If a gun shoots well as the factory chambering, does converting the same rifle to an AI have much of an effect on accuracy??

Sometimes, and not always good. Most guys go to the A.I. versions for more speed, less bolt thrust, better case life, etc, and not necessarily for more accuracy. Sometimes they shoot like a house afire, and sometimes they become more finicky about finding the right load that will let them shoot their best. If you have a good shooter, think twice before you "improve" it.

I beg to differ.

What more would you want,than to test drive a barrel? That is what you are doing,when taking a barrel of known performance and then Improving it.

Assuming a competent Gunsmith,it will likely shoot better. The Improvement will generally include an action blueprint and of course a properly cut chamber. Both are condusive to accuracy.

I've had lots of them built and have yet to be disappointed...........

To be fair with this subject we have to eliminate the "gunsmith" as the new work may not be as good as the old either.

On the average the only change is a small amount of extra powder burned which is not really condusive to accuracy. But the "extra" powder is really not that much.

I have had better groups shooting the fireform loads than the full power loads most of the time but they do hit low on the target.

I had a Sears M-51 in 06 "improved" and the accuracy was the same and the maximum velocity went up 50 fps.

Lysle Kilbourn had a good idea in thinking up the K-Hornet. It gave him more work and it amused his customers. Thats a win win.

Some say the 40 degree shoulder on the improved case aids in more consistent headspacing which improves accuracy. All I know is I've put together 3 so far and all are accurate. But I have put together standard chamberings and these were accurate too(so far). sure-shot