Strength 4 (S4) is the new universal power now. It used to be S3 prior to the release of the 8th edition Roll To Wound table.
This a great boon to Space Marines due to their ubiquitous bolter. It used to the case for the lowly lasgun but no more. As you can see from the first chart S4 wounds T6 on a roll of 5+ while the lasgun needs a 6+... twice as good ! If you have been playing a lot of 8th edition games you will come to realize the two most common rolls to wound are 3+ and 5+... therefore the lasgun is mostly wounding on 5+ at best now.
It is no secret now the assault phase is dead as a door nail now so take heed all you loyalist SM players... victory is through our bolters now !