600yard 223rem loads


January 30, 2013, 09:39 PM
I'm looking for a load that will be accurate enough to hit a shillout at 600yards
my rifle is a mossberg map varminter, 24inch barrel, 1:9 rifling, uses ar mags, right now I've been using 53gr vmax and 53gr tsx, i was looking toward the 75gr amax but was told i can't fit the round in an ar mag, so what you guys recommend, powder recommend, bullets? Cases? Primers? Tricks for preping the brass?

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January 30, 2013, 09:48 PM
75 gr AMAX won't fit in magazine. 75 and 77gr hp will nicely. Some 1-9 twist will stabilize 75gr hp. 24" barrel will help. Need to try them. 24gr Varget or Reloder 15 or TAC should work. Work up to this however.

January 30, 2013, 09:59 PM
I'd have to look at exactly how much Varget I was using Sierra or Nosler 77gr BTHP's seated about .01 off the end of the magazine (I don't have the actual length handy at the moment). Never had a problem, and suckers shot great.


January 30, 2013, 10:05 PM
While I'd agree that a 75gr A-Max won't usually fit in an AR magazine, I shoot A-Maxs loaded long and single load them with Varget .010 " shy of the lands.
Personally, I haven't had any luck shooting 75s in a 1/9 barrel but you may be blessed?
In your situation, I'd try 69s, long and hope for no wind condition.

January 31, 2013, 09:21 AM
I'm with doug. My load is a 69 SMK over a near max load of varget. In a 1:7 twist 16" AR it does well.

January 31, 2013, 10:51 AM
You will just have to try the heavier bullets and see if they keyhole. It is not a hard limit but most 1:9 barrels won't shoot anything heavier than a 69 SMK. A bud of mine shot 75 AMAX in his 1:9 and it worked out to 600 yards. I have seen others try heavier bullets in their 1:9's and not hit the bull at 300 yards.

I have shot the 69 SMK at 600 yards and it is wonderfully accurate. But the slightest puff of wind and that bullet sails off to the side.

January 31, 2013, 10:52 AM
Personally, I haven't had any luck shooting 75s in a 1/9 barrel but you may be blessed?Which 75gn? Hornady makes two. The Amax will not stabilize in a 1:9 the BTHP is a great deal shorter and usually will. The Berger 70gn VLD should also shoot well from a 1:9 barrel. It has a higher BC than the 69gn SMK and the Hornady 75gn HPBT. Its not quite as high as the Amax but that's the price you pay for being able to load from the magazine and stabilize in a 1:9 barrel.

January 31, 2013, 11:20 AM
75gr Hornady BTHP is shorter and fits better in AR mags than the Amax. I use 24.5gr Varget and load to mag length.

January 31, 2013, 04:37 PM
I also heard filling up a five gallon bucket with rifle brass and pet bedding, then putting it in the back of my truck and driving around could polish the brass, any truth in that?

January 31, 2013, 06:42 PM
The 53 grain Vmax is my load of choice out to the limit of my range, which is 550 yards. A 1:9 twist should be a perfect match for the 53.

If you look at the ballistics of that bullet you'll see that it gives up very little to any of previously mentioned bullets, and outperforms them all at shorter distances and costs a whole lot less.

Once you get past 600 yards then the 53 Vmax starts losing big, but if you're only shooting out to 600 yards, then you may just be spending extra money on bullets you don't really need. The only other question is whether your rifle will shoot the 53 Vmax accurately.

January 31, 2013, 07:44 PM
It puts the 53gr vmax through one hole at 100, on a 19gr charge of imr4198

January 31, 2013, 11:55 PM
The Sierra 69gr MatchKing bullet Part #1380 should work very well with Varget for what you are looking to do. You might also give the Hornady 68gr BTHP bullet Part #2278 a try bit I can't comment on it's accuracy because I have not tried them yet. I have shot the Sierra bullets.

If you have a 1:7 twist barrel my choices would be different.

February 1, 2013, 05:07 PM
I was hitting 55 gallon drums at 600 yards all day long with 53gr VMax over a stout load of W748. Works very well out of my 16" 1:9 twist. I was using the 4th mildot on my scope.

