Sorry I can"™t help you on ML. I"™ve never done it but I will add on the part about Cabela"™s.. I"™ve gone to that store maybe a dozen times in 2 years. I would suggest to go on line and order one of there catalog first so that you can compare prices to what you can get in Winnipeg. Here"™s there link..
www.cabelas.com Or you can just check from there web page.
You don"™t have to pay duty if the items are made in the states. Just make sure to keep your receipts and when it"™s time to come back, declare what you"™ve purchased. They"™ll convert it to Canadian dollars and you have to pay GST & PST. You might have to pay duty on clothing, this i"™m not sure but for reloading stuff and that includes ML, it"™s only the taxes. When you compare prices make sure to do the conversion to Canadian bucks.
Like I said , I"™ll usually leave early Saturday morning and I"™m be back by early afternoon. The saving could be really good so check it out. It"™s a 4 hour round trip, no different the going to Brandon and back.
I forgot to mention that I use my wife's car it"™s really good on gas so that might be something to consider when comparing prices. Good luck...