Who has successfully removed the mag box spacer in a 223?

[MZ5]

I have a 10FP-UV in 223 Rem, which is a standard short-action, stagger-feed, blind-mag, accu-trigger model with a Choate stock. It had the long bolt stop which I replaced with a 'normal' one from a long action 110 I used to have, and it has the magazine block in the back. That magazine block is simply an upside-down "U" shaped piece of steel that serves both as a block and also as the back of the magazine box. There are metal tabs/ears on both legs of the "U" which go through slots on the side walls of the magazine box. Bending those tabs out straight and then spreading the sides of the magazine box will allow you to remove the block. Once you do that, you no longer have anything across the back of the magazine; it's just 'open' at the back. Also, I found that more often than not the tabs/ears will break off when you try to bend them out straight. NOTE: You'll want to remove the magazine box entirely from the receiver if you intend to remove the block without destroying it or the magazine in the process, since at least for me it was impossible to spread the sides of the box enough without seriously bending things to accomplish this with the magazine mounted to the receiver.

I was messing with this on mine because I want(ed) to shoot 75-grain A-Maxes at 2.5" COAL, which obviously won't fit the magazine. They will, however, fit into the mag just one at a time (with just one round in the mag, the bullet tip is not low enough to hit the feed ramp or front of the magazine box). Doing this, I also cannot get the rounds to chamber properly. They hit the face of the barrel, just like they do on yours.

So, how did/do I solve this problem? Two ways:
1) I could load one-at-a-time, but not in the magazine; just lay them on top or start them into the chamber. This works, but not at all well for 'precision' rifle matches. An alternative is to use a single-shot follow, but that results in the same difficulty for the rifle matches I like to shoot in.
2) I switched to 77-grain SMKs. I can actually get them to shoot better in my rifle than the A-Maxes, and I can get them to do it at a COAL that just _barely_ fits the magazine. They're considerably more expensive, though, so this is not a 'high-volume' shooting solution for me. Perhaps the Nosler Custom Comps, or even the 69 grain SMK, will also shoot well for me; I haven't tried them.

HTH, if only a little bit.