I have been loading for the Raptor for four years now and have tried quite a few combinations.
Starting with bullets. Unfortunately, my rifle is not fond of the 200 gr Barnes bullet. I just can't get top notch accuracy with it. I know other rifles have found success with it. Due to its low BC this bullet has basically the same drop at 300 yds as the FTX.
The 275 gr Barnes on the other hand is reasonably accurate, but have have only been able to get top velocities of less than 2200 fps. given the low BC of this bullet, wind really hurts it. If I was not hunting open areas with shot opportunities to 300 yards, I would try this bullet on deer.
My go to bullet has been the 250 gr Hornady FTX. This bullet is very accurate but is simply the worst performing bullet I have ever used on game. It just comes apart and/or can't penetrate on a straight line. For this coming season I am going to try the Thompson Center Bonded Shockwave (blue tip). I believe this bullet is made by Hornady because it is externally identical to the 250 gr FTX. It shoots to the same POI as the FTX. We shall see if it holds together.
I have tried a couple of custom bullets but could not achieve acceptable accuracy with them. I have not tried the Cutting Edge bullets that some people have used successfully.
For powders I have tried H-110, IMR 4227, Accurate #9, Accurate 5744, and Ramshot Enforcer. I have not tried Lil'Gun due to the reports of burning out throats by the people at Freedom Arms. I know others have reported excellent results with Lil'Gun, but I'm not willing to gamble with my Krieger barrel.
The most accurate powder I have tried is AA-5744. This powder loses no velocity from 70* down to 14* (my chronograph results) but it produces velocities with the 250 gr FTX of less than 2300 fps. In fact I load this powder with a 200 gr Barnes for my daughter in her 450 Bushmaster.
The problem I see with the powders for this cartridge is lack of a temperature insensitive choice producing top velocities. The old H-4227 would be perfect.
I settled on Enforcer due to accuracy and velocity. It is predictable and easy to work with. It is however pretty temperature sensitive. I worked up a load with this powder (CCI 200) and the 250 gr FTX at 32* and was getting 2396 fps. Two weeks ago I chronographed it at 78* and was getting just over 2500 fps.
I experimented with primers and Enforcer. First of all, the manufacturer (in magnum handguns) states that magnum primers are not necessary. I did the work ups in the 30*-40* temp range. I discovered that WLR primers were beginning to exhibit pressure signs at lower velocities than CCI 200s. I was able to use heavier powder charges with the CCI 200s and net higher velocities without getting pressure signs than with the WLR primers. I see no reason to try magnum rifle primers with what is essentially a handgun cartridge.
For load data for Enforcer, go to Accurate Arms website and use the 460 S&W data.
The big challenge in shooting the 45 Raptor and 450 Bushmaster is the wind. I was shooting today out to 300 yards. With a slight breeze from 7:00 I had to put 1.5 min windage in to be on at 200 yards. At 300 the range is more open to wind and I had to use 2 min. At 300 yards a 5 mph breeze from 9:00 results in more than 11" of drift!
Experimentation is at least half the fun with this. Enjoy!
Mi Rifle
