thoughts from the night before, and the 30 caliber round

[Trickymissfit]

well I've kinda been wanting a new 30 caliber rifle for quite sometime (as if I needed another one!). Have always had an interest in the 30BR, but also knew it's limitations. Well I was looking at the 25WSM case drawings and got to thinking too much. Take the 25WSM case, and simply neck it upto .308. Kinda be like a 30BR on steroids, and slight bigger than a 30 Meyer (and a hell of a lot easier to make). Anybody here know how many grains of water the 25WSM case holds?
gary

 

[Lefty7mmstw]

well I've kinda been wanting a new 30 caliber rifle for quite sometime (as if I needed another one!). Have always had an interest in the 30BR, but also knew it's limitations. Well I was looking at the 25WSM case drawings and got to thinking too much. Take the 25WSM case, and simply neck it upto .308. Kinda be like a 30BR on steroids, and slight bigger than a 30 Meyer (and a hell of a lot easier to make). Anybody here know how many grains of water the 25WSM case holds?
gary

the 25 wssm weighs 213 grains dry and 268 grains to the top of the neck with a fl sized brass with a dead primer shoved back in it.

 

[wildchild]

I have this exact round round setting in my loading room loaded with a bullet, kinda cute looking! Id guess 30-06 performance maybe. maybe I could post a pic for viewing pleasure.

 

[brentc]

It already exists. Do a google search for 30 OSSM. It was developed by Olympic Arms to run in an AR platform along with the .223, .243, and 25 WSSMs. I believe HSM loads factory ammo for it.

 

[AZShooter]

Tricky,

Making a joke? 25 WSM necked up to 30 cal is a 300 WSM. Looks like you caught a few.....

 

[Lefty7mmstw]

Tricky,

Making a joke? 25 WSM necked up to 30 cal is a 300 WSM. Looks like you caught a few.....

Oh, well. Either way it's a smaller 30 cal..

 

[Trickymissfit]

Tricky,

Making a joke? 25 WSM necked up to 30 cal is a 300 WSM. Looks like you caught a few.....

The 25WSM case is 1.67" long while the 300WSM case is 2.10" long. Thinking that the 30BR is one of the most efficient rounds out there, but is best with bullets lighter than 135 grains, and best with 120 and lighter grained bullets. So why not create a slightly bigger 30BR that will handle 150 grain bullets without too much of a problem? All the numbers between these two case are similar except for the overall diameter. Just think it would be a great four hundred yard deer round. Using a 150 grain Hornaday SST at 2800 fps, you'd have 1290 ft.lb. of energy on impact at 400 yards. The round would fit nicely in most internal magazines. I calculated the ballistics using the 165 grain SST and it was still 1250 ft.lb. of energy. Wether or not the case could push a 150 grain bullet to 3000 fps is kind of a moote point (it might well do it). All I'm thinking about is a four hundred yard max deer round that is capable of taking a 300lb. animal cleanly, but yet work very well in a short action Mod. 700. I'd rather had a case that was about .10" longer between the shoulder and base, but also know whatkind of a task it is to push the 300 WSM shoulder back that far (not at all fun).

and while on the WSM rambleing this morning, I've also thought about building a better (and leagle) Indiana rifle round. Their case length is 1.80" max (stupid I already know). Why not take the 325WSM or a .338RCM (better round) and make a series of forming dies to push the shoulder back to 1.350 from the base to shoulder. Then cut roughly .315" off the neck. Expand the neck to .358". I think this would be similar to the .358 Winchester and maybe close to a 35 Whelen. I can see 2600fps without all that much of a problem using a 220 grain bullet. Or about 1550 ft.lb. at 300 yards. Heck of a hog round and a good short range deer round.
gary

 

[brentc]

I think you're suffering from a bad case of tinkeritis.

 

[Trickymissfit]

I think you're suffering from a bad case of tinkeritis.

well I'm a known tinke'r. Always looking for a better way out. The 30BR idea has been an on and off again project for about ten years now. But I think the 30/25wsm case is the best I've dreamed up in quite awhile. May do the 30 and the .358 just to further confuse my feeble mind. I'll order in a 1" diameter piece of Accuralloy one day in the next few weeks, and start cutting forming dies for the .358. I'll start to CAD them out in the next week or two unless I see a change in the horizon (rather do a super short .338RCM)
gary

 

[brentc]

Sounds like fun.

 

[AZShooter]

I read your detailed explanation. If you h1.670" isn't that the WSSM? You said WSM. As to using the WSSM for a 30 that would be very interesting and you'd have a very long barrel life too.

 

[AZShooter]

I read your detailed explanation. If you had said WSSM instead of WSM I would not have made my original comment. As to using the 25 WSSM for a 30 that would be very interesting and you'd have a very long barrel life too.

I have a 30 BR and it has a slightly longer throat than the usual Robinett version. I seat a 168 SMK out to neck shoulder junction and get 2250 or so with a 24" barrel.

I also took that reamer and made a 30BR/308 by going deeper and using a 308 headspace gauge. It has to have the neck wall turned to .0105" to fit the narrow chamber neck. It has a steeper shoulder angle and less body taper. I just fireform 308 brass. I use a RCBS FL die without the sizer ball and get .002" neck tension. It shoots the 168 SMK at 2600 fps very very accurately. It is amazing considering the nasty SS barrel I am using that has deep pits that look like city potholes from a bore scope. It was one of my first chamber jobs done by me and my funky 50s sheldon lathe. Lots of fun.

A 30 WSSM would be the next bump up and should be very cool. It will cost a bit to run it with special reamer/dies etc. But who ever said that should stop someone.

Be sure and report back when you figure out what you are going to do and later on when it is completed with details.

 

[brentc]

A 30 WSSM would be the next bump up and should be very cool. It will cost a bit to run it with special reamer/dies etc. But who ever said that should stop someone.

The 30 WSSM was commercially developed already, it's called the 300 OSSM. Olympic Arms offers dies and Ammunition. Although not common, it was developed as a hunting round to run on a standard AR lower receiver. It's still going to cost a bit more for dies, but not as much as buying full out custom.

http://jsgunparts.com/store/index.php?main_page=product_info&products_id=912