AR Sponsor
Posted: 6/6/2014 6:03:21 PM EDT
|
With some extra funds available, I've decided to jump on the SB15 bandwagon. I've been doing a lot of research, but still have a few questions so some help would be appreciated.
I'm set on .223 for the build; I plan on shooting this thing a LOT so 300 BLK is just too pricey, and I hate the curved 7.62x39 magazines on an AR so that's out of the question. The pistol is going to be for home defense, as well as tacticool plinking and your usual urban SHTF scenarios. With that being said, I want to build a pistol that will reliably eat any 55 grain I throw at it, (PMC, Russian steel case, XM193, etc etc). Home defense rounds will most likely be 75gr TAP since that seems to be what everyone likes. So with that info, here are my questions: 1. I'm going with a 10.5" barrel, 1:7 or 1:9 twist? From what I can gather the 1:7 is better for the 55gr rounds, but will there be any problems with the 75gr TAP rounds? 2. Chrome, steel, or melonited barrel? I'm leaning towards chrome due to the heat buildup. 3. What weight buffer will like the 55 grain bullets the most? 4. Wylde or NATO chamber... again which one will like the 55 grain ammo more? (I would assume NATO) 5. Adjustable gas block... will it help or save the money? 6. A full auto BCG is preferred for these shorties due to the heavier weight, correct? I'm not ready to dive into the NFA world yet, so there's no plans to add a suppressor. THANKS! |
|
Quoted:
1)*I'm going with a 10.5" barrel, 1:7 or 1:9 twist? From what I can gather the 1:7 is better for the 55gr rounds, but will there be any problems with the 75gr TAP rounds? 2)*Chrome, steel, or melonited barrel? I'm leaning towards chrome due to the heat buildup. 3)*What weight buffer will like the 55 grain bullets the most? 4)*Wylde or NATO chamber... again which one will like the 55 grain ammo more? (I would assume NATO) 5)*Adjustable gas block... will it help or save the money? 6)*A full auto BCG is preferred for these shorties due to the heavier weight, correct? I realize you are new here to some degree but if you are going to ask a bunch of questions it makes it way easier of you number them, instead of using "*". So to make it easier for the next person they are now numbered, perhaps edit your post. To make this easier for us 1) Actually 1:9 is going to work better for 55gr, where one 1:7 would work better for 75gr bullets, I would argue for 1:9 because most of you HD situations are going to very close range so the slight decrease in accuracy will not really be noticed. Even at longer ranges it would be hard to notice much difference. Ideally a 1:8 would be best of both worlds 2) Melonite is actually the best finish IMO, but it costs more generally it gives all the bonuses of chrome with out the accuracy decrease the chrome provides. To be honest you probably will not shoot out a barrel of any of the finishes. 3) I would use a "H" weight buffer 4) Doesn't really matter Wylde is supposed to provide slight better accuracy with .223 rem vs a NATO chamber, but they can both shoot .223, and 5.56mm interchangeably. 5) I see no need for an adjustable gas block unless you plan to suppress it, if there are not plans to suppress than save money and go with a non adjustable block 6) I prefer the full auto BCGs in all my builds, to be honest you will probably not notice a difference between semi and full auto BCGs |
|
Thanks for the feedback, I've edited my first post.
Any reason why 1:9 is better for the 55 grain bullets? Wouldn't the tighter 1:7 help stabilize the lighter bullets better? Also, I've read that forward-directing muzzle devices such as the pig help 7.5"ers cycle better by creating more backpressure... does the same go for 10.5" barrels, or will any normal flash hider/compensator work? (Don't worry, I won't be putting on a muzzle brake  )
|
|
Quoted:... ....I hate the curved 7.62x39 magazines on an AR so that's out of the question. I have a 7.62x39 AR Pistol, and truth be told I hated the curved magazine look on the AR as well. But it's not about its look, its about how hard it hits. Needless to say once you've tried it, your perspective will radically change and you'll have a new found respect for that curved magazine, then it actually looks RIGHT. You can ask any 7.62x39 AR owner who has put the time to make it run right ... just about every one of them will agree that the 7.62x39 gets more range time than the 556, and the last thing you could give a crap about is the shape of the mag... that's the truth. . Either way, good luck on your build. Maybe one day you'll have an opportunity to build a 7.62x39 and we'll be here to help. . |
|
Quoted:
Thanks for the feedback, I've edited my first post. Any reason why 1:9 is better for the 55 grain bullets? Wouldn't the tighter 1:7 help stabilize the lighter bullets better? Also, I've read that forward-directing muzzle devices such as the pig help 7.5"ers cycle better by creating more backpressure... does the same go for 10.5" barrels, or will any normal flash hider/compensator work? (Don't worry, I won't be putting on a muzzle brake )Its just how bullets work less twist will stabilize lighter bullets, more twist for heavier bullets. With a quality 10.5" you should have no reliability issues, also if you plan to suppress it 10.5" is the shortest I recommend for 5.56mm most suppressor manufacturers won't warranty it if you use less than 10.5" |
|
Quoted:
Thanks for the feedback, I've edited my first post. Any reason why 1:9 is better for the 55 grain bullets? Wouldn't the tighter 1:7 help stabilize the lighter bullets better? Also, I've read that forward-directing muzzle devices such as the pig help 7.5"ers cycle better by creating more backpressure... does the same go for 10.5" barrels, or will any normal flash hider/compensator work? (Don't worry, I won't be putting on a muzzle brake )The original M-16 used 1:14 in a 20" bbl to stabilize 55 grn bullets. The longer the bullet is, the faster it needs to spin to stabilize; 1:7" is to stabilize not M855, but M856 tracer. If you're running 75 grn out of a 10.5", you may want to research to find out the minimum RPM to stabilize them; 1:9 out of a 10.5" may not be enough to stabilize 75 grn bullets. |
|
Rainier 1:8 Match Barrel 10.5" might be a really good compromise.
They are a little on the heavier side.. but they are very very nice barrels. $200 bucks a its a solid compromise. |
|
Quoted:
I have a 7.62x39 AR Pistol, and truth be told I hated the curved magazine look on the AR as well. But it's not about its look, its about how hard it hits. Needless to say once you've tried it, your perspective will radically change and you'll have a new found respect for that curved magazine, then it actually looks RIGHT. You can ask any 7.62x39 AR owner who has put the time to make it run right ... just about every one of them will agree that the 7.62x39 gets more range time than the 556, and the last thing you could give a crap about is the shape of the mag... that's the truth. . Either way, good luck on your build. Maybe one day you'll have an opportunity to build a 7.62x39 and we'll be here to help. . Quoted:
Quoted:...
....I hate the curved 7.62x39 magazines on an AR so that's out of the question. I have a 7.62x39 AR Pistol, and truth be told I hated the curved magazine look on the AR as well. But it's not about its look, its about how hard it hits. Needless to say once you've tried it, your perspective will radically change and you'll have a new found respect for that curved magazine, then it actually looks RIGHT. You can ask any 7.62x39 AR owner who has put the time to make it run right ... just about every one of them will agree that the 7.62x39 gets more range time than the 556, and the last thing you could give a crap about is the shape of the mag... that's the truth. . Either way, good luck on your build. Maybe one day you'll have an opportunity to build a 7.62x39 and we'll be here to help. . He's right... My 7.62x39 goes with me every trip to the range, my .223/5.56 gets used considerably less Oh and I think the curved mags are ugly too, but that's just a minor drawback to the fun of a 7.62x39 AR |
AR Sponsor