A primer pocket uniformer is a needed piece if equiptment. While the statement above that people use it to achive better accuracy is true, It also uniforms your primer pockets depths, primer pockets in brass cases are not the same in depth from manfacturer to manfacturer and often not the same from case to case even thought the cases are from the same manfacturer. The primer pocket uniformer solves this problem, by making all the primer pockets the same in depth, If they're all the same depth them you can seat all of your primers below flush easily. It dosen't take alot of residue left over from the last fired primer in a primer pocket to make it difficult to seat primer below flush. What you're doing here, is smashing the new primer up against the residue left from the fired primer, I don't think this a good idea, With bolt action rifles,handguns, this isn't really a problem, but with a Semi-Auto like a M1/M14/AR15, these rifles have a floating firing pin, it just slides back and forth,If you have a high primer, the firing pin can slide forward hard enough to fire the cartridge before the bolt is locked. This is precisely why you need to uniform the primer pockets.you'll greatly reduce your chances of getting a high primer using a primer pocket uniformer. I use my uniformer every time I reload the brass, Sure it's a extra step, but I know without a doubt that the primers are below flush and I'm not going to have any problems. Ask Around over at the jouster forum, I think you'll find that many other people do the same thing as I do, I'm not trying to scare anybody. But I think you do need to be aware that when loading for a Semi-Auto rifle you must take a few extra steps when reloading, and take any steps nessessary to reduce any potential problems. A primer pocket uniformer will do just that. As I said read up on the subject, since you're going to try to go it alone, read everything you can on loading for M1/ M14/Ar15 type of rifles.Like you, I taught myself. I've been reloading now for 25 years, several times I almost gave up on it. Frankly, If you can find someone in your area who reloads, who would be willing to help you, and show you a few things, this would help you immensely, and save you alot of time and frustration. 25 years ago the internet was'nt around, so, it was alot harder for me to get good reliable info, you should'nt have that problem. There are alot of boards that have a reloading forum and help is alot easier to get. If you need help I'd also be willing to help you.