I cant tell you what bolt would have more lug stength . opening a ak 74 bolt to .470 face is going to have some issues an be harder .
I started this thread a long time ago an I still will not tell you the conversion is safe . I will tell you I have a 308 win ak an 300 savage an a 6mm brx among others .
I recommend you look hard a a galil 308 bolt an a akm bolt the only real differances I can see is the bolt face size , If that is true its a reasonable assumption the bolt is safe for that round if opend up if the metal an temper wre the same . who knows . its also known that saiga na veper an I think valamet have a third lug to pass CUP testing .
the Yugo m70 an rpk trunilns an the 8mm an some 308 Yugos look to have to have the same trunions . also the the PSL has a simular trunion . so one can some what assume the trunion is up tot he task .
I have built them I do not shoot factory 308 or 7.62x51 nato .
I can tell you I have accidently loaded a 6mmbrx to about 100,000 psi or so an lived to tell about it the case head parilay slit the the primer blew the face of the round bent into the extracer grove on the bolt anthe case was LC nateo new case so it heavy already . I know this dont prove anything but It would be hottet than a proof load an it still head spaced ok .
I relaod for all my 308 type aks an I try to stay on the light side. I do shoot facroy 300 savage as its a lot lighther than 308 an it gives up very littel .
I copy the 307 win loads for 308 win an it seems to be pretty close . A 307 is a rimed 308 for weaker lever actions the dies are the same .
with verps at about $550 you cant hardley build a conversion for taht an its got 3 lugs an a warrenty .
I do know a light loaded 308 will blow the doors off a x39 or a 300 BO wonder round ,
a 260rem loaded light will eat a 6.5 grendel
an a 243 win will smoke a 6mm ar loaded light
On of my swithch barrel guns will be a 308 win length mag well an Ill have 22-250 , 243, 308, 260 rm , 358 win an a 44 rimless of some sort . I will load them a bit light an sleep OK.
for what its worht using winchester powders tht they claim is the same as there factory ammo there are many laods you cant even get to SAMMI max pressures even using compressed charges . I suspect Winchester factory laos are not at SAMMI MAx as they powder will not fit in to do it . I cant prove this however there old load books show max loads well under the max .
your going from abut 7000 PSI bolt thrust to about 10,000 PSI bolt thrust .
FWIW there is a guy on weapons guild an UZI talk who built a 300 WSM on a akm bolt . I dont think its safe but hes shooting it an is still alive . its making like 50% more bolt thurst .