5.45 vs 5.56 for an SBR?

[Love Machine]

So I'm kinda torn on what caliber to base an SBR on. Difficulty-wise, an AR in 5.56 or an AK in 5.45 or vice versa is all the same. Is there a difference in effectiveness, based on someone's personal shooting experience?

 

[massBRS]

5.45 might be harder to come by in terms of ammo availability. That's the only reason I have two in 5.56

 

[warwickben]

Also barrels with the right twist for 5.45 aren't really available . At least for pre made Krinks . Looking into them for the Groza protype si found out they used a different twist rate . I couldn't even find blanks . I took a chance and chopped it down and it worked fine . But I went with 11.5 not the shorter krink length .
I figured if 556 11.5 long barrel used the same twist as 14.5-16" I should be fine . I was right . Getting shorter you might have mixed results .

Ar15 or ak?

300blk I think would be a better option if you reload for a sbr.

 

[dnepro-mike]

Arsenal AKS-74U nowadays come with 'improper' twist (same as 16") and so far results are very promising - no key-holing.
MAC tested it. couple of other guys on you tube did too. no key-holing.

there is also always a chance to build AKS-74K like this guy did.
it would be a lot cheaper than building krink with respect to finding parts. you can basically re-purpose standard AK-74 Bulgy kit which are 1/5 the price of AKSU kits

http://www.thefirearmblog.com/blog/...tm_source=rss&utm_medium=rss&utm_campaign=rss

 

[warwickben]

Arsenal AKS-74U nowadays come with 'improper' twist (same as 16") and so far results are very promising - no key-holing.
MAC tested it. couple of other guys on you tube did too. no key-holing.

there is also always a chance to build AKS-74K like this guy did.
it would be a lot cheaper than building krink with respect to finding parts. you can basically re-purpose standard AK-74 Bulgy kit which are 1/5 the price of AKSU kits

http://www.thefirearmblog.com/blog/...tm_source=rss&utm_medium=rss&utm_campaign=rss

^ x1000
You can get a v project combo block for short money .
Buying the special krink parts cost more then full parts kits .

I wasn't 100% sure the deal with the twist rate . I also know at one time some companies where building 5.45 guns with the wrong blanks so maybe that also where the twist rate "problems" came from.

 

[dnepro-mike]

yes infamous r-guns 5.45 barrels build on .223 blanks. those key-holed like crazy. they sold them along with the '86 krink kits they had few years back IIRC

 

[xtry51]

5.56.

 

[Love Machine]

The twist rate for the AKS-74U was an attempt at improving its accuracy and to use special ammunition that you don't have access to, so I'm not worried about chopping a regular barrel. It's more a question - at 100 yards, is there a difference between the effectiveness of one vs the other?

 

[Comrade Moustache]

The twist rate for the AKS-74U was an attempt at improving its accuracy and to use special ammunition that you don't have access to, so I'm not worried about chopping a regular barrel. It's more a question - at 100 yards, is there a difference between the effectiveness of one vs the other?

Build both and gel block test. duh.

 

[Love Machine]

How did I know that this would be the answer?

 

[shotgunwilly870]

I own an arsenal slr-104ur I chopped the barrel on this one and faced and crowned it with an 11 degree crown shoots perfect I also did my buddy's gun same thing no problems I also built a baddass 9" AK47 pistol parts kit on a nodak receiver it's a blast and was cheaper that my 104 I can't say which to build first but I'd recommend owning both at some point you won't regret it