What do any of you think about this new cartridge. I am thinking about selling a few guns to finance this new mag. Going to get a Winchester in a Laminate stock and have a 28" Wiseman barrel on it. I should pick up about 300 fps out of this barrel and the extra 4". What do you think?

Well, I'll admit right off the bat I don't know much about this round yet.  I'll also admit I'm an absolute nut for .277 cal cartridges for hunting.  Give me some specifics, I have a .270 Win. and a .270 Weatherby Mag. I knew this was in the works, but that's about it.  Would really like to see this one in the Winchester Featherweight with a 22-24" bbl.

The only problem with the shorter barrel length in the 20 -22" is you would defeat your purpose. The drop off in velocity would only be at its best that of a 270. You need the extra barrel length to get that fast velocity.

So your saying that a .270 Win and a .270 WSM both in a 24" barrel will have the same velocity?

Nope. The 270 Win was designed for a 20 - 22" BL. If you read all the data an the magnum cal, you will see that the test BL will be around 24 - 28". So if you use the load data for  your gun that only has a 22" barrel then you wouldn't be pushing as much. Powders are designed so when the burn rate is used to the length BL to create a push. Ever notice how short BL guns seem to have a loud muzzle blast.That is unused energy (gases)that is wasted. So if you have left over gases then you could use a longer BL to gain more speed. Most standard Cal. use powder that was designed to use all the energy within 22". A Mag. use's a slower powder therefore needs more BL to use up its energy.

Alright, I admit I'm gouging you just a little bit.  I could live with a 24" barrel, I'd just like to see a mag that's a little faster handleing, and trimmer than what you typically see in the magnum offerings.  My .270 Weatherby Mag, is a great gun but it's the Win M70 Classic and it just does'nt handle like my Brownings and Remington's.  I may have to go to the custom rifle makers to get what I'm after, although the new Weatherby SBGM fits the bill, alas no magnums.

You are in luck. They have a Winchester in a featherweight chambered in the 300WSM. The model # is 535004255

CIB, what have you heard about the new Weatherby Super Big Game Master calibers? No magnums? I've been holding off on a .300 WSM until finding out if it would be chambered in the Sako Finnlight or the Weatherby SBGM.

I think you are talking about the Weatherby MK V Dangerous Game. IT IS A LONG MANNUM ACTION.
And is chambered in .
1: 375 H+H
2: 375 Wby mag
3: 416 rem mag  (all with 24" BL)
4: 458 win mag

1: 378 Wby mag
2: 416 Wby mag  (all with 26" BL)
3: 460 Wby mag

It's a new model that hasn't started production yet. It is to have a tan Mcmillan fiberglass stock, weigh 6.5 pounds, and will look just like the Super Predator Master, but is supposed to be chambered in larger calibers. I was just wondering if CIB had found out the calibers in his research.

MrAssII:  I don't agree with you comparison of the 270WSM w/24" barrel to the .270Win.  The 'new' short action magnums achieve much of their velocity through the more efficient burning of the powder in the larger but shorter case.  Granted there would be a drop in velocity from 28 to 24" but to compare that velocity drop to a conventional .270Win velocity would be an injustice to say the least.  If you're really interested in the .270WSM, check out the article in the Nov issue of "Rifle" magazine.  There, you'll find a comparison to the .270Win, load data, and the author's opinions and range report using his cusomized set up.  His results were very impressive to say the least.  In addition, word has it that Kimber may be offering the Short Action Magnums (.300WSM, 300SAUM [Remington], 7mmSAUM[Remington], and .270WSM) in their 84 bolt rifles in the near future, however as to which one they'll go with is unclear at this point.  Winchester M70's and Browning Abolts in .270WSM are on the way!  One more point, Browning Abolts in .300WSM actually come with 23" factory barrels - I asked why?  Browning says that the additional 1" of barrel didn't increase velocity or accuracy enough to justify the additional length and weight - again SAM's (short action magnums) achieve their great velocity numbers from the more efficient powder burn of the short, fat case - this is the reason that the .300WSM (with less powder) produces indentical ballistics as the .300 Win Mag.  To sum it all up, I don't think that you'd need to demand a 28" barrel for a SAM and I'd be curious to know just how little velocity is gained by adding the additional 4".  In my opinion, because it's powerful enough, laser beam flat, and inherently accurate, the .270WSM will soon become the 'goat' (pronghorn) round by which all others are measured.

I agree with you 100%, But that is not what we was discussing about the BL length. We are talking about the diffrence it will be in a 20" - 22" BL. AS you know, If a gun is designed with load data for a 24" BL then you would lose some if you went to a 20" BL. I have a class A gunsmith that has been building guns for 30 years and he knows what he is talking about. He shoots at 1000 yards all the time and has crono maney diffrent guns with different BL length. He said that he does gain at the least 150 FPS by adding just a new Wiseman BL and another 150 - 200 FPS by using the 28" BL insteed of the common 22" or 24" BL for the magnums. I was leary of this at first, but a good friend of mine went out on the limb and had him build him a long BL magnum and has had very good luck. I am now a believer. His 14-year-old son just harvested a doe with this gun that my gunsmith Roc built at over 600 yards and I most say I was impressed. The dear never knew what hit her. My buddy, Gaylord, is getting a little over 1/2 group at 150 yards. So now I will have a new custom gun in a 270 WSM with a 28" BL. If it does not work then I can always have the extra cut off and recrown or push the chamber forewords a little and cut off the extra. Whatever Roc  would see fit that would work the best. All I was really interested in was if anyone had been using this new cal. and what he or she thinks about it. I dont want to waste my money on just a fad.

Well, I don't think that the 270WSM will be just a fad (Redding is or will be making dies for it) and 300WSM cases can be necked down to .270.  If it's big brother the 300WSM (which I own and adore) is any indication of its success, then it's sure to be a hit with the pronghorn hunters.  Anyway, it's your gun and I hope the 28" barrel works out well for you.  BTW, did you consider the 7mmSAUM from Remington?

For those of you considering Winchester WSM rifles, read this: www.ar15.com/forums/topic.html?id=73643

Mike

That doesnt matter because I am going to put a new BL on it anyways