Just strange they released this. Wonder if the original bolts are not holding up and this is Sig being Sig, introducing parts to fix issues and making the end consumer foot the bill. Or maybe they're releasing a hybrid case in 308 and 6.5CM?
- Thread starter oda175365
- Start date
I know they are having problems with the 277.
So I doubt they would release high pressure into standard cartridges at this time. I have 1000 277 hybrid cases and have formed them to 308 and 6 5 Creedmoor. Hand loaded to the 80,000 psi area in 2 regular rifle actions...400 rds and check action for set back, so far it's okay..
But not recommend.
As for standard 308 and 6.5 CM I use high pressure bolts in both calibers in AR 10 s which will take any load I put in the bt guns. They h a very the .062" firing pin...but I did Not put an 80,000psi load in the AR 10. But with an adjustable gas block 65,000 psi is doable.
how is the 6.5 creed accuracy at those high pressures? This sounds very interesting. Also, will the .277 cases fit in the 6.5 creed die sets?
In good barrels accuracy is very good. The hybrid case forms well in all standard steel dies.
If going to 6.5 CM use a 308 die first without the decapping rod set just slightly above the CM finished shoulder, then use the CM die to finish the forming. Trim to length some first and complete trim after sizing. Do not lube the shoulder area to be sized.
These new rds are noticeably more powerful than standard 6.5 CM rds. Useful powders are limited, and my favorite has been unavailable for several yrs. There may be something in the Vit line...check with QL. My 24" factory barrel likes 2990 fps with the 150 SMK, it will run 3050, but sustained accuracy is where ya find it. The 140 Nosler will run 3156 fps, as top load, but I was only interested in the heavy 147 ELD-M and the 150 SMK, at around 3000 fps.
I have a new 26" 6.5 CM barrel so I'm not concerned about barrel erosion. High performance has a price...be careful this is not recommended by any manufacturer... at your own risk work slowly...no pressure signs on SS heads, primers won't blow, case heads will have no marks. And you're at 85,000 psi your action or bolt lift is sticky ...you've just stressed your action... back off do not go higher. The primer teat is the only clue as that is brass and it will flow...
I you are going to try the 6.5 CM the powder is RL26, for the 140 to 150 gr...I use no other and my 8 lb keg is down to about 4 lbs...and it's been absent for several yrs. You need some reloading experience and a chronograph min. Normal powders like H4350 fall short. It's true with all these high pressure loadings. Powders are limited, that are useful... and many seem unavailable at this time.
The cartridge designers like Sig have the deep pockets to have powder companies blend over 60 powders to find the one for a small range of bullets for that caliber, to be loaded into the high pressure 277 Fury are for military use and unavailable to the public, and are top secret at the time of development. So all we can do is get close with what is available on the commercial market at this time. So that's why the reluctance to reveal load data, as there is no control of seating depth, or chamber, action strength, reloading practices, or component variations. All of which add or subtract to chamber pressure. Plus Sig seems to be having trouble, with certain aspects of their bolt gun, discharge when the bolt is closed was an early one...don't know if high pressure was a problem with any of the steel components.
But a significant improvement can be made for a careful reloader...and of coarse again none of it is recommended....but reloads void most firearm warranties anyway...as always be careful...don't push powders that don't get ya there.
Thanks for all the info. Probably going to wait for SIG to advance the .277 into the cross. waiting for proof research to make a carbon .277 barrel and reloading availability for the fury round eventually becomes available. I can only hunt with copper rounds so there are no options to use the fury round as of now.
Hornady and Barns make copper 277 bullets for for handloading. So they could easily be loaded in the .277 hybrid cases. If all this hybrid stuff takes off and Sig gets the 277 problems ironed out, it will all be more user friendly with load data and possibly new powders and bullets designed for the 277. Time will tell. In the mean time I'm working on other projects but have found a few powders through QL that are more readily available and work in the 6.5 CM resized 277 hybrid cases.
I'm reloading the 277 fury now with the hybrid case. You can buy unfired hybrid brass. Redding makes dies. I also only shoot non-lead for hunting. I just finished up my load development for the 140gr Badlands SBD-2 and the DRT 152gr Terminal shock. All the pre-fit people are making barrels chambered in it. I'm not a fan of carbon, so that keeps them quite affordable to.
There are only a few powders that get the pressure that high, with an elongated curve and also fit in the case.
And honestly, even the brass case at 65kpsi and that 140gr SBD-2, it's lethal on anything I'd shoot a 140gr 277 bullet at to past where I'd take the shot. The brass case is within 30fps of a 270win with the same barrel length. It does better than the 308w vs 30-06.
