I found a deal on a clean Winchester in .458,however I shoot a fair amount of cast bullets in every rifle I own. This one has been Magnaported...Is there a problem with lead and the ports? I would think with proper hardness,it should not be a problem?
I never had a ported gun,so my experience is none....

I have several ported handguns. What you get is some accumulation outside the ports with lead particles. It cleans off fairly easily and is no real issue.

My experience is identical to that of ElJuero.

Just clean regularly; I found that with very soft bullets, such as swaged 30 wadcutters, accumulation was more problematic. With hard cast bullets it was neglible, and easily controlled by cleaning. It should be no problem for your 458. My last magnaported gun was a 44 Magnum used solely with hard cast bullets, I made sure to clean the ports each time I cleaned the gun and had no problems.

Well thanks guys, I am going to try and make a deal today.

Mag-na-porting is great for big kickers. It doesn't actually reduce recoil, but it has a profound effect on muzzle rise and perceived recoil. On a .458, it will help your second shot recovery time tremendously.

Recoil is really not an issue,as I already shoot a lot of big bores now....458 Lott,.404 Jeff,.450/400. I'm not much into the porting thing as I've learned to handle the recoil.
I do enjoy the use of cast bullet,making' them,shooting them and using the rifle for more than it's intended purpose.
I hunted with PH's and have shot two animals off their shoulder and I don't think they would appreciate the extra blast.... but I'm still considering the rifle...

If you buy it and decide to sell, I'd be interested. I found the muzzle blast on my magnaported 44 magnum to be indistinguishable from another, unported, 44 magnum I had. Both were 5" Ruger Redhawks.

I have a Vias brake on my 400 H&H (smaller holes in brake) and have shot 100s of wheelweight cast bullets thru it and never done anything to clean it except the annual wipeout/boresnake/breakfree technique before storage. Goes from jacketed to cast and back w/o a hiccup.

The two key points to be made are this: you're unlikely to notice any more noise with the mag-na-porting (unlike muzzle brakes), and aimed follow up shots are likely to be significantly faster. When you're up and running, compare your .458 with similar loads in your unported Lott; you might be pleasantly surprised when you rapid fire three or four rounds.

Not a big bore rifle shooter but do have a 3 1/2" 10 ga Browning pump that I bought when I was a bit younger and more resilient. Had it ProPorted which is the shotgun equivalent of MagnaPort. Before doing so shooting 5 rounds resulted in both a blue shoulder and blue cheek. Afterwards it only resulted in a blue shoulder . Neat thing about it is on turkeys with a 2 1/4 oz load you can "see" more or less the shot charge eat 'em up. Still kicks like a banshee though.

Lol! I also have a Browning BPS 10 ga., and those 2 1/4 oz turkey loads will definitely get your attention.