Nosler 123gn Custom Competition over 3 different powders

[Hank Rearden]

Made it to the range twice in the last two weeks. Here are the results.

Nosler 123gn Custom Comps, Wolf SRM primers, New AA Brass, COAL 2.255

18" McGowen rifle length gas barrel.



Charge wt. Velocity fps. Extreme Spread. Standard Deviation


XBR8208

25.7, 2246, 32,
26.0, 2275, 36,
26.3, 2300, 25, 12.1
26.6, 2318, 9,
26.9, 2325, 23,
27.2, 2351, 22, primers starting to flatten

TAC

26.3, 2208, 26,
26.6, 2231, 3,
26.9, 2282, 16,
27.2, 2307, 30,
27.5, 2333, 14.3 ,
27.7, 2350,
27.9, 2384, 20, 6.4
28.1, 2402, 15, 5.2 Still got a little left, primers OK

AA2520

27.3, 2307, 29, 10.2
27.6, 2334, 18, 5.8
27.9, 2361, 20, 7.9
28.2, 2383, 9, 3.7
28.5, 2410, 22, 8.5
28.8, 2432, 33, 11.9
29.1, 2454, 19, 6.5 Primers starting to flatten
29.3, 2475, 17, 5.7





I've been pulling my hair out trying to match the accuracy and velocity of the factory 123amax load. 2475fps out of my barrel, and fantastic accuracy.

I'm open to any suggestions or criticism.

[LRRPF52]

What indicated that the 29.3gr load of AA2520 was way over pressure? The ES and SD are pretty low, but there is a slight upwards curve in velocity increase compared to all your other velocity increases per charge weight, even though you only increased by .2gr.

This looks like a textbook case of the value of using the chronograph to detect pressure, rather than just looking at brass, and you're probably right around max pressure there as you suspect, since the book data for similar bullets maxes out at 30.7gr for the 123gr Scenar @ 2.265", and 30.8gr for the 123gr SMK when using AA2520 loaded to 2.260".

Notice that you have very predictable velocity increases for .3gr increments of AA2520, with 27fps or 22fps steps every time, until you got to the 29.3gr load, which was 21fps for a .2gr step up.

What is the maximum COAL you can load to with the 123gr NCC in your chamber? I would try CFE and LeveRevolution next if you're not happy with the 29.1gr load of AA2520. That is a promising group right there, and your accuracy is tighter than the Hornady A-MAX Factory group you shot.

You might consider taking the 29.1gr load of AA2520 out to 400yds and see what it does. Remember that the 123gr A-MAX is built for the Grendel, with a nice bearing surface and overall pill length that works well with the Grendel case and AR15 magazine COAL.

[RangerRick]

I use 30.4 grains of AA2520 with 123 AMax bullets and a 20 inch barrel with no pressure signs. I've used SMK 120 and 123's with the same load with no problem. COL 2.25

I use CCI 450 primers, but I can't believe they make that much difference.

If you are getting pressure signs with loads that low, your bullet may be in the lands at the length you are loading. Not having a jump to the lands can cause a pressure spike. Try seating a little deeper.

I get sub moa groups with the Hornady AMax and Nosler 120 Ballistic tips.

The AA2520 is about the best approximation of the AMax factory loads. I get slightly better velocities and accuracy than factory loads with it.

CFE 223 is good too, but I have less experience with it.

Your velocities look a little high for the 2520 loads you have listed. How do you calibrate your powder scale?

RR

[Hank Rearden]

I'm using an RCBS Charge Master and verifying the first couple with my 505 beam scale.

My MAX COAL with the Nosler CC is 2.286. That gives me around a .03 jump to the lands.

In the past Ive always tried to play it safe, and stayed half a grain or so under the max loads. Most of the time that would allow me to have a faster and more accurate round than could be bought off the shelf.
308, 223, 22-250, and 45acp are all Ive loaded up till now.

Maybe I'm just being a little to skiddish, but when the primers started to flatten i got spooked.



After re-looking at all 5 of the 29.3gn rounds only one had the super flat primer.



With a little more thought and looking at a ballistics calculator, this round with a BC of 510 traveling at 2455 is still supersonic at 1000yd. At 600yd its still going 1555fps and carrying 609flbs of energy.

I'll work it up a few more and see if there is another accuracy node close.

If not, I'm still Good.

