Joe Root says it is "frightening" what England's batting order could be capable of and believes any of the top six have the potential to score a double-hundred in one-day internationals.

England surged to a target of 308 in 40.1 overs at The Oval, their third 300-plus chase in the last 12 months, having only previously done it twice in history. Jason Roy hit 162 off 118 balls to lead the latest of a line of stirring batting displays - last summer against New Zealand they hunted down 350 at Trent Bridge, three matches after crossing 400 for the first time. They also scored 399 against South Africa in Bloemfontein.

Post the 2015 World Cup - a tournament that has become a watermark in England's one-day history after they exited miserably in the group stages - they have scored quicker than any other international team, cantering along at 6.33 runs per over with New Zealand in second position on 6.05. Root acknowledged a new challenge will come on the subcontinent when they face Bangladesh and India this winter, but there is a confidence surging through the team's veins.

Roy fell six runs short of setting a new high score for England in one-day cricket, but while Robin Smith's 167 not out against Australia at Edgbaston in 1993 retains its spot for now, it surely will not for much longer.

"It's remarkable to see the lads do it consistently," Root said. "It's what you want to see, guys getting in and breaking records and with what we had to come in afterwards as well, it is quite frightening what we could be capable of.

"But it's about being consistent and doing it more and more. I suppose that's our challenge. We've got all this excitement and flair, ability and potential, but it's about winning big trophies, big series, if we're going to be serious about contending for Champions Trophies and World Cups."

Farveez Maharoof, the Sri Lanka allrounder, has been on the receiving end of the carnage, although his economy rate of 6.56 is far from the worst of the attack. He hadn't played against England for nine years - having been part of the side that whitewashed them in 2006 - and acknowledged their new-found belief.

"In my career, I've played a lot of games against England, this side has really good depth in batting especially," he said. "That's been the biggest difference, they are much more attacking than a few years back. They are on a good run. It's a good team."

Root was at the other end for a considerable portion of Roy's innings at The Oval - his second hundred in three matches after he and Alex Hales had added an unbeaten 256 at Edgbaston - during a second-wicket stand of 149 in 18 overs.

"With 160 under his belt, not really looking like he was trying to hit every ball for four and six and still scoring as quickly as he was. That's quite scary to see, isn't it? It's a great 'scary' as well. When you're sat at the other end, there is no pressure on you.

"You know the scoreboard is always going to be turning over, and the opposition is always under pressure. You can almost feel that atmosphere out in the middle, when you're batting with him."

Sachin Tendulkar was the first man to break the 200 barrier in ODIs, against South Africa in Gwalior in 2010, and since then there have been another five doubles. As a guide to what is achievable, Roy was out for 162 in the 38th over of England's innings; when Rohit Sharma made his world record score of 264 against Sri Lanka he reached three figures in the 32nd over of the innings and had 162 by the end of the 41st over.

The six doubles have all been made by opening batsmen - hardly a surprising statistic - but Root believes England's first double could come from a number of sources, even if he was a little more reserved about his own chances of reaching the milestone.

"Definitely, there are a number of players in our team that would be capable of getting scores over that. I think anyone in the top six, really. I'm not sure I'd be able to score that quickly, but you never know. If one guy is getting near 200, we're looking at a score of over 400 - which is what it's about, really."

An England one-day side talking with expectation of double hundreds and scoring 400. For so long a nation lagging behind the rest of the world, they are now blazing their own trail.

Andrew McGlashan is a deputy editor at ESPNcricinfo