Yet more .223 AR loading.

[mac86951]

Ok, so I've built my AR, (well lower anyway). Upper is a 20" WOA Varmint 1-7".

I've done pressure testing, with no signs up to 24.8gr Varget with the 77SMK.
Ladder testing showed a node between ~23.9 and ~24.5. I've chosen 24.2.

Since then I bought QuickLoad which shows I am way over pressure at 24.8, and 24.2 is over pressure too?
So does Sierra site, so does Hodgdon. My rifle says otherwise, Thoughts?

While scratching my head with that data, I've found that Alliant AR-Comp works well in the same load. Node is
21.8-22.2gr, I've gone 22.0. Same zero as Varget load above at 200 yards, but I need to test at a further
distance, or buy a chrono to see what the deviations are. Both are at ~1" groups at 200 yards.

Long Range question: I've got my scope mounted in a Burris PEPR, atop a WOA 20MOA rail. Mounts are fine, but this is
way high for cheek-weld. Anyone have a simple A2 stock solution that still allows the charging handle to cycle?

-Mac

 

[Rtheurer]

Since then I bought QuickLoad which shows I am way over pressure at 24.8, and 24.2 is over pressure too?
So does Sierra site, so does Hodgdon. My rifle says otherwise, Thoughts?


What chamber are you selecting in Quick load? 223 SAMMI or the 5.56 You wold better served with the 5.56 in your selection since its more than likely that you have the Wyled chamber which seems to me closer to 5.56 than 223 especially in Freebore.

That didnt work. 5.56 NATO increased the chamber pressure over the 223 SAAMI with the same Data input.... Intresting....


As for the scope issue...the charging handle makes it tough. Maybe a side charging handle would solve your issue but requires machining of your upper.
Thats a tough one if you have the scope in the lowest rings you can use and its still to high.

I hope some one with more Quick load experience jumps in as I would like to confirm my comment.

RussT

 

[broncman]

Pull your scope back in the rails, then mount a cheekriser that stops right at the charging handle. My f/tr ar is setup this way and love it. You dont have to have your nose on the handle!

I sliced a piece of alluminum conduit in half, cleaned it up, kg gunkoted and epoxied it to my stock for a riser. Works great and looks real clean. Will get a pic if you want.

 

[Turbulent Turtle]

Ok, so I've built my AR, (well lower anyway). Upper is a 20" WOA Varmint 1-7".

I've done pressure testing, with no signs up to 24.8gr Varget with the 77SMK.
Ladder testing showed a node between ~23.9 and ~24.5. I've chosen 24.2.

Since then I bought QuickLoad which shows I am way over pressure at 24.8, and 24.2 is over pressure too?
So does Sierra site, so does Hodgdon. My rifle says otherwise, Thoughts?

-Mac

I would think that all the reloading sites and data telling you that you load is overmax would be a pressure sign that should not be ignored. But then again, our rifles are always abe to handle the pressure because we say "every gun is different." And a lot of people believe that.

You are over max and your brass and other parts will wear out faster. If you insist on staying with that load, you might want to look at a CWS from Tubb's site and get a stiffer recoil spring.

My match load is in that range with 80gr bullets, but the bullets are seated further out thanthe 77SMKs at mag length; I'm impressed that you can get that much Varget in the case; you must be standing on the lever of the press when seating the bullet.

 

[Bradley Walker]

I shot highpower for many years using the 77s at magazine length.

I suggest you find the lower node... the one at 23.5 or slightly lower. Even at that lower nose I popped primers every now and again in the summer.

.223 Brass cannot take those pressures and get many reloads.... You are better off finding the lower node.

 

[pdhntr]

....Long Range question: I've got my scope mounted in a Burris PEPR, atop a WOA 20MOA rail. Mounts are fine, but this is
way high for cheek-weld. Anyone have a simple A2 stock solution that still allows the charging handle to cycle?

-Mac

http://www.midwayusa.com/product/775701/dpms-cheek-rest-ar-15-a2-buttstock-delta-style-synthetic-black

And if your handy, you can also build one with a cut-out for the C handle.

Jim

 

[jonbearman]

Black hawk makes a strap on soft very comfortable cheek rest and it is made so the charging handle still works.Getting a side charge conversion can result in way to much metal removal by inexperienced smiths,go to woa and ask what would cost versus the blackhawk.The blackhawk is about 30.00 and side charge is kinda expensive in my budget and for many others.

 

[mac86951]

I shot highpower for many years using the 77s at magazine length.

I suggest you find the lower node... the one at 23.5 or slightly lower. Even at that lower nose I popped primers every now and again in the summer.

.223 Brass cannot take those pressures and get many reloads.... You are better off finding the lower node.

Thank you all for your fast responses. I'm glad to know I'm not the only AR guy around (though at the range on a cold day I sure am). I'll be loading down for the lower node on the 77SMKs. I should mention that the 24.2 was developed at 5kft, on a 60°F day, and I don't want to find out the hard way that 105°F is overpressure for that load.
As for compressing, no problem at all. I'm using Federal cases weighed to +/-1gr, centered at 94.0gr, I have not done a volume check with Water. I don't use a drop tube, and I weigh every shot. 24.2 will seat the bullet to Mag length (no crimp of course) with almost the weight of the RCBS RCSupreme handle only. (there is some neck tension) and only a slight crunch is heard, but there is volume around the bullet. Neck Tension is ok, this is only slightly exaggerated, but I really don't need to stand on the press to get the powder to compress. In the federal cases, 25+gr with 77SMK would be tough. 24.8 was a bit of crunch.

