The experienced guys will know all this things and will laugh at me but I am sure many were there as well. This is why people are willing to spend more money on high end PCP's but they still need to know about tuning. I do have funds but just cannot afford to spend it on expensive toys. If I had to go through all this to get an expensive PCP to shoot well, I would give up on PCP's altogether.
When I first received my used budget pcp, the Artemis M22 in 5.5mm, I did not know much about tuning other than what I saw and read on the internet. The guy I bought it from also was not the first owner and he did not know how many owners it had before that. Later when I started to fiddle with it, it was obvious that this rifle has never been opened or tuned. The first shots I took with it over the course of the weekend was not good and I actually regretted buying it. But the price was OK as I bought it with scope, rifle bag, 7 tins of various pellets and a 7 litre 300 bar air bottle with filling equipment, all for the equivalent of $350. The pellets included was Norica Monster 26gr, 2 x Gamo something, I cannot remember as I gave it away, Preditor Polymag 16gr, and then some JSB and Cometa. Only the JSB and Cometa was worth keeping.
Like I said, first shots was not good at around 15mm - 20mm at 25 meter. The trigger was heavy, I think if I hanged the rifle by the trigger it would not go off, terrible. I think this was the reason everybody was passing it on and they did not know the rifle could be tuned and the trigger adjusted, the guy I bought it from certainly did not know. To adjust the trigger you must remove the stock, take off the trigger cover and then you can reach the trigger adjustment screw with an Allyn key. The trigger was better but not good. I was used to my Gamo Magnum with its crisp trigger set at 430 gram / 15 ounce. Now it did shoot better and did 6mm to 10mm groups at 25 meter with JSB 18.13, once it did a 5mm group. I felt better after this groups.
I also tested the speed and it averaged 868fps. I thought it was good as that is in the range everybody says a pellet must fly. OK, so I kept it there. I then started to shoot at 50 meter. O-boy, my Gamo Magnum did better. 40mm - 50mm groups was not what I would call accurate. At times I felt like just binning this thing. Selling it, knowing how it shoots is not something I would do. So it laid gathering dust for a while. I was also out of town a lot for work so all this took several months. I looked at the local shops for other pellets but all they keep is JSB and Gamo. Many people say JSB is their go-to pellets so that is what I used. I had H&N 18 before this pcp so I ordered some online. Immediately the 50 meter groups was better at about 25mm - 30mm in calm wind. I felt better about this rifle and then started to look for things to improve and watched videos about tuning.
It is not easy to adjust the regulator as it must be degassed by dry firing a lot, remove the stock, then adjust the regulator without knowing the pressure. It also does not have a plenum gauge. It went up and down, then it shoots OK, then it did not. Very inconsistent and the only thing that was consistent was the constant POI movement from shooting session to shooting session. If it goes like that I did not feel like shooting it and if I did I felt like I was just wasting pellets.
Other things I did to try to improve the accuracy:
I checked the O-rings and found that the O-rings inside the regulator was old and had marks of damage cracks on it. This only meant that the regulated pressure was not constant. I replaced all O-rings. The accuracy improved.
At a time it was leaking air and I knew where but struggled to seal it even with new O-rings. Now it is 100% and can lie for a week without leaking. I still don't know why it leaked like that, maybe some small dirt particles on the O-rings.
I increased the transfer port size as I read somewhere it helped the air to have less turbulent flow and improve accuracy. I don't know it that helped.
I ordered and installed a power plenum, it does help with the consistency. The original plenum was very small.
I removed all the trigger parts and polished it as much as I could. Now I am more pleased with the trigger at around 550 gram / 19 ounce. I would like it to be even lighter but that is how it is now.
As the trigger sear engage at the front end of the hammer it was sliding on the hammer as it goes forward, the marks was there as evidence. I removed some material on that part of the hammer in the hope it will run free. I think it helps. At some time I put some silicone grease on the hammer, thinking it would slide better but is caused inconsistency at different temperatures, so I cleaned it again. I do have some grease on other trigger parts.
