BHO not working on last round.

[Stoof]

Just put together a new Anderson lower. Palmetto parts kit. The bolt catch works on an empty mag when manually cycled. It will not work on the last round. This is out of an upper that I have never had an issue with.
Could it just need broken in?
Should I try backing out the buffer tube a full turn?

Upon inspection everything looks good a moves freely. Any advice?

[Stoof]

Switched the upper back onto the Aero lower and everything works fine. Bolt catch must be out of spec.
The only difference between the two lowers besides brand is the Anderson has a commercial tube. The Aero is milspec. Still scratching my head.

[35remington]

Stop putting Obama on your guns and the problem will disappear.

[Stoof]

Stop putting Obama on your guns and the problem will disappear.

Touche'

[Mesquite Archer]

Could the Anderson lower have a slightly heavier buffer spring?

[IowaHunter]

No, BHO is a ****** not a touche.

[35remington]

Must've called him a sandbaag ^^. What a horrible word. Definitely should be hidden from children's eyes.

[Stoof]

Y'all are allot of help. [emoji2]


-------------------------------
Violence never settles anything
-Genghis Kahn

[35remington]

Sorry, back on track. It needs to be broken in anyway, so yeah definitely shoot it. But to specifically address the problem, I'd start by trying another buffer, or buffer spring, and then another bolt catch.

[TacticalCowboy]

Your bolt isn't traveling far enough to allow the mag to engage the bolt catch. This can be caused by too little gas, but since you said it works fine on a different lower you either have too heavy a spring, buffer, or both.

[hellbndr23]

Take buffer and spring from working lower and put them into non working lower.
Only other thing that adds resistance to the bolt is the trigger. Unless it has a crazy stiff spring, it shouldnt matter.

[Stoof]

I did switch out springs and buffers. I am just gonna run it for a while and see it loosens up before I start pulling roll pins and trying new parts.

[hellbndr23]

What happened when you switched springs and buffer? Put calipers on the 2 BHO levers before you pull them out.

[Stoof]

What happened when you switched springs and buffer? Put calipers on the 2 BHO levers before you pull them out.

Same deal with both buffers and springs. Calipers are a good idea. Not sure why i didn't think of that.

[hellbndr23]

Does it have an adjustable gas block? Aftermarket drop in trigger in the functioning lower, and standard mil spec in the non functioning?

It just seems like a long shot that the BHO is out of spec. There a ton of tolerance in those dimensions, but anything is possible.