I haven't shot my AR in a couple of years,don't know why. I was checking powders and bullets I had in stock and realized I had misplaced my load notes. I think I was using a max charge of 788 with 50 gr. BTs simply because I have a bunch of both with CCI SR primers. This rifle has a 24" barrel and a 1 in 9" twist. Do you guys have a standard COL for the AR mags that you use, for some reason I think I wasn't seating to max length. Probably wouldn't fit in mag. I know I need to be more carefull about my notes next time, just hoping for some good spirited advice before I start all over. Also, do you guys have a favorite powder and load that works good for you?
Thanks in advance for any advice gentlemen. Chuck

Anywhere between 2.22" and 2.25".

2.25"...

I load all of mine at 2.260", never had a problem.

You've been lucky. Some mags - P-mags for instance are slightly shorter than others. Some HPBTM bullets vary slightly at the tips and a few can be longer than others when seated with the same die setting.

A buddy loaded some match ammo for me when I was out of town at 2.260 and it cost me 1/2 a string due to jamming due to overlong tips.......................DJ

Yeah, 2.26" is tempting fate.

Yep been real lucky, got about 50 P-mags that measure longer than 2.260 and have been using GI mags for years with daylight between bullet tips and the mag housing. I wish I was this lucky at the lottery.

As for your 1/2 a string loss, I'd chalk that up to a weak spring, a bad follower or a round loaded longer than 2.260".

Just checked a 30rd Pmag, 2.275" USGI 20rd 2.270" wall to wall, where it counts. Please check yours and report back.

2.250 is what I've run since the 80s. Its run in every magazine of 20 round capability.

30 round GI I shorten to 2.230 to be sure, and its been fine for NTIT rapid fire matches all these years.

ditto for me. 77gr Nosler OTM seated at 2.26" Several P Mags, some preban 30's and newer BCM 30's. Never an issue.

2.260 in some GI 20 round AL ones, with a full mag and wrong phase of the moon can get ya in a bind. Especially considering that a die seats off the ogive and all bullets are not the same OAL.

Though I would not be surprised to find that folks could fire thousands at 2.260 without an issue.

I"ve fired enough rounds to know that 2.250 is a much safer length.

IF seating with something like a dead stop, then 2.260 probably wouldn't bother me...

You are exactly right. Thats teh point. Not all bullets are exactly the same length, due to teh fact that no one i know of uses a deadstop bullet seater, but one that bears on the ogive, the the seater can be set for the shortest bullet ever, at 2.260 and could easily net a bullet at 2.270.

I will say I've used almost all GI mags my whole shooting career. None of the new mags. I will say that eating half a string of rapid fire was NOT uncommon with folks that just HAD to push that last few Nths of length that accomplished not a damn thing. seating just a bit deeper is safer and it doesn't affect performance in the least.

But like the trigger thread.... if ya want someone to bend your stock trigger springs a bunch, and buff off some surface hardening and reduce sear engagement and be happy, thats cool too but not for me.

Again, not refereing to new mags as i have no clue on them.

Kinda the same thing with triggers. Some people just don't shoot enough to understand the kinds of things that can happen and get a little too stubborn to listen to a voice of experience like Jeff's..................................DJ

I mean whats teh big deal about .010 shorter OAL. What is being accomplished by seating that further bit out?

Some people here still insist on seating bullets into the lands for LR shooting?????

Meanwhile you and others shoot 3" or better groups at 600yds with bullets seated deeply enough to ALWAYS function without worries.

Smart people learn from their mistakes.
Smarter people learn from other peoples mistakes ..................................DJ

Even though I've had zero issues at 2.260, 2.250 wouldn't hurt anymore than 2.260 helps. Load em how you like.

2.260 IS the listed SAAMI overall length and like Jeff said if your actual lengths are Always 2.260 they will feed just fine even in P-mags. I just like having some room for error since the ogives can vary a bit from lot to lot and with HP match bullets the actual noses can get jagged and vary a bit too.

My situation might have been a perfect storm, someone else loaded ammo for me with new components that I went and bought so I could participate in an out of town match. The Ogives might have been just enough different from what he was used to using that the actual COAL on the rounds that jammed in the Match might have been over 2.270, I shot the rest of them single shot at 600. Probably is an unusual case but it convinced me to just load to 2.250 and not worry about it.

If I had some load that consistantly shot bugholes when loaded at 2.260 and not at 2.250 I'd load em long too but before a match I'd make sure that none of them slipped through too long.

P-mags are shorter (well at least the one I just measured was). It was 2.270 from the back wall to the front. Brownells and Colt 20rd mags were 2.280 to 2.281 (again at least the ones I just measured).


So like TWR says load em like you want too. Just being aware of that if you are at the edge be sure you are consistant and not creeping over..................................DJ

I don't think I've seen a load that would shoot bugholes at 2.250 and crap at 2.260 or vice versa. Ever.

At least not different enough that I"d worry about accuracy over functionality.

TRUST me here..... I learned the hard way. And I leaned to the long side thinking less jump just had to win the match for me. Later on, hardheadness aside, I learned that winning a match was much more about me, than the tools generally speaking up to a point.

BTW new mags, as I've noted, I cannot comment on at all.

AND I'm the one that cut the front out of 8 round mags for matches so I could load them even longer at one point.... 75 jlk vlds run at mag length for 300 rapid were super.

Backing away from it and thinking of the issue, not what I've gotten by with all these years and I can see no reason to load at 2.260 other than it worked for me but so will 2.250".