I saw markings on pellets shot and looked inside the barrel. The last 20mm looked like something put a big ugly scratch inside the barrel. I took the barrel to a local gunsmith to cut it shorter to remove that scratch and he re-crowned and threaded the barrel. This helped improving accuracy.
While the barrel was off, I polished it with JB paste and concentrated on the high spots. Now it is smooth and helps a lot.
I put 7 thick, tight O-rings over the barrel, spaced evenly so it keeps the barrel and the shroud tightly together. This definitely helps.
I put thin tape around the barrel shroud and air tube where the barrel band fits to eliminate movement there as much as possible. The biggest help was the last ting I did. I took a piece of leather from an old key ring, cut it to size and placed it at the front end between the barrel shroud and air tube. I then wrapped isolation tape around the shroud and tube and then duct tape around that. I saw some people installed extra barrel bands on even FX rifles that helped improving accuracy. Now it is all one stiff barrel unit. The POI shifts is something of the past as the barrel-shroud combination cannot move around with normal handling. This also was the single biggest contributor of improving the accuracy and now I can do longer shots, up to 144 meter as shown in my other post. OK, choosing the correct pellet is just as important and having a good trigger as well.
Somewhere during this time I tuned it for different speeds. I found with the H&N pellets that 940fps was a good speed, lower than that and it would spread out. Now I have it on 957fps and it is doing good at longer distances. About 10mm groups at 50 meter, sometimes pellet on pellet for a few shots.
Besides the things I did on the rifle, I now mainly use H&N Baracuda 18 pellets but still try others as I find them. Also, for distances further than 50 meter I sort the pellets by head size and now I am sorting by weight as well. Doing this I want to see how far I can hit the 200mm x 200mm steel plate. I do have space for another 20 or 30 meter so I think I can go up to 175 meter / 190 yard, maybe a bit more, without having to travel somewhere.
This is just my journey so far with this pcp. If I had the spare cash I would buy the new FX DRS with the walnut stock, but I cannot. So, I make the best I can with this rifle.
I would like to hear what others did to improve their pcp's accuracy, budget or expensive rifles. That is apart from the normal things like tuning and pellet choice.
When I first received my used budget pcp, the Artemis M22 in 5.5mm, I did not know much about tuning other than what I saw and read on the internet. The guy I bought it from also was not the first owner and he did not know how many owners it had before that. Later when I started to fiddle with it, it was obvious that this rifle has never been opened or tuned. The first shots I took with it over the course of the weekend was not good and I actually regretted buying it. But the price was OK as I bought it with scope, rifle bag, 7 tins of various pellets and a 7 litre 300 bar air bottle with filling equipment, all for the equivalent of $350. The pellets included was Norica Monster 26gr, 2 x Gamo something, I cannot remember as I gave it away, Preditor Polymag 16gr, and then some JSB and Cometa. Only the JSB and Cometa was worth keeping.
Like I said, first shots was not good at around 15mm - 20mm at 25 meter. The trigger was heavy, I think if I hanged the rifle by the trigger it would not go off, terrible. I think this was the reason everybody was passing it on and they did not know the rifle could be tuned and the trigger adjusted, the guy I bought it from certainly did not know. To adjust the trigger you must remove the stock, take off the trigger cover and then you can reach the trigger adjustment screw with an Allyn key. The trigger was better but not good. I was used to my Gamo Magnum with its crisp trigger set at 430 gram / 15 ounce. Now it did shoot better and did 6mm to 10mm groups at 25 meter with JSB 18.13, once it did a 5mm group. I felt better after this groups.
I also tested the speed and it averaged 868fps. I thought it was good as that is in the range everybody says a pellet must fly. OK, so I kept it there. I then started to shoot at 50 meter. O-boy, my Gamo Magnum did better. 40mm - 50mm groups was not what I would call accurate. At times I felt like just binning this thing. Selling it, knowing how it shoots is not something I would do. So it laid gathering dust for a while. I was also out of town a lot for work so all this took several months. I looked at the local shops for other pellets but all they keep is JSB and Gamo. Many people say JSB is their go-to pellets so that is what I used. I had H&N 18 before this pcp so I ordered some online. Immediately the 50 meter groups was better at about 25mm - 30mm in calm wind. I felt better about this rifle and then started to look for things to improve and watched videos about tuning.
