I was wondering, first of all, can you bring your own rifle on most Asia hunts?

Second what calibers are appropriate for Ibex and Marco Polo Sheep?

Most of the guys I know that have hunted Asia have brought their own rifles which is a good thing as most of the hunting is Alpine or in open country where long shots are required. So a rifle that has been well set up for long range shooting is quite important.
The rifle I use is a take down Blaser in 300M which I think is a great set up.

Man I want one of those BAD!

Just about everywhere you can bring your own gun.
The best pick on caliber is a flat shooting 7mm or .30, whatever you are comfortable with. I prefer a 7mmSTW with 160gr premium bullets.

I would also suggest a Harris bipod, I think it's the 11"-25" one.

I would not recommend a scope larger than 6-12x50

You need to be comfortable shooting out to 400m.
You should be able to ride a horse.
You should be able to walk up and down a lot.

I recommend the "6 minute hill" workout. I have to credit Dennis Campbell from GSC/OVIS for this.
Pick a hill of any length or steepness that you can comfortably walk up and down in 6 minutes. Walk up and down for an hour and at the bottom each time do as many pushups as you can. After a couple weeks you will be in very good shape for mountain hunting. It sounds easy, but it works.

You can get an ibex for less than $8000, including airfare. Kettuchi paid about $5800, plus assume $2000 airfare but maybe less depending on the route.

Thanx Silkibex. I didn't know Ibex was so affordable! That price will be in my range in a few years. Thanks for the advice.

Hey Wayfaring Stranger
With a good Outfitter and all the red paper work on time, you can take your rifle to any country in Asia that offer sport hunting, maybe the only item to consider is where you will do the transfer. I prefer to go through Madrid or Paris to Istambul and then to any of the Asian Countrys except, maybe, China and Mongolia. To this places you must consider Seoul and of course Beijing.
I only have experience with East Caucasus Tur and Mid-Asian Ibex; I`d taken both with a Blaser R93, cal. 6.5x68, handloaded with Barnes TSX 120 BT and 66.7 grs. of RL 22.One shoot kills at between 166-422 yards away.
Yes, it is not the best choice for the USA standards, but I feel very confident with it. If I go to a Marco Polo Sheep Hunt or Gansu Argali next season, I will take it with me.

Regards

Asian Mountain hunt usually involves long shots at relatively smaller animals than Africa, I would never consider an Asian Hunt without my own rifle.

Most of the Asian hunts are difficult because of logistic problems and one should be fairly confidant to take the opportunity when it finally arrives. I can’t imagine what it would be like to miss the 62†Marcopolo sheep that we shot at 450 Yrds after spending four days just to get to the hunting camp.

We use 7mm Rem Mag with hand loaded 150gr Nosler Ballistic Tip and have taken the following game with this combination:

Marcopolo Sheep
Transcaspian Urial
Afghan Urial
Blanford Urial
Sind Ibex
Himalayan Ibex
Bezoar Ibex