So, according to my guestimates, you could cut the Gibbs down to 2.90", put a .40" neck on it, give it a .008"/inch taper, 30º shoulder and seat a 1.25"bullet from shouder to 3.75" COL, and the case capacity would be about 20% grater than the 550 Mag. (equals lower pressure for similarly insane wieght/velocity load.)
I know someone has to have thought of this already....

LMAO...

PM RNS on that!!

heh
jeffe

naw!...neck it down to 470 and give it a cal length neck rebate the rim to a rigby size and make it single stack and shoot 500 gr@ 3,000 fps on a cheap ruger magnum mk II gun!





that neck can use some trimming...

jeff...could this be the 470a.r. express???...2008???

boom
that's the 470 royale

oh yeah..."bonk!" (sound of head hitting the table) neeeevermind (my best gilda radner voice)

o.k. since gibbs brass is getting cheaper and more produced lets shorten it to 2.5" or 2.65" and make the 550 express #2 NO BELT!!!!

and the same except in 50, 470 and 458 for good measure

2010?

I'm sure all this is just a matter of time and case availabilty. Sure won't be me. The venerable Lott is starting to look like a pipsqueek.

quote:

Originally posted by fla3006:
The venerable Lott is starting to look like a pipsqueek.

HOLY S**T I gotta agree! That a big Rhino dropping round is looking small, is incredible!!!!

Forrest,
after the 550 express, I just couldn't face anymore recoil!!

the ARs are pleasant to shoot!!

and I aint gunna make a mondohuge short and fat 550 to single stack!!

jeffe

Jeffe or Ron, what does your algorhythm show a 550 Gibbs to be capable of? How would it compare with the 600 OK? Just curious, nothing more.

Forrest,
just guessing with quickload, 2650 at the same pressure as the 550 magnum, and 2320 at idle!! (42500 or so) and 2140 (550 express /577nitro class) at 32500....

recoil, #14
2130 - 99# at 21.43fps
2327 - 119@23.35
2650 - 153@26.5fps (194.6 in an 11# @33.73FPS)

so, even to me, BRUTAL



jeffe

Boom,
EVERY time you think of making a case off the 505 Gibbs brass, I want you to slam you left pinky in a desk drawer!!!

that's how much of a PIA it would be to
1: have a gun with enough boltface
2: make a singlestack (ok, that's not all that bad)
3: make it feed
4: make a $tock for it.

your choices, of reasonably priced actions (say under 1K) are...

enfield (2 choices)
CZ 550 magnum action.

and I believe that's it, unless the MRC PH actually ever comes out.

jeffe

boom stick, IMHO, your best option would be to base the round off of the new .408 Cheytac. It's already been shortened to 3.03, has a more feeding frendly shoulder angle, AND has a much stronger web than the venerable .505 Gibbs. Just run the case through a couple sizing dies up to .475, and call her good to go!!!

I hate rebated rims though.

quote:

Originally posted by jeffeosso:
Boom,
EVERY time you think of making a case off the 505 Gibbs brass, I want you to slam you left pinky in a desk drawer!!!

jeffe

its all for fun...its kinda like saying hey how bout we take pamela andersons chest, jessica simpsons leggs, jennifer lopez's butt and cindy crawfords face and say...hey wouldnt that be cool!...aint gunna happen but fun to think about it. (feel free to put whoever you want in that combo, its a free web

the rigby or lapua is the largest common sense cases thar bee...

ouch!...

i think i might need a pinkyectomy

quote:

Originally posted by boom stick:
its all for fun...its kinda like saying hey how bout we take pamela andersons chest, jessica simpsons leggs, jennifer lopez's butt and cindy crawfords face and say...hey wouldnt that be cool!...aint gunna happen but fun to think about it. (feel free to put whoever you want in that combo, its a free web

"the house that screamed" .. the second horror flick I saw in the theater.....


OUCH! will be common... say it after jeffe -- no gibbs based wildcats ---
jeffe

easy Boomer, yer talkin' about my wife there...

Rich

Seriously,

why not a 550 Gibbs? Looking at the dimensions, that big long neck is interesting (great for cast bullets), but unecessary with a properly designed lead bullet or the available jacketed stuff.

One of you CAD geniuses can draw this up and have it posted by midnight!

The 505 Gibbs is 3.15" long, but loaded round oal is just 3.75" in length. The box on my 30 Express is 3.6" long...a Hornady 458 Lott factory load just snuggles inside atop the follower and tries to squeeze in. That means a 4" box would take 505 rounds with nearly 1/4" to spare, right? Make a single stack box and feeding problems go away?

