300 WM vs. 300 WSM

head2h2o

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I have decided to go with another magnum caliber and want to go with the .30 cal. I have narrowed it down to the 300 Win Mag and the 300 WSM. I would like some pros and cons on both of these and a direct comparison if anyone can provide that. The information that I read about the 300 WSM suggests that many are not getting the numbers published in the reloading manuals in terms of velocity. I am looking for the cartridge that will take game at the longest distance. I also read that some people have a hang up with the belted cartridge. I have never understood this. I have spent plenty of time behind a 7mm RM and never saw were the belt made any difference in terms of accuracy say compared to a 30-06. If I can get the velocity out of the 300 WSM, and since I can use the same bullets with both cartridges, what is the advantage of the 300 Win Mag, especially since I would be using less powder with the 300 WSM.
 
Basically, for the mid and low range weight bullets, there really isn't much difference (other than the WSM being more efficient and shorter action). For 180gr and up bullets, the 300WM will give you a little bit of an advantage in velocity.

You said "I am looking for the cartridge that will take game at the longest distance." The heavier bullets will be better at long range and the WM will push them harder. If you really want the .30 hotrod, what about the RUM, or the 30-378? Those will really push the envelope on those heavier pills.


AJ
 
I agree with AJ. You said at the longest distance. The 300 win mag will push the 200 grain class bullets faster for long range work. I built a 300 wsm last year and am getting 3419 fps with a 150 grain bullet out of a 24.5" barrel. That is equal to the 300 win mag. But the wsm falls off with the heavier bullets. Those long bullets take up a lot of capacity in the short case. If you want to kill stuff a long way with a 30 caliber then get the 300 ultramag and push the 200 grainers at 3200 fps.
 
If you really want to get out there, look at the .338 RUM and up. ballisticlly better at long range. if I was to go with something a little lighter recoil wise I really like the 7mm WSM or 7mm-300 WSM. sorry that that is not even close to what your question was asking, but I think that ballisticlly ther are better options. If I had to go for one or the other I would say whatever you find for a good deal or in the model your after.
 
I selected the 300 Win Mag because of the reasons already mentioned and because Lapua brass was available. Then Lapua stopped manufacturing 300 Win Mag brass about 1 year ago. But RWS still manufactures 300 Win Mag brass to the best of my knowledge, and it's as good of brass as Lapua. So I'd still go with the 300 Win Mag and use RWS brass with 210 gr Berger VLDs for long range hunting.
 
Thanks gentlemen. This helps. My goal is to push the heavier rounds, say above the 180 gr mark. I am really looking to stay with the 30 cal bullet, but I do appreciate the suggestions on the 7mm. I like the 30 cal over the 7mm just because I can use a heavier round. I really am looking for something to throw rounds that weigh over 200gr. It sounds as though the 300 Win Mag is the better option.

If I decide to build this rifle and not go with a factory model, what length barrel would you recommend as optimal? I am not that concerned about the weight, I am just looking for performance. Is a twist rate of 1 in 10 good for the heavier bullets, or does it need to be slower than this?
 
Food for thought, I just put together a 300 WSM round of 71 grns of H1000 w/ a 200 SMK. My velocity is 2922 avg. with an ES of 14fps. I am cutting .5 MOA or less with this bullet if I do my part on a stock SS 26" Savage 1:10 twist barrel. This load according to 1500 ft lbs puts me right at 920 for elk. I can get to 1300 for Whitetail with 1000 ft lbs. Just thougt I would put that out there. The 200grn. SMK has a BC of .570 according to a calculator I use.

There is a smith that I know that is using longer barrels with the 300 WSM and getting 3000+ fps. (30-32 inch Barrels), but these are all hand loaded rounds. If you went with a 1:12 twist barrel or even a custom 1:11 you would get better speed. If you went with anything heavier than the 200 grain round then you would definitely need a 1:10 twist. Not sure if you are a loader. The 300 Win Mag would probably push that round to about 3050 or more. Good luck on your decision.

