09 November 2005, 17:28
tiggertate416-505 Gibbs
Now that I have acquired the reamer for this round from poster Kend, I was wondering if the 408 Cheytac was close enough to the 505 to open the neck and fireform. Anyone know how close it remained to the 505 Gibbs?
10 November 2005, 07:13
338guyI have a 505 Gibbs case and a 408 Cheytac case in front of me. The Cheytac can best be described as a semi-improved Gibbs. There is less taper to the body, shoulder is forward of the Gibbs and is around 25 degrees. Depending on the configuration of the cartridge you have you should be able to use the Cheytac by resizing/fireforming. The basic dimensions such as head size, length etc are the same.
Prairie Gun Works has a 416 that is basically the Cheytac necked up to 416 so the more common and versatile 416 bullets can be used.
14 November 2005, 23:07
tiggertateThanks for that info. I was hoping to use their brass

23 November 2005, 22:25
woodsracerFrom what I understand, the CheyTac brass is built with a much stronger web and thicker walls than the original .505 Gibbs so it could withstand higher chamber pressures. I would definitely recommend you using the CheyTac brass over the original Gibbs brass.
BTW, I am really wanting to build a .416 PGW or a .338-408 CheyTac. I'll probably wind up with both before it's all over with.

23 November 2005, 22:58
tiggertateI think so too. What are the retail outlets for it?
24 November 2005, 04:33
woodsracerquote:
Originally posted by tiggertate:
I think so too. What are the retail outlets for it?
>>>>>>Lost River Ballistics is the only place I know of.<<<<<<27 November 2005, 22:06
RIPtiggertate,
I toured the Jamison plant and he gave me both a single piece of CheyTac brass and a loaded dummy with a bullet in it.
They were different, and the empty brass had a shoulder location farther out than the loaded dummy, so I assumed I got a cull from a transitional phase in the development, and I still do not know what the specs are for the .408 CheyTac for sure, and I do not find it on the web.
The picture of the .408 CheyTac I posted on the Big Bore forum with the HA!/DOA line has been measured and seems to have the same body taper as the .505 Gibbs.
I too estimate the shoulder angle at 25 degrees.
I sure wish sumbuddy who know could provide a link to published specs. It's gotta be SAAMI, right?
The .475 Kifaru is in incubation.
If I get any more info from Mr. Jamison himself, I shall post. If sumbuddyelse who know beats me to it that would be appreciated.
29 November 2005, 06:51
tiggertateThanks. I suppose Jamison sells CheyTac brass direct? I couldn't find a source on the web.
02 December 2005, 06:46
RIPquote:
Originally posted by tiggertate:
Thanks. I suppose Jamison sells CheyTac brass direct? I couldn't find a source on the web.
tig,
I called Marc jamison today.
Price of either .408 CheyTac or .505 Gibbs is now (direct from him):
$1.25 per piece, with shipping being $10.00 per 100 piece lot.
I didn't pump him for everything but here are the few current specs I did get on the .408 CheyTac:
max case length: 3.035"
Gibbs = 3.150"shoulder angle: 22 degrees
Gibbs = 37.6 degreesdistance from base to shoulder: 2.422"(min) to 2.430"(max)
Gibbs = 2.458"diameter at shoulder: 0.595"(new unfired) to 0.603"(fireformed max, miked by Marc jamison in his rifle)
Gibbs = 0.600"Recall that the .505 Gibbs is also 0.600" at the shoulder, and 0.640" at the rim and head, identical to the .408 CheyTac, however, there are minute differences due to the headspace datum line (or base to shoulder distance) being different.
Dig up Jamison's address and send him a letter and a check and he will ship the brass to you.
I have done it before, and I am going to do it again.

BTW, Jamison is working on a different version of a .408/.505 Gibbs that will be a bit longer than the current .408 CheyTac.
Jamison is also going to start turning his own bullets for the CheyTac, .408 caliber solids of copper with driving bands.

Dave Kiff has the reamers and specs for the .408 CheyTac, including the throating, of course.
Another call if I get a chance ...
31 December 2005, 06:31
RIPBTT, having inserted the .505 Gibbs specs in red (above) now that I am sure of what they are, Birmingham Proof House.

Does anyone have anything else to add about the .408 Chey-Tac? Or how about this .510 Gibbs shortened in the neck by 0.14" so it will fit a 3.85" magazine box with a great array of bullets: