First of all Hi to everyone. I read somewhere that there were pressure problems with reloading for the 307 Winchester, that the 307 Win is tempermental to load for. Is my mind paying for past youthful indescretions with alcohol or is there something to that? I posted this here hoping more people would see the question. Thanks. Hal

Welcome to the forum NonPCnraRN. Rules are simple, be nice and join in.

Check out this thread it may help you with your 307 questions.

http://www.shootersforum.com/showthread.htm?t=5417

Boy I know what you mean by paying for those past indescretions.

I have commented several times about indications of high pressure on hot days with the .307. I am a big fan of the .307 but I have experienced some lever kick and signs of sticky extraction with published load data on hot days. I am talking about temperatures above 90 degrees. These problems were primarily seen with ball powders - Winchester 748, Hodgdon BLc2 and the 170-grain bullets. With round nose 180-grain bullets we also experienced some indications of high pressure on hot days.
When we switched to Hodgdon Varget and Alliant Reloder 15 we found greater flexibility in the cartridge. I am not aware of published (Loading Manuals) data for the .307 using Varget or RL 15.
IMR 4064, Hodgdon/IMR 4895 and Hodgdon 335 did not exhibit this behavior.
With 170-grain bullets we have seen quicker kills on whitetail deer at between 2350 and 2400 fps than at higher velocities with most bullets.
The modern powders such as the Hodgdon Extreme series, and Reloder 15 in my 20" .307 will safely push 130-grain bullets-2750 fps, 150-grain bullets-2600 fps, 170-grain bullets-2500 fps and the 180-grain bullets to 2450 fps.
The Winchester Model 94 AE and Marlin 336 reamed for the .30-30AI will push the 130-grain bullets-2700 fps, 150-grain bullets-2500 fps
and 170-grain bullets-2300 to 2350 fps on hot days.
I am a big .307 fan but I admit the .30-30AI will deliver surprisingly high performance with modern powders. Terry Murbach in posts here on the Beartooth Forum was the first guy to give us sound, specific advice based on his personal experience with the .30-30AI. His enthusiasm for the cartridge gave us the confidence to charge off into the unknown.
The .30-30AI at the velocities I quoted above is as fast as I care to go on hot days. The rifles are not going to come apart but there is no doubt they are working at high pressure. I have never had a primer leak of any other significant surprise with the .30-30AI when loaded within the quoted velocities.
Keeping all of this in mind, I do not use IMR 3031, Winchester 748 or Hodgdon BLc2 for high-pressure loads in summer in either cartridge.

There are at least two forum members who shoot the .308 Improved but I have never read specific details of anyone using the .307 improved.

Blackhawk
I cant find the thread where you said you wanted to try Reloder 15 in the .307.
I added several Reloder 15 loads to the Load Swap with 130, 150 and 170 grain bullets.
These are more less random samples. As i really enjoy shooting the .307 I have chronographed the same loads over and over in an attempt to graph them and learn some DEEP secret. Passes the time!
Depending on the time of year the velocities vary but an accurate load will be accurate year round.
I enjoy discussing Varget and Reloder 15 in the .307.