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I have the new bolt in and it is indeed different from the original that came with the rifle. See photos below. My original is loosing lots of its coating on the bolt face and actually came with a bit missing to start with. But you can clearly see the +P marking on the new bolt. Wondering if it'll change my headspace as I'm tempted to swap it in now.
None visible. Assuming it's all "under the skin" with different metallurgy. All the angles and dimensions look identical to me.
The "+" on the bolt lug.
There's no defined "+p" standard in rifle ammunition. Modern properly hardened steel actions will hold 75kPSI. Brass is the failure point. You could put "+" on a Savage bolt and it would be "+p" too.
I get that. They list the part as "new" and they've offered the bolt separately for sale before without the +P designation or + insignia on the lug. The OEM bolt is no longer listed but I often see things de-listed on Sig's site when they're out of stock and will be for some time.
Their official verbiage off the website;
"Factory replacement bolt head assembly for the SIG SAUER CROSS, .308 Win and 6.5 Creedmoor to support +P cartridges.
Factory replacement bolt head assembly, capable of handling +P"
Just the messenger here and bought it out of curiosity and posted up here to see if anyone knew anything about the decision to market a +P bolt and whether it was different from the original. At the very least I now have an extra bolt!
Their official verbiage off the website;
"Factory replacement bolt head assembly for the SIG SAUER CROSS, .308 Win and 6.5 Creedmoor to support +P cartridges.
Factory replacement bolt head assembly, capable of handling +P"
Just the messenger here and bought it out of curiosity and posted up here to see if anyone knew anything about the decision to market a +P bolt and whether it was different from the original. At the very least I now have an extra bolt!
I buy AR 10, 308, & 6.5 CM bolts from Toolcraft that are marketed the same way as +P for high pressure cartridges like 6.5CM, 308...but they also come with .062" diameter firing pin not the original. 075" diameter. Will they take a slightly higher pressure than the "regular bolts", ...maybe, maybe not,.. the brass is the weak link I shoot the same loads in the bolt gun as the AR 10 auto with no ill effects. Also have a lever action 454 16" barrel...it "looks" the same as the others but it shoots 65,000 psi cartridges, buy the thousands, 16" barrel 240 gr at 2300 fps or 300 at 2000 fps. They say it has a special heat treatment to the SS action.
I also run the reformed Sig hybrid 80,000 psi cases in standard factory rifle actions Rem & Ruger, in 6.5CM & 308, and run the to that pressure...but it's not recommended.
I also run the reformed Sig hybrid 80,000 psi cases in standard factory rifle actions Rem & Ruger, in 6.5CM & 308, and run the to that pressure...but it's not recommended.
On another note, how many rounds have you ran through your Sig Cross? Im at about 700 rounds on mine and have cycled the bolt probably a couple thousand times and it feels very smooth. This is very quickly becoming my favorite rifle. Even with there being a few custom rifles in the safe. Just wondering about the durability of this platform in the long term. I have a custom rifle built on an Impact action and it just makes you feel confident in the durability department. It feels like one of those actions that you buy, shoot the piss out of, and just wear out barrels on, you know what i mean?
Bolt guns will stand up to many thousands of rds of 65,000 psi ammo. I have one old trued Remington 700 that has over 20,000 such rds and a quite a few new barrels attached, when doing alot of LR shooting, years ago...but 80,000psi loads will most likely wear and stress the barrels and actions a bit more, check with chamber gauges to see if lug set back is occurring, no matter who makes the action.
I featured my Cross in this video, if anyone is looking for inspiration on how to set one up!
We have some extra .243 barrels for the sigs if anyone needs to get one quick! https://straightjacketarmory.com/product/sig-cross-overstock-sale/
Good idea, but it looks like that check rest is crazy low for an optic.
I 100% want that shortened handguard.
Is it me or is the scope base different? I would think so because the handguard/receiver junction is different as well.
ETA: Sort of crazy that they could only drop 0.4 pounds. That new stock must still weigh a lot. I know the original without the folder is 17 ounces.
That is the stock the Cross should have come with. The factory stock is trash.
Parker Mountain Machine has their "Kate Moss" which is similar but it has the option of a cheek riser in different heights so will likely be more effective. I have one on my Spear LT. Not sure what to think about the Trax, seems like a parts bin special with parts that aren't well thought out (stock and grip).
Where can we find unfired hybrid brass? I've been pulling assembled rounds for the brass.
Much appreciated and in stock.
That stock wont work. The Cross stock has the milled out slot that allows the bolt to come back. Also, the rise in the Kate Moss is too close to the receiver and would not allow for a full retraction of the bolt. I called PMM a while back and we talked over measurements on the phone. They were awesome.