February 1, 2013, 06:04 PM
I have good luck with my 223, 24" Heavy BBL 1:9 twist using 53grn A-Max, 60grn V-Max and 69grn Nosler CC with Varget and TAC. out to further ranges. Wind drift becomes a real issue however at the longer ranges.
Bullets are set .020 off the rifling and will not fit in the magazine, shooting single shot hand fed.

February 1, 2013, 09:35 PM
Some notes from precision long-range match shooters.

.223 for Palma Competition - http://riflemansjournal.blogspot.com/2012/03/cartridges-223-for-palma-competition.html

- .223 is a very finicky cartridge to load accurately (for 800, 900, 1000 yards)

- could never get the same degree of elevation control with the .223 that we could with the .308

- the theoretical wind drift advantage of the .233 just didn't amount to anything worthwhile in real shooting, especially in light of the increased elevation dispersion.

The .223's small case capacity and powder charge, however, are the root of another significant and perhaps insurmountable problem causing elevation dispersion - the primer ... primers just aren't as consistent as we want them to be. Their method of manufacture almost guarantees a significant level of variance in their power output.

The lowest standard deviation (SD) of chamber pressure was 400 psi with a corresponding extreme spread (ES) of pressure of 1,400 psi. The largest SD of pressure was 1,400 psi with a corresponding ES of pressure of 4,100 psi. These were all high quality primers in use by Highpower competitors, not bargain basement off-brand stuff.

... The .223 case has less metal surrounding the primer pocket than any other case used in Highpower shooting; add in the typical .223 shooter's propensity for heavy loads and you get the blown primer pocket failures that we see every week with this cartridge. Going back to your earlier comment about the increased effect of charge variance on pressure in the .223, consider also that the smaller case responds more dramatically to changes in temperature (and absorbs chamber heat more quickly); it's really just a recipe for disaster.

... point is that if the .308 isn't exactly ideal, the .223 is far worse. Everything that limits the .308 can be said with even greater emphasis with respect to the .223.

February 2, 2013, 05:29 AM
I would think anything longer then a 65gr Serria would have FITS trying to stabilize in a 1:9 twist, a 1:9 is best suited to the 55gr class stuff, you can still shoot 600yd with it but on windy days you will wish you had a 1:7" slinging 80gr VLDs or 77gr SMKs. Better yet a 308 or 6.5x55 :D

February 2, 2013, 10:24 PM
The 77 grain Sierra Matchkings are designed to shoot well when seated to magazine length. It's all in the design of the bullet ogive and Sierra made these specifically so Highpower shooters could shoot a heavier bullet from a magazine during the rapid-fire stages. How well they will shoot out of your 1/9 twist barrel is debatable but of course there is only one way to find out. I've shot tons of these bullets (from a magazine) out of my 20 inch 1/7 twist AR for highpower competitions at the 300 yard line and they shoot exceptionally well for me with 24 grains of Reloader-15. This is a slightly compressed load. If your twist rate is enough to stabilize them they are definitely capable of hitting a silhouette at 600 yards. I shoot the 80 grain Sierras at the 600 yard line because of the sleeker, higher ballistic coefficient of the secant-ogive shape, but they aren't designed to be seated at magazine length and must be loaded single shot.

February 3, 2013, 04:05 AM
1:9 is going to be iffy.

I got keyholes at a quarter mile with 77gr sierra Matchkings, ended up building a different dedicated upper with a 1:7 twist barrel in 223 wylde, which worked out real good. The only downside is that particular barrel don't shoot 55 gr for jack, and 60 grain is not great. The 223 Wylde has a heck of a long throat before the lands, meant to load bullets overlong and single feed. 55-60gr loaded at magazine length they jump so far to the lands they get a lot of velocity spread, and some runout.

35 Whelen
February 3, 2013, 09:44 AM
My High Power shooting buddies tell me you just have to try different bullets to see if the 1 in 9 will stabilize them. I set up a 600 yd. range here at the house for the Jr. High Power shooters to practice on before the annual trek to Camp Perry. They all shoot 75 gr. Hornady's, but I can't say with certainty what twist each of their rifles has. Remember: whether or not a bullet will stabilize with a given twist is more dependent on the length of the bullet than the weight of it.

