Originally Posted By: reb8600Originally Posted By: Hidalgo You'll have to pull the gas tube and replace it also.
No need to replace the gas tube either. He will have to removed the gas block and tube but not replace it. Just reinstall the same one.
It would depend on his FF tube length on whether the old gas block will work or not. I believe the MI comes in 12" or 15". If he has the 15", he'd need a low pro gas block to go underneath. The PP comes with a tall railed block.
He probably bought the 12" though, since he's trying to shave weight.
Assuming it is the MI SS FF handguard, it's already a full top rail. I might be tempted to put a smaller gas block on anyway if it was mine since he'll already have a full top rail.
And that handguard does come with a proprietary barrel nut also, so his current nut will have to come off.
*Edit, my comments on handguard length are assuming we're talking 20" PP, not 16", in which case you'd have same issues just 9" vs 12" handguard length