"Normally the M777 barrel can fire up to 2,500 shells before wearing out but barrel life depends on what type of shell your fire."
That's horribly few, but I don't know the figures for L/52 guns. Poor durability is probably a widespread problem and would be an even worse problem if the munition stocks were bigger.
A rule of thumb is 200 rounds per day and gun, 400+ was reported as peaks for some guns on some days in the ongoing Ukraine conflict.
An artillery battalion with 2,500 rds barrels would have shot some for training, so it would have its barrels worn out after 6-12 days.
The guns would have done incredible damage by then (unless they shoot much smoke / M777 would be destroyed by counterfire on day one or two anyway), but the brigade would still flare out after 1-2 weeks.
For comparison: WW2 howitzers were fine for 10k-15k shots. Cannons with 1k-3k rounds barrel life were considered excessively uneconomical and failed designs (save for anti-tank guns, rarely used heavy AAA and large calibre very long range arty).
Edited by lastdingo, 09 May 2018 - 1118 AM.