Winchester .400 Caliber Rifle Bullets 300 grain Subsonic Open Tip Range 100 Bullets. These characteristics vary depending on bullet design. Specifications for Winchester .400 Caliber Rifle Bullets 300 grain Subsonic Open Tip Range: Manufacturer: Winchester Bullet Type: Subsonic Open Tip Range (OTR) Bullet Weight: 300 grain Projectile Caliber: .400 Caliber Bullet Quantity: 100 Bullet Package Contents: Winchester .400 Caliber Rifle Bullets 300 grain Subsonic Open Tip Range Winchester WB400L300X: .400 Caliber Rifle Bullets 300 grain Subsonic Open Tip Range 100 Bullets