Reloading the 277 Fury 6.8x51 SIG Hybrid Case

For those of you that have been playing around with this I have a question.

Are you finding that powders in the middle of the burn rate for your cartridge tend to be best when using these cases? I assume that you will run out of room before hitting peak performance if using the slower powders.

I just picked up 200 of these cases to see if I can get 2900 with a 162 grain ELDX using my 20" barreled 7-08AI.
 
For those of you that have been playing around with this I have a question.

Are you finding that powders in the middle of the burn rate for your cartridge tend to be best when using these cases? I assume that you will run out of room before hitting peak performance if using the slower powders.

I just picked up 200 of these cases to see if I can get 2900 with a 162 grain ELDX using my 20" barreled 7-08AI.

I rely on Gordon’s reloading tool for powder selection and still stay conservative with my pressures.


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Wanted to just start a thread on these hybrid cases.
I’m working up some of these resized to 7mm-08 for a Ruger American action. One of my challenges with identifying loads up around the 80k Psi is that most retail powders aren’t made for this, so options seem to be too bulky or very little increase in velocity for the added pressure. I’m also not going to run 80k in the Ruger, but just looking at the load dev in Quickload for that for now. The realistic loads that I’m looking at are < 70k and will give a bit more velocity than normal. CFE223 seems to be a good candidate so far. Curious to hear any other thoughts and experiences with these.
Hi. I'm interested in doing the same for my Ruger American
This is an unmodified 6.8x51mm next to one that was run through an RCBS 7mm-08 FL die and loaded with a 150 TTSX.
View attachment 857114
just to clarify, you just lubed the case and resized it in a die, no trimming? I may get some primed brass. Can I just raise the mandrel so the decapper won't touch the primer? Thanks
 
Yes, if you're asking is that how to resize with the primed brass, you need to adjust the mandrel so it doesn't deprime but still resizes.
 
My 26 inch Rock Creek in 260 runs faster than I expected using H4350 and RP brass it launches 140 Hybrids at 2963. Drops are verified on Shotmarker up to 500 multiple times. Once at 750. Come ups runs along Shooter predictions.

I have a bag of Hybrid cases. With these cases, I am hopeful I can be knocking on PRC territory.

Screenshot_20250705_143945_Shooter.jpg

Anyone out there still running standard 260? Have y'all tried the Hybrid cases?
 
How do these hybrid cases do in the precision department? I have always heard that groups start to open up as pressure increases and that has tempered my enthusiasm for this new technology.
 
How do these hybrid cases do in the precision department? I have always heard that groups start to open up as pressure increases and that has tempered my enthusiasm for this new technology.

My last 10 shot group with my Creedmoor was 7/8”.

Pressure Increasing group size is a thought that has never crossed the mind of anyone who owns a 6PPC.

I’ve kind of wrapped up my thoughts on these cases after having played with them in 3 different chamberings.

Short answer as to if it’s worth it. No

Long answer: Sure it’s fun to mess with, fun to see the numbers climb and turn a Creedmoor into a PRC or a 308 into an -06. If you’re a one rifle guy it might make a bit more sense or slightly more emotionally justified. At the end of the day, wildcatting these cases is probably only going to decrease my reliability and not make an animal any more dead for me and my use case.


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My last 10 shot group with my Creedmoor was 7/8”.

Pressure Increasing group size is a thought that has never crossed the mind of anyone who owns a 6PPC.

I’ve kind of wrapped up my thoughts on these cases after having played with them in 3 different chamberings.

Short answer as to if it’s worth it. No

Long answer: Sure it’s fun to mess with, fun to see the numbers climb and turn a Creedmoor into a PRC or a 308 into an -06. If you’re a one rifle guy it might make a bit more sense or slightly more emotionally justified. At the end of the day, wildcatting these cases is probably only going to decrease my reliability and not make an animal any more dead for me and my use case.