I also think this was thrown together, with the exception of the shorter handguard. I want that. I am cool with whatever they want to bring to market as long as it keep the Cross in stock and aftermarket folks moving. So far we have barrels, selector levers, mag releases. A stock is coming soon, scope mount, handguard, and a few other things.
So I'm curious if anyone has any experience/pointers regarding balancing the rifle through rebarreling.
I'm at the point where I'm ready to rebarrel my 6.5 Cross pretty soon and I was hoping to do so in such a way as to move the balance point of the rifle just slightly ahead of the barricade guard/magwell. Ideally I'd like to keep the same barrel length same as stock as it fits my bag perfectly, and instead work with barrel diameter. I realize that's not the most efficient way to move weight forward and that I'll end up with a slightly heavier rifle, but I'm already saving a good bit of weight by going somewhat minimalist on the optic and willing to make that tradeoff.
Has anyone tried this, or am I way out to lunch?
EDIT: I'm in Canada and therefore a Suppressor is unfortunately out of the question. I'm running an Area 419 Hellfire brake instead.
I'm at the point where I'm ready to rebarrel my 6.5 Cross pretty soon and I was hoping to do so in such a way as to move the balance point of the rifle just slightly ahead of the barricade guard/magwell. Ideally I'd like to keep the same barrel length same as stock as it fits my bag perfectly, and instead work with barrel diameter. I realize that's not the most efficient way to move weight forward and that I'll end up with a slightly heavier rifle, but I'm already saving a good bit of weight by going somewhat minimalist on the optic and willing to make that tradeoff.
Has anyone tried this, or am I way out to lunch?
EDIT: I'm in Canada and therefore a Suppressor is unfortunately out of the question. I'm running an Area 419 Hellfire brake instead.
I wouldnt do a heavier barrel. Add weights when needed, take them off when not needed.
Slightly longer, but my Craddock with a 20” and ~M24 contour balances as described.
Found the link
BLK LBL BIPOD – SIG CROSS – BLK LBL BIPOD
The BLK LBL Bipod for the SIG CROSS uses our proven integrated bipod design housed in a smaller and lighter handguard designed specifically for bolt action rifles. Nothing is more stable than shooting from a bipod. But sometimes it not practical to do so. That’s the magic of the BLK LBL...
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If you want to get an Arca rail further back take a look at the Odin Works Arca Trax. I was able to mount the first slot (the single hole) nearest the magwell. As seen in the pics the split design allows a more rearward purchase. Its also super low profile.
*no affiliation, just something I found and wanted to try
*no affiliation, just something I found and wanted to try
Odin Works also has this one, which I’m gonna pick up.
Arca 3-Way Rail | Shop Now
Upgrade your AR-15 with high quality American manufactured parts. Fully built rifles, complete uppers, barrels, forends, and many other accessories. ODIN Works is your main supplier for made in the USA rifles and accessories. Shop now!
www.odinworks.com
I need a fairly well padded but still lightweight bag for a folded 16" Cross.
For an a light aircraft. Ideally with backpack straps.
I think the folded length is like 27" or so.
Any recommendations?
For an a light aircraft. Ideally with backpack straps.
I think the folded length is like 27" or so.
Any recommendations?
I have this bag (30 inch) and fits tight with a break on the barrel but fits (6.6 creed with 18 in) . It's comfortable on my back too.
Savior Equipment Specialist Series 30" 34" 38" Covert Tactical Gun Bag Backpack Soft Case with Compartment, Low Profile Bug Out Truck Bag, Hideable Backpack Straps, MOLLE Panel
Attachments
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Nothing on Odin Works’ website yet…
Spoke to them and they were still waiting on extensions from Sig. I asked how many, he said a lot. It will most likely be March according to another guy there.
Proof also waiting for the barrel extensions to ship out orders. Last I heard
Question for those that went to a 20 inch Creedmoor barrel, or have another model...
What speeds should I expect from a 140 class bullet assuming H4350?
I want to get the Proof barrel but I need the speeds for a 140 to be at 2700 to make power factor in NRL Hunter.
There are too many people being ok with slow speeds when I search. I am willing to push it a bit for competition loads.
What speeds should I expect from a 140 class bullet assuming H4350?
I want to get the Proof barrel but I need the speeds for a 140 to be at 2700 to make power factor in NRL Hunter.
There are too many people being ok with slow speeds when I search. I am willing to push it a bit for competition loads.
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Alliant Reloder-26 106.7 48.9 3.17 2943 100.0 62300 10908 1.180 ! Near Maximum !
What the heck is 4835?
The result of my dyslexic brain typing the wrong powder number... H4350. I fixed it.
Thanks, @Metzger those are some good numbers.
This isn’t nick but I’ll let him know
