no it is not legal without a lot of paperwork an a $200.00 tax stamp "ATF has long held that by installing a vertical fore grip on a handgun, the handgun is no longer
designed to be held and fired by the use of a single hand. Therefore, if individuals install a
vertical fore grip on a handgun, they are “making” a firearm requiring registration with ATF’s
NFA Branch. Making an unregistered “AOW” is punishable by a fine and 10 years’
imprisonment. Additionally, possession of an unregistered “AOW” is also punishable by fine and
10 years’ imprisonment. " atf.gov/firearms/docs/open-letter/all-ffls-may2006-open-letter-adding-vertical-fore-grip-handgun/download

Bryson, in addition to the requirement for an overall length of over 26 inches to be able to add a vertical foregrip, you also have to remember the muzzle brake/compensator, if not "permanently attached" (welded/pinned) then you have to remove the compensator before measuring your firearm for he overall length. The muzzle brake/compensator does not count in the overall length measurement.

Bryson, in addition to the requirement for an overall length of over 26 inches to be able to add a vertical foregrip, you also have to remember the muzzle brake/compensator, if not "permanently attached" (welded/pinned) then you have to remove the compensator before measuring your firearm for he overall length. The muzzle brake/compensator does not count in the overall length measurement.

If the overall length (OAL) of the pistol is greater than 26 inches then you can according to the ATF. https://johnpierceesq.com/can-you-add-a-vertical-fore-grip-to-an-ar-pistol/

If the overall length (OAL) of the pistol is greater than 26 inches then you can according to the ATF. https://johnpierceesq.com/can-you-add-a-vertical-fore-grip-to-an-ar-pistol/

Bryson, not without changing the "Classification" from a Pistol to an AOW. ATF Details here : https://johnpierceesq.com/can-you-add-a-vertical-fore-grip-to-an-ar-pistol/