It is not easy to adjust the regulator as it must be degassed by dry firing a lot, remove the stock, then adjust the regulator without knowing the pressure. It also does not have a plenum gauge. It went up and down, then it shoots OK, then it did not. Very inconsistent and the only thing that was consistent was the constant POI movement from shooting session to shooting session. If it goes like that I did not feel like shooting it and if I did I felt like I was just wasting pellets.
Other things I did to try to improve the accuracy:
I checked the O-rings and found that the O-rings inside the regulator was old and had marks of damage cracks on it. This only meant that the regulated pressure was not constant. I replaced all O-rings. The accuracy improved.
At a time it was leaking air and I knew where but struggled to seal it even with new O-rings. Now it is 100% and can lie for a week without leaking. I still don't know why it leaked like that, maybe some small dirt particles on the O-rings.
I increased the transfer port size as I read somewhere it helped the air to have less turbulent flow and improve accuracy. I don't know it that helped.
I ordered and installed a power plenum, it does help with the consistency. The original plenum was very small.
I removed all the trigger parts and polished it as much as I could. Now I am more pleased with the trigger at around 550 gram / 19 ounce. I would like it to be even lighter but that is how it is now.
As the trigger sear engage at the front end of the hammer it was sliding on the hammer as it goes forward, the marks was there as evidence. I removed some material on that part of the hammer in the hope it will run free. I think it helps. At some time I put some silicone grease on the hammer, thinking it would slide better but is caused inconsistency at different temperatures, so I cleaned it again. I do have some grease on other trigger parts.
I saw markings on pellets shot and looked inside the barrel. The last 20mm looked like something put a big ugly scratch inside the barrel. I took the barrel to a local gunsmith to cut it shorter to remove that scratch and he re-crowned and threaded the barrel. This helped improving accuracy.
While the barrel was off, I polished it with JB paste and concentrated on the high spots. Now it is smooth and helps a lot.
I put 7 thick, tight O-rings over the barrel, spaced evenly so it keeps the barrel and the shroud tightly together. This definitely helps.
I put thin tape around the barrel shroud and air tube where the barrel band fits to eliminate movement there as much as possible. The biggest help was the last ting I did. I took a piece of leather from an old key ring, cut it to size and placed it at the front end between the barrel shroud and air tube. I then wrapped isolation tape around the shroud and tube and then duct tape around that. I saw some people installed extra barrel bands on even FX rifles that helped improving accuracy. Now it is all one stiff barrel unit. The POI shifts is something of the past as the barrel-shroud combination cannot move around with normal handling. This also was the single biggest contributor of improving the accuracy and now I can do longer shots, up to 144 meter as shown in my other post. OK, choosing the correct pellet is just as important and having a good trigger as well.
Somewhere during this time I tuned it for different speeds. I found with the H&N pellets that 940fps was a good speed, lower than that and it would spread out. Now I have it on 957fps and it is doing good at longer distances. About 10mm groups at 50 meter, sometimes pellet on pellet for a few shots.
Besides the things I did on the rifle, I now mainly use H&N Baracuda 18 pellets but still try others as I find them. Also, for distances further than 50 meter I sort the pellets by head size and now I am sorting by weight as well. Doing this I want to see how far I can hit the 200mm x 200mm steel plate. I do have space for another 20 or 30 meter so I think I can go up to 175 meter / 190 yard, maybe a bit more, without having to travel somewhere.
This is just my journey so far with this pcp. If I had the spare cash I would buy the new FX DRS with the walnut stock, but I cannot. So, I make the best I can with this rifle.
I would like to hear what others did to improve their pcp's accuracy, budget or expensive rifles. That is apart from the normal things like tuning and pellet choice.
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