re: Official AR-15 thread

That's odd. The manual says .308 WIN is good to go.

I'm pretty sure I have read that many have used .308 rounds...

Yea I just saw someone say it says on page 21 of the manual it says .308 is ok to shoot. I didn't look yet but will before I shoot it. I have read of some having issues with feeding and ejecting...some say needing a brake in some needing to go back to sig. I hope this one just works :)

I'll have to look in the manual and see how it's worded...or put a call into them.

Sig 716 Manual

Take a look. .308 is fine according to the manual.

When you call, I imagine they are going to tell you what they have told everyone else who's called. 308 is fine to shoot.

Reloading may be a different monster. Commercial ammo is fine, according to SIG and numerous owners who have commented on the subject.

Also found this read interesting...

The difference between .308 and 7.62 is chamber size, slight pressure differences due to powder burn rates, not external case size. Both cases will have the same external dimensions while the .308 has a slightly higher pressure 60Kish vice 50-55 CUP psi for NATO**. NOTE: This is OPPOSITE from the 5.56/.223 rule of thumb. The NATO chambers have greater tolerances to help with reliable functioning of military ammo. The NATO chamber is ever so slightly longer at .013". This is significant in that for reloading purposes, 308 brass will stretch more in a military chamber upon firing, thereby reducing the life of the brass and possibly promoting case head separation. But that additional chamber length will allow a round to chamber in an incredibly dirty weapon, which is a requirement for military applications. Also be aware this is why mil NATO brass is thicker vice 308 commercial brass. You will also see this "thicker brass fact" posted about 5.56/.223 brass which is a fallacy.

**As a side note the reason the pressure issue is confusing is becuase the military measured 7.62 NATO chamber pressure (PSI) via CUP (in the 40s) vice the normal commercial rating of PSI measured (now) with electronic means. You will see many cling to the 50-55K PSI figure for 7.62 Nato becuase that is what the old Army TMs have in them. Since there is no conversion for the CUP measurement to the newer electronic measured PSI, they are two different numbers i.e no direct comparison. Many people will assume the CUP PSI is the same as SAAMI/Commercial PSI. It is not. Commercial PSI is derived from the direct pressure in the chamber through electronic means (piezo transducer or strain gauges). CUP is a crush measurement of a copper slug that has been fired, again not the same test.

That means any newer weapon will be able to fire 308 Commercial ammo as manfs would not let them out the door if they could not, due to liability. Don't believe me, run the numbers/powders in any internal ballistics calculator and they will all be close to the 60K mark. BTW the proof load for the 308 commercial is 75K PSI, so don't worry about the 60K.

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Take a look. .308 is fine according to the manual.

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And people who have have actually shot that gun with commercial .308 ammo have had problems.

You need more than just a little Google time to understand all the issues here. What you found leaves out some very important details.

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Also be aware this is why mil NATO brass is thicker vice 308 commercial brass.

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Do you even know where the brass is thicker? Do you know many commercial loadings are actually thicker in the case webbing and base?

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That means any newer weapon will be able to fire 308 Commercial ammo as manfs would not let them out the door if they could not, due to liability.

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They let them out the door all the time. Tolerance stacking is something no manufacturer can control 100%. There is a reason why people who actually know about these things recommend getting a set of gauges or taking to a gunsmith to get checked out. At the very least getting several brands of 7.62mm NATO and .308 Win commercial loadings and doing a soft hand load with the bolt to test headspacing.

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And people who have have actually shot that gun with commercial .308 ammo have had problems.

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Actually, people have had more problems with the NATO ammunition. Google.

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They let them out the door all the time. Tolerance stacking is something no manufacturer can control 100%

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I seriously doubt SIG is printing manuals that say 308 is fine to shoot while there being an issue with infact shooting 308 out of this rifle. C'mon man. This has little to do with tolerance stacking, and more to do with it being huge liability to tell the owner he can shoot something that is unsafe (i.e. the product manual). And it's been in print for a while now.

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Do you even know where the brass is thicker? Do you know many commercial loadings are actually thicker in the case webbing and base?

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The point that was trying to be made in that passage was more in recognizing the fact that there is not as much of a difference in the pressure between NATO 7.62 and commercial 308.

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There is a reason why people who actually know about these things recommend getting a set of gauges or taking to a gunsmith to get checked out

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Yeah, I get that. I have my builds (not factory) gauged. If it were me, since there seems to be controversy, I would not hesitate to get it checked. Then, go shoot it with 308.

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Actually, people have had more problems with the NATO ammunition. Google.

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Wrong. Quality NATO ammo consistently measures to hold tighter specs than a lot of the low to mid-tier .308 commercial stuff and even better than a lot of the hunting .308 ammo. Start looking at who has feeding, and more importantly, extracting issues with the Sig 716 and you see it's mostly commercial .308

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The point that was trying to be made in that passage was more in recognizing the fact that there is not as much of a difference in the pressure between NATO 7.62 and commercial 308.

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Pressure isn't the issue as much at cartridge OAL and headspacing.

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I seriously doubt SIG is printing manuals that say 308 is fine to shoot while there being an issue with infact shooting 308 out of this rifle.

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I seriously doubt Sig had Barnes Vor-Tx ammo in mind when setting up that rifle. Barnes, like the vast majority of .308 hunting ammo, has OAL's all over the place. Maybe you missed the part where this guy wants to run the Sig for hunting?

Been lurking for a little while. Figured it was time to join the party. Here is one of my rifles (my first sbr). It is 11.5" with the Geissele MK4 rail, innovative arms W.A.R. upper and the rest you can figure out. M4-2000 stamp should be back around September. The one in the picture is my friend's that I tried on I'll post some of my other black rifles later

I'd like to do that with "Violence Policy Center"...

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Read Windham is part of Bushmaster or something like that and that Bushmaster's rep/reliability has been shot. (pun intended) not sure on this

Heard DPMS QC is shotty. (on fire ) I agree with this

Stag components don't have the value of Spikes or PSA. dont nesseccarily agree with this. stag makes good stuff

S&W 15 OR doesn't have the same level of components as the Spikes ST-15 and is same price

Heard some horror stories on PSA CS. Could just be high traffic times (around christmas) definitely not the norm for them. they are a great company. they had their struggles just like everyone else during the great gun buy

Should I go 5.56, 300 AAC, 7.62, or 6.8? if its just hobby shooting then go 5.56. for your purposes i wouldnt entertain 7.62 (whole new rifle platform) and 6.8 is expensive and is not as fun to shoot unless you are shooting game with it (a good bit more felt recoil than 5.56 & 300blk). 300blk is expensive unless you reload, but the beauty is down the road if you want to make the switch, all your parts will suffice and you just need a 300blk barrel.

That's all I got out of 2 days of researching.

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see above.

of the ones you listed i would go with the PSA or S&W


ETA: also, i recommend that you hold off on optic and get a good sling (i like blue force gear the best), and spend the rest on mags and ammo. then shoot the piss out of it with iron sights. shooting with irons first will make you a better shooter down the road and when you put an optic it will feel even easier.