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That is refreshing to read! It does seem like an interesting science experiment and the velocities the extra pressure enable are certainly impressive. But there is no such thing as a free lunch…. For example, after all the initial launch of the 7 BC, the hype has kind of fallen off.
 
That is refreshing to read! It does seem like an interesting science experiment and the velocities the extra pressure enable are certainly impressive. But there is no such thing as a free lunch…. For example, after all the initial launch of the 7 BC, the hype has kind of fallen off.

Here is my take on why I am doing it.

I have a 7-08AI that I love shooting. When working up a load with 162 grain ELDX bullets, as I started going up in velocity, my group sizes started shrinking. The load that it shot the best resulted in primer pockets loosening up after 2-3 firings, so I know I was already above 65K.
With these cases, I can get to 70-73K and probably find the spot that this particular barrel likes best at this upper node. Even if I don't, I can fire that load that gives great groups without losing cases after 2-3 firings, rather than just having good groups with the load that is 0.5 grains less.
 
Here is my take on why I am doing it.

I have a 7-08AI that I love shooting. When working up a load with 162 grain ELDX bullets, as I started going up in velocity, my group sizes started shrinking. The load that it shot the best resulted in primer pockets loosening up after 2-3 firings, so I know I was already above 65K.
With these cases, I can get to 70-73K and probably find the spot that this particular barrel likes best at this upper node. Even if I don't, I can fire that load that gives great groups without losing cases after 2-3 firings, rather than just having good groups with the load that is 0.5 grains less.
That makes sense. I just don’t think it is going to be as revolutionary as many people first believed. It certainly does have applications in many areas (i.e., military & hunting). But I suspect there will always be trade-offs and precision is one of those. I would be surprised to see these hybrid cases on the podiums anytime soon. Neverthrless, I hope I am wrong about this because I love the innovation they represent!
 
My last 10 shot group with my Creedmoor was 7/8”.

Pressure Increasing group size is a thought that has never crossed the mind of anyone who owns a 6PPC.

I’ve kind of wrapped up my thoughts on these cases after having played with them in 3 different chamberings.

Short answer as to if it’s worth it. No

Long answer: Sure it’s fun to mess with, fun to see the numbers climb and turn a Creedmoor into a PRC or a 308 into an -06. If you’re a one rifle guy it might make a bit more sense or slightly more emotionally justified. At the end of the day, wildcatting these cases is probably only going to decrease my reliability and not make an animal any more dead for me and my use case.


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Any speculation on how Hammers would do? They seem very forgiving.
 
Any speculation on how Hammers would do? They seem very forgiving.

Negative, my rifles receive a steady diet of cup and core bullets. The accuracy I’m receiving from 147Ms is far better than I need currently


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Any speculation on how Hammers would do? They seem very forgiving.
I have a few 137 HH still on hand that I'm considering trying with these cases assuming I have a suitable powder on hand. I'm not sure i can get enough Varget in the case to push beyond normal load ranges. Maybe CFE223.

FWIW, I ran 5 of the fury cases through a Lee FL sizing die ( with decapper rod and removing the primer) and they sized to .308 easily and checked out for headspace via a Wilson sizing guage. Will shoot each with a standard pressure load first before going for gusto though.
 
I’m going to try this in my Ruger American Gen2 in 7mm-08. Looking at 150+/- grain bullet weight range. I was thinking about using staball 6.5, since the velocities listed in the Hodgdon website are higher for normal pressures already, and I'm only looking to get to about 3000fps in the 22" barrel. Is that powder a good candidate for this? Or should I look at another option? I only want to get to about 70000-72000 psi. Thanks
 
Hey all.

Just wanted to make everyone aware of a potential issue with using these cases to "hot-rod" standard cartridges.

