Due to lack of info on a short barrel 300 Win Mag (>21"), I figured I'd add my humble contribution to an odd load for the 300WM. (Note, I have been reloading on and off for 20 years, and as always build your loads carefully).
Money (and thus spouse) limited my options, so I got my Model 70 Win Mag (sporter barrel) cut to just under 21" so I could put a Specwar 762 on it rather than getting it rebarreled. Bottom line, I love this gun! I have killed many elk and deer with it over the last couple of decades, and though I have practiced out to 700 yards, my longest shot with it on game to date has been about 150. Most, including a 7X7 bull, were 25 yards and under. Still dreaming of longer range shots, and for fun, I bought a Specwar 762 to equip this and several other rifles (including a couple of AR-types). It make a huge difference in sound and recoil. My wife now shoots this instead of her .308 Rem 750 with which she took an elk last year, and I took a nice buck at about 250 yards.
After trying H1000 and R22 (low availability in this area) with AMAX 208s, I had a bad hit on a doe at about 12 yards (yes, I know, AMAX likes to be 300 yards+; it was all I had at the time). Though it was a vital shot, the bullet essentially exploded on impact and I had to follow with a second in her head (which was not an option with my first shot). I found fragments in the tenderloins... Thus I started looking for a bullet/load combo that would give me close range options as well as long range accuracy. Most loads assume a long barrel...which I do not have. Cabelas had an 8Lb can of IMR 4350 (faster than R22) so I figured I'd try it. Below are the results, and my new target and hunting loads.
Target: 71 Gr IMR 4350 Federal Nickel Brass CCI BR2 primers Hornady AMAX 178s. 3004 FPS with 65 FPS spread across 10 shots. Group size (six shots from an improvised rest at 100 yards) just over 1 inch...my shooting is probably not as good as the gun is capable.
Hunting: 66.5 IMR 4350 Winchester Nickel Brass CCI BR2 primers Nosler Accubond 200's 2780 FPS with 80 FPS spread on 10 shots. Group size about 1 inch on 4 shots from my hunting sticks.
Using Strelok+ for calculations, I was able to hit 4 for 4 at 500 yards yesterday (10 inch rock on the redneck range...sorry no better data on the group size) with each of these.
Other stuff I tried, that didn't work out:
Centerpointe Scope--I had good luck with this cheap WalMart scope on other guns...it did not stand up to the 300 Win Mag recoil, even with the comp and suppressor.
Remington Brass--lots of variation in the brass volume made this hard to load accurately and I am too lazy to sort (at this time) by volume.
WLR--Not bad, but I got a deal on BR2s
CCI 200's--same as above
CCI 250s--I got bigger FPS spreads and lost accuracy
WLRM--same issue with CCI 250s
Hornady 208 Match bullets--I ran out of bullets before I found a good load. But they were fun to shoot
Pushing the velocity up to 3200FPS--I worked up a few loads, but did not think the extra wear/tear and costs were worth it.
A note on the silencer: it is a beast, so I carry it on my belt and put it on the end of the gun when I get into the area where I plan on hunting. Even on a 21" barrel, it tips the gun on my shoulder. A longer barrel would make this much worse. I would not trade it, however, as I have probably put more rounds through the 300 since I got the can, than in the previous 2 decades. And my other long guns (except the .22s and .17HMR, also equipped with cans) are gathering dust.