Take the 505, which measures .640" at the base and tapers to .600" at the shoulder just 2.460" from the base to the shoulder. Shoulder angle is 38-degrees, and the neck is .660" long. No need for a neck over one caliber, and half that body taper is plenty. Blow out the body from.600" to .620", and shorten the neck .160".
Sharpen the shoulder to 45-degrees. What you lose in neck length and powder capacity, you make up by blowing the body out, give or take; so the net powder capacity remains about the same. It's a short-enough oal to make a box 3.8" long work, and that means I only have to lengthen the box .200". Mill the ends off the box and weld new ones flush with the outside of the original box, and you are there. Or, just bend up and weld a new one the right length. The only major hurdle to overcome is getting the original floor plate converted to an easy opening one.

Jeffe, you been down this road, or one very like it a hundred times. This sounds like minimal machine work to get the box length where it needs to be, and the rest should be manageable for any competent machinist/gunsmith. Would making a new box single stck size take care of feeding problems, or the Gibbs that big a pain in the ass?

Enquiring minds want to know.

Rich

****i think this aint a great idea, but ******

---boomy, go slam your hand in the desk....

Rich,
you could shorten the gibbs to 2.75 and STILL have a larger case than the 550 magnum...

could salient points
the 700gr bullet is cannelured at .800, so working with the "stock" gibbs case, you would have a 3.91 case.. .09 to spare, but if it was improved some, you could get down to 3.9...

Neal has a drawing, reamer print, and I think a reamer in the works for this...

So,
you could shorten the case to 3", blow out to .630 (.010 is MORE than enough), and open an enfield bolt to take it. .. I would shorten the neck more, to a 3.65 OAL, myself, just to save ALOT of work... the cost per foot inside a milsurp acttion is something lime $180,000/foot.... or just 15k per inch!!

Making the single stack, and being happy with the round count, and then making it feed in a convention mag all have been done before...

the bad idea parts...
it's TOUGH to get to feed
it's TOUGH to get it cut open enough (length)
gibbs cases are $4bucks each from horneber
it leave nill on the bolt face

all this work, and you can't actually beat (the round can.. humans cant' take the recoil of the potential of the case) the 550 magnum, which is far easier to make...

or the 550 express, which is fairly pleasant to shoot

jeffe

Jeffe,

THANK YOU MUCHLY!!!!!!

This is why I love this forum and the bright lads on it! You just knew guys before Bwana-be had looked at this, although Bwana-be deserves kudos!! for actually looking at numbers and postulating them here. BTW B-b, I did not mean to hi-jack your thread; you get all the credit in my mind since you got here first. Bravo!
I just miked the 30X and that boltface is only .694", so it would be P14 bolt time again. I hate to lose the guide on the M30 bolt.
I have only actually held a Gibbs in my hand a couple of times, at SHOT Shows, etc. Jeffe, you are probably right...but that big hulking case calls to me from the Dark Side. On the bright side...I can wait until my PH actions get here and use the one with the .640" boltface and Gibbs size box, etc.

Rich

Stay tuned here gentle readers...next week we M-A-Y publish photos of said case. That is all I can say until I actually get (if they materialize) my fat little fingers on one...or two hundred, whatever!

Rich

rich...

would you use the 408 chey-tak brass for strength???

it is the same as the gibbs but stronger brass and stronger web design.

Boomy..
the cheytac is Marc's cartridge... and marc makes the 505 gibbs brass....


you have the wife put ice on that paw?

jeffe

hmmm...

thanks for the info...

i ass-u-me you mean marc jamison right?

is his chey-tak brass the same as his gibbs???

el-jeffe...

how about a 2.5" or 2.65" version 550 gibbs???

would it not have about the same capacity of the 550 magnum and more than the 550 express???

kinda like the big brother of the 500 a.r.

boom stick,
Yes, Marc Jamison's .505 Gibbs and .408 CheyTac are made with the same case head, from the horse's mouth.

A 2.5" .550/.505 Gibbs??? Sure it could be done, but ...

GoodLorddeliverus, GoodLorddeliverus, GoodLorddeliverus.

quote:

Originally posted by boom stick:
el-jeffe...

how about a 2.5" or 2.65" version 550 gibbs???
would it not have about the same capacity of the 550 magnum and more than the 550 express???
kinda like the big brother of the 500 a.r.

Boomy,
are you thinking of a gibbs based wild cat again?

You know it won't fit the bolt face of just about anything, won't feed, and welll

quote:

Originally posted by jeffeosso:
Boom,
EVERY time you think of making a case off the 505 Gibbs brass, I want you to slam you left pinky in a desk drawer!!!

jeffe

i do have two pinkies

o.k. both are considered slammed in a drawer

just a hairbraned thought...

still cant wait to see the 500 a.r. come to be

Hey Jeffe,

when do we tell them our dirty little secret? I say we hold out for another week to ten days.

