i have a 7.62x39 AK right now, but i'm looking to get a 5.56 AK sometime soon. they're pretty hard to find so i was wondering if i could just get a tantal or other 5.45 AK-74 variant and just convert that to 5.56?

K-Var has a 5.56 barrel here: http://www.k-var.com/shop/product.php?productid=16265&cat=274&page=1

could i get a tantal kit and just replace the barrel with this 5.56 barrel and a 5.56 bolt or how can i go about doing this?

thanks!

 I am in the process of doing this conversion myself. I decided to go with ORF's Bulgy non-matching stamped kit and add the 16" K-var barrel. I have have emails from guys that have sucessfully done this conversion with only replacing the barrel.

http://www.ar15.com/forums/topic.html?b=4&f=51&t=86382

They have reported that have seen some damage to the case head on the 5.56x45mm brass cased rounds (from the 5.45x39 bolt). I am an avid reloader and have opted to do a more extensive conversion.
 Option1: replacing just the barrel: This barrel is 23mm in diameter around the chamber (it is intended to be used in a milled receiver weapon). The bulgy stamped receiver front trunnion is 22mm. This will have to be turned down to fit. (note: You may have to work on the feed ramp too.). Add your RSB, GB, and FS and you are ready to go.
 Option2: replace the barrel as above. Replace feed ramp with 5.56 ramp, Replace bolt and bolt carrier (either with a 5.56 or '47 carrier)

FYI: the $229 non-matching kit was all matching except the dust cover and the bayo. YMMV  


My receiver in process:


So if you are interested in doing this to a Tantle I would get someone to measure the inside diameter of the front trunnion, and take some measurements of the orgional 5.45 barrel around the RSB, GB, and FS. Compare this to the 5.56 barrel (I can get those for you) to see if this is possible without major barrel work.

i really dig your build. that's pretty much exactly what i'm looking for.

where do you get a 5.56 feedramp and would i be able to just use a 5.56 bolt on the 74 carrier?

   5.56 feed ramp is from K-var ($12 comes with rivit).  

  The 5.56 bolt is a "Large shaft" bolt, as is the 47', and so then both the 5.56 and 7.62x39 bolt carriers. The 74' takes the "Small shaft" bolt. So you will not be able to use it.  
So you have three choices:
1. Keep the 74' bolt and carrier, and except the damage to the brass (least expensive)
2. Purchase a 47' bolt carrier ($25 I bought locally), and K-var 5.56 bolt ($50).
3. Purchase a 5.56 bolt carrier ($80ish I think)and 5.56 bolt from K-var ($50).  

The cheapest route would be to build on a Romy kit.  Add a 5.56 bolt, barrel and feed ramp.  The carriers will work as mentioned.  If you get a new 5.56 bolt, you can even serialize it to match your kit numbers for an "all matching" setup.

Good luck!

May not be the route you had in mind, but you may want to consider converting a saiga.

i thought about converting a saiga, but i really like what LonghunterCO has. i might just sell my underfolder and buy a kit from ORF and put it together. or see how much ORF would charge for a sidefolder .223

Quoted: The cheapest route would be to build on a Romy kit.  Add a 5.56 bolt, barrel and feed ramp.  The carriers will work as mentioned.  If you get a new 5.56 bolt, you can even serialize it to match your kit numbers for an "all matching" setup. Good luck!

I am not sure as to the extent of the difference. The rommy kit would leave you the 47' gas system (45 deg GB, rear site would be to 1000m though, not sure as to the diameters of the parts as to the added to the barrel, or the trunnion demintions on the Rommy.
Rock bottom pricing on this could be. A home build. Using a ORF bulgy 74' non-matghing kit. Sell off the side folder on EE for $125 (or more!), buy a fixed stock trunnion for $10, do the barrel conversion to 5.56, run the gun with Wolf steel case or don't reload.
$229-$125=$104+$90 (barrel)+ $10 trunnion=$204 then add fix stock wood (bought wood set with US pistole grip at last show for $30)
add in all the compliance parts you need (you would need them with a Rommy too)
G2 trigger $35, Grip (see above), recievr $12, piston $18 (you have to keep that cool break)
$299 plus your gunsmiths barrel fee ( around $20)and shipping= $320ist.

What are Siaga conversions running?    

not too bad. i would keep the sidefolder though. would have to get up with a local build party and put it together.

To convert to 5.56 you will need:

5.56 Bolt
5.56 Carrier
5.56 Trunnion Block with feed ramp
5.56 Barrel

The bolts are not the same as 5.45 because 5.56 pattern is actually AKM pattern. The carrier is not the same as 7.62 at all, it is a modified AKM pattern for the 5.56. The trunnions are not the same as 5.45 or 7.62 and though a 5.45 can be modified, you will need a milling machine. Obviously the 5.56 barrel which BTW is made for a milled gun and not the stamped 5.56 trunnion so it will have to be turned down slightly. So basically no, it's not an easy swap, unless you do it right and have the right equipment, i.e. lathe, milling machine etc.

Someone really needs to moderate this post before someone gets hurt doing a half-ass conversion.  

C

i don't have any of the necessary tools to even attempt a conversion, so you don't have to worry about me!

Quoted: i have a 7.62x39 AK right now, but i'm looking to get a 5.56 AK sometime soon. they're pretty hard to find so i was wondering if i could just get a tantal or other 5.45 AK-74 variant and just convert that to 5.56?

There's another route to go.  It's not cheap, but it's not expensive either.  Buy a Yugo M95 kit from ORF for $450.  You'll get a free Vulcan receiver.  Buy a DCI receiver from nodakspud (which you can have serial numbered to match your kit for free) and sell or use the Vulcan receiver for something else.  For about $600 you'll have an all matching 5.56x45 chambered rifle that is rarer than a Galil.

Or you can just waite two weeks and buy an SLR106 Stamped 5.56 Bulgarian- probably cost around $650 or so.

C

demill a saiga u can get that whole rifle for cheaper then a kit

Quoted: To convert to 5.56 you will need: 5.56 Bolt 5.56 Carrier 5.56 Trunnion Block with feed ramp 5.56 Barrel The bolts are not the same as 5.45 because 5.56 pattern is actually AKM pattern. The carrier is not the same as 7.62 at all, it is a modified AKM pattern for the 5.56. The trunnions are not the same as 5.45 or 7.62 and though a 5.45 can be modified, you will need a milling machine. Obviously the 5.56 barrel which BTW is made for a milled gun and not the stamped 5.56 trunnion so it will have to be turned down slightly. So basically no, it's not an easy swap, unless you do it right and have the right equipment, i.e. lathe, milling machine etc. Someone really needs to moderate this post before someone gets hurt doing a half-ass conversion.   C

I will put my two cents in.  To convert 5.45 to 5.56, all you need is just the barrel and new mags (or new follower).  

You do not need new 5.56 bolt, carrier, trunnion, and bullet guide.  Any AK-74 kit with new barrel will work fine.

Just my two cents.