Thanks very much for all the advice!
They actually "were" shooting a little low and to the left. It was almost like they "corkscrewed" at the last 15 feet.
A little more info: I shoot right handed. I bought two dozen of these raw shafts. I made up a dozen arrows last year with self nocks, the 140 grain broadheads, and a few with field points.
This year, my father made up the rest for me with plastic nocks, the 150 broadheads, and a few with field points.
The arrows I made all seem to shoot great. When I got the ones from my father, the ones with the field points shot just as well. The only problem seems to be with the 150 broadheads.
I noticed that the nock point seemed to be a little off. This is from the plastic nocks being smaller than the self nocks. So I've been playing around with that trying to get it set just right.
I checked the brace height and it was set at 7", which is the highest recommended from the bowyer. I upped it another 1/2" and it seems to take care of the problem. They are still shooting a little low, but I think the nock point still needs adjusted. It was real windy out this evening, so I just finished up and will try again tomorrow.
I can't cut the arrow down as they are pretty much cut to exact draw length and really don't have any extra money to buy new ones this year.
I've been shooting for a long time and don't ever recall having this problem before.
Thanks again for all the help and advice. If you have any other thoughts, please let me know.