Safety ladders with CFE223 and 123gr. SST's

[Heywood]

I thought today would be a great day to start work on a load for my grendel using cfe223 and 123 gr. SST's. So I hunkered down to the ol press and rolled a few.
The first thing I wanted to do is establish some safe working loads so I made five loads each of ten different charges to begin.
Starting at: 30.2 and ending at 32.9. In .3 gr. increments, looking for any pressure signs on the brass or spikes in velocity with the chrony. All cartridges were loaded to 2.276 coal.
My factory Hornady 123 gr. SST load spits em out at 2480 fps. So I was looking to get a bit more velocity out of my 20". Lilja.
Here is what I ended up with.
30.2 average velocity= 2448
30.5 a.v. = 2452 + 4 fps velocity increase.
30.8 a.v. = 2485 + 33 fps increase
31.1 a.v. = 2503 + 18 fps increase
31.4 a.v. = 2534 + 31 fps increase
31.7 a.v. = 2562 + 28 fps increase
32.0 a.v. = 2573 + 11 fps increase
32.3 a.v. = 2605 + 29 fps increase
32.6 a.v. = 2624 + 19 fps increase
32.9 a.v. = 2640 + 16 fps increase
I checked each case after each individual shot fired. None of them showed any signs of high pressure. No primer flattening, let alone cratering. No ejector swipes (though mine is polished and rounded so I do not know how much it would show).
I wish there was a way for me to find out actual chamber pressure for my loads.
I plan on doing an OCW work up in .2gr increments but looking for some advice on a good place to start and possible ceiling. I was hoping to get around 2600fps if feasible.
Any comments or advice would be appreciated.
I may put together a few preferred loads after the OCW and send them to PF to have them tested.

[LRRPF52]

What chamber do you have, BTW? When I did this same type of pressure ladder, I saw velocities that were way more than I expected, having worked with a number of different powders beforehand. Seating depth can build or relieve start pressure considerations, depending on what chamber you have.

[Heywood]

What chamber do you have, BTW? When I did this same type of pressure ladder, I saw velocities that were way more than I expected, having worked with a number of different powders beforehand. Seating depth can build or relieve start pressure considerations, depending on what chamber you have.

I was looking for your original thread, I was just going to add this to it so it would be in the same place but I couldn't find it.
Anyway, I have the long throated chamber from Lilja on this AR740(their first run). I have a bit to go as far as possible length with this bullet. I purchased the replacement from them and will build another on that barrel soon.

[pds]

I thought today would be a great day to start work on a load for my grendel using cfe223 and 123 gr. SST's. So I hunkered down to the ol press and rolled a few.
The first thing I wanted to do is establish some safe working loads so I made five loads each of ten different charges to begin.
Starting at: 30.2 and ending at 32.9. In .3 gr. increments, looking for any pressure signs on the brass or spikes in velocity with the chrony. All cartridges were loaded to 2.276 coal.
My factory Hornady 123 gr. SST load spits em out at 2480 fps. So I was looking to get a bit more velocity out of my 20". Lilja.
Here is what I ended up with.
30.2 average velocity= 2448
30.5 a.v. = 2452 + 4 fps velocity increase.
30.8 a.v. = 2485 + 33 fps increase
31.1 a.v. = 2503 + 18 fps increase
31.4 a.v. = 2534 + 31 fps increase
31.7 a.v. = 2562 + 28 fps increase
32.0 a.v. = 2573 + 11 fps increase
32.3 a.v. = 2605 + 29 fps increase
32.6 a.v. = 2624 + 19 fps increase
32.9 a.v. = 2640 + 16 fps increase
I checked each case after each individual shot fired. None of them showed any signs of high pressure. No primer flattening, let alone cratering. No ejector swipes (though mine is polished and rounded so I do not know how much it would show).
I wish there was a way for me to find out actual chamber pressure for my loads.
I plan on doing an OCW work up in .2gr increments but looking for some advice on a good place to start and possible ceiling. I was hoping to get around 2600fps if feasible.
Any comments or advice would be appreciated.
I may put together a few preferred loads after the OCW and send them to PF to have them tested.

I ran a test like yours with CFE and 123 Nosler CC bullets last summer in a Precision Firearms Grendel and 22" Bartlein barrel using Wolf SRM primers. Air temp = mid 70's:
31.0 gr = 2537 fps, SD=6.4, ES=17
31.3 gr = 2560 fps, SD=7.4, ES=18
31.6 gr = 2599 fps, SD=10.0, ES=24
I stopped at 31.6gr even though I had no over pressure signs on the cases. I've gone back to 31.0 gr (2537fps) as my standard load with this bullet it shoots sub .6" five shot groups if I do my part.
I agree with you some actual pressure readings for this powder in the Grendel would be nice.

pds

[GSPHunter]

Heywood, Have you measured the water capacity of your fireformed but nonresized brass? I got about the same results from my 20" J&T. The fireformed case capacity for it with hornady brass is 37.2gn......1.8gn's more than the brass that comes out of my 14.5" sabre. That combined with an extra .045" of leade ( COAL of 2.290" ) helps it tolerate a bit more powder. Brass life sucks though....only got 9 reloads before the necks started splitting :-) Maybe need to bump the shoulder a bit less.