According to Frank Green (Bartlein Barrels) these cases will start to ring the chamber at the steel/brass junction and this will eventually lead to extraction issues. Here is the thread on Accurate Shooter where he posted this: https://forum.accurateshooter.com/t...-277-fury-hybrid-cases.4127403/#post-38975499

Addtionally, a member of the Long Range Hunting forum posted that he may be seeing this in his 260AI chamber. https://www.longrangehunting.com/threads/my-260-ai-using-277-fury-hybrid-cases.386028/

As I am just starting out on my journey, I have 100 of these loaded up with a "standard" loading to fireform in my 7-08AI. My plan is to shoot 20 and then shoot 1 of my already proven loads that use Lapua cases. That load is 0.5 grains below max pressure. Once that is done, I will start doing load development with the new cases. For me that involves loading 5 rounds at each powder charge and then shooting those at 200 yards, documenting the speed and the group sizes. Since the steel heads on these cases do an excellent job masking pressure signs, I am using Gordon's Reloading Tool to help determine what the pressure is. I am expecting the most accurate load to be somewhere in the 70-73K PSI range based on my previous load development. My plan is to fire one of my Lapua cased rounds after every 20 shots of the load development rounds.

I will post the results on this forum and AS and LRH. My current barrel is about halfway through its projected life. Also, while I love this rifle, the current barrel is a Rem Varmint contour that is just too heavy, so when it is done it will be replaced with a 0.750 Taperless contour that is fluted. So, if I do end up ringing the chamber and getting extraction issues, it is no big deal to me as it will only bring my timeline up by about 12 months, based on how much I shoot that rifle now.

Just wanted to put this information out there so everyone goes into it eyes wide open.
 
I've resized about 400 of these cases to 6.5 Creedmoor.
1000028185.jpg
A few things to note:

1. These are factory pulldowns (at American Reloading) for a reason. I've bought four different batches and seen huge lots to lot swings in case weight and velocity with the same charges. So buy all that you'll want at once so you don't end up weight sorting like me. On a good sale they are $0.40 each or less.

2. Resizing to 308 then 6.5 CM worked best for me, but I needed to anneal in between or it wouldn't completely size before work hardening too much.

3. For my Tikka CTR chamber and Hornady case gauge, I need to neck turn to chamber 6.5 Creed. The case body brass ends up much thicker than it should be at the neck. This was a massive pain.

4. After firing these cases are not hot at all, I think the steel has so much more heat capacity it has that effect. Annealing is also a bit tougher to do that usual for the same reason, hotter and shorter is best.

5. Overuse the case lube (and annealing) when sizing. Stuck cases are damned near impossible to remove the usual way, the steel bases will pop off. I ended up getting a very oversized tap and screw as below to grip on the brass body.
1000027452.jpg

6. For the same reason, I'm concerned about case life and case head separation. There are basically no pressure signs short of primer flow and sticky bolts, at which point you're probably way way over 80ksi. And short of the couple of times I was resizing and got the steel base to spin separately from brass, I'm not sure how you would tell if you're getting case stretch at the 0.2" line and at risk for separation.

7. I'm enjoying tinkering with these cases and I think are well suited for low volume hunting applications rather than the match gun I'm trying to use them for.
c87dda3e-a696-4b36-b200-6c9ecd90c756-1_all_61839.jpg
 
Not sure how safe this was, but I got up to 2850 fps from my 20" Tikka barrel using 140 ELDs, using a damned near full case of H4350. Got sticky bolts though, so backed off a bit. I think 2800 fps is achievable without that, but I'm running at 2750 with 44.0 gr.
 
I've resized about 400 of these cases to 6.5 Creedmoor.
View attachment 904178
A few things to note:

1. These are factory pulldowns (at American Reloading) for a reason. I've bought four different batches and seen huge lots to lot swings in case weight and velocity with the same charges. So buy all that you'll want at once so you don't end up weight sorting like me. On a good sale they are $0.40 each or less.

2. Resizing to 308 then 6.5 CM worked best for me, but I needed to anneal in between or it wouldn't completely size before work hardening too much.

