I did this the same in June with two checked bags. QR interlined them but for some reason when I walked past the belt one of my bags was on it! I took it to baggage services who sorted it (it made it to LHR). The queue for passport control was 10-15 mins IIRC, so with those two hitches I still had time to pop to the lounge for the toilet and a drink. All in all about 45 mins from walking off the plane to getting up the stairs in T2 (left going to lounge and right for passport check)
I did it landside connection. Assuming you land in time then it can be done easily.
There can be queues for T2 security but if your on J class you should be through quickly with the fast track gate on the left side.
I took the fairly short connection risk because if I missed it then the cost of a oneway from ARN to LHR isn't going to break the bank compared to a long haul.