Overview Reviews Product Description Glock 21 Barrel Threaded .578x28 .45 ACP 1-16 twist 416R Stainless Steel Stress relieved and heat treated to RC 40-42 Made to work with Lead, plated or jacketed ammunition Made in the USA Product Videos Custom Field Product Reviews (No reviews yet) Write a Review Write a Review × Glock 21 Threaded Stainless Steel Barrel .45 ACP .578x28 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name *Email *Review Subject *Comments