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308 ak

49K views 321 replies 44 participants last post by  1biggun 
#1 · (Edited)
0001
 
#209 ·
if only they were avalaible
Why don't we just make our own?????

If you have a rotating table you should be able to make one, even without indexing. Heck, I think my indexer (doesn't rotate) could be used to build one. Just need to heat treat it properly. I would use 4340, but 4130 may be good enough?
 
#211 ·
Might as well make it a 3lug design while were at is and longer so we dont have to move the trigger guard. a m76/77 style bolt but with three lugs some thhing that will handel 65,000 Psi would be nice. I wonder what a sagia 308 will actually handel?? It can be done and Ive looked at doing it but if I were to do it Id want to make a bunch of them and I just simply dont have the funds for it or the insurance to sell them. I am starting to see more and more guys with CNC equipment talking about doing bolts and trunions. Turbothis ahs been playing with a CHC mill on the AK forum and he has made some cool looking stuff he was talking of doing 19mm trunions.
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The Saigas and Veprs had to pass CIP proof testing which is 125% of standard max chamber pressure. They first tried a two lug 308 design that wouldn't pass CIP proof testing.
 
#220 ·
Well...I happen to talk to some of their designers and specifically mentioned this to them on a side note and they were very quick to correct me that the pressures were fine and that the reason they added that extra lug was to try and squeeze a little more accuracy out of the .308. I'll find out more on my next visit with them, but until I can see the actual "publication" and from what source...which I will ask them about and have them verify...I am going to remain skeptical. I have seen a few .308 builds that do just fine on hot handloads without a third lug. How many does the M76, PSL, .308 M90s have???
 
#222 ·
Those two lug models have heavy bolts. One of the design features of the AK is the bolt to bolt carrier weight ratio. Increasing the bolt weight with the same bolt carrier weight in theory would reduce reliability. The three lugs can't have anything to do with accuracy. The reason some bolt actions have three lugs is to reduce the size of the lugs so the bolt doesn't have to rotated as far as a two lug bolt with larger lugs. The increase in lugs in the AK is to handle more bolt trust from the larger cartridge.

During the designing of the Beretta AR70 and Sig 540, both Beretta and Sig teamed up at first to design one rifle. The design team included two American engineers. The Americans wanted a multi lug bolt like the M16 because they claimed it was more reliable in design because the bolt didn't have to rotate as much as having larger bolt lugs. Both Sig and Beretta rejected the multi lug bolt design because they claimed it would hurt accuracy by not being able to always get even loads on all of the bolt lugs. They both went went to two lug bolts for "accuracy", because they felt even lug contact was possible with two bolt lugs. I would have rejected the mutli lug bolt due to not always being able to have even bolt lug contact, but my reason would be the strength would be weaker with higher bolt lug loads on less then all bolt lugs.
 
#224 ·
Well stay tuned guys...as I may be able to get a monthly or weekly Q&A post type of deal with some of THE guys...you guys could post a question or two that I take to them and then I come back and post their responses. They might think it as fun too. We'll start with the .308 bolt and WHY it has a third lug and HOW MUCH pressure can it and the trunnion take. I'll start a new thread and post this question and their answer after I talk with them. Sound good? :)
 
#243 · (Edited)
I am finally going to be able to make this a reality. Talked to the BIG bosses in Russia and they agreed. I'll be putting this on my website that is currently being developed as an "Experts Corner" or something like that. I'll let you know when it's up, but the address is Red Dragun Weapons | Coming Soon. We just finished importing some of these:nanabang::







Top two are my crappy photos (which will soon be better) and bottom one is for better reference.
 
#230 ·
Well its almost christmas and I dont know what its going to end up as but my 9 year old is going to get aa big box of misc gun parts. The plan is were going to do a Father/Son build of a undecided calibure. the objective will be a light weight sporter that is carryable by a young hunter it will need light recoil but have at least 2600 FPS velocity with a 100 grain bullet or bigger and be 6mm or bigger. Im thinking a Yugo trunion with a opened up 5.45 bolt that will shoot some thing from the 308 Win line of brass. I have a remington 243 take off barrel as well as a 308 barrel. he is still pretty small so Im leaning toward the 243 loaded light. I have decided that i will not go over 49,000 PSI on the ammo with a two bolt trunion. I am thinking a longer than normal blank with a extended bolt will allow a large gloves on trigger guard. I want a push button saftey. Im thinking of a drop out trigger housing and some other cool ideas that I have had in the back of my mind. I have untill next thanksgiving to get it built and and get him shooting well enough shoot from a stand on white tail. Im not sure of the legalitys of a minor bending his own flat so ill have to look into it. I was actualy thinking of a multipul barrel assembly set up with a .223 varmit, 243, .30 an a .444 in a cool custom case that would cover all hunting scenerios he might find in the future. i really wish i had a 3 lug bolt for this build :(. Im thinking of making this as custom as possable with the finest work i can muster.
Sounds great. I was thinking of making maybe a 6mm-223 AK. An opened up 5.45 bolt to a 308 bolt face should handle some mild handloads.
 
#234 ·
wouldnt a 6mm-223 use a 223 size bolt face??

I keep thinking the 300 savage may be the safe bet but the damm brass is pricy and not avalaibe surpluss like the 308 win. I really hate the Idea of my kid getting a hold of a full blown 60,000 Psi round accidentaly and possably getting hurt. I could alway rebate the brass so and use a standard bolt and then there is no way a bolt can close on normal ammo. but that will reqire a fair amount of work and im hoping to get my son a chance to do some serious shooting and that means a lot of brass. if it was just deer hunting 40 rounds would last 5 years.

i read a interesting article about how a rough or sanded chamber VS a polished one can have significnatly lowere bolt thrust but at the same time the brass will get worked more and shorten reloading life. stared maging me thing about a groved chamber to keep the round from going back ward into the bolt so hard. is this what the futed chambers do on other types of weapons??? either way i will not have a polished chamber. Ill try to find the link to the article.
Yeah the 6mm-223 would be with a 223 Saiga or maybe a 5.45 AK74. I handload 222 Remington brass for 5.45 so the rim is no problem.
 
#238 ·
Hello 1biggun,
You got the wrong area !!! Area of a circle = 3.14 x Radius X Radius. That means first you have to divide the diameter in half to get radius.

The pressure formula is fine ie: Pressure in PSI x Area in square inches = Force on the bolt face in pounds.

Keep all the measures in their inches or pounds to be consistent (and correct).

Another hint is to use decimals rather than fractions. So: .5 inch x .5 inch = .25 inches (squared)

Then .25 inches (squared) x 3.14 = .785 square inches.

.785 square inches x 63, 00 PSI = 49,480 lbs Force.

VD
 
#240 ·
Hello 1biggun,
You got the wrong area !!! Area of a circle = 3.14 x Radius X Radius. That means first you have to divide the diameter in half to get radius.

The pressure formula is fine ie: Pressure in PSI x Area in square inches = Force on the bolt face in pounds.

Keep all the measures in their inches or pounds to be consistent (and correct).

Another hint is to use decimals rather than fractions. So: .5 inch x .5 inch = .25 inches (squared)

Then .25 inches (squared) x 3.14 = .785 square inches.

.785 square inches x 63, 00 PSI = 49,480 lbs Force.

VD

ERRRRRRRRRRR I suck at math.
 
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