</font><font color="blue" class="small">( it seems to me that even a little compressor like mine can supply plenty of air for a short burst )</font>
That's right, but while I don't have the numbers to back it up, I'll bet you don't get the full volume needed by that 3/4" impact for its full rated power through a 3/8" hose. When I was repairing air tools, I worked on quite a number of 3/4" impacts, including the IR261, and I could check to make sure they were working properly with a 1/4" hose, but you certainly were not going to get full power. Since my own air tools were 1/2" and smaller, I normally used 3/8" hoses, but every 3/4" impact I got in for repair came with couplers for a bigger hose (1/2" at least). I made up my own adapters so I could use the quick couplers on my 1/4" and 3/8" hoses in my shop.
So you're also right in that you have a huge mismatch between compressor, hose, and wrench, but if it has enough power to do what you want to do, so what, who cares? That's all we want from our tools anyway, isn't it; to do the job at hand. /forums/images/graemlins/wink.gif
In most cases, a very short burst of air serves the purpose of breaking a nut or bolt loose, or even of tightening it back. But the "rated" power is usually either a 5 second air flow of its rated SCFM (sometimes referred to as working rating) or its "ultimate" power rating, which is continuing the rated air flow until it just stalls and can't turn a bolt any farther. And like horsepower ratings for tractors, it doesn't really matter what the number is if it's doing the job. /forums/images/graemlins/wink.gif