Am starting to educate myself on selecting parts for an AR for my son.
Trying to go for long distance accuracy.
Looking into buffer systems/gas management .systems info.
Is the Geissele braided springs or Sprinco springs good ?
Good barrel options and gas tubes also.BARREL OPTIONS, COMPLETE OR BUILD ?
FYI we are starting with the SanTan TacticalSTT15 upper and the Radian AX556 lower and TRIGGERTECH B.A.D. Edition.
Black hole weaponry poligonal barrel chronograph faster for me than normal rifling. To get the maximum velocity out of a 223 you will need 26” or so of barrel. Whiteoak used to sell such a long barrel. I like the flat wire springs like Tubbs/Strike Ind better than most. A well fit free float handguard with bipod or bags would be quite helpful. Building it yourself, lube and torque the barrel nut on, this is done in steps. Assure the muzzle crown is square to the bore. I also use a 308 size muzzle device if I use one at all. The next step is highly consistent ammo. You may end up weighing each casing, powder charge and bullet. There is much to accuracy. It seems to me, the smaller the bullet the bigger effect changes in process incur.
I did a bit of research, a 5.56 26” barrel has an equivalent velocity to a 223Valkyrie with a 20. Of course with the longer barrel a lighter bullet would be in order. There is a balance to bullet weight and barrel length per cartridge for maximum muzzle energy. If you were preferring heavier bullets in the range for 5.56 you will find shorter barrels will maximize the velocity. 24” would work well with 70gr where 55gr will increase in velocity up to 27”.
The bullet length is as important as the weight. I use a lot of machined copper bullets. They are longer than their lead counterparts. Changing the length and weight you can see how the stability changes in the calculator.
I’m a fan of ARP barrels. He leans toward the 6.8 spc and wildcats but he makes some great .223 wylde barrels as well. Check the website often as he adds stock regularly to keep from being overrun with orders.
Length of barrel affects velocity, trajectory but not accuracy. Quality of barrel more likely to affect that.
1:7 or 1:8 if you plan on shooting 62+ gr bullets
Truing or “lapping” the upper receiver face is an important and often missed step in an accuracy build.
Solid optic mount that cantilevers off receiver
Consistent ammo. If you don’ have a chronograph or radar get one. The best gun in the world will only be so so if it doesn’t like the ammo. Get your SD’s down to low single digits. A slower bullet with a lower SD will group better then a faster bullet with a higher SD all other things being equal, but higher velocity does help in other areas, like wind drift and ranging.
Just my opinion.
Albroswift, Mic, and MrMachinist, THANK you guys for the feedback .
Using that calculator that was the NON ANSWER I came up with an “in stock” item at WHITE OAK ARMARMENT.
20" predator (semi bull)
Rifle gas length
low profile gas block
I shoot 55 and 62 gr so I feel ok with the twist.
I’ve seen twist rate charts that disagree but 1:12 will not be a good match for any AR bullet >36gr. Even .308 AR’s run 1:10. But fortunately, when you see keyholes and 6" groups on your 200 yard targets it’s easy to change barrels on an AR platform.
Not really - just buy XXXL targets just kidding - kinda have to define what “long” distance means for you. Longest at my range(s) is 400 yd. Many posts I see on FB are 500+ yds out to 1k and beyond (maybe those a XL long distance for sure.)
Also, run some AR 15 ammo through your fav ballistic calc. From what I recall, the “battlefield zero” is about 8 inches out to 300 yds. Aim for center mass and expect results.
And remember, my credentials are only good on TV and soap boxes.
My AR-15 is for distances between 25 and 100 yards. I have a red dot with a flip up 3x multiplier behind it. No scope. I consider 100 yards to be “long distance”. Lol
So given that, I imagine not a lot of issues with a 1:8 twist?
Did you read the link in my reply above about “Best AR15 Barrel Length and Twist Rate” ?
Scroll down that article until you see the charts that explain the numbers you get from the calculator above .
The values I get from info you gave gives a Sg of 1.956(figuring bullet length of .91" and velocity of 3100 fps) which is a 1.956. So that is at the upper end of the 1.5 to 2.0. which is " Stable and long range".
Read that link to see all "levels of Sg catagories.