Well, I'll get it all loaded up and start the node search around 23.5gr.

I got to see my first local precision tactical rifle shoot. Quite interesting to see 8 guys line up and all score a 1 shot hit at 760 yards on cold barrels, then move right to 100 yards and shoot sub-MOA within 15 seconds.

-Mac

 

[mac86951]

Ok, I'm reviving an old thread, but only because I still see this topic post quite often.

My 'match' load has been the 77SMK and 23.4gr Varget, or another powder to produce similar results. N-140 or AR-Comp did that, even CFE223 was close.

Now I'm out of 77gr SMKs, and I found a good deal on a bulk of Nosler 77grs. Doing a load work-up I found that these perform best at a much lower velocity than the SMKs, as expected from the thinner jacket. In truth, where SMK liked 23.4gr Varget, the Nosler is closer to 22.5gr Great groups at 100y, so I'll try them at long-range, but I'll have to read the wind that much better. In retrospect, I would just buy a bunch of SMK or JLK 77gr CO bullets and call this thread done. The 75gr Hornady HPBT is inbetween the SMK and Nosler for velocity needs, and I haven't tried the Berger 73gr yet.

-Mac

 

[stool]

owning quickload WITHOUT a chronograph is like owning a gun with no ammo, a drivers lic with no car...

info in quickload is very generic....you MUST use it with DATA form your gun and your loads,,,and you have no DATA without a chronograph.

SIMPLE QUESTION..HAVE YOU MEASURED THE CASE VOLUME OF YOUR BRASS ?

Ok, so I've built my AR, (well lower anyway). Upper is a 20" WOA Varmint 1-7".
buy a chrono to see what the deviations are.
-Mac

 

[mac86951]

Yes, its posted in an earlier thread, Quickload default was too low. I don't have quick load, but I do have a chrono. I've found that combined with ladder and group testing to be better. You are right, Quickload helps when you put in the correct data. The results are that it gives me an improved recommendation of powders and good velocity measurements. Guess what, Quickload won't tell you the Nosler 77gr 22.8gr Varget instead of the 23.4 that works better with the 77gr SMK.

Quickload also will give a list of recommended powders, but that doesn't mean they are readily available at this time either. I find it best to use quick load as a guide, but the end user must collect his/her own data to validate the program.

-Mac

 

[bigedp51]

Something to think about below...................

The longer throat on the 5.56 AR15 will make load data for the SAAMI .223 approximately be 8,000 psi lower in chamber pressure. Meaning "WHY" are you looking at short throated SAAMI chamber pressures when you have a "LONG" throated AR15 rifle???

The max load for the 77 grain Sierra and the .223 at the Hodgdon's website is 23.7 grains (compressed) at 50,700 CUP and 1,300 psi BELOW the max chamber pressure for the .223 and 5.56.

Quick load has three pressure listings for the .223/5.56, one is for a short throated .223 at SAAMI pressures, one is for a short throated European CIP .223 pressure readings and one for the military long throated 5.56 using the CIP pressure reading.

The three pressures listed below are the same exact chamber pressure measured three different ways.

52,000 cup (SAMMI copper crusher)
55,000 psi (SAMMI transducer)
62,000 psi (European CIP transducer with the pressure taken at the case mouth)

Now Google Mk 262 Mod 1 ammo for your military load data for the AR15 and the 77 grain Sierra MK. You will find that around 25 grains of Varget is a max load for the AR15. (if you can get that much in the case)

 

[Beau]

That does seem low. What is the velocity?
Nosler 77s hammer for me with 24.5gr of Varget out of WOA 20" Wylde-chambered barrels on an AR. Gives about 2680fps.

 

[akajun]

24.2 grains of varget is a standard Highpower load with a 77smk. In fact Its what I load for my Junior team for 77smk's loaded to mag length and 82 Bergers loaded to 2.480. The load functions well and is accurate, and since its varget, you dont have to worry about temp sensitiivity. These loads shoot in th 90 deg heat of Louisiana and the 20 Deg weather we have been having recently, to Camp Perry Ohio, to Camp Butner. Never an ammo problem and we only buy barrels with a wylde chamber. My personal experience with Varget when I got close to 25 grains, I started popping primers in my WOP upper. I Backed down to 24.2 and shot that for a while before switching to reloader15.
My personal gun is a WOP with a 1/7 krieger which I shoot 24.1 or r15 at mag length with 77's by sierra nosler or berger and 24.3 loaded to .015 off the lands with Berger 82's. Reloader 15 gives me about 75-100 fps more than Varget which I like at 600. They also shoot well in the Green Mountian barrels I have been chambering recently with a Wylde Chamber.

 

[JamesnTN]

I've gotta try me some RL15 in my ar

 

[mac86951]

That does seem low. What is the velocity?
Nosler 77s hammer for me with 24.5gr of Varget out of WOA 20" Wylde-chambered barrels on an AR. Gives about 2680fps.

Yea, that is where I'm not lucky.
My AR is also a WOA wylde chamber 20" barrel. I start punching primers not far over 24gr Varget.

Interestingly, two chronos have measured 2670fps at 23.5gr Varget (but I'll justify I have an adjustable gas block and turned way down)

Given that my rifle chrono'd 2670 with 23.5gr Varget, I'd estimate my 22.8gr at 2580fps. There are some posts about the jackets spinning off of some lots of Noslers at a faster velocity, so that might by my lot too.
As to the velocity differences, I'll chalk that up to the difference in rifles.

-Mac