This is a very long post, but I think it will be worth your time. I was interested in the .300 Varminter and noticed there is substantial controversy on this forum concerning it. After reading quite a few posts, I broke out QuickLoad and decided to see if it was even close for a .300 WSM to drive the 125gr Nosler BT to 4000fps. At first glance it seems it is not, at least with reasonable pressures. However, QuickLoad is just a model. Professionally I am an engineer and I have done quite a bit of modeling/simulations and analysis across many different fields; I still have much to learn. One of the things that is often forgotten is that most of the equations we have from physics and we engineers use are simplifications, models. They only work under a given set of assumptions. Should be common sense, but if I had a nickel for every time someone refused to believe what they were seeing because the model said it couldn’t happen… It is also important to build the right kind of model. Too often engineers get caught up in our models and want to model/simulate everything, even when there are other more accurate/reliable solutions. A wise, old engineer/physicists told me a story once about how a particular government program wanted to build a simulation. It was going to take a significant amount of money and time to build the simulation and test it. Then even more money and time to actually run the simulation and get statistically valid results. This older engineer pointed out that a simulation was pointless because there was an analytic solution and you usually use the analytics to validate the simulation. So he got some paper and solved it analytically in a day. The moral of the story is only build a model/simulation when you need too and only trust it when it agrees with the analytics and the real world. Now that that bit of modeling philosophy is out of the way, let’s take a look at the .300 Varminter claims. It seems some of the .300 Varminters critics like to cite the Hodgdon reloading data. Unfortunately, the Hodgdon data does not specify barrel lengths nor twist rates. To evaluate this data I used QuickLoad, the Hodgdon reloading data for the 125gr Nosler BT in .300WSM, and the Modern Reloading Second Edition by Richard Lee. The data for the .300WSM and a 125gr jacked bullet (page 459) is identical to the Hodgdon data. Unfortunately, no barrel or twist rate is given. Using QuickLoad, I played with the barrel length until I was able to minimize the error in pressure and velocity on all of the Nosler 125gr BT loads from Hodgdon (both Min/Max loads): QuickLoad Data Bullet 125gr Nosler BT Starting Pressure (PSI) 3626 Barrel Length (in) 24.5 COL 2.81 Starting Powder Grs FPS Delta PSI Delta H4350 69 3343 11 51354 -4,446 H414 68 3303 -15 51392 92 760 68 3257 -61 47857 -3,443 IMR 4007 65.8 3247 4 52047 2,347 H380 68 3426 80 59274 4,174 Varget 61 3203 -109 48827 -5,873 H4895 58 3078 -236 42420 -14,180 Max Powder Grs FPS Delta PSI Delta H4350 73 3548 67 62426 -574 H414 72 3500 -40 61918 -1,382 760 72 3457 -83 57877 -5,423 IMR 4007 70 3454 -33 63457 657 H380 71 3572 79 68403 5,803 Varget 65 3390 -88 58648 -4,452 H4895 61 3215 -216 48808 -14,192 Everything is default QL except the COL and barrel length. I tested other cartridges with the Nosler 125gr BT and the starting pressure seems correct for this bullet and QL (data presented further on). It appears that the Hodgdon data is from a 24.5” barrel (+- 0.5”). Interestingly, Varget and H4895 both have substantial differences in pressure/velocity between QL and Hodgdon/Lee. Returning to the QL defaults (COL 2.860” vice 2.810”) and a barrel length of 24.5” I get 3371fps, 53314psi for 70gr of N550. This is Richard Franklin’s suggested starting load. However, his .300 Varminters are built on 30” barrels yielding: 3579fps, 53314psi, for 70gr of N550 in QL. A far cry from 4000fps, but still not close to max pressure either. Richard’s 4000fps load is supposed to be 75gr of N550. QL results are: 3610fps, 67226psi for a 24.5” barrel and 3773fps, 67226psi for a 30” barrel. Still 250fps shy of 4k and already approx. 3000psi over CIP MAP. If we stopped here it would be easy to say someone is a liar or the loads are easily over 70k psi. I decided to push onward and check some base assumptions and things get interesting. I decided to pull up Lapua/Vihtavuori reload data. At least in theory, their data should be spot on for their powders. Fortunately, Lapua specifies barrel length and twist rate. It should be noted that the twist rate for the .300 WSM test barrel (1:10) is tighter than optimal for the 125gr Nosler BT and much tighter than the 1:15 Richard uses. I compared the Lapua data for N550 (Richards recommended powder) against QL: Test Barrel: 24.5” 1:10 twist COL: 2.709” Otherwise QL defaults Bullet Grs FPS Delta PSI Lapua 123gr FMJ 62.7 3117 Lapua 123gr FMJ - QL 62.7 3016 -101 37565 Lapua 123gr FMJ 67.7 3468 Lapua 123gr FMJ - QL 67.7 3258 -210 47283 Interestingly, QL is giving 101fps lower for the starting load and 210fps lower for the max loading. Just for fun I wanted to see what the max load was under QL was: 74.4gr of N550 for 3580fps in a 24.5” barrel. About the same as what I got for the Nosler. Bullet Grs FPS Delta PSI Lapua 167gr Scenar 54.9 2730 Lapua 167gr Scenar - QL 54.9 2600 -130 36007 Lapua 167gr Scenar 61.3 3025 Lapua 167gr Scenar - QL 61.3 2882 -143 48907 Again, QL gives data that is much slower then Lapua’s N550. Max loading in QL was: 67.1gr for 3130fps in a 24.5” barrel. Bullet Grs FPS Delta PSI Lapua 185gr Mega 52.6 2572 Lapua 185gr Mega - QL 52.6 2454 -118 35031 Lapua 185gr Mega 59.1 2844 Lapua 185gr Mega - QL 59.1 2727 -117 47836 QL is still 100fps lower in the .300 WSM than the Lapua factory data. It does seem the heavier bullets give less error in velocity than the lighter bullets. It is also possible Lapua’s data is junk (not likely). It should be noted that Lapua wasn’t specifying pressures, so I have no idea if the QL number above are even close. Nearly every Lapua factory load I tested during this inquiry QL calculated the pressure right at MAP – 25%. To test the quality of QL predictions with Vihtavuori powder and the .300 WSM I tried comparing some more loadings. Cartridge 300 WSM Test Barrel 24.5" 1:10 COL 2.709" Powder N150 Bullet Grs FPS Delta PSI Lapua 123gr FMJ 59 3159 Lapua 123gr FMJ - QL 59 2943 -216 37252 Lapua 123gr FMJ 63.3 3386 Lapua 123gr FMJ - QL 63.3 3142 -244 45618 Cartridge 300 WSM Test Barrel 24.5" 1:10 COL 2.709" Powder N160 Bullet Grs FPS Delta PSI Lapua 123gr FMJ 66.1 3127 Lapua 123gr FMJ - QL 66.1 2871 -256 35891 Lapua 123gr FMJ 72.5 3428 Lapua 123gr FMJ - QL 72.5 3174 -254 47990 This is only two other factory Lapua loadings, but both are showing similar results to N550, 200+fps low in QL. It doesn’t seem to be a problem with the 5 series of powder, but most comparisons are needed.