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got bored

Printed From: Kiwi Airgunners
Category: Technical
Forum Name: Pauly's Technical Area
Forum Description: Technical information, Modifications and DIY projects are all in here
Printed Date: 28 Sep 2020 at 9:15am
Software Version: Web Wiz Forums 10.14 -

Topic: got bored
Posted By: dvlnme
Subject: got bored
Date Posted: 30 May 2017 at 7:47pm
some time ago was given a gamo co2 extreme 177 cal rifle,like said got bored n decided to make up a very bassic screw in hpa unit to replace the normal 88 gr co2 cylanders etc,only 70cc capacity running at 1000psi,7,72gr pellets chronoed as follows for 9 shot strings,these two strings are pretty much identical
 to the other 8 strings i shoot.
 Have to admit was quite surprisedat how this very bassic hpa unit worked,as rifle is allso shooting rather more accuratly than it did on co2
 Could be worth looking into making a larger capacity regulated unit for this rifle using 3000psi cylander 
 regulated to 850/900 psi.
 got bit more respect for what has to the uglest rifle i have ever owned eh!!!
 Cheers Mike

Posted By: Novagun
Date Posted: 30 May 2017 at 8:14pm
Well get bored again soon and continue the project.  And remember to report results.

Posted By: dvlnme
Date Posted: 31 May 2017 at 7:45am
surprisingly this rifle seems to have some good potentual on hpa considering its nothing special n the uglest rifle i have ever owned,struck a bit an accuracy issuse,rifle been laying round the workshop for
 18months,barrel seems to have developed a rust ring in the muzzel,barrel fully enclosed in plastic
 moulded on shroud,so have cut front sight off to expose muzzel n removed 20mm of barrel getting rid of rust,recrowned,pushed several pellets thru ,cant feel any tight or rough spots now,so will test for accuracy
 will lap barrel out after test if accuracy good to really clean it out.
 Now think if rifle produces the accuracy i feel its capble of will go ahead n make larger capacity n higher 
 pressure hpa cylander and regulate it to approx 900psi which seems be its sweet spot as producing 11.5
 fpe in this pressure range,tend to think free flowing valve some may get it to just over 12fpe which 
 would be a handy 177 cal rifle as dont have a 177 pcp.                                                                                Cheers Mike                                                                                                                                                                                                                                                                                                                                                      

Posted By: nunga
Date Posted: 31 May 2017 at 10:24am
some photos would be nice :)

2nd place HP springer - WFTF World Championships 2014

Posted By: dvlnme
Date Posted: 31 May 2017 at 7:39pm
unfortunatly i cant do pics,dont hav any sort camera,never did learn how do pics,but guna sort that 
 soon,figure if guna get rite into forum pics necessy eh
 Did some accuracy tests today after recrown etc,groups tightened up considerably,but still room for
 improvement,so will now polish crown just case still some small burs present,still chronoing pretty much same consistantly,tried several pellets know are accurate in a co2 version same rifle which is out shooting 
 the hpa version,so dont believe ammo the accuracy issuse,logically its the barrel.
 allso tryed the hpa unit in the other rifle,accuracy exellent,bassically this confirms to me its the barrel
 and likely the have slugged barrel n cant feel any tight spots and bore now like a mirror,so need figure this one out. 
 Cheers Mike

Posted By: dvlnme
Date Posted: 04 Jun 2017 at 3:11pm
Sorted the barrel issuse,which was bit a mission due to barrel being fitted into a plastic housing,as couldnt
 remove the plastic assume its not removable,rifle now actually grouping,not as good as any pcps,but lot
 better than the 50mm groups before did thebarrel.
 Now getting 10 shots into approx 40 cal hole,guna leave it at that,good nuff for rats.
 When sorting out the dismal trigger,found trigger has what guess would be a transferr bar of sorts 
 attached to trigger with a steel rod,unfortunatly this mongrel device only works if trigger is pulled
 completly to its max rearward travel postion,which happens to be quite some distance from where the
 sear releases,in other words its a usless bit crap,thats only purpose far i can see is to prevent gun being
 discharged unless trigger is deliberatly pulled until it cant go ant further eh!!!
 Because this nasty little bit steel needs to be between the hammer and valve stem for the bleeding gun 
 to discharge,the hammer being too short to reach valve stem without it.
 Have managed to actually get the trigger itself down to a nice clean breaking predictable unit but damned gun wont fire when trigger releases as trigger needs travel bout nather half a km before the the bleeding 
 transferr bar engages,SO looks like guna have rip the damned thing out,make new longer hammer
 that will reach valve stem without transferr bar,now waiting to catch up with the Gamo rep so can find
 somewhere safe to shove the bloody useless thing up eh!!
 Thats nuff for this episode.
 Cheers Mike

Posted By: dvlnme
Date Posted: 15 Jun 2017 at 8:20am
Living some distance from town,things can take a while at times round here to get completed as i tend
 to run outa things like materials for projects,and only go to town if really need somthing or run outa beer 
 etc n still got beer so no need go town just yet,so guna put this project on hold for while until absolutly have go town for more beer and will get wot need to build a new larger hpa cylander for next stage of 
 project,but having fun with rifle as it is tho 10 shot count bit a pain,rifle is more accurate n powerful
 than when using co2,so was worth while project.
 Cheers Mike

Posted By: dvlnme
Date Posted: 17 Jun 2017 at 8:45am
Back on this project sooner than thought would be,ran outa beer,sharon told me only had one roll dunny 
 dunny paper left,noticed she been getting bit scatchy,proberly run out wine n prozac eh!!As didnt want her
 putting epsume salts or other laxitive in me tea,having found the sharp stones on tanker track bit hard
 on the rear end as dunny paper figuered was asolutly essentual i went into town asap yesterday.
 All worked out good,now got months supply beer n dummy paper,sharons back to normal so must got 
 what works for her to,but got to visit me mate at gunshop,loaded up on pellets n 22 ammo,got the alli
 i need to build the endcaps for the rifles new hpa cylander,will use the 1-1/4 inch tubing wingman gave
 me to make new cylander.
 Thought better check n make sure new batch beer was ok,so spent evening on lathe making the new 
 threaded endcap to screw cylander into the valve,must be something wrong new batch beer,coz turned
 out beauty.
 will cut tubing to length n make new frontend cap n fill vave today,even tho to keen going town turned
 out was good idea,got plenty beer n dunny paper,sharon appears to be perfectly i guess all is
 well again in my little world beyond the burnt stump eh!!
 Cheers Mike

Posted By: dvlnme
Date Posted: 18 Jun 2017 at 9:04am
Anybody know anything bout pcp regulaters and how to build them,want set this new hpa unit up for
 2500/3000psi fills and run it at valve for 900psi,as gun is running at this pressure in its sweet spot at
 just under 12fpe,perfect for wot i need.
 Am wondering if there is a paintball hpa regulater thats one inch or less outside diameter,this would fit
 inside the alloy tube am using for hpa cylander and could possibly be screwed directly into font end cap 
 of cylander ahead the guns valve.these regulaters not expensive n some adjustable,anyone got any 
 thoughts on both ideas???
 Cheers Mike

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