3. For my Tikka CTR chamber and Hornady case gauge, I need to neck turn to chamber 6.5 Creed. The case body brass ends up much thicker than it should be at the neck. This was a massive pain.

4. After firing these cases are not hot at all, I think the steel has so much more heat capacity it has that effect. Annealing is also a bit tougher to do that usual for the same reason, hotter and shorter is best.

5. Overuse the case lube (and annealing) when sizing. Stuck cases are damned near impossible to remove the usual way, the steel bases will pop off. I ended up getting a very oversized tap and screw as below to grip on the brass body.
View attachment 904181

6. For the same reason, I'm concerned about case life and case head separation. There are basically no pressure signs short of primer flow and sticky bolts, at which point you're probably way way over 80ksi. And short of the couple of times I was resizing and got the steel base to spin separately from brass, I'm not sure how you would tell if you're getting case stretch at the 0.2" line and at risk for separation.

7. I'm enjoying tinkering with these cases and I think are well suited for low volume hunting applications rather than the match gun I'm trying to use them for.
View attachment 904184
I got much of my information from 45-90 on SH for using the 277 Fury cases in my 260 AI. Lancetkenyon over on LRH also gave me some good info. 45-90 used Lee Resizing Lube when sizing to other cartridges. He stated failure to do so resulted in stuck cases. I got hard bolt lifts with my 260 AI due to not bumping the shoulders enough. The primers were nice and radiused, not the least bit cratered or flattened. The last load I did I was getting 3000 fps with 145 gr Barnes Match Burners with slight flattening of primers, slight cratering and a hard bolt lift. I still think I needed to bump my shoulders another thou or two. 120 rounds into the loading and three times fired on forty cases the ringing was enough that I could feel it with my fingernail. So at this point I am discontinuing the use until I can figure out a way not to damage my chambers. A hint I picked up, the cases with different headstamps weigh different and have different capacities. Hornady One Shot worked well enough for me to size to 260 AI and leave a false shoulder for fire forming. After that I used the Lee Resizing Lubricant. In the future when sizing to 308 Win or 7-08 I'll use the LSL. Be safe and I hope that helps.
 
I got much of my information from 45-90 on SH for using the 277 Fury cases in my 260 AI. Lancetkenyon over on LRH also gave me some good info. 45-90 used Lee Resizing Lube when sizing to other cartridges. He stated failure to do so resulted in stuck cases. I got hard bolt lifts with my 260 AI due to not bumping the shoulders enough. The primers were nice and radiused, not the least bit cratered or flattened. The last load I did I was getting 3000 fps with 145 gr Barnes Match Burners with slight flattening of primers, slight cratering and a hard bolt lift. I still think I needed to bump my shoulders another thou or two. 120 rounds into the loading and three times fired on forty cases the ringing was enough that I could feel it with my fingernail. So at this point I am discontinuing the use until I can figure out a way not to damage my chambers. A hint I picked up, the cases with different headstamps weigh different and have different capacities. Hornady One Shot worked well enough for me to size to 260 AI and leave a false shoulder for fire forming. After that I used the Lee Resizing Lubricant. In the future when sizing to 308 Win or 7-08 I'll use the LSL. Be safe and I hope that helps.
You said you had worked with 45-90 to get started, did you ask him about the ring? He gas been loading it for years in a multitude of Calibers. He may have some better long term knowledge. I've only been reliading these about 2 years, but he's been doing it quite a bit longer, I haven't had the chance to look at my chamber to see if it has a ring yet. Just curious what he may have seen...?
 
Yeah I've messages with 45-90 and he's recommended the Lee lube too, which I've tried. I didn't think it made a big difference, annealing well did. Edit: just tried it again and it actually is way better than lanolin/IPA, just a paint to apply. I only tested up to 4x finings on the cases so far, but mostly I'm at 1x.

I've put 233 rounds of the hybrid cases through my barrel, next time I get the bore scope out I'll look for ringing.
 
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