Sport II Add-on 18" Barrel Ejecting Not Feeding

[paulfukuhara_1125]

Bought an 18" Arrow Barrel for the Sport II Lower, it ejects normally, but mostly the BCG does not travel back enough to feed the next round, randomly it attempts to but the round is halfway into the round chamber, I was told the weight of the spring and buffer are too heavy, what is the default weights for the Sport II ?

 

[Eric300]

What buffer spring/buffer is in it right now? The standard carbine ones that came from the factory? You just changed the gas system from a carbine length system to a mid-length system by lengthening the barrel. The first thing I would do, assuming you're currently running the factory buffer spring and buffer, would be to swap out the factory buffer with something like a Spikes T1 buffer and try that in conjunction with the standard buffer spring. That should work. If not, then lighten the spring with something like a Sprinco reduced power spring (yellow).

 

[paulfukuhara_1125]

Thanks for the suggestion, its the factory items, I'll look for the suggested items.

 

[paulfukuhara_1125]

So far the Spikes T1 buffers lightest weight is 3oz,same as the factory default buffer weight, I ordered the reduced spring, I let you know what happens.

 

[Eric300]

So far the Spikes T1 buffers lightest weight is 3oz,same as the factory default buffer weight, I ordered the reduced spring, I let you know what happens.

A couple more things:

Are you sure your action is properly lubed?
Are you running any other type of muzzle device other than an A2 style FH? (ie: a muzzle brake of some type)
If you load just one round in the magazine and fire it, will the bolt lock-back like it supposed to?

 

[paulfukuhara_1125]

Sorry for the long response had a busy weekend. The problem was with the factory standard 3lb buffer, it was too heavy. I bought an adjustable buffer and set it to 2lbs, it worked like a charm, oh and FIY, if you get an adjustable buffer, use the aluminum slugs they are lighter than the tungsten slugs.

Thank you all for your suggestions

 

[Eric300]

Sorry for the long response had a busy weekend. The problem was with the factory standard 3lb buffer, it was too heavy. I bought an adjustable buffer and set it to 2lbs, it worked like a charm, oh and FIY, if you get an adjustable buffer, use the aluminum slugs they are lighter than the tungsten slugs.

Thank you all for your suggestions

3lb and 2lb buffer?! Yowzer those are some heavy buffers. They usually come in ounce weights....

Yeah, tungsten (and depleted uranium) is quite heavier than aluminum.

Glad you got it sorted out.

 

[paulfukuhara_1125]

Wow, thanks for the shout out, I meant ounces, Better To Look Twice before sending.