Rifles for sale at a gun shop in Merrimack, N.H.A In California, gun shop ownerA David Strickroth says he's been selling six or seven guns a da - See this story on www.npr.org David Strickroth does steady business at High Impact Tactical Firearms in Upland, Calif. It's a small shop, as gun shops go, with several dozen firearms hanging on the olive green walls and sitting in a glass display case below.