Galahad .22 Leaking air from rear of mag when fired

[dave.walker]

Hi all , new here so please bear with me . I owned a .177 Galahad around a year ago . Sold it and regretted doing so . I have recently purchased second hand a .22 version Galahad in a lovely Walnut stock .
Problem Im having is when I load the magazine into the block and fire , I have air escaping from the rear of the mag . I chronographed it afterwards and found it was only producing 7.32 ft/lbs . Any help would be appreciated

[RichieRich612]

Sounds like the breech seal has gone, simple fix

[dave.walker]

Thanks for the info regarding the breech seal . I watched a few vids on youtube about how to install them . Tried it myself as there were a pack of small seals that I took for breech seals with size etc . Bit fiddly to fit but certainly did the trick .
Thanks again

[RichieRich612]

Thanks for the info regarding the breech seal . I watched a few vids on youtube about how to install them . Tried it myself as there were a pack of small seals that I took for breech seals with size etc . Bit fiddly to fit but certainly did the trick .
Thanks again

They're a devil to fit but soon get the knack of it once you've done a few.
I'd get a few spare breech seals for the future as it's advisable to change them every 6 months if you shoot regularly.
Make sure they're actual breech seals though and not something similar sized because the o ring compound might be different, too soft and it won't last long, too hard and it might not seal the probe.
Rich