Which for some unknown reason is what my Nosler 77's are loaded to. Well the reason is I'm lazy and that's where they ended up at with my die set for Sierra's.

There's something to be said for "If it aint broke don't fix it".

I just want to learn to be smart enough to fix stuff before it breaks instead of learning from too many of my screwups ........................DJ


TWR, How have the Noslers been shooting for you? I've started to shoot more and more of them since they are a good bit cheaper than the Sierra's and so far have shot pretty well but I'd like to hear other reports.

I get a little bit more velocity/pressure swapping bullets only and they aren't quite as accurate as the SMK's. I quit messing with them and delegated them for my Colt chrome lined barrels where accuracy ain't bad but not in the same league as my Noveske and Krieger barrels. Who knows 2.260" might put em in the zone.... grin

I have yet to kill anything with them but will fix that soon enough, reports say they are better in that reguard but I like to see for myself.

supposedly a big nosler price increase coming fairly quickly IE April IIRC...

at least thats the rumbling I hear.

Nosler 77's have been very accurate in my first Noveske barrel, under 1/2" at 100, and certainly 1MOA or less out to 700. I'll buy some Sierra cannelured 77s soon to compare though.

It's been a couple, but if IRC, the last time I measured Hornady 75gr BTHPM, they varied in length by up to .017". Lessee, what is 2.26something" + .017"?

When you feel froggy, measure the length of at least 50 bullets out of your box and write down each one. Subtract the longest from the shortest.
Then figure out how you are going to be sure that your magazine has the same inside length 2" down as it has at the mouth.

Then tell us how sure you are about loading to 2.26".

The Rost knows! Listen to him once in a while.

I think some of the issue is that some folks don't run BTHPs they run other types and IIRC, measuring things like BTs and such, they tend to measure a lot closer to true length.

I always get on my soapbox and then I recall what a buddy said... leave them alone, let em all shoot 80 sierras at 2600 fps.... that way you've beat all of those shooters instantly, quit telling em about 80 jlks and N500 powders and speed....

Trigger wise... should be the same thing too.... your money, like kids have to do, learn it the hard way.

Now... when did sierra start selling cannelured 77s? And are Nosler 77s cannelured? That must be after I quit shooting.

I measured about 30 or so 77 SMK's last night. They varied 5 thousandths, yep I'm still sure enough that the remaining 4-500 out of the last 1000 loaded at 2.260 are gonna stay that way.

Alot of the "old info" is obsolete with Pmags and Magpul followers. Here's one for you Barry, load some rounds of your choice at 2.260 and see if they work. If they go in, they'll come out.

Jeff, Sierra started making a slight cannelure in the 77's so they wouldn't lose the DOD contract. Nosler was happy enough to oblige DOD but Sierra finaly won out when they saw the light. The results is MK262 Mod 0 (no cannelure) and MK262 Mod 1 (w/cannelure). Whether or not Sierra is selling them or not I don't know, mine do not have the cannelure. DOD test's showed the bullet broke up easier and created a better wound channel with them.

Sometimes it takes a little while for stuff to sink in. I remember being a little taken aback when a couple years ago when Jeff (rost495) told me that my Jewell AR triggers weren't the best thing since sliced bread.

Two years and 4 Geisselle triggers later I'm starting to think that he might have been on to something ......................................DJ

Luck is for people who don't understand statistics.

Good info on the 77s. Had not heard that. Thats what I get for stopping competition in 03....

As to the new mags, there would really be no reason they can't accept rounds a bit longer. The old GI mags had some parts in them and some rivets and such that limited space. Redesign and you gain length.

You have pretty close to reliable results there on the measuring of the new projectiles... I used to have a standard set of lengths for 75 amax... over this and they likely were not formed well enough to shoot great, under this and they were. Things have gotten better over the years.

BUT lets say you set up a die for the shortest bullet, 2.260, and then hit a bullet that was 005 longer. And had a slightly over size ogive.. then you are at or really close to 2.270. That would scare me in a standard mag. Hence our use of 2.250 over the yeras.

Hmm... DJ... the biggest thing I"ve been called on is saying Jewel sucked in an AR... I've not seen or felt a bad one in a bolt gun. As I"ve said the very early ones we ran as prototypes at Camp Bullis... they were really good. Though the lock time always "sounded" slow compared to my Milazzo's. Then a good friend that posts here told me otherwise on their production quality... I said he was nuts... and then I bought a new one and dang if he wasn't right. He is more anal about testing and playing than I ever was. Thankfully he lives in Hawaii.... if we both lived close together we'd have never gotten work done for playing/testing AR theories.... Comes here as Chris F..... as fine a man as I know.

Jeff

Midsouth has the 77SMKs w/ cannelure in stock. I found them in stock in several other locations as well. I was wondering for a moment if they were a limited run.

http://www.midsouthshooterssupply.com/item.asp?sku=000079378

Wow, last I paid was $93/500. Looked at the Noslers and they are $148/1000 but on overdue order. They weren't that far behind Sierra's in the accuracy dept...

14.80 per 100. Wow. Thats more than what I used to pay for 168 smks per 100 when I started shooting.... guess Im showing my age...

But scrap is up... 8 bucks a hundred for scrap steel again.... means who knows what regular copper is up to or lead...

I was running my .223 loads at 2.240" COL for both my R15 & RRA ARs and never had a problem in any mags with them.
In my 6x45 AR my COL was 2.255", never a problem in my mags with that COL either.