[SCAMP62]

I've had great luck with CFE-223.....
http://www.65grendel.com/forum/showt...FE-223-powder-!!!

[Hank Rearden]

I've had great luck with CFE-223.....
http://www.65grendel.com/forum/showt...FE-223-powder-!!!

Ok.
What the heck, one more pound of powder won't break the bank.
Your the 2nd or 3rd person to steer me in this direction. So why not.
Thanks.

[SCAMP62]

Enjoy !

[terrywick4]

Ok.
What the heck, one more pound of powder won't break the bank.
Your the 2nd or 3rd person to steer me in this direction. So why not.
Thanks.

good luck trying to find it. Not having much luck getting it around here.

[Mav714]

It seems to me, correct me guys if I'm wrong but flattening of primers is not always a sign of too much powder. I read it in here somewhere.

[LRRPF52]

Flattening primers in a gas gun is often ok, as long as you're not seeing erratic jumps in velocity, cratering, or pierced primers. In bolt guns, it can be a sign of extra headspace, even when loads are totally tame.

Using a chronograph is critical in my view, when doing load development, because it's your first indicator of excessive pressure signs. We covered this in-detail in the 6.5 Grendel Reloading Handbook. You don't ever want to be in a situation where you're increasing charge weights blindly without seeing what the velocities are, in summary.

[RangerRick]

I'm using an RCBS Charge Master and verifying the first couple with my 505 beam scale.

My MAX COAL with the Nosler CC is 2.286. That gives me around a .03 jump to the lands.

In the past Ive always tried to play it safe, and stayed half a grain or so under the max loads. Most of the time that would allow me to have a faster and more accurate round than could be bought off the shelf.
308, 223, 22-250, and 45acp are all Ive loaded up till now.

Maybe I'm just being a little to skiddish, but when the primers started to flatten i got spooked.

Yes, the mag length is usually the limiting factor with the skinny ogive bullets. It looks like an extractor mark on there too.

I see you have an adjustable gas block. I'd try cutting the gas down as much as possible. The brass looks pretty clean, but you still may be unlocking at a fairly high pressure, so that could be the primer backing out a little.

That will improve your brass life, too.

RR

[Hank Rearden]

CFE 223 and 123 Nosler CC's

Finally had a chance to test a few more, and I'm glad you convinced me to try the CFE223.
Not only did it produce the highest velocities but it also produced the tightest 5 shot group.

CFE223, Nosler 123 custom competition, new AA brass, Wolf SRM primer, COAL 2.255

29.5gn-2376fps-es14-sd4.7
29.8gn-2399fps-es12-sd4.4
30.1gn-2427fps-es19-sd5.7
30.4gn-2423fps-es49-sd15.4 chrono showed an error reading?
30.7gn-2442fps-es21-sd7.7
31.0gn-2483fps-es21-sd7
31.3gn-2508fps-es27-sd9 Best Group .579inches
31.6gn-2528fps-es19-sd5.8



Very impressed with this powder. Primers all looked normal.

[ricsmall]

hank,
Very nice groups, especially the 31.3. I think Ill try that one in mine. I have to seat them way out in my stick to get closer to the lands, how far off lands were these in your gun at 2.25?
did the recoil impulse of your rifle feel normal with the cfe, or harder? I tried it briefly and the recoil was unusually hard, although my primers looked normal. just wondering. Thanks.

richard

[Hank Rearden]

hank,
Very nice groups, especially the 31.3. I think Ill try that one in mine. I have to seat them way out in my stick to get closer to the lands, how far off lands were these in your gun at 2.25?
did the recoil impulse of your rifle feel normal with the cfe, or harder? I tried it briefly and the recoil was unusually hard, although my primers looked normal. just wondering. Thanks.

richard

My MAX COAL with the Nosler CC is 2.286. That gives me around a .03 jump to the lands. 2.255 is the max I can load in the magazines.

The recoil impulse felt about the same as the factory Hornady. Haven't shot any of the others in the last several weeks so its hard to judge.

[LRRPF52]

Very nice. Hornady' 9th Edition has data for CFE through an 18" barreled AR15, and I think they maxed out at 31.2gr at 2500fps, so you're looking to be dead-on with their data. I'm loading 31.0gr right now for my 16" carbine under 123gr A-MAX and SST's at 2460fps at 81 degrees F.