Mossberg 930 SPX wont cycle ;-(

[SMILEwait4Flash]

A friend of mine owns a mossberg 930 SPX that no longer will cycle basic birdshot rounds. Out of the box it worked like a champ, but then he replaced the hand guard with a quad tactical rail system from bulldog and it no longer cycles properly. Anyone in the community have trouble getting there 930 to cycle? If so, any tips on how to get it up and runnin again? fyi - it does cycle slugs though just not birdshot. Thank yall

[srt-4_uk]

you sure he put it back together correctly?

[Syntax360]

I'll bet he didn't re-assemble it right - the gas system is located right under the handrail, and if anything is backwards or missing or hanging up on his new rail, it's not going to cycle. He should try tearing it down, verify everything is as it should be, and re-assemble with the factory handguard and try again - that way he can identify whether the rail or the gun is at fault.