Hey guys anybody know what the standard thread pitch on the end of the barrel is on the piston driven 556 model sig rifles. Also are these reliable and accurate rifles. Thanks for the intel. Have a good one
Josh
Josh
sig 556 piston
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Re: sig 556 piston
cant help you with the pitch question cuz i dont know. I have shot my 556 a good bit and it performs well. It is much more reliable than my Bushmaster CAR15. My Bushy can get picky if not cleaned routinely...but my 556 seems to just keep on eating whatever I throw at it. Im shooting iron sights with it and it is shooting good. I would love to throw one of my scopes on it and really see what it can do. My buddy has a 556 DMR that shoots sub moa with SMK's
cant help you with the pitch question cuz i dont know. I have shot my 556 a good bit and it performs well. It is much more reliable than my Bushmaster CAR15. My Bushy can get picky if not cleaned routinely...but my 556 seems to just keep on eating whatever I throw at it. Im shooting iron sights with it and it is shooting good. I would love to throw one of my scopes on it and really see what it can do. My buddy has a 556 DMR that shoots sub moa with SMK's
Re: sig 556 piston
The threads are standard 1/2"x28. I have shot mine a fair bit and have expierenced zero malfunctions. Good luck.
The threads are standard 1/2"x28. I have shot mine a fair bit and have expierenced zero malfunctions. Good luck.
Re: sig 556 piston
confirmed, 1/2"x28 and zero malfunctions in several years and unknow amount of 3gun matches.
confirmed, 1/2"x28 and zero malfunctions in several years and unknow amount of 3gun matches.
Re: sig 556 piston
I have two 556 SWATs and a DMR. Accuracy of the SWATs is in the 2 MOA range, maybe a hair better, depending on the ammo. SMK 69 and 77 gr seem to do best. The DMR is definitely sub-MOA using Black Hills 68/77 or FGMM 77. All of these employ the same piston/receiver setup and are absolutely reliable.
I have two 556 SWATs and a DMR. Accuracy of the SWATs is in the 2 MOA range, maybe a hair better, depending on the ammo. SMK 69 and 77 gr seem to do best. The DMR is definitely sub-MOA using Black Hills 68/77 or FGMM 77. All of these employ the same piston/receiver setup and are absolutely reliable.
Re: sig 556 piston
I have a 556 ES model - with a SE Vortex flash hider on the front... nice because you don't need a crush washer! Plus, the more you fire it, the blast direction actually tightens it more. I've got some 75 gr privi partisan rem match to try. Plus, i heard some on the sig forum had success with 52 gr BTHP SMK's, even though it's a 1:7 twist.
I have a 556 ES model - with a SE Vortex flash hider on the front... nice because you don't need a crush washer! Plus, the more you fire it, the blast direction actually tightens it more. I've got some 75 gr privi partisan rem match to try. Plus, i heard some on the sig forum had success with 52 gr BTHP SMK's, even though it's a 1:7 twist.
Re: sig 556 piston
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cyrekzz</div><div class="ubbcode-body">I have a 556 ES model - with a SE Vortex flash hider on the front... nice because you don't need a crush washer! Plus, the more you fire it, the blast direction actually tightens it more. I've got some 75 gr privi partisan rem match to try. Plus, i heard some on the sig forum had success with 52 gr BTHP SMK's, even though it's a 1:7 twist. </div></div>
The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cyrekzz</div><div class="ubbcode-body">I have a 556 ES model - with a SE Vortex flash hider on the front... nice because you don't need a crush washer! Plus, the more you fire it, the blast direction actually tightens it more. I've got some 75 gr privi partisan rem match to try. Plus, i heard some on the sig forum had success with 52 gr BTHP SMK's, even though it's a 1:7 twist. </div></div>
The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups.
Re: sig 556 piston
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups. </div></div>
to me that just seems weird maybe... i always thought/read that the higher the twist, the heavier bullet you'd want to use, in terms of accuracy. But are there other factors? Bullet velocity? or amount of powder? or??? Damn, i have 3 boxes of the 75 match privi - now i'm going to have to look for 52 gr SMK's? Any factory rounds out there you'd suggest or where to find?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups. </div></div>
to me that just seems weird maybe... i always thought/read that the higher the twist, the heavier bullet you'd want to use, in terms of accuracy. But are there other factors? Bullet velocity? or amount of powder? or??? Damn, i have 3 boxes of the 75 match privi - now i'm going to have to look for 52 gr SMK's? Any factory rounds out there you'd suggest or where to find?