A bolt rifle that uses AR mags?.....why?

February 3, 2013, 09:47 AM
A bolt rifle that uses AR mags?.....why?

Experimentation. :)

February 3, 2013, 10:06 AM
I had a Savage 12FV barrel (26", 1:9) that shot 5 rounds sub half-MOA at 200yd with 75gr HPBT and 24.0gr Varget...2860fps in multiple types of brass (Lapua, Nosler, RP, LC, FP) with CCI 400 or 450.

Hits on 8" steel @ 650yd were easy and repeatable...so long as the wind call was accurate.

A 1:9 20" Savage 11 Hog Hunter shot the same load a fuzz under MOA.

35 Whelen
February 3, 2013, 10:09 AM
Experimentation. :)
Good point!

February 3, 2013, 12:01 PM
Good point!

I wanted to try to build the "most accurate AR-15 I could build." I won't lie, that upper cost me a mint to put together. And it mostly just sits on a shelf collecting dust!

The last experimenting I did on it was with seating depth of 77 grain SMK's. I've had a working theory for a while that bullets with the base seated deep in to the casing, with the bearing surface "floating in space", get perturbed and distorted prior to fully entering the throat. I first noticed the phenomenon on 300 win mag, 220 grain bullets, seated with the bearing surface deep in to the cartridge (3.300 OAL). I lost an entire MOA of accuracy if the bullet's bearing surface was seeted deeper than the neck, vs. an OAL matching my lands with the base NOT extending in to the cartridge!

The same thing happened when I tested it with 223. Seating a 77 grain bullet deep in to the case, so it fits in a magazine, shoots much less accurately than the same bullet seated over-long, with the start of the boattail matching the end of the neck. My group sizes at 1/4 mile (440 yards) were averaging about 3" with the rounds loaded long, and single loaded, versus an average of 6.5" groups from rounds seated deep and fed from the magazine. The groups opened up in each direction, but also grew oblong vertically, and the chronograph showed much a higher velocity spread on rounds seated "deep."

My theory for this is the that A] the bullet has enough bearing surface for the charge to cause it to "tilt" prior to fully entering the throat, and B] the base of the bullet actually expands under the high pressure, and then re-forms to bore diameter as it enters the throat. (Copper & lead are pretty malleable, and deform much like a wad of jello when faced with 55k PSI of pressure... The rear of the bullet is getting shoved in to a front that is facing resistance, causing the back of the bullet to balloon out slightly, then re-form to bore diameter as it enters the throat.)

Granted, I don't have the ability to SEE this happening, and can only form hypothesis based on external data gathered, but the velocity spread difference was pretty telling!

I ALSO believe that the 1:9 twist issue on 77 grain that SOME people (including myself) have seen, with bullets not stabilizing, while OTHER people can shoot those just fine out of the same twist barrel, has a LOT to do with where the leads are located and how much throat erosion there is.

If the bullet has sufficient free-bore (from an eroded throat) it will "skip" ahead in the bore much easier, the base won't expand as much under pressure, and the bullet will be a little less likely to tilt under pressure as it engages the lands.

The only data I have to support that theory is from shooting 77gr loaded to magazine depth out of a 16" barrel 1:9 twist that keyholed at 440 yards. The barrel was brand new, the lands were sharp, and the measured velocity spread was MUCH greater than from my experimental 223 wylde chamber which has an additional .25" of freebore over the standard AR barrel (by design, for seating 80 gr bullets overlong).

The same load in one rifle was engaging the lands almost immediately, while the base was still very deep in the cartridge, while on the other rifle it skipped forward without resistance .25" allowing the base to almost clear the cartridge before engaging the lands. The velocity and accuracy was still not close to what I got with the bullet loaded long, the freebore pays a price...if you don't take advantage of it.

So my theory on that is the 1:9 twist barrel CAN stabilize a 77 gr bullet *IF* the lands are somewhat worn. (There might also be a chrome lined barrel vs. steel difference, too, but I haven't tested the differences as I don't have a non-lined steel barrel handy that's 1:9, only CM.)

Anyway, that's the whole story on the "experiment."

