AR15 question.

[Tacit Blue]

I have a AR15 that doesn't fully lock up after hitting the bolt release. This is with the mag in the chamber, so I'm thinking it's a weak/worn out buffer spring. It does about 10% of the time, and I usually have to use the forward assist to ensure proper lock up.

Could you guys recommend some good springs?

[roll2li]

I favor DPMS Springs

http://www.midwayusa.com/product/191371/dpms-buffer-spring-ar-15-rifle

[Tacit Blue]

My spring measures at 26 cm. But I have over 2,500 rds through it. The spring is moderately carbon'd up/dirty.

[roll2li]

I'm guessing you're running a carbine spring then. Does it look like you have an M4 style short buffer? That will confirm you have a carbine sized buffer tube.

http://www.midwayusa.com/product/210662/dpms-buffer-spring-ar-15-carbine

Also keep in mind if you run a heavier weight spring you may need to upgrade buffer weight to keep the chambering consistent and not "slappy." Which is why I prefer springs are good machining quality but close to "stock" specifications.

[Tacit Blue]

Yes carbine. Yeah isn't the standard a " H buffer", that should cure that " slappy" problem.