Barrel Breech O ring

[mick.c]

Hello just wondering how to change the said O ring in the barrel breech is it difficult and has anybody got any vids or could talk me through it.....its a pre anti tamper s410....cheers

Mick

[Roger5]

They can be fiddly, how I do it is to put a cleaning rod down the barrel, put a vfg cleaning pellet into the breech just the other side of the seal groove, then lube the 0-ring and push it in, the rod is to stop the vfg moving, should say pick the old seal out first and don't damage the seal seat. Rog

[tonyc]

It's fiddly on the S410/510 especially if you use an oversize ring... if you search the forum you'll find some posts on this. The o-rings always flip sideways, making them difficult to get into the groove when you have restricted access. If you have trouble with a rod in the barrel, here's what I did.

I made a tool from a brass cheese head screw (?6BA or M3.5). Reduce the head diameter to 4mm, remove the thread next to the head and put a bevel on the head (so the head is cone-shaped down to the shaft) leaving a shaft diameter 3mm. Take off any sharp edges. Keep some thread to fit a retaining nut so you don't loose the bolt down the barrel and cut to length. Make the assembly long enough to just slip into the magazine slot and down the barrel. Take the nut off, slip the o-ring on, refit the nut and slip the bolt head into the breech. Tease the o-ring into the breech with a cocktail stick and push it past the slot. The o-ring will distort but can't flip sideways. Lever the bolt back gently and it will pull the o-ring square and pop it into the groove.

I used a lathe to make my tool but there's no reason why you couldn't make one with a drill and needle files, plus a larger file to reduce the head diameter initially.