40 grs wont cut it. Wont take much wind to eat your lunch.
You' probably you shoot the NMC which is 200 yards standing, 200 yards setting rapid, 300 yards prone rapid, and 600 yards slow fire.
You can also shoot the 1000 yard service rifle match at 1000.
You need the proper twist to use the heavier bullets. Like I said, I use 77 SMKs for 200 & 300 and 80 gr SMKs for 600 and 1000. I have a 1:7 twist. 1;8 will work for 80s and smaller, but you need a 1:7 if you want to go with the 90 gr pills.
You should take in a High Powder match or two prior to Perry.
At least go to the CMP Website, go to sales then the e:store, click on the Book store and get the USAMU Service Rifle guide. ($6.95) best resource to get you started. Problem is they are back logged and it will be slow coming.
Might be quicker to get one at Amazon.com