I see a lot of anecdotal references, which have their place (e.g., my wife & I have a half-dozen degrees between us & are both active shooters, hunters, etc.) - but I think the answer to your question probably has less to do with field of study, etc. than it has to do with mindset PRIOR to said education.
IN GENERAL (dangerous words, I know), I believe someone who does not have strong opinions & beliefs is much more likely to be influenced in such things by the totality of their education. MOST (not all) higher education has a liberal bent, so many who do not begin their education with well-developed knowledge/opinions/beliefs will probably become less tolerant of firearms, religion, "old-fashioned values," & conservatism in general. Those who started out leaning left will simply have their belief structure reinforced & validated. Hardcore conservatives will be challenged, offended, & even ridiculed, but most (like many of us here) will not be swayed.
I do agree that certain fields of study may exhibit more (P.S., liberal arts?) or less (Economics, Statistics) leftward lean than others.
That's just the way I see it...
edited to add:
My personal experience:
Undergraduate: BSs in CJ & Psych. - conservatives in the minority (large public university)
1st Master: Business Administration - about a 50/50 split (small public university)
2nd Master: Public Health - token conservative in a sea of far-left-wingers (large public university)
My wife's experience:
Undergraduate: BSs in Math & Physics - conservatives in the minority, despite private Baptist university
Law School: ditto
Personally, I believe (and I certainly can't back this up statistically) that we would have been much more in the minority outside of the Deep South...