The Accurate Reloading Forums
.577 Tyrannosaur on a ZKK602?
05 February 2024, 14:17
Certus.577 Tyrannosaur on a ZKK602?
Does anyone know if the bolt body is big enough? Length should fit it. Not looking to have one built, just curious what readily available actions it can fit, other than P14/M1917.
I’d like to own one some day. Not to use, but I’m a fossil nut so having that name on the barrel would be a must

05 February 2024, 17:40
BitterrootThe ZKK 602 has a .700" diameter bolt which is really not big enough to make a proper T-Rex. There wouldn't be any rim left on the bolt face to hold the case during loading and extraction. Would it fire? Yes, but it would be a cheezy way to do it. I've always used the Granite Mountain African Magnum for my T-Rex's. It has a .750" dia. bolt. I often wished someone made an action with a larger bolt dia. than .750", in an action that is in a hunting configuration, not McMillan et al.
06 February 2024, 00:03
Lefteris Vassiliadis.780" for the Heym Express.
https://www.heymusa.com/assets...ess_Catalog_2017.pdf06 February 2024, 02:02
CertusP14/M1917 it is then.
06 February 2024, 03:12
jeffeossothere's arguably a case for using a 17 action, and a 14 bolt - but it's been over 20 years since i measured and debated the specifics - iirc
06 February 2024, 10:41
CertusI’ve had someone say you need to cut the action and weld a piece in..but I don’t think A-Square did this?
06 February 2024, 17:10
jeffeossoquote:
Originally posted by Certus:
I’ve had someone say you need to cut the action and weld a piece in..but I don’t think A-Square did this?
This is the "how NOT to do it" approach -- Art welded the "custom" mag box to the action and then welded the barrel lug to the barrel - with apparently little thought, and less good results, in temp control --
the "custom" mag box looks like a high school metal shop student eyeballed the chop saw and then made dinosaur turd welds to "tack" it to the action.
quote:
. Magazine boxes are manufactured from plate steel for rigidity and are also welded to the receiver.
http://d6holocron.com/wiki/ind...odel_577_Tyrannosaur07 February 2024, 10:18
CertusNo, I’m referring to lengthening the action itself through cutting and welding a piece in. Which doesn’t sound right, though I’ve heard of older gunsmiths doing it to make magnum length Mauser 98’s. And a short Mauser, using 2 actions to make 1.
07 February 2024, 17:18
jeffeossoWell, okay - that's unneeded, as the "problem" with the trex is width, not length - it's shorter than the 505 gibbs, but the case has a greater diameter, which results in a requirement for a (MUCH) wider magbox, unless done as a singleshot --
While ye olde mini mauser has been done (i have one i didn't build in 7.62x39 - it's super cute) and some guys built longer actions from the remaining parts, that's an exercise outside the realm for a trex
when contemplating such a MONSTER, much care should be taken in keep the weight up and stock reinforcement
you CAN rebate the rim, btw
08 February 2024, 02:17
CertusI thought it wasn’t nescessary. Thanks for confirming.
Rebating rim isn’t the same though. Definitely wouldn’t want single shot.
As for weight - that’s the other issue - would want it heavy without looking chunky like a lot do. Proportions and strength. Lots of factors. If I ever have this done it’s “only” getting loaded to .577NE velocity. With a nice long barrel because like most monster bores it’ll never see the game it’s intended for so probably go 26”.
Anyways thanks for confirming about NOT needing to chop and weld.
08 February 2024, 03:06
jeffeossoi mistyped -- rather than single shot, i meant single stack mag - which would likely result in a 2+1 config
if you are looking for 577 NE in a bolt gun, the 550 magnum is another route to the same solution, but no woodleigh bullets for the .550
08 February 2024, 09:50
CertusThe only reason for the Tyannosaur is the name - fossil nut here, or else I’d go for the Nyati on a 602

Ah yes. Nothing wrong with 2+1 single stack.
08 February 2024, 16:57
jeffeossocool
btw, IF you are hardened to recoil, a 750@2150 (oh, i won't go off on a tangent here) in a pretty straight line stock, isn't all that bad -- it's a bunch, and it's significant but it's NOT the lightening strike of a full blown 577 trex