The shooter provides the power to cycle the bolt, extract the empty case, and feed another round. Why? Because burning propellant has only one purpose in a bolt gun-to propel the bullet out of the barrel. Developing safe and reliable handloads in a bolt-action rifle is less complicated than it is for a gas-operated autoloader. I’ve walked the walk, and now I want to share what I’ve learned. A lot of you are out there, and I, myself, fell into this category not so long ago. Hornady’s 75 grain 223 TAP load produced three 10-shot groups fired in a row at a distance of 100 yards from a Krieger barreled AR-15 that had an average extreme spread of 1.03” with a 30-shot composite group that had a mean radius of 0.32”.This article is intended for handloaders who have experience reloading for their bolt-action rifles and now want to handload for an AR-style semiautomatic rifle. Hornady’s 75 grain TAP FPD produced three 10-shot groups fired in a row at a distance of 100 yards from a 20” Colt HBAR that had an average extreme spread of 1.14” with a 30-shot composite group that had a mean radius of 0.37”. I haven’t spent any appreciable time hand-loading the T1C projectile, but I have done a fair amount of shooting with the factory loaded versions of this bullet. The 75 grain BTHP pointed, has an average G1 ballistic coefficient of 0.353, while the 75 grain TapFPD, has an average G1 ballistic coefficient of 0.344. Both of these references show identical dimensions for the projectile, yet have different ballistic coefficients listed. On page 63 of the book, the T1C is referred to as “75 grain TapFPD”. On page 58 of the book, the T1C is referred to as “75 grain BTHP pointed”. The third edition of Ballistic Performance of Rifle Bullets has some conflicting information on the T1C (the version with the cannelure.) This process is conducted in a semi-progressive manner on a Dillon XL-650 press using a Pact Digital electronic powder dispenser and scale to dispense a powder charge of 24.1 grains of the VihtaVuori N140.Īccording to Ballistic Performance of Rifle Bullets by Bryan Litz (2nd addition), the Hornady T1 has an average G1 ballistic coefficient of 0.356. The cases are primed with Federal GM205M primers and charged with VihtaVuori N140 powder and as mentioned above, the T1 projectile is seated to a COAL of 2.245”. Don't even view this information in the presence of children or small animals.įor this hand-load of the Hornady 75 grain BTHP bullet, I use virgin Lake City brass that has been weight-sorted, match-prepped and neck-sized. Usage of this information for the actual loading of ammunition may result in malfunctions, damage and destruction of property and grave injury or death to beings human in nature or otherwise. No warranty, guarantee or assurance that these loads are safe is stated, suggested or implied nor should any be inferred. It is not intended to be used for the actual loading of ammunition by the reader. ![]() The information provided here is for educational purposes only. Reloading is an inherently dangerous activity. These figures are contingent upon a variety of variables, such as the particular chamber reamer that was used for your barrel, the number of rounds that have been fired through your barrel when the measurement is obtained, the particular lot of bullets used and whether you use a virgin case, a fired case, a resized case or a head-space gauge to obtain this measurement. The jump to the lands figures stated above where obtained using a Sinclair bullet seating depth gauge and a Forster 223 Remington 1.4636” head-space gauge. ![]() When fired from a Larue Stealth barrel with a 223 Wylde chamber, this COAL will create a jump to the lands of 115 thousandths of an inch and when fired from a Krieger barrel with a 223 Remington chamber, this COAL will create a jump to the lands of 78 thousandths of an inch. When fired from a Colt SOCOM barrel with a 5.56mm NATO chamber, this COAL will create a jump to the lands of 178 thousandths of an inch. The lot of T1 projectiles used for this article have a nominal length of 0.988” and I load them to a nominal COAL of 2.245”. According to Ballistic Performance of Rifle Bullets by Bryan Litz, the Hornady 75 grain BTHP has an average G1 ballistic coefficient of 0.356 and an average G7 ballistic coefficient of 0.183. ![]() I use the Hornady 75 grain BTHP bullet to load match-grade hand-loads for my semi-automatic AR-15s chambered in 5.56mm/223 Remington.
0 Comments
Leave a Reply. |