Originally Posted by MontanaRifleman
Sweet looking rifle Kirby! I was under the impression that the Raptor was built with a special/propitiatory action and barrel?
Did some number crunching using H2O capacities of 107 and 134 (guessing) for the 300 RUM and 338 Raptor I came up with overbore indexes of 1444 and 1494 for each respectively. Using the 230 gr and 300 gr bullets I came up with bullet weight to case volume ratios for each cartridge of 2.15 and 2.24. If 100 gr of 33 is a good working max for the 230's in the 300 RUM, that should equate to about 97% case capacity.
Based on the above, I am going to go out on a limb and predict the max charge of RL33 in the Raptor will be 92% case capacity with "good" velocity
The 300 and 338 Raptor are designed to be used specifically with my APS Raptor receiver to offer the max performance level offered in a conventional Lapua bolt faced receiver that is no larger in diameter then a Rem 700. Because of their length, they have to be single shots unless you step up to using the CheyTac DM systems but to do this you also have to step up to a Cheytac class receiver so the receiver is long enough to work with the mag length. If you do this, why not just go with the Allen Magnum and get another 200 fps performance.
The barrel on my Raptor LRSS rifles is a custom contour I designed and is made for me by Lilja. It has a 1.350" shank diameter that is 7.5" in length and then basically contours down to a #7 contour from there out with a 30" finish length. Muzzle diameter is roughly 0.875". They use the dual flute pattern seen on the rifle. Other then that, nothing special about the barrels, standard 1-10 twist, 6 groove design.
I am getting my hands on some RL33 right now but in all honesty, I do not expect it to be THE powder in the 338 Raptor. The reason I say this is because I have been working with RL50 quite a bit and I am hitting 100% load densities right about the same time this powder pressures out and getting near 3200 fps velocity with top pressures. More comfortable pressures are in the 3175 fps range which I prefer and this is with around a 97% load density.
Now, unless RL33s burn rate is much closer to RL50 then it is say RL25 or Retumbo, I think I will just be pressuring out sooner with lower load densities. This does not mean it will not get good velocities and be very consistant, I am just not expecting any magic to happen.
That said, in the 338 Allen Xpress, I could see where it could be very impressive. Still, in my testing of the AX, in 30" barrel lengths, its easy to get 3000 fps with Retumbo which is similar to the velocities your getting with your RL33 load so we will have to see.
My main question is about burn rate with RL33. I have not seen any good data showing its burn rate compared to more estabilished powders. I know when RL25 came out everyone was claiming it was magical with a burn rate significantly slower then Retumbo. That did not turn out to be the case, as its slightly faster then Retumbo.
Now, if RL33 turns out to be about right between Retumbo and RL50, could be impressive. Time will tell.