Why I load to 2.247" Cartridge Overall Length. Make sense?

[BabaOriley]

Early on while loading for my AR, I noticed all bullets vary from ogive to the tip, whether it's a plastic ballistic tip, hollow point, or lead point. I noticed because I had to pay attention to loading them to fit in the AR-15 magazine. I noticed some bullets varied by as much as .01 longer than the average in one lot. Since the most common magazine I use is a C-Products, and I've found them to be pretty consistent, I've found 2.260" is about the longest that will feed reliably from them. I'd like to stay about .003" away from that maximum length, so what I do when I first start seating bullets, is keep adjusting the seating die until I get a total COAL (Cartridge Overall Length) of 2.247" on the first cartridge. On the second cartridge I seat it, then measure it. If it's longer than 2.247", i adjust the seater die until it's right on 2.247". I do this until I've loaded 10 rounds, then go back and run them all through the seater again. I then can load in bulk, comfortable that it's not likely any extremely out of spec bullet in the lot will push that 2.26" maximum. I know that if I'm checking the first 10, I could probably load to 2.257" and be fairly assured it's a consistent lot, but I'll give up the .010" to worry about it even less. Does that make any sense to you guys?

I've been considering trying to grind on a couple mags to see if I could start loading out to 2.28" or so, but not sure it's worth the effort. Never know until you try it, so I might.

[jo2009]

if your measuring from base to tip of bullet you will get inconsistent measures. you need to measure from the ogive of the bullet!

[giterdone]

FWIW...Seating dies are usually made to make contact with the Ogive of the bullet not the tip of the bullet, so the distance to the lands will remain the same (using the same box of bullets) regardless of the O.A.L of the cartridge. O.A.L is usually going to vary, thats why its better to use C.O.A.L instead.

[BabaOriley]

Thanks, but I think both of you may have missed the fact that I'm loading for an AR-15, semi-auto action. The round needs to fit in and feed from a fixed length magazine, which in this case, is shorter than the optimum length for accuracy with the .204 Ruger. Because of that, all I'm able to do is load them as long as possible. (To begin with. Further testing may prove shorter is more accurate for some bullets.) What I'm saying is if you want to load as long as possible for a given magazine, you must ignore the ogive, and load to a length that guarantees no bullet in a lot will be too long, or the gun may jam. When I say COAL, I'm saying Cartridge OverAll Length, base to tip. I guess, no, my original post didn't make sense, I hope. Or, maybe I really am just going about it all wrong. Keep in mind though, this isn't a bolt action, and I'm not loading one at a time. Of course the length of the bullet varies. That's my whole point.

[OldTurtle]

Please Delete

[OldTurtle]

Delete - Duplicate.... Stuck "Enter" key??

[OldTurtle]

I load all of my ARs off of the ogive...and never worry about the measurement to the tip, as long as it fits in the magazine.... I use Forster Benchrest dies and they seat off the ogive as well... If I get one that comes even close to mag length,, I have no problems saving it for my bolt actions...but,that may be only one out of a thousand..

I have a Hornady chamber gauge and a comparator to check new loads, but once I have the die seating depth set, I never have a problem with feeding or accuracy..

[BabaOriley]

Is there a seating die that doesn't make contact on the ogive? I'm not talking about measuring each finished cartridge to make sure it's 2.247" I have a feeling you guys aren't even reading my entire first post. What I'm getting at, is when I'm loading 600 of the same bullet/charge, I don't want to measure each finished round, therefore if the bullets have a variance of +/- .01" from ogive to tip, and my magazine feeds OK out to about 2.26, if I want to be more assured none will push that 2.26, and leave some clearance, even if it's a long tip, I load to 2.247" maximum over the first 10 loads. I then check some periodically. That way I'm pretty much assured none are going to cause feeding problems.

OT, are you saying you leave your seater set the same for a variety of bullet makes/models? I didn't think so. Again, alluding to my point here, if you worry about whether it fits in the magazine and feeds well, hadn't you better worry about the maximum ogive to tip measurement in a lot of bullets? If you don't, you're open to getting one that's too long, especially in the plastic ballistic tipped bullets that can vary quite a bit.

I guess I'm surprised the responses on this have sounded like "don't worry about max COAL base to tip". Are you serious?

[Charlie AR15]

Oriley, I too load an AR . I know what you're saying. As you astutely know, ogive be darned when loading an AR ! It's all about the mag. length. My upper builder, Lee Mosher of Insight Shooting Systems, knows from a lot of experience what the COAL needs to be. Both my calibers have the exact same seating depth, a MAX. of 2.265. However, due to differing slopes of ogives in differing bullets; you may get better results seating some bullets SHORTER than 2.265. I don't know what it is, but an AR chamber lead to lands and the mag. restrictive length still works. In bolt guns , you can seat way out. We can only shorten; but the effect does the same; increase or decrease accuracy, pressure and velocity. You gotta experiment. I found out that way. One bullet wanted deeper seating and lead me to seating my "go to bullet" a tad deeper and it shot better too. Maybe yours does not need to be seated as long as you think either. Try it, you may find it likes it. Good luck and I hope you'll report back here ! Shared knowledge is a good thang.
Charles

[Valar]

I check every load with caliper to see that it is between 2.256 and 2.260 overall

[Joe O]

I agree with your procedure for seating the bullets to go in the AR clip.Sorting bullets with a bullet comparator,will reveal as much as .015 difference with bullets out of the same box.(mostly long slender ones).
I sort bullets for consistance,when shooting groups,but don't bother when loading hi-volune, once I have my load,and COAL.You could also remove your seating stem and see how/where it contacts a particular bullet.Some shooters modify the contact of the stem with a tappered stone or drill.

You are going to have a long bullet jump anyway,so worrying about the orgive is a mute point.I single load in a bolt action to 2.355 for the 204r and have gone to 2.400.Hornady loads their 40gr 204s @ 2.248 with a very tight crimp.I believe they did that in deference to Autoloaders.They shoot in the 1/4" range,in guns,right out of the box,in most cases.