Re: sig 556 piston
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cyrekzz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups. </div></div>
to me that just seems weird maybe... i always thought/read that the higher the twist, the heavier bullet you'd want to use, in terms of accuracy. But are there other factors? Bullet velocity? or amount of powder? or??? Damn, i have 3 boxes of the 75 match privi - now i'm going to have to look for 52 gr SMK's? Any factory rounds out there you'd suggest or where to find? </div></div>
I'm good frieds with Ulllie the site moderator for the SIG 556 site and we both agree this is weird. I've tried 4895, 3031 H110, 748, and varget in all the bullet weights I mentioned and ladder tested all of them. I even bought at Ullie suggestion 1 box of Federal 69 grain GMM and 1 box ox 77 grain Federal GMM, same results. We came to the conclusion it's just my rifle for some unknown reason. I tried for over a year to see if anything other than the 52 grain SMK's with 26.2 grains of 748 would shoot well to no avail.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cyrekzz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The only bullet that will shoot consistantly under 2" (Usually 1.5" or so) inmy 556 is the 52 grain SMK. I've tried 53 grain smk's 60 grain Hornady HP Spire points, 69 an 77 rgain smk's as well as M193's and M855's. All with various powders and all shot 2-3" groups. </div></div>
to me that just seems weird maybe... i always thought/read that the higher the twist, the heavier bullet you'd want to use, in terms of accuracy. But are there other factors? Bullet velocity? or amount of powder? or??? Damn, i have 3 boxes of the 75 match privi - now i'm going to have to look for 52 gr SMK's? Any factory rounds out there you'd suggest or where to find? </div></div>
I'm good frieds with Ulllie the site moderator for the SIG 556 site and we both agree this is weird. I've tried 4895, 3031 H110, 748, and varget in all the bullet weights I mentioned and ladder tested all of them. I even bought at Ullie suggestion 1 box of Federal 69 grain GMM and 1 box ox 77 grain Federal GMM, same results. We came to the conclusion it's just my rifle for some unknown reason. I tried for over a year to see if anything other than the 52 grain SMK's with 26.2 grains of 748 would shoot well to no avail.
Re: sig 556 piston
Well - after doing a somewhat quick search, i guess i've only found black hills and HSM for factory rounds... however, i don't think they're the Sierra MatchKing's - just match BTHP bullets. I suppose for the 52gr. they would have to be made? I don't reload, so that blows. Guess i'll try and make the best of the 75gr privi Remington match - a few have said this is pretty good, maybe a near 2nd place to the 52 gr SMKs?
Anyways - as far as the original post goes - I think they are accurate enough for shooting larger things like coyotes, human size targets, CQCB stuff... but i wouldn't necessarily think longer range (like past 300) prairie dog or target shooting would be any good.
Well - after doing a somewhat quick search, i guess i've only found black hills and HSM for factory rounds... however, i don't think they're the Sierra MatchKing's - just match BTHP bullets. I suppose for the 52gr. they would have to be made? I don't reload, so that blows. Guess i'll try and make the best of the 75gr privi Remington match - a few have said this is pretty good, maybe a near 2nd place to the 52 gr SMKs?
Anyways - as far as the original post goes - I think they are accurate enough for shooting larger things like coyotes, human size targets, CQCB stuff... but i wouldn't necessarily think longer range (like past 300) prairie dog or target shooting would be any good.
Re: sig 556 piston
Sig 556's are 1/2x28 pitch. Best load I have found for them is Hornady 72gr. BTHP Match. Along with a AWC Raider unit these loads hold 3/4" groups in both my SBR and Classic systems.
Sig 556's are 1/2x28 pitch. Best load I have found for them is Hornady 72gr. BTHP Match. Along with a AWC Raider unit these loads hold 3/4" groups in both my SBR and Classic systems.
Re: sig 556 piston
Don't despair about the 52 gr SMK's. Most of the SIG 556's I see shoot reasonably well with 69 or heavier bullets. Mine is the weird one.
Don't despair about the 52 gr SMK's. Most of the SIG 556's I see shoot reasonably well with 69 or heavier bullets. Mine is the weird one.
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