An EABCO barrel blank is precision gun drilled from the best Chromoly and Stainless steel alloys. Bore dimensions are reamed consistent to air gauge within .0002" (2/10,000ths) of proper bore dimension. These are then Two-Pass button rifled in the various twist rates we offer to suit particular accuracy requirements.One at Time Barrel Making - True, center-to-center barrel turning at a rate that minimizes stress while keeping the bore in the middle. True, center-to-center chamber reaming insures centering and linear alignment of the chamber with the bore. Each chamber's headspace is checked and confirmed with gauges. True, center-to-center 11° target crown, applied after finishing, insures that bullets exit the barrel with perfectly even gas pressure. (You can tell an EABCO Accuracy Barrel by the bright metal crown). Forend Screw Positions - By popular demand barrels over 17" will have the factory standard 2-Screw carbine forend set-up. 9-15" barrels will have the factory standard 2-Screw pistol forend set up. Single screw or any other set up must be specially ordered at extra charge.Also, please check out our ready-made Standard Accuracy Barrels... Same Custom Precision and Accuracy with a lower price and faster delivery.We are Thompson Center Arms specialists.