Short stroke on new build

[Mad Charlie]

The stock I have is a smoke composite with a Magpul buttpad. The website states: When you purchase a Rifle Length Stock we shorten the stock so that when the rubber buttpad is added, the overall LOP remains the same as our standard rifle length buttstock (11.00"). https://www.smokecomposites.com/parts-and-accessories

I was thinking that the shortening the stock .5" likely also contributes to the short stroking?

Whether it does or not, the first thing you need to do, as suggested above, is install a standard spring and buffer, then see how it works. Don't start chopping on anything.