Depends on what you consider “hampered,” honestly.
The CDC in the 1990s publicly admitted they were going to reframe gun control (e.g. limitations and seizure specific policies) as a public health issue, to bypass the Second Amendment, and the Republicans smacked them for it. The literal rule stated that they could do all the research they liked, but they couldn’t use that for policy advocacy. The CDC and left media sources have since claimed that the rule had a chilling effect on CDC research, and it may have, but I’m not sure that totally holds up because the CDC did in fact do plenty of research after the law. Sometimes, in fact, they buried the results of their own research if it would be seen as pro-gun, such as in the case of “lives saved through self defense,” which aren’t often properly counted since a crime literally doesn’t occur. Turns out those are quite large, although I didn’t cover that element in this or any of my other articles on gun policy.
The “CDC is prohibited from doing gun research” narrative became a left media talking point going into the last budget, and the Republicans tacked on a “clarification” to the budget amendment that stated clearly that the prior rule was not to prohibit research, but to prohibit federally funded activism.
So the honest answer to your question is “maybe, depending on your point of view.”