G
Guest
Guest
I started this project since few ppl on our finnish forums were building and having some awesome results with 5.7mm gunbarrels fitted to different type of airguns. Generally its pretty decent caliber since you can buy some ready 22LR bullets from RWS and you can also have some pretty high BC numbers out from certain long bullets while driving them on decent speeds with under 200bars.
I found SPA M10 on sale with pretty decent pricetag of 295€ from Krale and decided to fit 222remington barrel from LW on it. Stock the gun was pushing 28.4gr eu jin pellet at 730fps.
First I started by opening everything except barrel to 6.5mm and removing closing spring from valve to reduce force needed to open it fully. After that I fitted barrel on it and added some extra 3.3mm lockingpin to make sure barrel stay on its place with alot higher forces than stock gun is designed to take. There is also fairly big risk with the bolt of this gun shooting on ur face if the one and only screw that holds it lets go when fireing so some extra locking mechanism was added. I did also cut barrelband away and added some silicone type material between air resevoir and barrel to make it semi freefloating barrel to try to improve harmonics.
This still is on work in progress stage mainly just testing and trying to find right preassure, speed and bullet combination but when maxed out it pushes 41.4gr RWS 22lr bullet at little over 1000fps and Noe 51gr spitzer at 920fps maxing out at 130j. With a slight hammerspring adjusting to reduce power you can get 5 really steady shots out from it at 95% of the full power but it was purely built to shoot as externally regulated gun.
Noe 51gr spitzers
100meter group. But still far from meeting sub moa constantly.
I found SPA M10 on sale with pretty decent pricetag of 295€ from Krale and decided to fit 222remington barrel from LW on it. Stock the gun was pushing 28.4gr eu jin pellet at 730fps.
First I started by opening everything except barrel to 6.5mm and removing closing spring from valve to reduce force needed to open it fully. After that I fitted barrel on it and added some extra 3.3mm lockingpin to make sure barrel stay on its place with alot higher forces than stock gun is designed to take. There is also fairly big risk with the bolt of this gun shooting on ur face if the one and only screw that holds it lets go when fireing so some extra locking mechanism was added. I did also cut barrelband away and added some silicone type material between air resevoir and barrel to make it semi freefloating barrel to try to improve harmonics.
This still is on work in progress stage mainly just testing and trying to find right preassure, speed and bullet combination but when maxed out it pushes 41.4gr RWS 22lr bullet at little over 1000fps and Noe 51gr spitzer at 920fps maxing out at 130j. With a slight hammerspring adjusting to reduce power you can get 5 really steady shots out from it at 95% of the full power but it was purely built to shoot as externally regulated gun.
