The load data I've seen is they appear to be closer to a Federal 209a. Like yourself I'm primarily reloading the Winchester 209's. I have reloaded a few thousand with the Cheddites and am very satisfied with them. No piercing, mis- fires or anything unusual. But, I don't see breaking away from the Winchesters for good anytime soon.
Doug, Those primers should not enlarge the primer pocket in your shells, unless they are some really old ones. I would suggest you only try 100-200 primers before you buy alot of them. For some reason they seem to have a thin cover over them. Some guns shoot them fine, while others of the same make or model will have problems with piercing the cover and the flash back can burn the end of the firing pin with will need to be replaced if it happens often enough. So you need to find out it they work for your gun or not before you buy alot of them. Good Luck and Break-em all. Jeff
IMAGE-RANCH, I'd say you have other mechanical problems rather than the Cheddite primers not going off? I've shot several thousand of those in different guns and haven't had a failure to fire yet that was the primers fault! I have had short firing pins and broken springs to hit a primer too light but that isn't the primers fault. Are you shooting a B semi-auto?
Just had a problem with one. Tried to fire it in 4 different guns. The only gun which would dent the primer was a 1100. A rem ,browning and a Franci only left a very slight mark. The primer face was flush. Shell reloaded on a Mec. Haven't had a chance to cut it open, but it shure looks to be a very hard primer. Have loaded 10K without a problem before.
Gone through 30,000 cheddite primers and not one mis-fire. Also during this time would mix in winchesters, remingtons, CCI's, and even herters that my dad would buy at auctions and give to me to use up. Never had a problem with enlarged primer pockets.
I just looked at my records, and I have gone through 84k Cheddites and think they are great. I found that on a real light load they tend to burn through occasionally, so I use something else on those. No problem with fit on other brands (Rem, Win) after using Cheddites. RM