122 to fully engage and permit all slots 144 to engage all protrusions 146 the springs 176 178 must deflect inwardly toward the interior space 126 as shown by arrow 234 in fig9 b for spring 178 spring 176 will deflect in an opposite direction but still outwardly relative to the interior space 126 after the springs 176 178 have been deflected inwardly the rearmost portion 232 of the upper part 122 may drop down into engagement with the lower part 124 as shown by arrow 236 in this regard the sidewalls 134 136 may be positioned within the channels 145 143 further the springs 176 178 are positioned inwardly relative to the sidewalls 134 136 finally the upper part 122 may be moved forward in a direction indicated by arrow 240 whereby the springs 176 178 may then extend outwardly such as shown by arrow 242 for spring 178 spring 176 will deflect in an opposite direction but still outwardly relative to the interior space 126 once the springs 176 178 have deflected back to the original positions such as shown in fig4 the springs 176 178 will generally abut the rearmost portion 232 of the upper part 122 this will cooperate with the slots 144 protrusions 146 and channels 145 143 to substantially maintain the upper part 122 in the same position relative to the lower part 124 the hand guard 100 may generally be configured to permit the hand guard 100 to be at least partially removed and then reinstalled so that the relative position of the hand guard is maintained in the same position as initially installed in this regard any accessories mounted to the hand guard 100 can maintain their u201c zero u201d for example a scope not shown.