I have the opportunity to purchase 2 Four [4] pound jugs of N 310 for $118 each. The only caveat [if you can call it that] is that they were both manufactured in 2008. It will probably take me 3 to 4 years to use it up. Should I go for it? Thanks. 

As johngalt noted it should be an excellent choice for light recoiling target loads but not suitable for high energy loads. As for how light, you'll probably find that you can't make Major powder factor using this powder. In addition in some semi's with a shorter barrel length it may be a bit borderline for reliable function. However, if you intend to use it in a 5 inch 1911 you'll find it's just the ticket for a low recoil training load with very little muzzle flip.
Another plus is the charge weight for 45 ACP is quite light, so you'll be able to load nearly 1750 rounds per pound of powder used. However, one thing you absolutely MUST pay attention to is the potential for a double charge. That is the one negative of loading with a fast powder that features light charge weights, if you miss a double charge you WILL blow up your gun.
I have the opportunity to purchase 2 Four [4] pound jugs of N 310 for $118 each. The only caveat [if you can call it that] is that they were both manufactured in 2008. It will probably take me 3 to 4 years to use it up. Should I go for it? Thanks.![]()
N 310 is an outstanding powder in 45acp & 32 S&W long target loads . Quite a few of us Bullseye shooters use it including USMC & AMU teams . With a Zero swaged 200 SWC try 3.6 - 3.7grs , with a swaged 185 try 3.8 - 3.9grs & with a Nosler , Zero 185 JHP or Rem 185 MCWC try 4.3 - 4.7grs . Many action pistol shooters also hold it in high regard too .