.300/.223 Dies

[libertyman777]

The chamber on my Whisper will be .300/.223 rather than .221. Will standard Whisper dies work for reloading?

Thanks,

Paul

[LouBoyd]

It depends on what you mean by 300/.223. There is a 300-223 wildcat cartridge which is a standard 223 case necked up to 30 caliber without shortening it. It's been around a long time. It's longer and has significantly more case capacity than the 300 Whisper cartridge. It's a supersonic cartridge even with heavy bullets. If it's loaded subsonic it has no advantages over the 300 Whisper.

The "generic" 300 Whisper cartridge bears the name 300-221 or 300 Fireball to avoid copyright infringements whether it's made from 221 fireball, 223, or any of several other other cases with the same case head. What differences may exist between the 300 Whisper and the 300-221 or 300 Fireball depends on who makes the chamber reamer more than what was used as the donor case. Case choice does affect the brass thickness which change the case capacity and has an effect on the loads and performance. I don't think a 300 Whisper made from the 221 Fireball or the 223 Rem case is better or worse, but there are small differences. I don't mix brass with different headstamps even if they have the same weight.

You cannot use 300 Whisper dies to form or resize the 300-223 wildcat cartridge. It might be possible to use it for seating but it would be sloppy. I own a Thompson contender pistol with a 300-223 chamber. The loaded cartridges are much too long to fit in a AR-15 magazine when shooting moderately heavy bullets. It's suitable though for a short action bolt action rifle or an XP-100R pistol.

For handgun silhouette or hunting the 300-223 is useful because heavy bullets will remain well supersonic for a couple of hundred yards avoiding stability problems in the transonic range. My 300-223 T/C pistol has a 10" long x 10" twist barrel. The 300 Whisper can have longer useful range because it never goes transonic, but has much less energy and more drop up to the distance where the 300-223 becomes unstable. If you want even more energy in a 30 caliber TC pistol the next common step up is the 30-30 Win. Other necked up 223 cartidges include the 6mm TCU, 257 TCU, 6.5mm TCU, and 7mm TCU. I believe the 300-223 got it's name before The TCU line was started, otherwise it would probably be called the 308 TCU.

[Hoser]

Contact the gunsmith that built your gun and ask him. That is the best bet.

[kanton]

LouBoyd,

Where did you get your Thompson Contender barrel with a 300-223 chamber?

Thanks.

[LouBoyd]

Originally Posted by kanton

LouBoyd, Where did you get your Thompson Contender barrel with a 300-223 chamber?

I bought it at a gunshow in Phoenix. It's a T/C factory 300 Whisper barrel which was rechambered by a previous owner.

[libertyman777]

It's a Whisper round. The rifle hasn't been built yet but the reamer is for (I'm not sure about the nomenclature) 300/223 Whisper rather than 300/221 Whisper. If I understood correctly, this was to allow for the thicker neck of forming from .223 brass that won't require neck turning.

Anyway, can this be reloaded with the normal 300 Whisper dies?

Thanks,

Paul

[amafrank]

Originally Posted by libertyman777

It's a Whisper round. The rifle hasn't been built yet but the reamer is for (I'm not sure about the nomenclature) 300/223 Whisper rather than 300/221 Whisper. If I understood correctly, this was to allow for the thicker neck of forming from .223 brass that won't require neck turning.

Anyway, can this be reloaded with the normal 300 Whisper dies?

Thanks,

Paul

Read all of the above postings first. Your question can't be answered simply from the info you've posted so all of the above applies. If you have more information like who made the reamer, what the length is and other pertinent info that can help everyone figure out your issue than maybe you'll get a reasonable answer but until you give the info the answer is maybe?
Right now it looks like the answer is no, you can't use 300 whisper dies to reload for a 300-223.
Since you can use normal .223 brass to make whisper cases without mods (to many kinds of brass) than the explanation that the 300-223 reamer you have is to allow the use of .223 brass makes no sense. On the other hand, as noted above, there is a case based on the .223 in full length necked up to .30 cal and its called 300-223 so you can see the reason for the lack of answers here.....I hope. More info from you will help
Frank