syborg Posted October 20, 2010 Report Share Posted October 20, 2010 hi folks.. im new to this site but have been using air rifles for quite a few years.. quick question.. i bought a titan xs mainspring for my gun a few years ago from john knibbs along with a full seal kit and hinge pin and locking pin.. after i fitted the spring the accuracy went out the window and the recoil was just ridiculous... the initial first few shots dieseled and gave me the same kind of kick as a 0.22 rimfire!!!!! after a few slugs it settled down but was still well too pokey and couldnt get a decent grouping at 30 yrds.. a year later.... about a week ago..it kinda siezed up and fired with a thump sound... anyway i stripped it down and found the chamber quite dry and gunky.. i cleaned it out and relubed all the insides... ive read that fitting the titan xs can take a rifle over the legal limit so i lopped off about 5 coils and reground the ends to ensure flatness..and thus found re-assembly alot easier than having to to brace myself against a brick wall and a coal bunker just to get the trigger mech back on... the gun now has very little preload tension, cocks easier and is not so violent on firing. so my question is... does reducing the mainspring give better accuracy? obviously power will be reduced... it still has plenty of power and embeds slugs about 1/4 inch deep at 15 yrs into 3/4in thick plywood target backing... at 30 yrds it appears to have a decent grouping... any advice on the mercury and modding issues would be greatly appreciated... many thanks syborg... Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted October 20, 2010 Report Share Posted October 20, 2010 Seem to remember that the mercury has a plastic piston head and "o" ring washer-if the spring is too pokey the piston could have been hitting the end of the cylinder as the pellet was leaving the barrel way before the piston came to the end of its stoke-the resulting shock could cause all kinds of problems.I seem to remember that you need a specific type of lube for these seals and the incorrect oil could also cause problems.The mercury was a very good gun and somewhar under-rated IMHO-they will be getting rarer with passing of every year so ,if it were mine, i would get it done properly and look after it. Quote Link to comment Share on other sites More sharing options...
syborg Posted October 20, 2010 Author Report Share Posted October 20, 2010 Seem to remember that the mercury has a plastic piston head and "o" ring washer-if the spring is too pokey the piston could have been hitting the end of the cylinder as the pellet was leaving the barrel way before the piston came to the end of its stoke-the resulting shock could cause all kinds of problems.I seem to remember that you need a specific type of lube for these seals and the incorrect oil could also cause problems.The mercury was a very good gun and somewhar under-rated IMHO-they will be getting rarer with passing of every year so ,if it were mine, i would get it done properly and look after it. cheers mate. the original spring came out like a banana so thought it best to replace it.. im gonna take the mercury out to some nice open land and set a few targets up at 5yrd intervals and see how she goes before ordering any more parts... it was abused when i bought it as the pins had been drifted out using a centre punch!!!! thats why i ordered all new pins and seals..i also lubed up the ram using molycote... i also have an old 1960 bsa cadet...the original washer was leather and shot to bits..so whilst working at a machine shop i turned up a ptfe ram with 2 nitrile o rings and made a new breach seal.. i kept the original spring and i now call it the "one shot wonder" i can hit a bottle cap at 30 yrs freehand....although it lacks killing power its ridiculously accurate.... dont worry mate....my guns will be with me till i turn my toes up,lol ive always been a bsa man and always will be i think... cheers syborg Quote Link to comment Share on other sites More sharing options...
johnbaz Posted October 20, 2010 Report Share Posted October 20, 2010 Hello syborg It appears to be the case that if you put one of the square silicon manganese springs in most rifles that accuracy can suffer, recoil is horrible and damage to the gun can happen due to the forces on the gun that it hasn't been designed to take, i once put an Ox in an Original mod50 type 01 and it was horrible to shoot but in my defense, i didn't know where to get a round section original spring and the gunsmith told me these 'new' square Ox springs were the mutts nuts Here's my BSA Mercury with a BSA spring fitted, it's lovely and smooth John Quote Link to comment Share on other sites More sharing options...
syborg Posted October 20, 2010 Author Report Share Posted October 20, 2010 hi john the titan spring i bought was round but like i said the recoil was so bad the scope used to jump along the rails..and eventualy id hear a "ching" and find a clamp at my feet.... thats why i cut 5 coils off the spring...it now has the feel of my old meteor... my stock was also quite scruffy so sanded it down....i will eventualy revarnish it but i kinda like the feel and look of raw wood. i may just oil it with some teak oil... it was an ebay buy before they banned them... im still looking for a replacement set of open sights as i find these to be alot more accurate on break barrels due to the slight play on the barrel lock pin.. but until then i,ll make do with me small scope... if all else fails ive still got me 1960 bsa cadet that i picked up for a bargain 20 quid....the sears where worn and it would go off in your hand....so i redressed the sears using a fine needle file and now i couldnt ask for more... opensights......no rails....lovely oak coloured stock....a right fine filly.lol cheers syborg Quote Link to comment Share on other sites More sharing options...
FalconFN Posted October 20, 2010 Report Share Posted October 20, 2010 I did the same thing a couple of years ago with a Weihrauch HW98. I bought it for a bargain price because it was only putting out around 7 ft/lbs. I fitted a new mainspring and piston seal and it was like being kicked by a mule, it dieseled badly and the report was like a rimmy. I thought it must be over the limit so decided to take it to a gunsmith who tested it and found it was only at 8 ft/lbs! He cut down the spring and gave it a service for £25 and it came back sweet and accurate - money well spent in my opinion, and I don't think I'd do it myself if I had another springer, it's a bit too hit and miss. Quote Link to comment Share on other sites More sharing options...
hyflier Posted October 23, 2010 Report Share Posted October 23, 2010 I have a Mercury and did the same thing with the same result The Titan mainspring is a brilliant air rifle spring but obviously not in the Mercury. I can only think that the Mercury is too light and doesn't absorb the recoil associated with the Titan spring. I took the Titan out and replaced it with a standard spring, it now shoots much more accurately Quote Link to comment Share on other sites More sharing options...
syborg Posted October 25, 2010 Author Report Share Posted October 25, 2010 well folks. after i lopped off 5 coils off the mainspring...and relubed all the inards...i took her for a target practice.. i paced out 35 yrds and used a cardboard sheet to zero in the scope...sorted... then i set it back another 5 yrds...40 yrds in total im now getting grouping within around 3 inches whilst leaning on a post at 40 yrds...and there was quite a head wind... the power seems to not have been affected too much as at that distance it was entering the base of a beer can and coming out the top!!! alot better than it was but still quite a bit of recoil which i can cope with... happy days... Quote Link to comment Share on other sites More sharing options...
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