new cartridge/

[badshotlal]

Good evening to you all.

  This is my first time, in a very long time, that I visited you folks.  Have a question, that probably you all will say, " Dah" !!
  In this months GUNS is a reference to a 5mm/35 SM cartridge, ostensibly chamered by Savage, loaded by Cor-Bon, and brass sold by Hayden.  Well, I ain't no cyber-space guru -- or nothin' else for that matter, but darned if I can find anything on their sites.
  Would sure appreciate a comment(s), other than fore-mentioned, "Dah"!!  Thanks.  Hope most of you are snow and ice free.  Here in mid-Ks. still trying to chip ice covered by snow.  Have a nice week-end!

Easily confused,

badshotlal

[The Sodbuster]

The SMc family of cartridges were designed by some engineers to maximize powder efficiency, i.e. - the most bang for the grains of powder used.  There are some principles common to each SMC cartridge: an inside case diameter of 2.1 times the bullet diameter, and an elliptical case shoulder.  Since case diameter will vary with caliber, they won't necessarily use the standard case diameters such as .473" and .532".  You reach a point, I think around 6.5mm caliber, where theoretical case diameter becomes to large to fit in any existing rifle actions.  There was a good article on it in a Rifle Shooter magazine last year and you can read more about it at www.superiorballistics.com.  They can explain it better than I can.

I think Savage only chambers the 5mm/35SMC through their custom shop.

[badshotlal]

Hey Buster,
  Thanks for the reply;  sound like an engineer.  Too late to try and understand the science of which you speak -- little chance I would with a fresh cup of coffee and a morning paper on the table!
  But, I did sleep in a Holiday Inn last night -- naw, but I really do have past issues of most of the Rifle and Handloader, including the firstest of each, and several consceutive years thereafte.  Soooo, tomorrow a.m. I'll dig out what you referenced.
  Thanks again for your reply.  Hope you have a great week-end!

Confused as usual,

badshotlal

[Catfish]

Sounds to me like a .20 BR with a rounded shoulder. I think that they are tring to do a sell job here. The most effectant case is a straighted wall case. I think they pulled that 2.1 times the bullet dia. out of the air. For some reason I have grave doubts about any of the claims they make.

[The Sodbuster]

I think that they are tring to do a sell job here. The most effectant case is a straighted wall case. I think they pulled that 2.1 times the bullet dia. out of the air. For some reason I have grave doubts about any of the claims they make.

I put a lot of stock in what they say.  There's a lot of talk about cartridge "efficiency", but I'd say this is more than just talk.  It's backed up by lab research.  One of the designers worked with solid fuel rockets prior to getting into cartridge design.  Trust me, when you're sending millions of dollars in to space and every ounce counts, you put a lot of engineers on the job to get it up there in the most efficient manner possible.  When your firing pin strikes the primer, there's physics at work inside that cartridge and some designs will get the job done more effectively than others.

Does that mean it's worth chucking your old rifle for a new one chambered in the latest offering science has to offer.  Probably not.  But for folks still building their collections, it's another choice.