Home Forums Hunting & Shooting Custom Rifles & Wildcats 300 WSM barrel length

we did a 21" 338/378 KT a while back it is a kick butt round

Mark D

Bet it was a kick butt rifle, too! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

<img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

and that's my point.

what does everyone have against a short action 20" barreled rifle that gets 2800+ fps with a 180 grain bullet?

As 458Lott pointed out, it depends on how you see the 300 WSM. But to make blanket statement that a short barrel "defeats the purpose", is a bit narrow in view.

I plead guilty to narrow POV <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I have a 20" .308 that pushes 180's 2600 fps (Remington factory loads), I can't see burning 50% more powder for another 200 fps, but to each their own.

I do like magnums because of increased muzzle velocities, whether the new short ones or traditional full size, but I just can't see cucolding them with a short tube. I also like light rifles, and skinny barrels can shoot just as well as thick ones, so you don't have to give up barrel length to save weight.

I simply fail to see what a short barreled 300 WSM has to offer, buy I'm all ears. Well, I'd think after firing a bunch of rounds through a short wizzum, my ears would be aching <img src="/ubbthreads/images/graemlins/frown.gif" alt="" /> Hearing protection while hunting simply isn't an option for me, and I'll do everything I can to protect my ears, which is one of the advantages I see in a longer barrel.

Brad,
Not arguing, just asking. Did you run those through Quickload, or just back into the numbers via some formula (i.e. 25fps per inch of barrel length?)

If I accept 2800 as a reasonable max for the 30-06 out of a 24" tube, and 3000 for the same bullet ouf of a 24" 300 WSM, assuming 25fps per inch loss (a bit on the high side IME) by cutting the 300 barrel back, we still end up with the WSM outrunning the -06 by 100fps.

Not really much to argue about, but still a bit of an edge to the WSM.

IME, 15 fps per inch is probably closer to reality, especially in a cartridge with bore to capacity like the WSM. That gives the WSM a little more of an edge, though still not much to quibble about.

I just looked back, and Charlie Sisk found 19fps loss per inch with a 180 in the 300 Win Mag in his testing. I can take that info and interpolate that the 300 WSM would outrun the -06 by @ 125fps comparing 20 to 24" barrels respectively.

CAS, if you read the entire thread you'll see where I cut a 300 WSM from 24" to 22" and lost 85 fps... I'm not guessing.

What it will do below 22" is a guess. I'll never actualy know because I think cutting a 300 WSM below 22" is silly. Most 24" bbl'd 30-06's will go 2,800 to 2,850. From my test I'd comfortably bet a 20" bbl'd 300 WSM wouldn't break 2,850 on average and might not do that.

I think one would burn roughly 25 more grains per pop. For that you would get about 200 fps.

Being the math and data man that I am (yeah right) I just ran some quick numbers. Assuming that a fella shot 500 rounds a year thru it you would burn roughly 1.78 more pounds of powder. In this area that would equate to about $32.

There is a lot of ways in this world to burn $32 bucks, for me this is not one of the places that I would personally do so.

Not pounding on you 458, just doing some quick economics work.

Lastly IMO if a fella desires a short rifle, personally I see no reason why it shouldn't be a WSM if that is what turns his crank. IMO it will still yield the 200 fps over a std round in the same length tube and that to me is what is important to consider.

To me, the idea of comparing a short wsm to a std length 06 in a std length just doesn't make sense.

Talk about comparing horses to vacas

Mark D

Brad,
I read the whole thread, but what you posted was so far from anything I've seen that I was just making sure.

I'll take you at your word that you got what you got, though I suspect that losing 85 fps in 2" is at the extreme high end and atypical.

Of course, I've never seen a 30-06 that would do 2850 with 180's, (at least with sane pressures) but I've only owned a half dozen over the years.