I have 12 different AR barrels sitting on a shelf downstairs, various gas length, various designs, various profiles, various muzzle breaks, it's fun to experiment if your willing to take the time with a barrel wrench. :)

February 3, 2013, 04:19 PM
Its a pretty solid rifle, the at mags give me the ability to hold as much ammo as i need, i can load it with the with the bolt closed, mags are fairly cheap, i had mags, my friends use ars so in a practical situation itmeans that i can use their mags, the action is smooth the ability is there why would you make a rifle chambered in 5.56 use anything but the most common magazine in the world, and for further clarification, this is by no stretch of anyone's imaginations a modified ar15

February 3, 2013, 08:31 PM
Heck a bolt gun that takes AR mags isn't a bad thing in my eyes. :)

That MVP is about $600 less than I spent on that AR upper I built. Sounds like it's more inherently accurate, too.

February 4, 2013, 07:03 AM
I mean, i built an ar15 for less then 600, then traded it for a rifle that cost more then that and a Stevens 350 hd, the reviews where better then the remington 700 so i thought, why not? I just got more vmax, and I'm going to start trying some h4198 see how it does

February 4, 2013, 10:41 AM
Sounds like you made out pretty good.

Toss a 5 or 10 round mag in that (whatever's legal) and that'd make a pretty handy hunting rifle. If you can get it to swallow 77 grain pills without keyholing, you'd be in great shape. I'd almost be willing to put money down, that rifle would do better and be more precise with 69's.

Have you determined where the lands are yet? Load a dummy round "way too long" (making sure you've still got enough in the neck for positive retention), mark it with a marker or similar coloring, CRIMP it, chamber it. I say crimp it because if it engages the rifling enough, sometimes you can extract an empty casing and leave the bullet in the lands, which you then have to tap out, and start all over again.

Anyway, the rifling will leave marks and scrape away your coloring of choice.

Now measure the base of the case to the start of those marks. That's your reference point on how far forward you can get the bearing surface of loaded projectiles out there.

I know you want to feed from the magazine, but it certainly wouldn't hurt to know where your lands are, so you can have an idea of what's happening when the powder starts to burn. :)

You can probably squeeze a little extra length out of rounds and still have them fit in the magazine and feed OK.

You want to get as much length as you can, to get the bearing surface close to those lands. With some rare exceptions, the less freebore the bullet travels, the better those longer, heavier bullets are going to shoot.

But there's no telling how your rifle will behave until you try. :)

February 4, 2013, 05:16 PM
Well i just checked the lands and it looks like its at 2.112, does that sound about typical?

February 5, 2013, 02:03 AM
Actually it sounds like you got quite a bit of free bore.

That's definitely not a bad thing if you're shooting longer bullets.

You should be able to load 69 and 77 grain bullets out pretty far, if you want to.

February 5, 2013, 02:08 AM
Just confirmed this, SAMMI specs for S dimension (length to end of bearing surface on standard round) is 1.855" putting the nominal lands position at 1.955". So looks like you've got about .157 of wiggle room over a standard chamber.

Not quite as much as the 223 Wylde chamber I played with, but definitely long enough to stretch those rounds out a bit. When you start loading those longer bullets I'd definitely play with OAL once you're done laddering up your powder and settle on a charge.

February 5, 2013, 07:08 AM
Well its clambered for 5.56 so I'm guessing that's why?

February 5, 2013, 11:15 AM
I just checked my old notes and in three different uppers, one a NM, all three had a depth to the lands of 2.000" measured from the ogive, using 69g SMK's.

All 5.56 chambers.

If you can just drop in a loose round and have it chamber easily in the MVP, then single loading won't be a problem. But if it's like an AR then the BobSled makes single loading much easier. You can get one at Creedmore easy enough.

February 5, 2013, 11:25 AM
Its interesting, the bolt face is almost an exact copy of one from an ar

February 5, 2013, 11:39 AM
I have to get my hands on an MVP, just never have seen one in stock locally. Probably the best idea ever.

February 5, 2013, 12:59 PM
Well its clambered for 5.56 so I'm guessing that's why?

No, that OAL is significantly longer than a standard 556 chamber.

