Grendel upper on Springfield Saint lower.

[92vanguard]

My first Grendel. The Springfield 5.56 upper is a mid length gas system. The new 6.5G upper is rifle length gas system. Any chance I might have cycling issues with the original heavy buffer in the Springield lower?

[Sticks]

Welcome to the Horde.

You should be fine if it's a standard rifle length buffer. Who made the Grendel upper?

[92vanguard]

Bca.

[Sticks]

Of all the issues I have heard of with BCA, gas ports were not one of them. You should be GTG. Do a test fit with the ammo though. You should be able to drop a round in the chamber, turn the rifle barrel up and the round should fall out, or a light tap to drop the round.

Next is chamber a round in the upper only, push the bolt in to battery and it should extract easy and not leave any marks on the bullet aside from a couple of longitudinal scratches from the lugs. Making sure it (bullet) does not get jammed into the lands.

[ported45]

Wish you good luck!

[92vanguard]

Thanks!