. In another instance I had a Remington 700 in 222 with a 22 inch barrel that shot a few fps faster than a buddies 24 inch varminter shooting the same load. If I'm remembering correctly this 1%/1 inch business pertains to a known velocity in a given barrel and that given barrel being lopped off in 1 in increments. See what I'm saying?

That being said I in fact took this 1%/1 inch deal out of context in my original post. I figured it based on the test gun used in Barnes load development therefore it would only pertain to that particular rifle if the barrel were cut to 18.5 inches.

9. Clone:
You are right, that big drop may have been a result of that rifle and not so much the length.

A few years ago I had a 25-06 built on a 1903-A3 action and a Whitehead barrel. It had a 26 inch barrel and a very tight chamber. It shot great groups....then... For some reason I took total leave of my senses and decided to cut it down to a carbine for my sweetheart.

My hot handloads for 100 and 117 grain bullets lost 30 feet per second per inch when I cut it down to 24 inchs and 35 fps per inch when I cut it off at 22 inches. I should have stopped there and made a schnabel stock for it,,, but I had a Mannlicher style stock blank in the shop. So I whacked it off at just about 18.75 inches. I ended up with a huge muzzle flash, lots of noise and 2 inch groups. The last 3.25 inches cost me 140 fps. Granted, I did not crown the barrel until it as done, so who knows what would have happened. And different powder would have done differently....maybe,,, I sold it at a gunshow...

I asked a guy who worked at Speer and he said that the higher velocity and higher capacity cartrdges (magnums) loose more per inch than the lower speed rounds, or straight sided cases rounds.

Later I looked at the Lyman books and found more info. Lyman 43 and Lyman #45 both have sections of barrel length vs velocity.

Here are some samples when they went from 24 down to 20 inches.

270 Win./130 grain bullet was 37 fps per inch.
270 Win./150 grain bullet was 32 fps per inch.
300 Sav./180 grain bullet was 17 fps per inch.
30-06/180 grain bullet was 15 fps per inch.
35 Rem./200 grain bullet was 11 fps per inch

From 26 to 22 inches on this one

264 Win. Mag./140 grain bullet was 32 fps per inch

http://www.shootingtimes.com/ammunition/stmach2_032706/

http://www.shootingtimes.co.uk/featu...el_length.html

http://www.riflebarrels.com/articles...l_velocity.htm

Basically I think that a 30-06, 308, 358 Win, 338 Federal, 35 Whelen, 338-06, 375 HH, 450 Marlin or a 45-70 makes a better short rifle cartridge.

I also think that the 325 WSM and 350 Remington mag would still be better than the 338 Win Mag in a 18 or 19 inch barreled carbine.
Although they start to loose a lot and have a huge muzzle blast from short barrels....ask anyone who has shot one of the old 660s in 350 Rem mag....

10. I've had some meager experience with short barrels, and it's caused me to be agin’em. My view is that 18.5 inches might be OK, for something like a 30-30, but for a modern high-pressure bottleneck cartridge, 20 inches is absolute minimum, and 22 inches is mow bedder.

Now, a short barrel SEEMS to be lighter and handier, but there are the downsides to consider. You know, like velocity loss, muzzle blast, recoil from the lighter weight, and harder to shoot accurately.

You can say, “Aw, they don’t amount to much”, but I betcha you will notice them all.

Smitty of the North

11. ## 338 WM short barrel

I have been shooting a Winchester MD 70 with a 20" barrel for about 33 years now. I am not sure what I would have gotten out of a longer barrel but whe I was shooting the 175 Barnes X I was getting 3120fps. Yes I was pushing them and I was able to clover leave three shots at 100 yards. I have since switchd to Sierra 215 grainers and Barnes 225 X. I have not check to velocity on these but hope to when things slow down some.
When I first got this rifle we were doing a lot of bow hunting and handgun hunting. We want something that has some knock down power but would be quick to handle. When I have to replace this rifle I will be looking for a 22-24 inch barrel though.

12. I can see the other side of the equation, although I don't know much about the technical stuff relating to short versus long barrels. For example, I would think that such a carbine is built, not for speed, but for launching a relatively heavy bullet at modest speeds. In that case, all that is being accomplished is just shortening the trajectories of the bullets used by perhaps 100+ yards. yes, there is a blast closer to one's ears, but such is also the case with short-barreled rifles (45-70, .450AK, etc.), and powerful handguns from the .354 Casull and up.

Some folks out there have shortened their .338s, .375s, .416s, and even shotguns to 18" (or so) barrels for close work.

13. A couple of years back I had an 19.25" Sako battue rifle, brand new in the box. Made in 1986. I loaded for it and shot it a few rounds then sold it to Allen on this forum and I guess he still has it. I have load data and velocity comparisons with that rifle and a 22.5" Sako hunter model.

Win cases fed 215M primers
DATA-------------Velocity
225 gr. Part------22.5"-----19.25"
RL-19, 70.0 gr---2683-----2488
RL-19, 71.0 gr--- N/T -----2554
RL-19, 72.0 gr---2742-----2626
RL-19, 74.0 gr---2812-----2697
RL-15, 60.0 gr---N/T------2478
RL-15, 61.0 gr---2643-----2570
RL-15, 62.0 gr---2721 ----2607

250 gr. Kodiak-----22.5"----19.25"
RL-19, 70.0gr----- N/T-----2488
RL-19, 71.0gr-----2626----2517
RL-19, 72.0 gr----2689----2587
CCI-250, 72.0gr--2712-----N/T
RL-15, 60.0 gr----2578----2443
RL-15, 61.0 gr----2608----2472
RL-15, 62.0 gr----2670----2502

What did I find here? RL-15 is a good powder for the 338 even with heavy bullets and it gave the lowest SD numbers in the short barrrel with less muzzle flash. I could easily reach 2500 fps with 250 grains in the 19 inch barrel. I could also hit 2700 fps with the excellent 225 grain partition. There is a pretty big velocity loss in just three inches of barrel but the 338 mag can still be a very useful caliber in a carbine.

