The 300 Raptor is based on a heavily modified 338 Excalibur parent case. The case is necked down and shoulder location moved forward significantly to increase case body length for a sizable increase in powder capacity over the parent case. Unlike other wildcats from APS, the 300 Raptor actually increases case body taper compared to its parent case. This is simply because the Excalibur case has case body which has been proven to be marginal when used with top chamber pressures. The result can be premature extraction issues. Since the Raptor wildcats are designed to be loaded to the top safe, working range of the parent case, it was decided to increase the body taper to improve extraction performance with high pressure loads.
Left to Right: Top of the conventional long range precision chamberings, 338 Lapua Magnum, 300 Remington Ultra Magnum, 338-378 Weatherby Magnum, 338 Kubla Kahn, 300 Raptor and finally the 338 Allen Magnum for comparision only.
The 300 Raptor has the same body diameter as the 338-378 Wby so as you can see, its increased case capacity is dramatic. In fact, the 300 Raptor case capacity is nearly exactly between that of the 300 Allen Xpress(Lapua based) and the 338 Allen Magnum(408 Chey Tac) capacity. From the picture above you can see that the body length of the 300 Raptor is actually longer then the 338 Allen Magnum which is based on the 408 Chey Tac parent case. It is a large chambering!!!
All this while being designed to be used in a conventional sized receiver suitable for the 338 Lapua diameter chamberings. Because of the length, most receivers will need to be used as single shot rifles. The APS Raptor receiver does offer the potential for the 300 Raptor to be used as a repeater using the Wyatts 3.990" interal magazine box or the Seeking 3.990" detachable magazine box. That said, OAL needs to be limited to allow this and performance will be reduced slightly.
Performance: The 300 Raptor is designed to be used with heavy long bullets. Absolute minimum recommended bullet weight is 180 grains but the 200 grain bullet weighs is preferred as minimum. As with most large capacity chamberings, efficency and consistancy only increases as bullet weight increases. This is what you can expect from each bullet weight when the 300 Raptor is chambered in an APS Raptor LRSS rifle platform with 30" barrel length:
180 gr. Accubond 3650 fps
200 gr. Accubond 3565 fps
230 gr. Berger Hybrid 3340 fps
240 gr. Sierra Matchking 3280 fps
These are not inflated numbers, in fact in testing, it appears that the 300 Raptor may well be able to improve on these numbers with the new Bertram brass but for now, these are comfortable numbers out of this wildcat and the Raptor LRSS rifle platform. Compared to its nearest competition which would be the 30-378 Wby and its sibling, the 300 Allen Xpress, you will see a solid 100 to 125 fps increase of velocity potential over the smaller 30 caliber wildcats.
Preferred Reloading Componants: As with all APS wildcats, the Fed-215 magnum large rifle primer is the only primer recommended for use. So far, the ultra slow ball powders are proving to be the best choices. Those being Hodgdon US869 and surplus powders such as WC860 and WC872 are proving the very best. Some of the slower stick powders are also showing some impressive results but the ball powders certainly have an edge all around for high velocity, consistancy, accuracy while maintaining comfortable chamber pressures and long case life.
Here are some pictures of the very first 300 Raptor prototype rifle on the Raptor LRSS platform. This is a single shot rifle design.