To avoid POI changes I only take my M1 Garand apart to clean it during the season if it rains during a match. I’ve gotten lucky and only had one match in the pouring rain, knock on wood. Constant disassembly can also cause excessive wear. So during the season I use a bore guide and just clean the barrel, reapplying grease as needed.

Bore guide:

After the season I do a detailed field strip and clean everything. Don’t remove the gas tube as every time you take it off it could loosen it and cause accuracy issues. I leave the key and the tube only removing the gas plug so I can clean the carbon build up.

Before putting it back together I like to hand rub a light coat of pure raw linseed oil on to the stock which helps seal it up and restores the spots on the stock that have dried up due to me sweeting on it all season.