The clunkier the action the more likely the straight bolt for better leverage. Bu then there were Mausers with stragiht bolts.
The belt bolt is better at avoiding snags.
I suspect that tradition, national pride, manufacturing capabilities, urgent combat needs, and any of a dozen other inputs decided these things in some places.
כד יְבָרֶכְךָ יְהוָה, וְיִשְׁמְרֶךָ. The LORD bless thee, and keep thee;
כה יָאֵר יְהוָה פָּנָיו אֵלֶיךָ, וִיחֻנֶּךָּ. The LORD make His face to shine upon thee, and be gracious unto thee;
כו יִשָּׂא יְהוָה פָּנָיו אֵלֶיךָ, וְיָשֵׂם לְךָ שָׁלוֹם. The LORD lift up His countenance upon thee, and give thee peace.