[Zilog]

I am positive I have seen this but cant think of what case it is. Ammunition with cases expanding outwards just after the rim. Is in a small base to the case and then quickly expands outwards. Can any one point be at examples of this and do you know how the case was supported in the gun to stop it blowing out? Thanks

 

[jeffro]

Zilog, are you referring to having a rebated rim. One of the cartridges that is rebated is the 50 beowulf.

 

[MikeG]

.425 Wesley Richards also?

 

[Zilog]

Thanks guys I knew there was at least a few out there. It was these newer ones I was thinking about. I was thinking it must be the bolt some how that supported it.

 

[kdub]

.284 Winchester. Made to provide 30-06 case capacity for their then new Model 88 and 100 rifles with short actions.

 

[oneoldsap]

Actually Kdub `I read somewhere that they were trying to put .270WIN ballistics in a short lever action . The 88 is a slick handling rifle and the .284 win. is the original Short Mag . Plenty capable of taking any game animal in the continental U.S. Why the rebated rim ? Maybe to reduce bolt diameter , to shave off a whisker of weight . I'm sure it is probably written down somewhere !

 

[MikeG]

The rebated rim allows the use of the same bolt face that would handle the rest of the .30-06 and .308 Win families of cartridges (and everything derived from the 57mm length mauser case also). No need to change that part of the production to put the fat case in an existing rifle. Cheaper, basically.

So.... since you end up with the same case capacity as the .30-06, give or take a few grains... and since the .280 Rem and .270 Win are ballistic twins... then, you and kdub are both right.

Gonna duck while the .270 and .280 fans duke it out...

 

[ribbonstone]

On the other end of the scale, the .41 AE.

Most of the time, will find that the rebated rim is done to be able to fit a fat case into an action, but use an existing bolt face. Hasn't been the most popular of ideas, but nothing wrong with any of the calibers mentioned.

 

[Tang]

The rebated rim allows the use of the same bolt face that would handle the rest of the .30-06 and .308 Win families of cartridges (and everything derived from the 57mm length mauser case also). No need to change that part of the production to put the fat case in an existing rifle. Cheaper, basically.

So.... since you end up with the same case capacity as the .30-06, give or take a few grains... and since the .280 Rem and .270 Win are ballistic twins... then, you and kdub are both right.

Gonna duck while the .270 and .280 fans duke it out...

If forced to choose, I would choose the .280 just because of that punk O'conner. Not to mention the 7mm bullet selection is soooo much better.

.41 AE and .50 Beo are the only two I can think of right off. But the .300 RUM falls in there too, 0.550" body and 0.534" rim. Some overlook the RUM family as DG cartridges on that fact alone. Not to mention the fact they dont come in CRF configurations. Also, the WSM's run a rebated rim also. 0.555" body and .535" rim.

 

[ArchAngelixi]

Unique round style you could always say the .50 Beowulf, uses a .308 rim and a .50 round and casing...quite the cannon...slimmer rim attached to larger case...334 grain pounder...

http://www.ammo-one.com/50AR-BEOWULF.html


Chuck

Edit: Oops...didnt see Tang's post all the way thru must give him credit the site still has some great pictures and side profiles of the case and round...has some good info on it.

 

[Tang]

The rim on the .50 Beowulf is actually the same as the 7.62x39.

 

[ArchAngelixi]

The rim on the .50 Beowulf is actually the same as the 7.62x39.

Actually, the .50 Beowulf can either be turned to .308 or 7.62x39 (.310) but both those numbers relate to the projectile size like the 7.62x54mmR uses a .308 projectile, regardless they are very close to eachother and Alexander Arms was created by a UK armorer but was developed in the United States, which was my reasoning behind using the .308 Win comparison as opposed to the 7.62x39. This was in Gun World Magazine if you want to check it out in the early 2000s I believe...


Chuck

 

[mattsbox99]

Tang, you can like the .280 because its got a different shoulder location than the rest of the '06 family.

Rebated Rims just look funky.

 

[Tang]

You know me, I stand by my convictions

 

[fguffey]

Zilog, cases after firing can be reloaded, as to fit? There is a press, die and shell holder, the shell holder has a deck height of .125 meaning the bottom .125 can not be sized in the die and there is nothing about a shell holder that sizes 'PLUS' the bottom of the die has a radius so the case while being sized can not be sized .125 plus radius. Then there is the unsupported case, that is the part of the case that protrudes beyond the chamber of the barrel to the bolt face, examples, the Mauser 98 type rifle has .110 protrusion + head space, in the perfect world that would be .115, Springfield's and M1917s have .090 protrusion from the bottom of the extractor groove to the case head, there are claims the protrusion (unsupported case) is as much as .175, I have never seen one that bad, bad because the thickness of the case head for military cases is .200 + or - very little. When the radius of the chamber opening is added + head space, the case is at the 'very ragged edge of not being supported' this leaves the case body to support the high pressure created when the case is fired. If this condition existed commercial brass like R-P 30/06 cases would be a better option because of the thicker case head, .260+.



Then there are chambers that are larger in diameter for what ever reason, chambers are not measured with a tapper type gage so the effect of having been hammered with high pressure 1,000 + firings as high as 55,000 psi? cup? is not considered as a cause and of effect, then there is the possibility the cases and chamber may not be a clean environment, so the case when extracted/ejected can have the appearance of swelling at the beginning of the case body ahead of the case head it should not swell on a new chamber or an old chamber that has not seen a lot of use.

F. Guffey