Tank
 
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Tank,

I am a handloader, so thank you for the information. If you have any more relative to what you are using to load your rounds, please share. Any information is appreciated.
 
head2h2o,

Traditionally the WM has had a slight edge over the WSM, especially in the heavier bullets. However, with the introduction of RL17, the 300 WSM "may" now have an edge over the 300 WM. I recently shot 180 E-Tips @ 3193 out of my Sako 24 3/8" barrel with 67.5 gr of RL17 and...... I also shot 210 Bergers @ 2935. These velocites exceed published data for the 300 WM by about 100 fps give or take 50 fps. Having said that, not everyone seems to be getting extraordinary results with RL17, but many do. Also, RL17 may increase WM performance, but probably not to the same degree because it was actually designed for shorter, fatter cases.

If I was to build a 300 WSM, I would use a standard size action and the liberal freebore I currently have in my Sako to allow seating depths that seat the bullet to the lands without encroaching on case capacity. When I seat a 210 Berger to the lands in my Sako, the bearing surface of the bullet only catches about 2/3rds of the neck. If I tried seating a 190 Berger to the lands, it might be falling out of the neck. So in doing your build, whatever you decide, make sure you use an action and chamber the throat for the bullet range you want. On twist... any custom .30 cal barrel I ever order will have a minimum of a 9 twist (and maybe 8) to accomodate the longer high BC custom and wildcat bullets.

Bottom line... If the build is properly designed, and with the right powder and primers, a 300 WSM will come very close to the WM if not actually exceed it, even with the heavier bullets. Assuming the performance of the cartrides is roughly the same, the advantages of the WSM will be longer barrel life and a shorter action compared to the WM. The advantage for the WM is better brass. But you can get Norma brass for the WSM which is great brass if you dont push the pressure limits.

My 30 cal preference... If I were to do a build right now it would be a 300 Dakota which has better performance than the WM or WSM. It also has a fat, somewhat short (not long) case which might be favorable to RL17 performance. it could theorhetically come close to the 300 RUM in performance with significantly less powder. Brass for the 300 Dakota is made by either Hornady or Norma and is not cheap.

Finally, if you really want to shoot to the "longest" ranges and rifle size/weight does not matter then get a 300 RUM or LARGER, fit it with a 9 or 8 twist 30" barrel Sendero contour and you will be killing elk @ 1500 yds or more, especially if some good custom high bc bullets come out. With that size of rifle, recoil should be very tolerable.

Hope this helps and have fun with your project,

Regards,

-MR
 
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The 300 WSM competes very well with the WM due to its higher percentage of useable case capacity. When you look at the cartridge designs side by side you will see it is actually the WM that runs into case incringment problems first. I think too much is being made of the short fat case vs the traditional case.

The WSM SAMMI OAL is 2.86 and the case length is 2.1". That means .76 inches of bullet can be set outside of the case and no capacity is lost. The wm by comparison has an OAL of 3.3402 and the case length is 2.6201. That means only .72 inches of bullet can be set out of the case before case capacity is lost.

When you look at the dimesion beyond the neck and to the case itself the WSM actually has a bigger advantage. the distance from max OAL to where the shoulder starts on the WSM is 1.058 inches vs only .984 for the WM.

Due to its longer case the WM case gives up slightly less capacity than the WSM does when bullets encroach into the case below the shoulder. With long bullets this can negate the WSM advantage in useable capacity.

If you pick the right action, magazine, and throat the barrel to allow the bullets to set out of the case the WSM will run right with the WM over a broad range of bulletweights and lengths because it is useable capacity that really matters. That being said if your action will allow you to do the same with the WM with its 10 grain case capacity advantage and it will be 75 to 100 fps faster.

My personal choice would be a WSM chambered rifle that could feed rounds 3.1 to 3.2 inches long to handle high BC 180s and 200s.
 
This load is near maximum in my 300 Win Mag bolt rifle: <1/2 moa out to +600 yd
Lilja 25.5" barrel
Lapua Brass
Federal GM210M
74 gr IMR 7828
210 Berger VLD
2970 fps MV
 
Guys, thanks for all the information. I knew there was a reason I came to this site to ask this question.

Am I going to see any advantage to a barrel longer than 26" with either caliber. I have typically always stayed around that length but would certainly consider going longer if there would be a reasonable addition of velocity.

Also, can anyone tell me the pro and / or con of using a belted cartridge vs a not belted.
 
Also, can anyone tell me the pro and / or con of using a belted cartridge vs a not belted.

"Belts" are unneccessary and I just dont like them :) I have also shot a 7RM for many years. Other than that, not not much of a difference except maybe some minor handloading issues with head spacing and FL sizing vs neck sizing.


-MR
 
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