As a general rule, I shy away from Lee dies, except for their factory crimp die in straight taper cases. I just prefer the solid quality of Redding dies.
However, we get to the Lee Collet dies and I have found them to be extremely useful. Yes I have loaded some very, very accurate ammunition with them, but my reason for buying them is for an entirely different reason.
I have really enjoyed several of the Ackley Improved cartridges over the years, they have delivered what they were designed to do in every case, and often times much more. There is a stumbling block there, and that is the cost of the wildcat dies! Some of them run nearly a hundred bucks!
In doing a little research, and ordering some of the Lee Collet dies, I found, in EVERY CASE, where the case neck of the brass remains the same as that of the parent cartridge, the Lee Collet Dies will work wonderfully for both sizing and seating the Ackley Improved Cartridges!
I tried a set experimentally in the .375 H&H, hoping that they would suffice for sizing my then newly rechambered .375H&H Ackley Improved. (Ever priced a set of either RCBS or Redding .375 H&H AI dies??? OUCH!) Well the dies came, and they worked superbly, both for sizing and seating! I do employ an "M" neck expanding die, but it is of course Lyman generic.
I have tried the Lee Collet Dies for .30-06 AI, .280AI, .375 H&H AI, .223AI and 7x57 AI with perfect results. A twenty dollar set of dies for these cartridges surely beats the alternatives... especially if you are on a budget. By the way, loading MOA ammo with these dies has not been any problem what-so-ever!
A last note... in some cases I had to turn down the mandrel in a lathe (you could do it in a drill press with emery cloth just as well), in order to get a tighter bullet fit in the neck in a couple of sets of these dies.
Just a thought or two FWIW.
God Bless,
Marshall