[Amps] Tolerance of a bird wattmeter slug

[Larry]

This may be a bit of a silly question, but if I use my 1000H (2-30mhz) at
VHF frequencies, How far off will the meter be? Before anyone bashes me, I
am buying the right slug for the meter, but I just finished my AM-6154 and
tuned it up with my 100 watt slug and wanted a ballpark figure of my max
output. At ~4 watts in, I'm seeing 200 watts out with the 1000H. Could
anyone do a comparison for me? Thanks & 73's... Larry