'Just looking at the stocks in the ad above, the expanded area beyond the forearm where the bottom metal is, is pronounced lower (esp. in the wood stock.) I'd guess 4. Could be 5, but 'going with 4. Many are only 3, so 'probably ahead of the game. But your guide and tracker will offer 4-8 more rounds! If you put that 400 or 450 gr slug in the right place, you'll only need 1! 'Took my son on an elephant/hippo/buffalo hunt (he as backup and PG for him w/ his 375.) I took 3 shots w/ my 416. He must've used all of 5 (including a great follow-up shot on the elephant when it spun and ran!) Compare the stocks you're contemplating to the 458 shown above. The 416 appears to have an extra round. You can get a bigger mag well or convert to a box-style mag, if really desired. Typically you will not get more than 2 shots in..one way or the other! My 416 holds 3 and Son's 375 4. Never an issue beyond 1-2. Montana was a semi-custom mass-produced gun, so they tended to improve things, as needed. 'Sons stock is trimmer than above and holds 3 in the mag. In some Mauser-style actions, you can pull the bolt and insert a 4th (or 5th) rd onto the boltface and under the extractor, if you feel more comfy with more!