Bumping this thread.
Im trimming brass to 1.74"
77gr nossler cc w/canelure
Bullet set the where the canelure is just showing
Cci 41 primer
23.6gr tac did not cycle
23.8 did half the time
24.0 cycled but I may have ejector swipes? Does this make any sense?
Barrel is 5.56 centurion CL, has been reliable with 556 and wolf gold, and fiocci 223.
Last edited by MegademiC; 03-19-22 at 16:01.
Megademic,
I've gone to 24.4 grains of TAC and the same bullet in a BCM 18" 5.56 barrel. Got some pressure signs at 24.7 grains. But every barrel is different. If your using once fired brass are you sure the swipe is from this load??
I use a bunch of once fired LC brass that I got processed, and I've been fooled before. I look for swipes on more than one case with the same load. TAC is also a bit temp sensitive like most ball powders. It's also easy to overcharge TAC since it's settles so well.
Last edited by BobinNC; 03-19-22 at 18:06. Reason: spelling
24.4-24.6gr of TAC. Sigle digit sd and es on 2 triarc barrels and 1fn.
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Ok thanks all. The swipes are super light and may be from first fireing since its 5.56.
Ill bump up the charge and work up some more loads.
Yeah... like you already said. You won't go from "won't run" to swipes that quickly with TAC. (Chrono is critical)
As far as trimming. I set mine up to trim at 1.76. The more neck the better. (up to a point). There's an old belief that long necks are the end of the world. But Black hills reman ammo used to be MASSIVELY over case length, and guys shot tons of that ammo without issue.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
I've run loads of the 77grn Nosler CC, 24.0 grn TAC, CCI #41, LC brass sorted by year, 2.250" OAL through 3 different AR-type rifles - all 16" Chrome lined, 5.56 NATO chambered, 1:7" barrels (2 Sabre Defense and one Centurion Arms barrel). Chronographed from 45F to 75F degrees with 2,580 to 2,630 fps avg velocity, SD 9-21 fps. No swipes or other pressure signs in our rifles.
Worked up from 23.0 grn to 24.5 grn TAC (other stuff as above), all functioned in our rifles. At 24.5 TAC got light slight swipes in the one rifle it was tried. Used the 24.0 grn load for general shooting. These are from components purchased several years ago. Used to be that TAC and the Nosler 77 grn CC were a nice, readily-available, inexpensive combo that shot well.
24.0-24.1 TAC or 23.2 8208XBR in a LC case and CCI#41 primers is my go to with 75/77's. Oddly enough, the TAC load is a bit more accurate and consistent with a medium crimp, no idea why. Both run ~2640 in my 16" spikes Chf(fn) barrel, and right about 2600 in my Rosco 16".
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
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