Cross Machine Tool UHP15-SSA Ambi Lower Receiver

[titanse05]

Rainier Arms going to carry these? Seems that this would match up with the SMOS Upper/Handguard perfectly.

[UWone77]

Rainier Arms going to carry these? Seems that this would match up with the SMOS Upper/Handguard perfectly.

Yes.

[titanse05]

Yes.

Excellent. I'll try and be customer #1 for that lower. :)

Any insight as to when?

[UWone77]

[UWone77]

[Duffy]

I assume the right side bolt release uses a factory spec bolt catch and doesn't need anything special?

[UWone77]

I assume the right side bolt release uses a factory spec bolt catch and doesn't need anything special?

Oh it already got the special treatment Roger. It's the same lower as several pictures ago. Has the ABC installed

[SINNER]

Pretty much standard components for me now. And even I will admit a LDFA may be overkill on a lefty upper. Still had to use one though. Lol

[Duffy]

Oops I meant the left side bolt catch

The LDFA was designed for left hand shooters, and really any ambi charging handle user in mind. For a left hand shooter, I'd imagine it'd be used more often than it would for a right hand shooter.

If you hold the grip with your left hand, you'd use your right hand to pull back on the right latch of the ambi charging handle. On standard uppers where the FA housing hasn't been moved closer to the ejection port (such as Vltor, Santan Tactical, etc.), the rim of a standard FA is directly underneath the right latch. If you remember to always curl your finger as to avoid contact with the rim of a standard FA, or use your palm, you can get around it.



For right hand shooters that train shooting from their weak side, we don't practice shooting from the weak side nearly as often as we do our strong side, so it's harder to build that into muscle memory and would require a conscious thought to curl the index finger to get it out of the way.

LDFA isn't a crutch to replace training, it's just more accommodating for those that don't train every day, week, or month.

In the words of Matthew Hazard of jerkingthetrigger.com who writes much better than I can:

Roger speaks about the LDFA in evolutionary terms. The idea is that as a carbine and its associated manual of arms evolves, so should that carbine’s controls. In this case, the forward assist is shrinking into a vestigial tail of sorts due to its less common use. It is an interesting way of approaching development for a weapon that has changed as much as the AR-15 has over the years.