Is there any difference between the cases I have mentioned above in title of post? I am looking to build a wildcat in the form of the .264/300WSM and need the data to go ahead with this project. I hope to end up with a rifle for long range shooting as well as for use on speed goats and mule deer. My goal is to have a rifle that will recoil wise be in the 24lbs of recoil and still deliver 3200fps using a 140 grain bullet.

So I went down to the gunstore yesterday to try and seek out information and measure the cases of the 270WSM and the 300WSM. Checking with the human eye, they look the same length and diameter. I was told they are indeed the same case, only the shoulder and neck diameter or changed.

The only visual difference I cold see right off, was in the necks and slight shoulder difference as I could see. Now the Nosler reloading manual says they are the same basically. However when I put a set of calipers on the two cases, I found out that the case diameter size, just at the shoulder was larger in the .270WSM by almost .04 thousandths. The rear of the cases were the same diameter. Anybody got any information on the amount of powder or water each case is supposed to hold? I suppose I could call Winchester and get the information from them. It would most likely be faster you supose?

2bits,

www.ammoguide.com is a very good web site for cartridge info. Log in with the user name of - demo. Then use the password - demodemo.

That is where I got the attached. The 270 WSM and the 300 WSM are identical except for caliber. The shoulder angle will be different because the caliber is different. The capacity in grains of water is 77.643 for the 270 WSM and 78.656 for the 300 WSM, but the usable powder space is the same. I obtained these figures from the program "Load from a Disk".

JJ

2bits,

The actual saami dimensions:

www.gmdr.com/levern/270300wsm.jpg

and btw: there are already pretty standard 6.5 WSM wildcats already out there, ie, dies and reamers are available.

do shoot straight,
greg
www.gmdr.com

ps. disclaimer: the drawings are from rcbs.load, which I have a vested interest in it - I wrote it... and my apologies to anyone offended by this post.
pps. version 3.18 includes a drawing for a 6.5-270wsm

ps. disclaimer: the drawings are from rcbs.load, which I have a vested interest in it - I wrote it... and my apologies to anyone offended by this post.
pps. version 3.18 includes a drawing for a 6.5-270wsm[/QUOTE].


Greg,

I have used your site as recently as yesterday, and have recommended it to others on this and other forums. However, I am of the opinion that the information that 2bits requested did not necessitate cartridge dimensions out to four decimal places, three being sufficient for the intended purpose.

Nitro -

No offense intended - my apologies.

What caught my eye was: a case capacity that although was to 3 decimals, we seem to disagree with by some 5%; and the comment on different shoulder angles.

W/re to 4 digits - saami publishes their dimensions to 4 and 5 digits (SAAMI Technical Committee Manual, Vol XI, Cartridges and Chambers) and since that's what we work from, those are the only dimensions we have to share.

w/re a 6.5-270wsm: given that we're a great fan of the 264 (in fact currently taking data for it, again), and given the great success we had with the 300 wsm, we're very much looking forward to building up a "6.5wsm" - the short fat cases really are ballistically more efficient. [Our other 6.5 project is a 6.5-450 marlin - basically puts a 6.5remmag into a marlin 1895mr.]

do shoot straight, sorry, and thanks,
greg

ps. and as far as comments about .load - again sorry - we'd gone 5+ years and 800 or 900 posts and that's the first time we ever mentioned it... may we now got another 5+ years w/o.

No offence taken. I have been a 6.5mm junkie for 20 years. My varmit rifle is a converted Swedish M96, circa 1905. It will launch the 85 grain Sierra hollow point at 3350 fps out of it's 29.5" barrel with a max dose of H380. A little much for a dog town, but works excellent on coyotes. When zeroed at 300 yards, point blank range is 4" out to 350.

Hopefully you and 2bits will keep us posted on any new 6.5's.

Keep those drawings coming, Greg - good addition to the forum, and we thank you!

Didn't know you had written the .load program, don't be afraid to talk about it, nice to be able to contact the author if there are questions, comments, etc.

Machinging to 4 decimal places is pretty tough, but good to have the information, even if most of us aren't skilled enough to use it.

Keep those drawings coming, Greg - good addition to the forum, and we thank you!

Didn't know you had written the .load program, don't be afraid to talk about it, nice to be able to contact the author if there are questions, comments, etc.

Machinging to 4 decimal places is pretty tough, but good to have the information, even if most of us aren't skilled enough to use it.

MikeG............I am holding off on this project rifle as I heard that Winchester just might come out with a 6.5WSM and that would solve me having to put a lot of time in and hassle with other sources inorder to obtain my caliber rifle down the road. I just keep my fingers crossed and wait a while longer.

Hi folks. Mike Haas here, creator of http://AmmoGuide.com/ - the website that generated NITRO's diagrams. (Glad you like the diagrams, NITRO, and thanks for the link!) A friend told me about this thread and I just had to register to join in the fun.

Hi Greg - bought your program years ago (maybe 10?) at the SF Cow Palace Gun Show (or maybe the San Jose GS). Nice work.

http://AmmoGuide.com/ provides a lot more visual help than just case diagrams. Here's another contribution to the "What's the WSM look like?" discussion...
http://ammoguide.com/gfx/web/wsms.gif (http://AmmoGuide.com/)
Compare any 8 rounds, all to scale - .01 inch accuracy on your screen. (I reduced this image by 20% for the forum.)

If you like computer-generated imagery, you've GOT to check out the "Cartridge Master List" at http://AmmoGuide.com/

Enjoy. (After all, that's what all the toys are for!)

Mike

PS. Reloaders need 3 decimal places, gunsmiths (reamer makers, etc) need 4.

Hi Mike, welcome. Stop by anytime :)

Hi folks. Mike Haas here...

Haas, you are dumb! You should have included a link to your latest article
"The Original Short Magnum, Part 1" (http://ammoguide.com/?article=osam0408 )

(Hope you like it.)

Mike

Mike:

Great article. The 284 was a great cartridge for the Model 98 Mausers that came onto the surplus market back in the 50's and 60's. I had a like new Model 98 in 7X57 back in the 60's and just had the barrel set back and rechambered. I did have to open the feed rails for it to feed , but it was a tack driver with the heavier bullets. It was the ballistic twin to the .280 Rem. and could be loaded in shorter actions with the same results, but with the youngest son on the way, we needed cash and it went. Every once in a while I wish for another .284 when I go out west for a hunt. Your type of information is always welcome with me.

Lee L.

Mike:

Great article. The 284 was a great cartridge...

...and by MikeG

Hi Mike, welcome. Stop by anytime...

Thanks, folks. The "information age" has been a boon for ammunition craftspersons! We've always been a community which quickly utilized technology as it became available. And the web was almost custom made for us.

I sometimes wonder what non-shooters think as they stumble upon our websites.

Well, for THIS "Shooter's Forum", I bet they'de say "seems like a pretty friendly place..."

Mike

Mike:

Great article. The 284 was a great cartridge ...


And still is. Ask any wildcatter :-) (But that's part 3 - see below)

Part 2 is now posted...
http://ammoguide.com/?article=osam0409

BTW, if any readers have experience with the .284 or one of it's wildcats, I am now eliciting comments for "The Original Short Magnum, Part 3". Maybe a paragraph about what you think of the xxx-284, what you use it for, etc. Get a mention, quoted and a link to your website (if you have one) in Part 3! Just drop a line to ammoguide@mmoguide.com

Thx amigos,

Mike