CFE 223 Temperature Sensitive

[rattleguard]

I'm from South Texas where it is typically fairly warm, even in the winter. I found a good load for my 129 gr Nosler Accubond Long Range bullets with 30.4 grains of CFE 223. Other than it running pretty dirty with my suppressor, it has been an excellent load. Super accurate and good enough velocity to be ringing steel out to 1,000 yards. I just came back from a meat hunt in the hill country where we were after some tasty axis does to fill the freezer. The temps dipped into the 50s and I had two consecutive failure to ejects. This has never happened before so I don't know what else could have caused this. After dropping the two does the first evening I did some predator calling the next day and got a fox. The temps were back in the 70s and the empty round cycled flawlessly. Could the drop in temperature have caused this malfunction? The gun was clean and oiled prior to those first two shots. Has anyone else had any similar experience with temp sensitivity of CFE? If so, what would be a good replacement powder?

[Joseph5]

Yes it could have. If your load was borderline for functioning a 20 degree drop in temperature could do it. I have some factory 123 AMAX that states on the box the velocity is 2580 fps. I have factory 123 SST with a stated velocity of 2620 fps. The SST will cycle with my gas block set for my reloads and the AMAX won't reliably.

[rattleguard]

I guess I won't be using that load for my Alaska trip after all

[LRRPF52]

30.4gr of CFE under the 129gr ABLR should run the gas system plenty hard, even in the cold. That's around a max pressure load, if not max.

I suspect something else is going on. Are you using an adjustable gas block?

I need a lot more information about the details of the gun, namely:

Barrel length and gas system length (CLGS, MLGS, RLGS?)
Chamber
Gas port diameter
Bolt carrier group source
Recoil system (carbine/rifle, buffer weight)
Lubrication?

[Joseph5]

I don't think there are any powders that are totally immune to temperature sensitivity. Some are just less sensitive than others. You could work up a functioning load by getting your test loads close to or colder than the expected environmental conditions of your hunt. Refrigerate or freeze your test loads. There have been threads on here about the degree of temperature sensitivity of various powders that could be found with the custom google search engine in the sticky post in the AR forum. Right off the top of my head AR Comp is one of the least temp sensitive powders.

[PA_Allen]

Rattleguard,
I had the same thing happen twice this hunting season with my suppressed 16", 123 SST, and 31.2 gr of CFE223. Both were failure to eject in cold weather and the first shot (cold rifle, lube etc). I never saw this with my XBR 8208 load. In my case I think I just need to open up the adj. gas block another click or two. My gas block was tuned with my 8208 load and suppressor.
- PA

[rattleguard]

It's a JP Enterprise CTR 02. Everything on it is JP Enterprise. The gas black is adjustable and tuned for the load. The gas system is rifle length. Also forgot to mention I was running my Specwar suppressor

[LRRPF52]

I would look at the adjustable gas before anything else.

Cold weather + adj gas tuned to run with minimal perceived recoil in the summer usually = problems cycling in the cold.

[reddrock]

I have a jp adjustable block on mine, I agree with LRRPF52 open the gas block a little more.

[rattleguard]

I actually run it virtually wide open. It's as open as it can get per the requirement of having two full threads and loctite.

[reddrock]

you might check the alignment of the gas block with the port and the size of the port.

[McFireFighter]

I get similar issues with that powder and bullet combination. Running 30.9 grains and seems going shorter oal had more failures. No adjustable gas block here.

[rattleguard]

Going to be testing the temp sensitivity for myself here soon.

[motoxxx_ryder]

what kind of oil are you using? some oils get very tacky in the cold (frog lube applied incorrectly was a major complaint).

[McFireFighter]

Don't think it's oil on my side. Temps were not that extreme when experiencing the failure. I don't use anything special.

M-Pro 7 LPX Gun Oil

Things have been running better as it wears in. My 5.56 is like butter using M-Pro 7.