job done. You could add more mass to the piston. Also try it with lighter pellets - hobbies and FAPs - as the piston is still very light for the bore and stroke.
With help of a friend who has good metal working skills and equipment, I tried to follow JB's Meteor tuning recipe, for as far as I know the ingredients.
Quad ring (plus almost 1 ft/lbs), 3 mm transfer port, 10 gram steel top hat, 2mm off the face of the piston head, scope stop screw, increased preload on the barrel latch spring.
Result: 10,8 ft/lbs in my Mk4 using 15.89 gr .22 JSB's. Smooth and accurate. A dry "thud" and no nasty vibrations.
The trigger is quite heavy. I need to test this setup in my Mk5, as I've found with previous equal power tests that the Mk5 trigger is way more adjustable than the Mk4 trigger.
On the Mk4 trigger, there's only one setting where the sears engage; a tiny movement either way, and it doesn't work anymore. On the Mk5, there's lots of room for adjustments. Not sure how this works.
Haven't got photos of the Mk4 yet, but here's the Mk5, which has an old spring, a green nylon Chambers spring guide, 10 grams worth of steel rings to act as a piston weight, and a Lightning barrel (the Meteor barrel was damaged by - I think - darts, and grouped like a shotgun). It's putting out 9,1 ft/lbs.
I need to work out how to secure the front stock screws better. After about 50 shots, they need to be re tightened.
Lastly, I've just received a parcel from Hsing-ee, containing another squared off piston head and Maccari piston buttons. Thank you Hsing-ee! More experimenting on the way.
Last edited by jirushi; 14-12-2018 at 10:47 AM.
job done. You could add more mass to the piston. Also try it with lighter pellets - hobbies and FAPs - as the piston is still very light for the bore and stroke.
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
Another possibility could be to try an earlier Mk1 or 2,the pistons appear to have a thicker wall and possibly greater mass.
The trigger mechanism is definitely superior.
I'm down to one and a half Mk1s now,still not entirely sold on the aftermarket piston seals.
The leather items always seem to produce consistent high power levels.
Were the mk1 Meteor ever factory nickel plated?
I have this .177" Mk1 Meteor that is nickel plated but it's worn through in places so may have been factory done or maybe as an aftermarket option some time after, I think it's been done for a lot of years!!
Serial is NH286..
John
for my gunz guitarz and bonzai, see here
www.flickr.com/photos/8163995@N07/
Unfortunately I've no idea how to insert an image.
A Mk1 .22 ultra carbine,around 11ft/lbs at the muzzle with superdomes.
All standard internals including a new mainspring from protek.
ive got a mk1 meteor but it not got the bsa logo on the rear dovetail, but its unusual in that the barrel is proof marked
It remains a mystery to me,maybe it's the sunflower oil used on the piston seal?.
Strangely all the chopped early Meteors I've had produce good power compared to the standard length.
Inertia on firing opening the breech slightly perhaps?.
yep, just started reloading for it