The gunsmiths who built your rifle knew their business, and knew people would want to do long range shooting with it.

Truthfully, I'm REALLY surprised you're getting one-hole accuracy with 55 grain. with that much freebore on a 55 grain bullet I would expect some velocity spread. Maybe it'd be more telling at longer ranges? Either way you're probably getting a tad higher velocity out of 55gr compared to an equivalent AR since that bullet can get moving easier (not to mention, no gas diversion for cycling the action). At the cost of a little velocity spread, that's a good tradeoff for a hunting rifle.

I'm REALLY curious what sort of accuracy you'd get out of 69gr Sierra Matchkings on that barrel, loaded long until they're close to the lands.

There's a follower you can buy (mentioned above) that allows you to very quickly drop an over-long round on to an AR mag for single loading. It basically changes the rifle to single shot, but lets you easily and quickly load and shoot those custom, longer cartridges that should really shine at 300-600 yards.

February 5, 2013, 01:51 PM
The previous method of measuring your distance to the lands will work, however I've found that these tools offer a no-guessing, foolproof, absolutely dead on way to measure that distance. Unfortunately you'll have to dish out some cash.

You need this.


and this


And it really helps to have this.


Screw the modified case in to the OAL gauge, drop in your bullet of choice. Jam the case in to the rifle's chamber until it's nice and snug, push the wire to move the bullet out of the case until it hits the rifling, then tighten the lock nut.

Remove the assembly and measure using a caliper with the proper bullet comparator insert installed. Repeat a couple times and you'll find the depth within a few thousandths and you can trust it.

Remember that the base to tip measurement is only important for fitting in to the magazine. The base to ogive measurement is what will determine how far off the lands the bullet is.

Unfortunately in a 5.56 rifle it's rare or impossible to get a round to both fit in a magazine and have an optimum distance to the lands. Not all bullets perform equally though. If it's shooting to your satisfaction now, then you have a good fall back position if all other experiments fail.

February 5, 2013, 09:38 PM
Cash is something i really ain't got a lot of right now, for anyone interested in getting one of thread rifles, ill warn you about the magazines right now, most of them will have to have a little bit of the "lips shaved off, and i had fits with the thermolds falling out of the magwell, but those are easy fixes

February 6, 2013, 08:12 AM
Cash is something i really ain't got a lot of right now, for anyone interested in getting one of thread rifles, ill warn you about the magazines right now, most of them will have to have a little bit of the "lips shaved off, and i had fits with the thermolds falling out of the magwell, but those are easy fixes

Thermolds falling out of magwells, I thought that was a design feature! :evil:

While it's good to have the right tool sometimes, this is something that you can do with the components you already have with a marker. A long time ago I used to blacken the bullets with soot. Anymore, I just use a black sharpy. After my little boy tried to set the house on fire playing with matches, we don't keep stick matches laying around, and those long bbq lighters don't "soot".

February 8, 2013, 07:08 AM
Well, i checked the lands about 5 times now, and they all give me the same result, i also made me a "bobsled" out of one of my thermolds, it seems to work, but i still gotta get it out for some shooting, if all else fails i might set it out at 200yds and try putting a 3 shot group on it

February 8, 2013, 08:19 AM
You wouldn't be the first person on this board to perforate AR magazines that malfunction.

In fact, if you went walking in the woods behind my house, you'd find a couple at the bottom of my hill by the lake where I shoot pistol occasionally. I took my FS2000 down there a last year to re-test two mil-surplus magazines that had shown problems in my AR. With the FS2000 being so reliable, if IT jammed, I view it as absolute confirmation that the mags are hosed.

I've had *some* very *limited* success at getting bent feed ramps straightened out on aluminum magazines but more often than not, I can't ever get them 100% again.

Anyway once I confirmed those magazines just don't work, in either of my 223 guns, they became targets for my 45ACP. :)

I once saw a guy at the range become so frustrated with a magazine that he tossed it out at about 7 yards and unloaded 8 rounds of 00 buck in to it.

I think he felt better afterwards.

(Although he spent more money killing the magazine than the magazine cost)

February 8, 2013, 10:22 PM
I think of it as "recycling"

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