CAS, I was suprised too. WW PP ammo went from 2,980-ish (average) to right at 2,900 (same box). Ditto a variety of 180 handloads. As you say, probably extreme but certainy a "real world" excercise not a guesstimate. "Atypical"... maybe, maybe not. IME, some cartridges lose more than others, sometimes substantially more. And, some inches cut lose more than others (going from 24-22 vs 22-20 as an example). It's never an even loss and I can't even say all bullet weights lose the same either. I only tested 180's. You aren't convinced, absolutely no big deal. I trust my chronograph, what I saw and the thoroughness of my test which was over months, not one range trip. I was dissapointed in a 22" bbl'd 300 WSM as I expected a lot less loss than I got based on cutting other barrels.

Reading through this, I can see where it would make sense if you needed a short barreled rifle but still needed to duplicate the prformance pf a lower velocity cartridge in a longer barrel.

You don't lose anything to the "lower velocity/longer barrel' round, and depending on what you went with you still might stay ahead of it.

My main concern would be the muzzle blast. It has been proven (read your old Handloaders) that the same slower powders that produce max velocity in longer barrels still produce max velocity when the barrel is shortened.

The problem here is muzzle pressure. The powder burn rate is the same, the pressure curve is the same, so you might think of a shorter barrel as releasing the bullet "more to the left" on the pressure curve. Instead of letting go at, say 10,000 psi of pressure in the barrel, you're letting go when there is 15,000 or 20,000 psi in the barrel. That is LOUD with a capital LOUD.

And don't underestimate loud. After being around guns and shooters for some 46 years, I am positive that muzzle blast is a large part of inducing flinches. Not the greatest part, but if I had to grab a figure out of my nether orifice, I'd say 35-40% of the reason for flinching can be attributed solely to the volume and pressure of the muzzle blast.

Just my preference, but I like a certain balance. That is, first think of the rifle mission, the goal that is, and then balance all the factors of that goal with an appropriate or needed muzzle velocity and with the rifle handling and weight, recoil and muzzle blast.

If you need the most powerful weapon you can find and need the shortest barrel you can get, say like a 20" .375 H&H made specially for chasing bears in thick alder, then the mission here would say go for it and you'll just accept the cost of increased blast. That would certainly be an acceptable trade off.



The original question was whether to cut down a .300 WSM 700 SPS from 24" to 22", and how short a barrel can be and still have the rifle be balanced - in this case handling balance.

I'll stick by my previous statement that a 22" Model 700 balances very well. My 700 BDL's in .30-06, .270, 7-08 and .308 all balance and handle very well indeed. Also have a 24" SPS in 7-08 and it is obviously a bit more muzzle heavy but still handles pretty well.

And since the rifle has already been bought it is a moot point to recommend what "should have" been done.

You just have have to weigh what is most important to you. You won't lose too much velocity. You will definitely increase muzzle blast some. You will end up with a slightly faster or quicker handling rifle, but just marginally so. You may or may not get a slight increase in accuracy (shorter barrel = stiffer barrel etc.) but that is a gamble. You just might also move the muzzle right into the worst part of a vibration node and totally destroy the harmonics of that particular barrel.

If better handling is your most important criteria then chop away, just be aware of the pros and cons.

I'd probably just get it recrowned and have it 23 & 7/8" long... <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

Cheaha, ironically the M70's are all 23 7/8, not 24!

Jim, the biggest suprise, and one I can't explain, is that muzzle blast was less obnoxious in my 22" bbl'd 300 WSM than a 22" bbl'd 270! I found no problems with a 22" bbl'd 300 WSM and I've gotten more and more finicky about excessive muzzle blast as I've gotten older. I'd also add I TOTALLY agree that muzzle blast has as much to do with flinching as recoil... while it's impossible to know what the percentage is I wouldn't be suprised if it's more than your 35-40%!

I think a 180 at 2,900 is no slouch and agree balance and feel are more important than a few fps.

fit and feel are always (at least to me) more important than a few fps...

Mark D