Intial load work up, .223 - 69gn HPBT - Pressure Signs?

[Rmitch223]

Ive been hand loading for bolt actions for quite some time, but recently I built a AR-15, with a 24" ER shaw bull barrel (Model 1 sales upper).
Chambered in . 223 Rem., So Im somewhat new to loading for a semi.

I worked up a great load with Nosler 55gn Armageddon bullets with 26.5gn of CFE-223. Great load, shoots very well, no pressure signs at all.

Then I began my workup with the Nosler 69gn HPBT Custom Competition bullet.
CCI -400 primers
CFE-223
Federal Brass
OAL of 2.255"

Sized Headspace: 1.452"
Fired Fomed Headspace after workup: 1.460"
Obviously too much shoulder bump, which was unintentional. How far should I bump the shoulder on these cases for a semi auto? .005".
On my bolt rifles I only bump the shoulder back .002".

I use OCW for load development so I loaded 25 cartridges at 5 different charge weights:
23.5gn
24
24.5
25
25.5

While working up my chronograph had a error that I wasn't able to fix until I get home.
But after shooting the 5 at 25gn my primers seemed really flattened.
My initial thought was that it may be due to the fact that I used the chamfer tool to remove the military crimp, in doing so it leaves a slight countersink into the primers pocket, so possibly the primers where flattening because they were filling in that countersink/recess. I immediately stopped at 25gn and called it a day.

My question is do these pictures attached of each charge weight look like they are over pressured?
I'm within the Hodgdon load data and Quickload is saying that 25.5 grains is only 53,000psi, plenty below Pmax.

Please see attached pictures and let me know if you think I'm seeing pressure signs.
The bottom row is 23.5gn and each row up increases by .5 up to the 25.0gn that I stopped at.

Any opinions appreciated.

Thanks,
Ryan

 

[Billl223]

Those primers look O.K. to me. I full length size 223 for an AR to just about max on a standard gage. I helped a friend set up his Dillon yesterday and we were trying to duplicate a Federal load that uses the Sie 69 HPBT and claims 2950 fps. Out trial load was 25.0 CFE @ 2.250" but it hasn't been shot yet. I load 25.2 Varget with that bullet and get 2700 fps out of an 18" barrel. That load shot 3/4" @ 200 yds.

 

[ksthomas]

Ryan,

You've got a real mish-mash of brass here! Case differences alone will make trying to read pressure signs virtually impossible. Sort your brass, and keep to a single type to do your load work ups here.

 

[X-fan]

Ryan,

You've got a real mish-mash of brass here! Case differences alone will make trying to read pressure signs virtually impossible. Sort your brass, and keep to a single type to do your load work ups here.

Well....There's your problem!

 

[Rmitch223]

Ok, I should have done that. I never mix brass on my bolt rifles so I don't know why I thought it would be ok here.

How much should I bump the shoulder back from the fired formed dimension when full length resizing? .003"?

 

[Paulyr450]

I think the chamfer on the brass is going to make it hard to tell no matter what you do. Just try it with some fresh brass,all the same kind.

 

[Paulyr450]

Go to the hide and seek post in options and accesories and there is a good list of places to start looking.

 

[Paulyr450]

The last time i checked palmetto state armory had some in stock. Hope that helps.

 

[Rmitch223]

I just ordered 50pcs of Lapua brass from Bruno's. They have them in stock and are selling them for .62 cents per piece.

 

[dogmessiah]

Definitely start with fresh brass. Primer flattening isn't a real good way to tell pressure, especially on gas guns. Sometimes gassing issues can mascaraed as pressure signs. Bring out your calipers and measure case head expansion as well.

 

[Deadshot2]

Obviously too much shoulder bump, which was unintentional. How far should I bump the shoulder on these cases for a semi auto? .005".
On my bolt rifles I only bump the shoulder back .002".

The answer to the amount of shoulder bump is really what works best with your rifle. I would start with a .002" bump and if it is 100% reliable, with the bolt going fully into battery every time. That's good enough. If not, add a "thou" until you get the desired results. I would definitely stick with F/L sizing, just adjust the die for the desired "bump".

Unlike with a bolt gun with a big bolt handle you can't "crush fit" in a gas gun as easily. If case life is real important, just anneal more often.

 

[1lnbrdg]

.002 / .003 bump has always worked for me. I shoot ~10,000 rounds a year and haven't had a feeding issue yet with this amount of bump.

 

[JeffinTX]

To the OP:
Fed brass for .223 is known to be thicker and heavier than most other .223 brass. It is also softer than most. You will see pressure signs with Fed and primer pocket loosening with Fed before most others. A "warm" load perfectly fine with LC, WWC, win commercial, RP, etc will often fail with the Fed. It will be OK with low to mid range loads.
.003" bump should be fine with the gas gun. Less than that then there's chance it won't chamber due to dirt, chamber fouling build up, slightly out of spec resize, etc. Don't need to bump more than .005" as that will over work the case.

 

[tobedell]

Going to your 69gn HPBT
I have loaded 26gn of Varget with that bullet and used it in everything from a mini 14, Bushmaster 16 inch BBL to a Rem 700 VSF 26 inch and found that to be kind of a pet load.

 

[exx1976]

I load 69gr SMKs in Lake City brass with Tula AR primers and 25.2gr of CFE-223 for use in a 20" Lilja 1:8. My AR loves them. They are loaded to mag length. No pressure signs, chrono says:

String 4
1) 2701.0 -7.2
2) 2715.0 6.8
3) 2716.0 7.8
4) 2700.0 -8.2
5) 2726.0 17.8
6) 2720.0 11.8
7) 2722.0 13.8
8) 2733.0 24.8
9) 2702.0 -6.2
10) 2722.0 13.8
11) 2712.0 3.8
12) 2720.0 11.8
13) 2706.0 -2.2
14) 2694.0 -14.2
15) 2699.0 -9.2
16) 2713.0 4.8
17) 2693.0 -15.2
18) 2719.0 10.8
19) 2677.0 -31.2
20) 2674.0 -34.2

High: 2733.0
Low: 2674.0
E.S.: 59.0
Ave.: 2708.2
S.D.: 15.3
95%: ±7.5