Rich
what if the hokey-pokey IS what it's all about...?

RIch,
we wait till boomy has catcher's gloves for fingers!!!

jeffe

I grew up on the Illinois side of the mississippi river, about 8 miles from the cardinals ballpark in St Louis. I met Joe Garragiola when I was about 15. He had caught at the major league level for eleven years, and since he was a kid. Shaking hands with him was like grabbing a baggie full of peanuts! I got an immediate visual on that post to Boomer!

As an aside Jeff:

my gunsmith has cured feeding problems when converting old model 70's from standard cases to H&H magnums by just milling half of the diameter difference between the two off of the follower lip. It works every time. I have seen a dozen at least this year, including making my old model in 30-06 into a 458 Lott. Original box and everything. Soooooooooo, hypothetically speaking; could you do that with a Model 30 Express 30-06 going to the Gibbs case? Just curious...

Rich

i'll put a catchers mit between me and the gun!

i think the right nam for the 550 Gibbs should be , 550 Richers Scale,as it will probaly make noticeable sign on the Earthquake scale when you shoot it !!

there's a thought worth having...

Rich

Rich,
....... i talked to manson today...... you are a busy boy!

just trying to keep my mind occupied, and keep the readership here entertained. I also found out that the guy I got my very clean 30 Express from has four more in about the same condition.

Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm...................................

Rich

Jeffe, et al:

just thinking about the possibilities on a 505 Gibbs...

It is 3.15" long, but the shoulder begins at 2.46" and the neck is .660" long. What's up with that?
Taper is a ton, from .640" at the base to .600 " at the neck. If, if you were to shorten the neck to .500", blow the shoulder forward that .160" you shorten the neck by, and reduce taper from .600" to .625" at the new shoulder, you would gain an incredible amount of case capacity, and still be able to have bullets sticking out of the casemouth 3/4"; while staying at or just under 3.90" oal. I just measured a 416 Rigby cylindrical case and they measure about what Neals' 550 Magnum does. .556" ID on the neck, and .582" on the OD, plus or minus. Would that make for a real crumpler, or what? Just thinking...

Rich

Rumor has it...

a two reamer set has been ordered, dies to be made by said reamersmith, and a cylindrical to tapered octagon barrel ordered, custom mould maker contacted, and a replica of the 750gr jacketed bullet drawn up.
Can the 550 Gibbs be only weeks away?

stay tuned,

Rich

i am doing chest and shoulder weight lifting so i can take the recoil

Boomy,
are you dreaming of a gibbs wildcat again?

MURAHAHAHAH

Good work Rich!
jeffe

the time is now! Jeffe and I have access to a pile of 505 Gibbs cylindrical 3.200" long. First off we need to thank R Neal Shirley for his pioneering work with the 550 Magnum, he gets the credit (or the blame according to my wife) for getting this show on the road. Next, we need to pass along a tremendous THANK YOU!!! to Marc Jamison for offering a cylindrical Gibbs case.

About that case: it is hard to fathom just how B-I-G this basic Gibbs case is! By comparison; you can drop a .500NE 3" case down the inside to the rim. A 416 Rigby cylindrical will do the same thing, although it IS a snug fit. The inside neck diameter is .600"..my gosh what a case. I am sitting here with a box of 100 cases and all I can say is WOW!!!!

Neal has done some preliminary design work on what we are going to call the Jamison 550 Magnum-XL for now at least. I have my own thoughts as well, and we will see what Dave Manson's two cents are tomorrow. Neal's initial design he has dubbed the 550 Jamison Magnum; with a .020" taper , a body length of 2.4883" and a 36-degree shoulder has 197.2gr water capacity. Yes, 197.2gr of water.
My initial concept is a bit bigger, but otherwise verrry close to Neal's. I set the shoulder at 2.620", the rest is pretty much R Neal Shirley. I guess great minds do think alike.
Neal's more practical version (relatively speaking, if there is a practical side to the Gibbs case) is 3.000, just a bit shorter neck is almost as good. But, but...it only has a 188gr capacity. It also has the advantage of being 3.820" OAL vs 3.970" for the longer one.

Am I going to have Dave Manson make me a two reamer set and a set of dies starting tomorrow morning? Only if the sun rises in the East.

My gosh what a monster case...wow!


Rich

quote:

But, but...it only has a 188gr capacity.

only!

you are a wild one mr rich!

cant wait to see pics