My standard loads with the 225 Partition and my 22.5" rifle is 74.0 grains of RL-19 for 2800+fps.
My standard load with the 250 grain Kodiak in this rifle is 72.0 grains of RL-19, at almost 2700 fps. The 19.25" gun gave up about 100 fps for each of these loads.
The short barrel performs better with 250 grain bullets. (has less velocity loss)

14. Originally Posted by Eastwoods
I appreciate everyones replies.

I have a 338 fed in a Kimber 84 that I really like. However, I am eyeballing a Sako Battue with an 18.5" barrel in 338 WM.

If elmerkeithclone's formula is accurate I think I could live with 2500 fps for a 250 gr bullet out of a fast handling carbine. The best a 338 fed would do is approx. 2300 fps (I think), maybe not a huge difference but, significant.

Of course as brav01 states, with a long action the 338 fed could squeeze out a little more if seated longer. However, the Kimber is not only a short action, it is rather short overall because its a "match" chamber (lands are closer yet).

I do agree with dorm that if looking at a new build or an existing rifle of choice a 338-06 may be the most efficient with a short barrel with a 250 gr. I have a Ruger 77 30-06 Tang safety that I often contemplate rebarreling to a 338-06.

thanks all,

Eastwoods
There is much more to this story as you may have guessed.

Remember no two identical guns will give the same velocity.
I think the 338 mag is a pretty good carbine. The only real down side is muzzle blast. Also I have a 20" 338 WSM that will out perform the 19.25" 338 mag Sako, with less powder. Also the bigger the bore the shorter the barrel can be and still get good or at least acceptable performance and the blast is less because the exit velocity of the gases is lower. It is lower exit pressures using faster powder (RL-15) also.

I had a 338 necked up to 358 in a 20 inch barrel and it was the exact equal of the 338 mag I had at the time (24") with 250 grain bullets. The 358 used RL-15, the 338 used RL-19 and both hit 2740 fps with the 250 grain bullets. Now I understand the SD of those bullets was different but muzzle energy and bullet weight was the same and one gun was 4" shorter.

This Battue you have found may have a 18.5" barrel if one of the earlier guns or it may have the 19.25" as the one I wish I'd kept. (sniff) I do love the Battue rifles. Did you ever wonder how the Battue got it's name?

15. ## Battue

Originally Posted by Murphy
Did you ever wonder how the Battue got it's name?
I BELIEVE, Battue is a driver or beaters self-defense firearm. Used by people who drive animals for shooters, especially boar in wooded or close in encounters. Correct me if I'm wrong.

16. I have one of the 80's vintage Sako full stock carbines in 338. I like it very much. I enjoy the handling of the short barrel. It has always been accurate for me, with a leupold 2x7 on it. I have never shot it over a chrony, just found a load using 4831 and a nosler 250 gr partition that this particular rifle likes and went hunting. Probably don't know what I'm missing but the moose don't seem to know the difference. It does let you know when you touch one off but how many critters are you going to kill in a year?

Last fall I found another stock that fit it and cut it down for my 11 yo son. He loves shooting cast bullets thru it at magnum pistol load levels using the iron sights. He doesn't know how spoiled he's getting using a sako for his first "real" rifle and being a lightweight short barreled carbine it's the perfect size for him.

17. Float Pilot, Murphy or anybody. I have a short barreled .458 Win mag, 17.5" before the muzzle brake, and I've always wondered how much velocity, in general numbers, it would loose over the published numbers. I know I should carve out the time and check with a chrony, but hey! it's fishing time. Does that 1% per inch rule work for the .458? Thanks for your help.

Murphy, are you sure that .30-06 barrel you sold me had been fired before? It sure looked brand spankin' new to me! Thanks!

19. Originally Posted by .338-06
Float Pilot, Murphy or anybody. I have a short barreled .458 Win mag, 17.5" before the muzzle brake, and I've always wondered how much velocity, in general numbers, it would loose over the published numbers. I know I should carve out the time and check with a chrony, but hey! it's fishing time. Does that 1% per inch rule work for the .458? Thanks for your help.

Murphy, are you sure that .30-06 barrel you sold me had been fired before? It sure looked brand spankin' new to me! Thanks!
You know, I'm not sure. The old Sears JC Higgins rifle looked brand new and I didn't shoot it at all. Until this past week end and that was with the new barrel of forty caliber. I would actually be guessing but if it were shot it wasn't much. The bolt had no indication of ever being fired but sometimes they can be clean up enough. I hope it is a good barrel. It is lightweight and has a very smooth bore. I hope it works well for you. I am using the rest of the rifle, even routed out the original stock to fit the much larger barrel in it. I think I'll bed it and shoot it until my fiber glass stock arrives. I think that rifle was made about 1953.

20. ## get the shorty

Go for the short barreled 338, you won't be sorry. I took a Rem. Model 700 KS mountain rifle, in 338 wm. I wanted a short barrel but didn't want to chop the factory barrel, so I picked up a remington 338 wm stainless take off at a gun show, had it cut to 19.5". I consulted Murphy on load data and went with his suggested loads of RL 15. I switched the bullet to a Hornady 250 gr RN, I'm getting a 1" group with 62 grains of RL 15 at 2490 fps. Recoil is very tolerable in this light rifle, and its a joy to handle. Just my .02.

Page 1 of 2 12 Last

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•