Originally posted by Chrazy-Chris
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"Max" load for AR Comp and 123s
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Let's go Brandon!
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concrete bench shooting with bipod
Originally posted by Chrazy-Chris View PostI did a ladder with 123 SSTs and 123 NCCs and found 27.3 and 27.6gr AR Comp were the tightest shooting out of my Wilson 20" fluted. About 1.25 MOA with flier; .5-.75MOA with single fliers removed. I have a bunch more loaded up for further testing to see if the fliers were me (most likely). Sorry, no chrono data at this time.
Interesting note - I shot better using a bipod than a Caldwell rock Jr front rest on my Grendel and .223 Heavy-barreled AR. Small rear squeeze bag on each. I though AR's were supposed to be picky with bipods but it worked out well this time. Shooting off a smooth bench with no way to "load" the bipod. As with anything else, I think consistency is key.
Scott
Nube Grendel rifle and forum user.
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Originally posted by rscottb View PostI use a braided Walmart rug with rubber matting shelving liner sewn to the bottom, I take off the bipods pinned in rubber feet and the bipods metal legs dig into the rug. The other end of my now bench matt is anchored to me and my rear bags. This is fairly stable to load my bipods on a concrete bench. This is the closest I can mimic using a bipod on the ground.
Scott
Nube Grendel rifle and forum user.
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So I recently took some AR Comp out with some 123 Hornady ELD-M's to try a new load. I was pretty happy with the results. I shot two different groups. I do a 7 round group with a Magnetospeed Chrono attached for the velocity readings, and I do a 3 round group with the Chrono off the barrel to see how well it'll shoot. I've had mixed results with group size with the Chrono attached, hence why I do two different sets. I'd prefer to do 5 round groups with the Chrono off the barrel but I got tired a while ago of essentially throwing bullets away for the sake of testing, and I want as much as possible with the Chrono on to get better numbers. Anyways, here's the results I got:
Charge / Avg Vel. / SD / ES / Group size with Chrono / Group size without Chrono
27.0 / 2379 / 6 / 17 / 1.8125 / 1.096
27.2 / 2397 / 6 / 20 / 1.25 / 0.914
27.4 / 2421 / 8 / 21 / 1.156 (6 shots were under 1") / 0.187
27.6 / 2416 / 7 / 18 / 1.8125 (5 shots were under 1") / 0.423
27.8 / 2443 / 11 / 33 / 1.8125 (most shots were stringing vertically) / 0.655
Barrel is a Lilja 18" 319, Hornady brass, CCI 450 primer, 1.663 base-to-ogive (~2.245 COAL). I also noticed the 27.8 primers looked much flatter then the rest.
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AR Comp & 123 Nosler CC
First I want to say thank you for this thread! I had been trying to find a powder/powder charge combination for these 123s for a while now. My best so far had been 26.4 grains of 8208 XBR but was only getting very low 2300s fps. Reading this thread got me to try AR Comp.
18" Odin Works DMR profile stainless barrel with Odin BCG.
My first test ladder started at 26.7 grains and went up to 28.5. Conditions were 75 degrees, sunny and dry.
An ES and SD node may have been hit at 27.3 grains but accuracy wasn't there. When I went to 28.2 grains is when things fell together. Average velocity 2534fps, ES 3.18 and SD of 1.71 with 4 touching holes and a flier. Minimal if any pressure signs.
IMG_3296.JPG
28.5 grains had 4 touching holes plus a flier but no where near the ES and SD numbers, plus the brass was showing slight ejector swipes.
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28.2 grains looked to be the next reference point for the next test ladder.
IMG_3298.JPG
2nd test ladder went from 28.0-28.4 grains. Conditions were 63 degrees, cloudy and humid. It would seem that 28.1 grains is the load to stick with. 2540 fps average, ES of 5.33, and SD of 2.44
IMG_3299.JPG
Granted I have a left and right flier but they aren't terribly strung out vertically like the others in the group. Its sure nice when things come together.
AR Comp is going to be my powder to use with these Nosler 123 CC.
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I've been messing with CFE-223 and just was not getting the results I wanted. Also discovered it can be temperature sensitive. Last week found some AR-Comp in my powder stash and thought I would give it a try and was impressed. Shooting less than 1" three round groups was easy. This is my first 5 round group with it. No signs of excessive pressure even on a 95 degree day. Gonna keep working with it.Attached FilesCliff
USN Ret., FPD Ret.
Nobody is coming. It's up to you.
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"Comin', comin', comin' around, in a circle"
Seems like this thread was yesterday. Who can name that tune without google?
Scored 2 lbs of AR Comp at Bruno's today and PV shipped out 120 gr Match Burners this morning. He said it was the first time they've had AR Comp in over a year. It's nice to find your old load notes on the interwebz. Looks like I'll be revisiting. I'm hoping the horizontal stringing I previously experienced was the grip demons I continue to attempt to exorcise. I tend to tense and pull left so I'm wondering if I was relaxing too much in each subsequent shot and walked them right. We shall see next week. Just hoping for slightly under MOA with the Burners.Let's go Brandon!
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Originally posted by StoneHendge View Post"Comin', comin', comin' around, in a circle"
Seems like this thread was yesterday. Who can name that tune without google?
Scored 2 lbs of AR Comp at Bruno's today and PV shipped out 120 gr Match Burners this morning. He said it was the first time they've had AR Comp in over a year. It's nice to find your old load notes on the interwebz. Looks like I'll be revisiting. I'm hoping the horizontal stringing I previously experienced was the grip demons I continue to attempt to exorcise. I tend to tense and pull left so I'm wondering if I was relaxing too much in each subsequent shot and walked them right. We shall see next week. Just hoping for slightly under MOA with the Burners.
From the thread on the bullet hole analysis. My recalling what bench resters used to say -- and maybe so today. Vertical stringing, not enough powder. Horizontal stringing -- too much. Won't even venture a guess but may be worth a try.
LR-55
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Originally posted by LR1955 View PostSH:
From the thread on the bullet hole analysis. My recalling what bench resters used to say -- and maybe so today. Vertical stringing, not enough powder. Horizontal stringing -- too much. Won't even venture a guess but may be worth a try.
LR-55
I wonder if there's something psychological about stringing, i.e., subconscious tension manifesting itself in grip when it's hot, or giving a little extra nudge with your shoulder when it's not. I usually sense a ladder is getting hot before it shows up on brass/primers and my last charge before I shut it down probably does have more horizontal dispersion than vertical.Let's go Brandon!
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Originally posted by StoneHendge View PostYeah, I'd be more than happy a grain lower these days and in the high 2400s. When I ordered the Burners, I planned on trying A2495 since I've had decent results with it else where and it keeps hitting the shelves, and wouldn't expect much more than the low 2400s. The AR Comp was on the shelf when I popped in for some carbon cleaner and was "only" $40/lb so I figured why not revisit. I can always feed it to a .223 if it doesn't.
I wonder if there's something psychological about stringing, i.e., subconscious tension manifesting itself in grip when it's hot, or giving a little extra nudge with your shoulder when it's not. I usually sense a ladder is getting hot before it shows up on brass/primers and my last charge before I shut it down probably does have more horizontal dispersion than vertical.
I have not shot the match burners so don't know if they have their quirks or not.
Psych issues that result in stringing? With you -- I doubt it. Load? Probably part of it. Sloppy position? Maybe. If you are shooting in heavy and shifting mirage -- yes. Approach to the target with a trigger pull just a bit off that day is likely to be part of it too.
You are a good enough shooter to know if it is you or the load.
LR-55
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