450Bushmaster.net

I have seen were someone is cutting down 308 cases then processing them through the 450BM dies the firing them to get the cases fire formed to the 450BM chamber. Is anyone else doing this and if so will other cases work as well. there are several cases that have the same case head size.

dunno how that would work as the base of the 450 is bigger than a 308.

.4728 rim for .308
.473 rim for 450 BM
The 450 parent case is the .284 Winchester
I think this could work..

above the rim it is .499

jwkeech wrote:I have seen were someone is cutting down 308 cases then processing them through the 450BM dies the firing them to get the cases fire formed to the 450BM chamber. Is anyone else doing this and if so will other cases work as well. there are several cases that have the same case head size.

jwkeech-
I'm really curious about this. It would be really helpful if you could indicate where you have seen described this technique for making 450B brass. It would be really interesting to see a photo of a 308W case formed in this manner.

Your description resembles what I remember about the method used to form brass for the 45 Raptor, which is a sort of rimless 460 S&W. Both of those cartridges use the same bullets as the 450B, and have similar case capacities.

As Al pointed out, the base diameters of the 308 and the 450/284 cases differ markedly, although their rim and extraction groove diameters are identical. ((See drawing below.) In the world of cartridge dimensions, the difference of 0.03 inches in base diameter between the 308 and 450 is large, and firing such a die-formed case may result in a rupture just in front of the cartridge web. (The difference in diameters is about equal to the difference between the 44 Special and the 45 Colt. It's probably not advisable to shoot a 44 Special cartridge in a 45 Colt chamber.

Here are a couple of older thread on the possibility of forming 450B cases from other than 284 and 6.5-284 cases:
--Alternate cases for forming 450 Bushmaster
--More on Alternative Brass

One of these mentions some early efforts with 7.5x55 Swiss brass. In fact I did manage to fire one of these. It went BANG as expected.

Thanks.
--Bob
.

edited to update image url

There's a post in our FaceBook group. I warned everyone to seek out Tim's opinion on this before proceeding. Here's a screen capture of the post.

Texas Sheepdawg wrote:There's a post in our FaceBook group. I warned everyone to seek out Tim's opinion on this before proceeding. Here's a screen capture of the post.

{screen capture image resized}

TSD-
Your posting the information from Mr. Parker is really helpful.

There are many open questions about his conversion process. Before this can be taken seriously, two really significant questions require an answer.

(1) What is the base diameter (diameter in front of the extractor groove) of his converted cartridges?

(2) Have any of these converted cartridges been fired in a standard 450B chamber, and if so, what was the result?

Assuming the base diameter of the converted cartridge remains about 0.470, then firing Parker's converted cartridge in a 450B chamber is about equivalent to firing a 7-08 Rem cartridge in a 284 Win chamber. The results of attempting this are likely to range from disappointment on up to seeking replacements for assorted body parts.

Please let us know what you find out.
Thanks.
--Bob

Thanx. I just linked this thread to the FaceBook post. I hope these guys heed the warning. We don't want anyone getting hurt.

Texas Sheepdawg wrote:Thanx. I just linked this thread to the FaceBook post. I hope these guys heed the warning. We don't want anyone getting hurt.

10-4 and also speaking to Pitted Bore's assertions. Early on, I tried this, and was rewarded with 100% splits at the base, the worst possible place.

You can open up a 308 for .451" bullets. After all, stretch a 45 ACP case and you end up at a .308 Winchester case. But then you've induced more problems than you might care to overcome, none the less "Extremely" poor feeding reliability, from an AR Mag. (Maybe with a dedicated mag, with a dedicated Mag Well, maybe, maybe, maybe! If you do one mod, that leads to a dozen others!).

It is my knowledge that the 45 Rapture, has as it's parent case the .308win. As I said, I did this years ago, and personally rejected the idea, due to reliability/saftey issues, among just some of the many negative issues.

I'm not going to say anything to the Raptor Guys, because their Customers will do all of the telling, making us look exceedingly good.

My Recommendation, is not unlike the Dawgs here.."Going down this street is fraught with danger" (as described)!! To say nothing of Heart-Break. I for one, Recommend that you stay away from the .308 case, in these endeavors, unless of course you are a Mad Scientist, with a lab, and capable of containing safety issues..

..t