I bought primers at Cabelas in Lacey, Wa this week. They allowed 1k of each available product per customer. I was able to get 2k total and my wife the same. I also was able to buy 3# of powder on the same run. Good stop for me that day. The restricted allotment is what I consider fair. I was able to get both Remington 6 1/2 and 7 1/2 on Tuesday and none left today (Thus) going back thru Lacey. (I share my finds with my reloading partners) I read the notice on the package about 6 1/2 in .223 loads. Here again, the clerk said that both work fine in the .223. The Calhoun article specs indicate that the same specs apply for the 400 primer. I haven't had any failures in .223 and AR loads with the 400 since I started. I read some other threads on this note on the box and some interesting opinions are out there. Some reloading manuals call for 6 1/2, some for 7 1/2. Some indicate that the 6 1/2 can be used in some handgun loads. The Calhoun article indicates max loads and I don't do that. Other input in threads when you Google "Remington 6 1/2 primers" show blowouts in bolt faces etc.. I am interested in what you guys have to say. Trade em' or use em'.... what say ye?