Reloading for the new .277 Fury from Sig
- Thread starter C-130 Dude
- Start date
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Thanks! I suspect that the fired 277 Fury case would gain some volume, so they are very close.
Yep.
I know with my new barrel, the bolt closes on a Go gauge, but not on a Go gauge with 0.003" of tape on it. If it ever starts closing on that, I assume I've had lug setback. Indirect but seems like it should work.
thanat101
New Member
I continue to load in small grain increments and will have more data soon. I have both the straight brass and the hybrid brass/steel cartridges.
With the loads right now, I'm around 50,000 psi. I don't plan on going over around 65,000 psi with my loads. Just looking for a nice cycling, good functioning round for the semi-auto.
The factory rounds I'm shooting from SIG 135 full metal jackets are way over the published muzzle velocity. Close to 2900 and when suppressed it just destroys the fired cartridges neck and heads.
I have the hitman industries 277 fury barrel that supposedly will handle 80,000 psi, a high-pressure bolt carrier group, SA adj gas block. I'm using the a Toolkraft BCG with reduced pin hole diameter size for the extra gas.
thanat101
New Member
Not exactly scientific, however, with both type of cartridges, the exact same trim length, each cartridge will hold 51.1 gr of powder up to the top of the neck.
Yes. I agree you're not able to read the actual pressure, but you sure can feel it when firing in a semi auto rifle. I bet in the future SIG factory rounds won't generate as high pressure, because it's uncomfortable for the shooter.
thanat101
New Member
Got some new data on muzzle velocity for 277 Fury on my gun. PLEASE NOTE YOUR GUN WILL HAVE DIFFERENT RESULTS. START AT MINIMUM LOAD and work up to safe level. I started with 33.4 gr. of powder. See prior post from April 14, 2024.
I continued reloading in small increments. I shot 3-4 round groups using magneto speed pro 3 on a suppressed 277 Fury AR-10 Build, 16 inch barrel.
135 grain FMJ with 16" barrel on .277 AR-10 Build.
Used Pulled Sig 135 grain FMJ projectiles.
Used Accurate 2015 smokeless powder
Used Unis Ginex, 5 5/N primer for large rife
Used once fired Sig 277 Fury Brass
Trimmed case length was 2.0185 inches
Overall cartridge length was 2.805 inches
35.5 gr - 2520 muzzle velocity
36.0 gr - 2550
36.5 gr - 2570
37.0 gr - 2600
37.5 gr - 2644
38.0 gr - 2652
grouping was all tight, I saw no noticeable difference for standard hunting/plinking.
I think between 38.5-40 gr. of "Accurate 2015" smokeless powder is going to be the sweet spot for an AR-10 style Fury. Will let you all know. I want to keep the pressure well below 65,000 psi chamber pressure for wear n' tear.
I continued reloading in small increments. I shot 3-4 round groups using magneto speed pro 3 on a suppressed 277 Fury AR-10 Build, 16 inch barrel.
135 grain FMJ with 16" barrel on .277 AR-10 Build.
Used Pulled Sig 135 grain FMJ projectiles.
Used Accurate 2015 smokeless powder
Used Unis Ginex, 5 5/N primer for large rife
Used once fired Sig 277 Fury Brass
Trimmed case length was 2.0185 inches
Overall cartridge length was 2.805 inches
35.5 gr - 2520 muzzle velocity
36.0 gr - 2550
36.5 gr - 2570
37.0 gr - 2600
37.5 gr - 2644
38.0 gr - 2652
grouping was all tight, I saw no noticeable difference for standard hunting/plinking.
I think between 38.5-40 gr. of "Accurate 2015" smokeless powder is going to be the sweet spot for an AR-10 style Fury. Will let you all know. I want to keep the pressure well below 65,000 psi chamber pressure for wear n' tear.
Ret 11B
New Member
For you guys pushing velocity in the hybrid cases, what primer are you using?
I haven't gone crazy with velocity, but per GRT I'm over 70 ksi, and both the primers American Reloading sends (yellow color, maybe CCI?) and Federal Large Rifle (not Magnum, just didn't have any) have worked fine.
I lost a Fed 210 in a 260AI pushing a 140 Barnes Match Burner at 3236fps. I haven't calculated pressure but I bet it's north of 70k.
Ret 11B
New Member
That's hot for sure. I have a Savage 10FCP I'm wanting to develop a new load for. It's currently still on its factory .308 barrel. I'll probably use a proof barrel (very nice discount through expertvoice) in 6.5 creedmoor and hope it likes the berger 144s. Granted, a 260ai does hold a bit more powder than a 6.5 creed.
With my 6.5 CM hybrid cases, I'm getting >2820 fps with 140 ELDs *from a 20" barrel*. Pressure signs are the tough part, you really just have the primer and bolt lift to go by, but so far neither one.
The factory ones that came in them, plus Federal 210 & White River Large Rifle.
RUFFIAN R - NY
Well-Known Member
Just ordered 300 rounds of 277 Fury Hybrid OFB brass. Am sitting back to see how all of this plays out before I go on another build. Any suggestions would be very nice info ???? Who's dies with bushings on the FL ones? Thanks in advance and good shooting and reloading.
