No-Tune uppers are simple: Use a certified trigger with decent ammo and go shoot.
Use one of two compatible triggers:
ARC-FIRE (Milspec trigger version)
V2 preferred: https://activesafetydesigns.com/ar15/arc-fire-trigger-v2-ambi-kit-0-90-180/
V1 works as well, but will likely need a shim: https://borebuddy.com/product/arc-fire-timing-advance-shim/
Using a reduced power hammer spring is recommended.
Reduced power hammer spring kit: https://borebuddy.com/product/reduced-power-hammer-spring-tuning-set/
Our ARC-FIRE completion kit contains the springs as well as a hammer: https://borebuddy.com/product/arc-fire-completion-kit/
The CARL 3-round burst limiter is compatible when using an ARC-FIRE! Those can be purchased here https://borebuddy.com/product/carl-3-round-limiter-system/
Atrius Forced Reset Selector with Rave Trigger:
Selector: https://atrius.dev/atrius-forced-reset-selector/
Certified No-Tune triggers to pair with the Selector:
Rave 22: https://borebuddy.com/product/rave-22-trigger-borebuddy-x-rise-armament/
(Rave 140 also works)
Notes on other Triggers with the Atrius: Other triggers listed as compatible with the Atrius may or may not work as no-tune. As we certify triggers we’ll add them to the list.
Notes on Other Forced Reset Systems:
Other triggers including super safeties, Kabuto, Atrius/ARC clones MAY work without tuning, but variations in trigger quality prevents us from certifying them as no-tune as some tinkering may be required.
Ammo:
12″ and 16″ barrels:
High Velocity:
Generally, any halfway decent quality HV ammo runs well in No-Tune uppers.
Mini Mags are the de facto gold standard for reliability for semi-auto (and FRT). We’ve tested a large variety of High Velocity ammo ranging from expensive (Eley Force) to the cheapest available (Armscor, Aguila, Golden Bullets) and generally find all of it to work well with the No-Tune. If you run into cycling issues with one ammo type, try another. Cheap ammo varies significantly lot-to-lot.
Standard Velocity/Subsonic: 1050fps minimum, Suppressor recommended.
CCI SV runs well as do most subsonic loads. These will be a find an ammo that your rifle likes and stick with it. CCI Quiets and Quiet Semi-Auto will not generally run. CCI Clean polymer coated is not recommended.
7″ barrels:
High Velocity:
40gr High Velocity ammo with a minimum velocity of 1235fps recommended.
Mini Mags are the de facto gold standard for reliability for semi-auto (and FRT). We’ve tested a large variety of High Velocity ammo ranging from expensive (Eley Force) to the cheapest available (Armscor, Aguila, Golden Bullets) and generally find all of it to work well with the No-Tune. If you run into cycling issues with one ammo type, try another. Cheap ammo varies significantly lot-to-lot.
SV and Subsonic NOT recommended. Note that due to the short barrel, many high velocity ammo types are actually subsonic as the short barrel generally takes 100-200fps off the published box velocity. We recommend finding one that stays subsonic and cycles well and using that rather than trying to run subs.
CCI Clean polymer coated is not recommended.
Recommended Magazines:
Our two recommended magazines are Kriss and Black Dog with nylon feed lips (older steel lip Black Dog mags are not recommended).
Black Dog: This is our recommended basic magazine. They are a available in 10 round, 15 round, 25 round and a 50 round drum. The Black Dog mags do not provide true last round bolt hold open, but they will hold on the follower after the last shot. For true LRBHO, use Kriss mags.
Kriss: This is the best magazine overall. They are a available in 10 round, 15 round, 25 round and 10 round in a 25 round form factor. Use a bolt catch and upgraded springs for true last round bolt hold open.
MAGAZINES NOT RECOMMENDED:
CMMG (Gen 1 and Gen 2): Due to feeding issues, we recommend against using CMMG magazines.
15-22: While these feed great and can be used with a magwell adapter, magazines made after 2020 are prone to warpage in the sun, which will render them unusable or induce malfunctions at random.
Colt: These are a Gen 1 CMMG clone. See above.
3D printed magazines: Due to variations in print quality and design, we do not recommend printed magazines. This does not mean there are not great designs available and you’ll not have great results if you know what you are doing. Quality depends on the skill level and material/equipment used to make the magazines.