What is the gun you intend shoot these in?What is its condition?What is the load you used(powder type and how many grains,bullet weight,age and condition of brass)?Mag primers are hotter burning than regular and are known to increase pressure a little in large cases but a lot more in small cases(around 3K PSI and even a little more)and the 38LC is a small case.
To answer your question;if you ask the question it is because you have a doubt and when in doubt,don't.Better safe than sorry.You certainly won't blow yourself up but you might damage the gun.Have fun and be safe
Qc
Qc