The Sam Yang Big Bore 909
Jim Chapman
I do most of my big bore airgun hunting with  DAQs (in .308, .457, and .50 calibers), and more recently the Career Dragonslayer. I like all these guns; and while the DAQ .457 has become my primary big game gun, I have found the Dragonslayer a fantastic shooter and a great medium game gun. The Dragonslayer did come up to its limit on some big pigs I shot a while back, but was all I could want when hunting smaller antelope. Many people have asked me what gun Id recommend in addition to the DAQs for larger animals, and Ive been shooting all the big bores I can get my hands on so that I can offer and informed opinion.

The Sam Yang Big Bore 909 .45 caliber air rifle is one of the powerful production guns out of Korea. I recently ordered one to take out deer hunting to see how it would perform on larger game. Ive now had a chance to use it quite a bit for target shooting and in the field for hunting.

The Big bore 909 is a single shot .45 caliber rifle, loaded via a port in the receiver that is accessed by a sliding cover that is slipped forward to open, then slid back to close after the bullet is loaded. Cocking is achieved using a separate bolt action, making this a two step procedure to cock and load. The 21 barrel has an internal diameter of 0.454 inches and is threaded at the muzzle for accessories.

This gun is a real handful with an overall Length of 42 inches and weighs in at a bit over seven pounds. The two piece stock and forestock are a nice Asian hardwood with decent checkering, and for me at least, a fairly good ergonomic fit. The length of pull is a little short for me, but I intend to add a slip on butt pad. The gun comes equipped with sling swivels mounted

The Big Bore 909 has a double tube reservoir that fills to 3000 PSI using a male probe (included with the gun) for charging. Unlike many of the other Korean guns the 909 does not have an onboard pressure gauge, which is too bad as I find this a useful feature. My gun is set up to deliver 5 full power shots in the 670 fps range with 180gr cast lead pellets.  This yields a power output near 200 fpe, which makes it a viable large game gun.

There is a varied selection of bullet weights and shapes available. Pyramyd Airguns, the store I ordered my gun through, makes pellets to order for this gun; I tried the 170, 180, 190, and 200 grain versions but settled on the 170 grain pellet. This pellet produced velocities of around 700 fps and proved to be fairly flat shooting. 
The 909 is a fairly ergonomic package, though the length of pull is a little short for me. Still, the gun points well and I found it pretty accurate under field conditions.
This big bodied eight point buck was hit further back than I'd have wished, but was dead when I walked up.
There is a variety of bullet styles and weights available, to cover a range of applications. I have found that round ball also is an accurate and hard hitting projectile, that penetrates suprisingly well.
While not really a tack driver, this gun is more than accurate enough to be considered an excellent medium and large game gun. This fifty yard three shot group was easily in the kill zone of a woodchuck sized animal.
Two of the Korean heavy hitters; the Dragonslayer .50 caliber (top) and the Bigbore 909 (Lower) in .45.

I mounted a Leapers 3-9x 50mm scope which I zeroed at 50 yards, then settled in to shoot groups off my sticks to get a feel for the gun under hunting conditions. I found that I could easily put my shots into 2-3 inch groups out to 70 yards with nary a flier. Which is what I wanted in a big game hunting gun.

Based on a few weeks of target shooting and plinking, I felt confident carrying this gun along on a recent whitetail hunt to see how it performed doing serious work! To use the gun for this trip, I had to convert to a muzzle loader by fabricating a sheet metal saddle that fits just distal to the port cover and bolted in place. I tested the gun with cast lead roundball and found that it was a little less accurate, but still not too bad. Thus equipped I charged the gun and headed off to my tree stand early one morning, getting set up well before daybreak. I sat watching the squirrels play (in large numbers which never happens when Im squirrel hunting!) and the occasional doe meander by, I was about to call it a morning. As I stood in my tree stand and slowly turned around, I saw a nice buck walking along a fence line about 70 yards away. Dropping back down I lined up the crosshairs a little high and behind the shoulder, flipped off the safety, and followed as he move closer. At about 40 yards I let out a little yelp to stop him, I was surprised that he just kept walking along. Fearing I was going to loose him behind the brush, I squeezed the trigger as he was about to step behind a tree and possibly disappear. The projectile flew true and he hopped a bit before taking off through the brush. I sat for awhile, then climbed down to have a look. I found a blood trail pretty quickly, but it kept petering out on me. I wont give a blow by blow, but I trailed him for about a quarter mile before finally spotting an antler propped off the ground on the side of a little pond. Id hit the lungs and done some damage, but it was little far back and it had taken this big animal a while to go down.