There is no evidence of a moderator slowing down pellets, I have heard back from several customers and a well known maker of big bores who have tested their guns with my moderators on them and have seen an increase in velocity. Not much but 15fps on a big bore is a welcome increase. I am not sure why you think the moderator would slow them down, it is holding the energy behind the pellet longer, just as a longer barrel would and you know a longer barrel increases velocity. I have also noticed a slight increase in velocity, it is only small but it still indicates that a moderator does not adversely effect the velocity of pellets, Neil.