I have built a few rifles based on the .416 CZ.

One of the things I like about the big action is not having to replace the bottom metal to get 4 rounds down. But it is really tight to get 4 down and one in the chamber for a .416 Rigby and even worse if you are doing a wild cat on the big Rigby case.

Wayne over at AHR made this suggestion.."try the 458 CZ box." So I ordered a couple of them up from CZ. Same box as the "375 marked" box that all the other caliber guns use, just no ribs internally. So it is a drop in part and cheap for these guns.

Here is the outcome. Made a huge difference for my 505 based on the Rigby case.

Obvious difference with three .416 Rigby cases in either mag box. 458 box is on the right and 375 box on the left.



Even a bigger difference with the less tapered .505 rounds.




Hats off to Wayne @ AHR for the sggestion.

In the FWIW catagory. Duane Wiebe @ Sound Metal Products LLC will be offering a 4 round .416 Rigby intergal drop box mag and trigger guard that will bolt on to the CZ by this fall.

It would be a slick addition to a custom rifle if you are restocking anyway.

Interesting. Would using this box allow 6 down with the 375 H&H?
I would of thought the box for the 458 would be to short, or do you order the box for the 458 Lott?

Surfed the CZ site and can not locate the part. Could you provide the part # and the price? Thank you

Wayne and CZ customer service both mentioned that all the magnum actions either come with a 375 marked mag box or the 458 marked mag box.

No clue what the 500 Jeffery box or follower is but would like to know. But a Gibbs drops three in and feeds no problem.

Cost was around $25. Call the CZ USA customer service number and I suspect they can hook you up.

Easiest way to check if the 458 mag box will add a round is take your gun as it is now and see how much room you need to squeeze in one more round and still close the bolt easily. If you are close to being able to add one more round, the 458 box may do it for you.

But no guarantees how it will then feed. It was the perfect answer for my .416. But I need more width in the mag box at the shoulder to do the same for the .505. My 505 case is almost a straight walled case and much closer to a 458 case than a .416 Rigby case taper. So I'll need an almost square box or at least a middle bend in the box to get 4 down instead of the tapered 375 or 458 box and likely some metal work on the action to attain all the room I'll need to get 4 down on the 505.

Thankfully Duane Wiebe has agreed to tackle the job once his mag boxes are ready for retail.

Costly. I was hoping to sneak around that one and stick with the same stocks and the $80 CZ bottom metal.

duane,

if you are reading this: will the bottom metal you are creating be only for 416+ or will it also be for those of us with the lowly 375 H&H?

I just popped open the floorplate of my cz and on the inside there are two ribs on each side of the mag box. So, which one do I have?

The ribbed boxes are marked 375 H-H. The unribbed boxes are marked 458 W.M.

"Same box as the "375 marked" box that all the other caliber guns use, just no ribs internally."

thank you very much.