CA's are generally slightly upgraded in the gearbox; so while the accuracy may stay the same, effective range may increase. Also another thing to note: My CA AUG (while TOTALLY unrelated) had very soft/poor hopup buckings reducing range and accuracy, if this may carry over to your rifle, and thus possibly affecting accuracy as well.
Also note: CA M4A1's (which now according to WGC cost something like 3 grand) and TM Old Style M4A1's shouldn't be available (if you're buying new), so no problems like barrel wobble should arise. Only thing that might become an issue is that plastic body for the new TM M4.
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