If you post this in the "Himilayan Imports" sub-forum you will get answers from the Kukri experts around here. I am no expert but from what I understand as far as the tangs go.... A "rat tail" tang is plenty strong enough on most kukris and helps keep vibration and shock from transferring into your hand. The full tang is stronger but it will transfer more shock into your hand while chopping. Good luck buddy!
Well Sticks, I can only speak for himalayan imports, but most khukuri makers will offer some of the same variety we have.
The two common tangs are the Stick or rat-tail type tang and the Chiruwa tang ( full visible tang, also known as Panawal by other makers)
There is also a short rat tail type, but that is mostly used on true villagers and ornamental khukuri. All H.I. khukuri have their rat tail tangs peened at the buttcap for more strength and security.
At H.I. we offer many types of different woods from traditional nepali woods, american hardwoods and sometimes other exotic species when available. There is also traditional water buffalo horn, but when available we can also offer whitetail stag, sambar stag and at times have even used elk antler.
Your friend is mistaken, but he has a right to an opinion. The rat tail tangs have a completely different feel in terms of balance, it makes the blades seem livelier. I actually prefer them over chiruwa tangs.
It is easier to re-handle a chiruwa tang if you ever have a failure.
FWIW, Here is an X-Ray of some of my hidden tang (could be called rat tail maybe, but kangaroo tail is more appropriate) khuks from HI. The bottom and top are your standard hidden tang HI WWII type khuks. The others are special partial tangs (Hanuman khuk and Bilton, along with a karda. I have beat the top WWII severely and it laughs at me. You can see how stout the tang is in profile and, I assume, it's spine width for the most part. That puts it at over 3/8" thick hand forged 5160, and is peened at the butt cap. Hopefully this will make you feel a little better about the HI hidden tangs. Take care. Link to my thread: http://www.bladeforums.com/forums/showthread.php/871579-HI-Khuk-Handle-X-Ray
Sticks IMHO you absolutely cannot go wrong with a stick tang and any of the Nepali hardwoods that come on any H.I. Khukuri!!!:thumbup:
Even with some of the, "Nepali, not so hard woods" you're still going to be alright because of the tang being peened over making the whole unit the same as, "One Piece."
As far as an H.I. chiruwa tang being any stronger than an H.I. "stick tang" I personally doubt it very much!
But then I'm horribly prejudiced against the chiruwa or visible tangs on khukuris... For the reasons already stated as well as another problem noted by a lot of the folks after they've had and used 'em for awhile... Which is that either the wood or horn shrinks away from the steel tang leaving sharp edges that can really hurt you until you're able to file or grind the sharp edges on the steel down flush with the handle material... Either that or wrap the handle with something to guard against being cut!!!