I think if the standard deviations are good I'd be looking anywhere around 32gn for a nice load....I stayed at 32.0gn just because it shot well and was going over ~2550.

[Jakal]

So what is the CFE223 max charge with Hornady brass and the SST 123's? I have a load ladder from 31, 31.3, 31.6, 31.9. I understood that 32 was about max. I have seen different MAX loads with this powder and none of them seem to agree.

I have a Lilja 20" AR740 (second run) profile also. The factory 123 SST's run right at 2465 fps out of mine.

[Bwild97]

A chambering that allowed the SST / Amax to be loaded to a COAL of 2.300" could allow a bit more powder in the case. Take some pics of fired case heads, I'm curious to see your results.

[Heywood]

PDS. Thanks for your info.

GSP. No I haven't taken that measurement. I will though soon. Thanks

Bwild97. I will take some soon, hopefully tomorrow, I just don't have the energy tonight. 16 hour days 6 days a week is a lot harder on me than it used to be.

Jakal. I have no idea...

As far as sending some loaded rounds to PF to have them tested, maybe we can go in on this together. We could decide on a selected charge, and send them in. Spread the cost, spread the knowledge.

[Heywood]

image.jpgimage.jpgimage.jpgHere are some pictures of my fired brass at 32.9 grains CFE223 behind 123gr SST's it looks identical to the factory ammo I have fired. Let me know if you need more.

[GSPHunter]

Well Heywood, I am soooo hesitant to comment on your pics and data when there are so many people on this forum with about a billion times more experience than me, but I guess I'll take a stab at it,

Primers 3,5, and 10 look like they are just starting to crater, and primers 2,3,6, and 7 are looking a little flat for my comfort level. Assuming those are CCI450 primers, you can always try a slightly thinner cupped primer (eg. federal 205M) and see how they look......I'd definitely stay with a magnum primer though....

Looking at your data, it could be that your velocity is starting to plateau after 32.6, if the extreme spread and standard deviation are getting bigger, thats a sure sign you're heading into a bad place. I think Hornady does list a max load of 31.7gn for the 129gn bullets, so you're not off into crazy land yet :-)

I would guess that 32.5 might be a reasonable max load for now. To me, the trouble with CFE and LVR is that they are so mellow that Its easy to get in to a slightly overpressure load that is going to beat your bolt to failure without knowing it.

[LRRPF52]

You're starting to head over the edge if you go past 32.0gr of CFE with a 123gr. There will be more data coming forth when it is ready for presentation, but I personally can't recommend loading hotter than 32.0gr.

Using some pressure estimations, it looks like 32.6gr is over the SAAMI Maximum Average Pressure. Given the velocities that we have already achieved with 31.5gr, I'm more than happy. 31.5gr is below MAP with quite a bit of room for margins, as is 31.7gr with a 123gr cup and core pill.

I'm at 2520fps at 2.275" COL with 31.4gr from a 16" barrel with a SAAMI chamber that allows pretty long seating depth with the 123gr A-MAX.

32.0gr puts me at 2553fps from a 16" barrel.

[LR1955]

Well Heywood, I am soooo hesitant to comment on your pics and data when there are so many people on this forum with about a billion times more experience than me, but I guess I'll take a stab at it,

To me, the trouble with CFE and LVR is that they are so mellow that Its easy to get in to a slightly overpressure load that is going to beat your bolt to failure without knowing it.

GSP:

You have more experience than you give yourself credit.

A guy can get away with enough shots of these overloads that they think nothing will happen. Then they shear lugs.

LR1955

[LRRPF52]

For those that are wondering what kind of real world longevity you might get, I have been loading 31.2gr of CFE under the 123gr A-MAX since late 2012, when I did my first pressure ladder with CFE/123gr A-MAX.

The pressures are very low with 31.2gr, but still give me 2500fps. 31.1gr gives me 2489fps, and 31.4gr gives me 2520fps, again from a 16" little carbine.

This discussion is another great example of how small increments equal large jumps in pressure with a case that holds 34-35gr of water.

.3gr of charge weight increase increases the pressure substantially. I would consider loading in .2gr increments as you pass 31.0gr just to help dial-in an accuracy node.

[Jakal]

This thread hit at the right time for me. They way I work up a load is to run 1 charge of each weight just to look at the primers and see were the edge is. So from a 30 to 32 ladder, I will load up 30 30.5 31 31.5 and 32. I shoot these to get a baseline. I then go back and drop off maybe the 30 and 30.5 but run 5 rounds each of the 31 31.3 31.6 and 31.9. I will take the low and high accuracy nodes and go to .2 of a grain both above and below those charges. So if the 31.3 and 31.9 are the low and high, the next charge ladder will be 31.1 31.3 31.5, & 31.7 31.9 32.1. Run all of these over the CED chronograph while watching for primer issues.

By this time I have a real good idea of where the load will be. I will take the fastest and accurate load. Even if that means I settle on the low accuracy node. I'll sacrifice speed for accuracy.

[Heywood]

Thanks to all who gave constructive info. I planned on doing OCW work in .2gr increments when I settled on a safe operating pressure with good velocity. With this input I will start at 31.0 and work up to 31.8 and see what I come up with. Then I will look at seating depth a little more closely.
Thanks again.