The Accurate Reloading Forums
Jamison 550 Magnum-XL...say it ain't so...
26 September 2006, 05:23
Idaho SharpshooterJamison 550 Magnum-XL...say it ain't so...
Yes It Is!!
I have sitting here on the floor next to my desk 550 Gibbs cylindrical brass, and not just a handful either.
I have a phone conference in the morning with master reamer maker Dave Manson to finalize up on OAL and specs, FL is like 197.2gr of water; and this project is a go!
Stay tuned...
Rich
Yes, I said one hundred-ninety-seven point two grains of water capacity.
26 September 2006, 06:00
GrandpasezIdaho- How long are the straight cases.
I took straight nyati basic brass and made my
3.45 inch long belted 585HE. One of a kind
to experiment with. 13,000 ft lbs.Ed
MZEE WA SIKU
26 September 2006, 06:30
boom stickrich...send me pics and i'll post them for you. add in a ruler and some std carts for comparison
26 September 2006, 06:46
Rodney H.{500Jeffery}I would be very interested in the cartridge! I've had a Montana PH action on back order for some time, should get it sometime in late 07. The 550 would be perfect. Keep us posted. Rodney
26 September 2006, 06:50
Tyler KempI may have heard about this proposition...

Post plenty of pics or pm me some Idaho!
Love shooting precision and long range. Big bores too!
Recent college grad, started a company called MK Machining where I'm developing a bullpup rifle chassis system.
26 September 2006, 07:00
boom sticki think naming it the 550 p.h. is a great marketing/p.r. move...
the p.h. action to be by mrc is ideal!
26 September 2006, 07:25
Idaho Sharpshootergentlemen,
I will try to do so tomorrow. I have a thought to make a crude form die on the mill and lathe, and turn a small ingot of lead alloy into a 3/4" square on the mill so I can chuck it into the lathe and make a dummy bullet to show and tell.
Hubel: 3.185" long, .626" or so at the mouth.
Boomer: PM me you Email address.
Rodney: just stay tuned for the details.
Rich
did I say 197.2gr of water capacity?
26 September 2006, 07:28
Rodney H.{500Jeffery}Was going to do the Montana PH in 500 Jeffery but I'II re-barrel a CZ 550 Magnum for it. I need dimensions for the 550 magnum so I can let the Montana folks make the changes to my order. Don't like to assume but I'm thinking it will feed the same as the 505 Gibbs?
26 September 2006, 09:51
Idaho SharpshooterRodney,
I will have a reamer print to post sometime tomorrow I hope. Just tell them it will be coming and make it for the Gibbs. I see you refer to it as the 550 Magnum...that is R Neal Shirley's awesome design on a 460Wby straight cylindrical case. Find a drawing of the 505 Gibbs and just imagine it at .550" bore instead.
Rich
26 September 2006, 16:17
jeffeosso550 Jamsion Mag - Gibbs case
550 magnum - weatherby case..
Great Work Rich..
550 magnum is just a rebarel away for a 416 rigby gun,
jeffe
26 September 2006, 16:29
.366torqueWho makes the bullets? I did a quick search and no answers.

26 September 2006, 18:39
jeffeossoAlaska bullet works 700gr
Hawk 700 and 650 gr
Custom cat bullets - 665 and 715 gr cast
Bridger Bullets - 700gr solids
CH4D - 650g solids
jeffe
26 September 2006, 18:44
.366torque700 grains. That's hefty! 2300 fps or there about?
p.s. My shoulder felt a twinge when I wrote this.
26 September 2006, 19:45
Idaho SharpshooterYesssss! But again we all need to face Arizona and salaam to R Neal Shirley, then spin towards South Dakota and salaam to Marc Jamison. These two gentlemen are the ones who made this happen. I have a call in to Dave Manson this morning. We will work out the two options for length, which Neal has pretty much done for us, and figure out which way to run first.
Thanks for all the interest
Rich
27 September 2006, 01:52
SnowwolfeTo those who know more than I,
Will this will fit into the larger Hein action?
My biggest fear is when I die my wife will sell my guns for what I told her they cost.
27 September 2006, 02:52
Idaho Sharpshootercall them and ask if a 505 Gibbs will fit and feed.
This is that case necked up to 55 caliber.
Rich
27 September 2006, 11:04
RNSGents
I am going to have some 800gr bullets made up by ABW for me and there are plenty of 700gr right now. The 550 Magnum (weatherby based with a 700gr is just short of 2,400 fps with my 26" tube) the 550 Jamison Magnum is going to really step up the HP on the 700gr or move the 800gr real nice. Rich do you need some 700 to play with although they have been known to cause mental problems. Like you will never look at a 500gr .458" the same way again.
RNS
RNS
27 September 2006, 20:39
WaffenfabrikHeinquote:
Originally posted by Snowwolfe:
To those who know more than I,
Will this will fit into the larger Hein action?
Yes
27 September 2006, 21:07
Idaho SharpshooterAnd it would look verrrrrrrrrrrry good there as W F Hein's big(gest) offering, wouldn't it Karl?
Just a thought...
Rich
27 September 2006, 22:03
WaffenfabrikHeinquote:
Originally posted by Idaho Sharpshooter:
And it would look verrrrrrrrrrrry good there as W F Hein's big(gest) offering, wouldn't it Karl?
Just a thought...
Rich
Actually, it would not be on our 'biggest', as our N-5 is designed specifically for the 416 Rigby to 505 Gibbs sized cases.
Our biggest is large enough to hold the 585 Nyati, 577 Trex, etc... If you want to see a picture of this one, click here
http://www.rifleactions.com/customactions.htm28 September 2006, 03:09
Idaho Sharpshooterlet me rephrase that...and insert the words useable/practical somewhere. But, I am willing to up the ante if you will build the rifles...
We will turn the current .640" rim down to .500" and do the brass washer threaded and screwed on as Ed Hubel does on his 12GA FH and offer you the .600" or .620" version. At 3.2" long it should return the heavyweight title to the northwest.
Hmmmmmmmmmmmmmmm...........................
Rich
PS: I went to the site, those are just drop dead gorgeous rifles you gentlemen build.
28 September 2006, 07:27
Rodney H.{500Jeffery}700gr. at 2300FPS is about 8,218 LBS energy-what is estimated {MAX} velocity for the 800gr. bullet in a 25 inch tube. My goal with the Jeffery is to break the 7000# barrier with a 600gr at about 2300FPS in a 25 inch tube! The 550 will be an excellent choice for penetration over anything near it in bore diameter!
28 September 2006, 09:28
Idaho Sharpshootermybe 2600fps
Rich