Coming from shooting bolt actions, I find that ultimate accuracy seems to be a well hidden needle in the haystack. Finding the perfect load for a rifle requires running down every side street looking for that one variable that hits the sweet spot with the given rifle. Do you guys find with the semi-autos that you need to increase the bullet jump a little by seating deeper due to the nature of the semi-auto action and the possible feeding problems generated by rapid fire with small tolerances? Any advice? What kind of tolerance for the jump are you using with your favorite loads and with which rifle?
I've learned on this forum that lots of folks have handloading ideas that are all over the map. Anything I say is based on my experience and my ideas only. But here goes. I don't fool around much with seating depth, preferring primarily to stay with OAL that is at or near what factory or milspec ball is. I also crimp, which means that if the bullet is cannelured, then my seating depth is sort of fixed. If the bullet has no cannelure, then I seat to spec, then apply a non-deforming crimp (ie, don't overdo it). For me personally, it's all about safety because gas operated semi-autos are a different breed of gun, and can bite you in a hurry.
In the search for accuracy, I try mostly to test quality bullets, and use modern powders that have a reputation for superior accuracy. I don't use match primers, nor match brass. But I must add that I'm not a top notch match shooter; I don't go to Camp Perry. By the way, crimping is controversial on this forum. If you don't want to crimp, at least try to get a very tight neck tension by way of the sizing die. (Just my thoughts, hope they help.)
Thanks for the reply. It's been a while since I've been on here, so sorry for the late reply.
I'm realizing that you are absolutely correct when it comes to reloading for SA vs bolt action. The concepts of accuracy loading for bolt actions don't really compare apples to apples with SA reloading.
I don't crimp for bolt action for obvious reasons (not needed and impacts negatively on accuracy), but the need to for SA is also obvious.
Thanks for the reply. It's been a while since I've been on here, so sorry for the late reply.
I'm realizing that you are absolutely correct when it comes to reloading for SA vs bolt action. The concepts of accuracy loading for bolt actions don't really compare apples to apples with SA reloading.
I don't crimp for bolt action for obvious reasons (not needed and impacts negatively on accuracy), but the need to for SA is also obvious.
Thanks for you input.
Room
Thanks for the post.
Hi guys, Im a newbie. Nice to join this forum.
Room, I guess I should have mentioned that I don't crimp for bolt actions either, with one possible exception. I've got a .375H&H Mag that I sometimes crimp for, simply to make sure the bullets don't walk out of the neck due to the severe recoil. But that's a special case. Also, in bolt guns, I try to get a seating depth that gives minimal bullet jump to the rifling, IF the magazine accepts it and the rounds feed OK. I'm seeing more and more modern bolt actions, though, that have a very long leade before the rifling starts, so much so that the magazine is definitely the limiting factor.
Wecome to the wonderful world of "heave metal" AR10s!
This is what MSH had to say on this topic a few months ago:
You all have all got me rolling. Your making the reloading into a night at a cheap Vegas cat house. If I didn't no any better I would think the union was involved. Look make this easy trim all the brass to 2" it will grow over time and be back to 2.010 fast. The most important accuracy tip that is never talked about is getting all the flash holes the same size that makes the most difference in accuracy. Make sure your primers are seated oo2 to 004 below flush with the case for these ARs. These AR rifles are easy on brass and most brass should last reloading over a 100 times if taken care of. You can use slow burning powders because the bolt is the opp rod. Don't seat the bullets touching the lands because when the rifle cycles it will reseat the bullets every time and not always the same. That kills the throat in the barrel. I had a Pugnocker exlpain how good that worked on everything at a match yesterday. My 495-39X ended the bullet seating disagreament as Pugnocker was down 200 and some points. Don't worry about a 10th of grain of powder eather, none of us shoot good enough to respond to a 3 10th difference. Get close but not over on the powder measurment. Learn the heat index for the types of powders. Load your ammo on the loose side for these ARs. Test the brass in the chamber before putting the powder in. There was a shooter (new) that had to borrow my leather hammer to open his bolt because he was not sizing his brass 003 under. He sized to 0 on the brass guage. keep plenty of lub on the cases it aids when cycling.MSH
Glen Zediker gives the same warning about random set backs from seating into the lands for semi's in his excellent book The Competitive AR 15 "AR-II". This book is chocked full of AR info for both rifle building and reloading. I think 7.62 chambers are throated long enough that you can't reach the lands and still fit the magazine.
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