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PUNCH-S core seat external hollow point open tip.

RBTO-4-S Rebated Boattail Open Tip die set.

The equipment necessary to make long range subsonic rifle bullets in calibers from. (Corbin Manufacturing thanks The Bullet Depot (54) for the use of the photos and information.) They were fired into Corbin Sim-Test(tm) Simulated Muscle Tissue ballistic test media. 308 bullets were made by The Bullet Depot,6785 Hwy 62, White City, OR 97503, using Corbin swaging equipment. Too heavy a bullet would usually make the bullet so long that it might not be stable without a faster twist rate, but a somewhat heavier than usual bullet moving at low velocity, with a fairly round nose to shift the center of gravity forward, can be quite stable in a standard twist rifle. This is permissable because with lower velocity, the powder charge is reduced and the pressure is also reduced, meaning that more inertia can be allowed in the projectile without over-stressing the firearm. To gain some of it back, the weight of the bullet is generally increased. If the velocity is below 1/3 that of a conventional supersonic bullet, around 1000 fps or less, then the energy with the same weight is considerably reduced. The energy a bullet carries comes from the product of the mass and square of the velocity.

(With RBT, the same bullet design and over-all length would be in the 185-190 grain range.)Īnother factor in the design of subsonic bullets is the weight. The following example 218 grain 30 Whisper bullets are flat base design, which permits the use of more weight in the same jacket length compared to a RBT base. It helps retain energy to support expansion, which is potentially more valuable at ranges beyond 100 yards. The Rebated Boattail is not a necessity for short to moderate range bullets. For RBT bases, the SDD-2 adjustable length serrator must be used to avoid putting serrations in the rebate junction.

Subsonic fps full#

The SDD-1 serrator is a full length style, which is only suitable for flat base bullets. 300 Whisper using Corbin J-30-125 jackets. 015 inches deep in order to provide excellent performance even at velocities as low as 750-800 fps with proper sized hollow cavity and nose shape, with the. Using a SDD-2 jacket serrator die to put six shallow cuts in the OD of the jacket provides stress-riser lines, so that the bullet will peel back evenly along these slightly weaker points on impact. The 3/4-E ogive works in nearly all handguns.Īt very low velocity, the jacket may prevent expansion even with a good-sized hollow point cavity and a blunt nose. The 1-E elliptical ogive typically gives good feeding in most rifles. The more blunt (round) the tip, the more easily it can be expanded on impact (with a hollow point design).

Since most of the drag on a subsonic bullet is on the base, rather than the tip, the nose can be as blunt as possible (to still permit reliable feeding). Therefore, the jacket needs to come to the end of the bullet, and the hollow point down inside the core, which is inside the jacket (not exposed as in a lead tip).Ī sharp spitzer point brings the jacket material toward the tip in a strong tapered column, which tends to prevent or delay expansion. In magazine-fed firearms, the tip needs be strong enough to handle feeding pressures, which often eliminates large hollow point lead tips. With single shots and revolvers, the tip can be made with exposed lead and a large hollow point cavity. The principle problem which subsonic bullet design must overcome is lack of expansion at low velocity.

Subsonic fps crack#

Subsonic bullets in legal suppressed firearms are also fun to shoot for target practice, eliminating the sonic crack that requires hearing protection, distrubs neighbors, and frightens livestock. Sometimes the use of a suppressed weapon in civilian animal control situations is politically wise, as it allows the necessary use of firearms without attracting undue attention from irrational activist groups. Subsonic bullets are useful not only for military covert operations, but for animal control officers and others who need to use a nearly silent or legal suppressed firearm to avoid alarming other animals, upsetting nearby livestock, or bothering the neighbors.