Capt Ruff, I agree with an earlier comment. Outside weather temperatures and size of meat matters. However not unusual consumption.
I have the Weber SmokeFire EX6 Gen2. On Christmas Eve one year I went through three 20 lb bags to smoke a brisket because the weather outside was six degrees. In the summer I might go through one and a half bags.
Also not all pellets burn the same. Over the years I have tried every pellet from Walmart, Sam’s Club, Costco, Lowe’s, on-line, etc. I have settled with two pellets now: Smokin Pecan SHELL Pellets (fantastic for low & slow, burn longer, but a bit expensive), and Royal Oak Charcoal Pellets (great for grilling, burn the longest, cheap).
I actually do a combination on long cooks. Start by dumping in a box of the Smokin Pecan Shell Pellets and then dump on top a bag of the Royal Oak Charcoal Pellets (you can even start with a half of box, 10 lbs, of the Smokin Pecan Shell Pellets). Here is why: all meat stops absorbing smoke when the internal temperature reaches 140 degrees, and that point the smoke is only building bark.
So keep the meat in the refrigerator until the smoker is up to 180 - 200 degrees (smoke boost), put the cold meat on. Once the meat reaches 140 degrees internally increase the smoker’s temperature (275 - 300 degrees) to help render fat and continue to build bark. Once the meat reaches 175 - 180 internal temperature either wrap, foil boat, or leave alone (do your technique) until probe tender (195 - 208 internal degrees).
The 10 - 20 lbs of the first Smokin Pecan Shell Pellets are for the lower temperature and smoke flavor. Once you burn through those (and they are the most expensive) then your smoker will start to consume the Royal Oak Charcoal Pellets at the higher smoker temperatures (like finishing it off in your oven but better, and they burn longer and cheaper)
Last tip, I always put the meat on the top shelf and a water pan under the meat on the bottom rack. Three reasons: add much needed moisture in the cook chamber because pellet grills use a fan to circulate air, helps protect the under side of the meat from the heat when the grill is 250 - 300 degrees, and it catches all the drippings for easy clean up.
