[dwwhite]

I don't think I would try it...

#1
A large rifle primer is slightly taller than a large pistol primer, as you have noted, it will not seat flush, or below flush, as is required for safe loads. Will this result in a slam fire? I don't know, however, I wouldn't want to find out, especially in a cartridge as enthusiastic as a .44 mag with a case full of H110. While this may not happen when manually cycling the slide, it very well could under recoil.

#2
If I am not mistaken, a large rifle primer ignites much more energetically than a large pistol primer. This can result in pressure spikes, especially given the relatively small case capacity of a pistol cartridge. I have done some experimentation with small rifle primers (which are dimensionally identical to small pistol primers) in 9x23 cases, and found that a safe charge over a pistol primer is WAY over pressure with the rifle primer.

#3
This is the most minor issue, but as you have noticed, I think you'll experience light primer strikes and misfires.

This advice is worth what you paid for it, but as I stated before, I think I'd put the project on the shelf untill you can find the proper primers. The supply chain is starting to open back up and if you keep your eyes open, you should be able to find some in the not too distant future.