I've got a chance to get a 7.62x39 upper at a local pawn shop, but I'm not sure if it's worth getting.
What can I do with a 7.62 AR that I can't do with 5.56 AR?
Other than a larger bullit diameter (.30+/- vs .22+/-), what are the advantages of using the 7.62 over 5.56?
Would it a good round for whitetail deer?
What does it compair to, 30-30, 30-06, 308?

Thanks  

Hunt in some states.



Within 150 yds, yes.  It's comparable to the 30-30.

Cheaper Ammo.

My opinion only:

You could not give me one of those 7.62 uppers.  What can you do with a 7.62 upper?  Well, one thing is for sure, you will have less $$$ to spend on your AR15.  You will need two different size bullets, and replacement parts for two different rifles.  The 7.62X39 does'nt impress me that much either.

A .30 rifle will have a LOT more knock down power than 5.56.  I do not hunt large game but a 5.56 is probably a caliber to avoid doing such.  That is not to say it can not be done.  With a 5.56 you will probably be picking pieces of metal out of your teeth at the dinner table due to its fragmentation.
30-30, 30-06, 308 are all very good rounds for hunting.  The 7.62X39 would be at the end of my "deer ammo" list but it also would probably do the job. (Although not much beats a good 'ol 30-06)
All things being fair a 7.62X39 upper would be an inexpensive way to experience a different caliber in your AR.     To each his own.

It'd make a great 150 yard deer gun...excellent!

I wouldn't mind making a 7.62AR just for that purpose.

Although there's nothing like hunting with a trusty ought-6.

Hunting would be about the best motivation I can think of. With loads like the Lapua 125 gr Spire Point that are capable of penetrating 17" and expanding to .62", it would be very effective on deer sized game. And it could work for self defense in a pinch as well. Another good load for it is the Winchester Super-X 123 gr SP. It offers slightly less penetration but still expands well. If you don't already have a better hunting rifle then it this seems a reasonable solution. And last, you may not have a need for it, you may just want one. That's all the justification you need if so. LOL.

-Charging Handle

Um....shoot 7.62x39mm ammunition?  Sorry, had to say it.  The rest of the guys covered the answer pretty well.

After going to the range last weekend, I am totally a fan of the 5.56.  My pal had a MAC 90 and I the Armalite.  We both shot at a steel plate at 100 yds (about 1/2 inch thick).  His 7.62 left huge welts but did not penetrate.  The 5.56 (62 grain) left nickel sized holes in it.  I also tried out some 55 grain, and they put holes through it about half the time.
As for 7.62, I used to have a mac 90 and I shot a deer with it.  The round worked well, but I was only 15 yds from the deer.  7.62 is slightly less powered than the 30/30.

7.62x39 in an AR15 will kick up bigger puffs of dust when it hits downrange and recoil a bit more with the cheaper ammo.

For the price of a 7.62x39 upper for your AR15 you can buy a new Romanian SAR-1 and have a complete rifle of Kalishnikov design.  I think that is the way to go.  Either way you will not have the accuracy or flat trajectory of good 5.56 ammo in your AR15.

As for hunting, be sure to use good hunting ammo if you go after deer with a 7.62x39 (not FMJ).  The biggest difference between 30-30 winchester and the 7.62x39 is bullet weight.  the 7.62 using 125 grain bullets whee the 30-30 has standard loads of 150 and 170 grains which may peneters further.

Also concider a Marlin or Winchestr lever-action ($299 brand new at Big-5).  Lever guns can be a nice change from 'spray and pray'.

The Lapua round is excellent, but not always easy to find and a bit on the expensive side.

In talking with many who have shot the 7.62 X 39 round on deer, the 125 grain bullets will work, but lack pentration if they hit bone. The 154 grain ammo works quite well after hitting bone, and is very accurate by this rounds standards.

Honestly, I agre with BillSP1. I wouldn't get it.

I once considered a Colt AR in 7.62 but glad I hesitated and went 5.56mm, especially after looking over that franken-weld magazine that came with the Colt 7.62 gun. Major issues there.

If I want a 7.62x39 shooter I'll just buy a cheap AK.

Otherwise, for a real 30 caliber I'll go .308 FAL!!

Don't buy/look at mags from the same guy selling gold and diamonds, you'll definitely pay too much.
The 20/30rd AK Franken mags routinely selling for $35 on this board.  I recently picked up 3 30rd Franken mags on another board for $32 each shipped.

The 7.62x39 upper runs really well in the AR and is a must have for the full auto owner.  The only parts that are different than 223 is the barrel and bolt; the 30rd 223 mag works fine with 6-7 rounds.  I was able to get a 7.62 barrel and bolt off the Equipment exchange a while back for $270 and built up using spares laying around.  Have put over 5-7k full auto thru it on various M16 lowers.  Great fun.

Thanks to all who have replied.  I knew I'd get the answers I needed here.
I really don't "need" a 7.62 upper, I just thought it would be a neat addition to my current AR15 (RRA 16" A2).  I already have a good deer gun (Marlin lever action .35 Rem), but thought it might be fun to take the AR once in a while.  I really don't want to try bringing down a deer with a 5.56, although I realize there are some soft point rounds available that would work at close range and good shot placement.
If the 7.62 is closest to a 30-30 in power and the magazine choices are no better than it appears they are, I think I'll just pass on the upper.

Thanks again to all.

Good choice.