GTA
Support Equipment For PCP/HPA/CO2 and springers ,rams => Tuners => Topic started by: nced on September 24, 2019, 10:25:41 AM
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My favorite spring for my .177 R9 and .177 HW95 has been the ARH E3650, however it was unavailable for for a while and when it returned I ordered a couple........
https://www.airrifleheadquarters.com/catalog/item/251488/5414946.htm (https://www.airrifleheadquarters.com/catalog/item/251488/5414946.htm)
With the previous E3650s in my .177 R9 (chronied a couple days ago) I got 844-850fps with 7.9 grain CPLs and 833-839 with 8.4 grain Air Arms domes. I could boost the 7.9 grain CPL velocity range to >880 with more spacing but I preferred the "850fps range".
Well......with my new E3650 spring fitted with TIGHT Delrin spring and top hat, after a few break in shots over the chrony I'm getting 7.9 grain CPL velocities around 910fps and 8.4 grain AA dome velocities around 890fps. The "issue" (perhaps not an issue) is that these velocities are with minimal spring spacing and the velocities can't be reduced.
Another surprise is that the R9 with the late E3650 and tight guides has a surprisingly nice shot cycle at almost 14.5fpe for the CPL and almost 15fpe for the AA dome! I just shot a couple groups with both the CPL and AA pellets and at only 18 yards sitting on a bucket resting the gun on cross sticks the accuracy is "normal" for me. I haven't taken the R9 to my 50 yard practice lane so it remains to be seen what the "stretched out" accuracy will be.
I've been reading "stories" and watching videos of pellets spiraling with too much velocity so I have a question about the 8.4 grain AA pellets at 15ish fpe.........is the poi generally stable at longer distances?
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My favorite spring for my .177 R9 and .177 HW95 has been the ARH E3650, however it was unavailable for for a while and when it returned I ordered a couple........
https://www.airrifleheadquarters.com/catalog/item/251488/5414946.htm (https://www.airrifleheadquarters.com/catalog/item/251488/5414946.htm)
With the previous E3650s in my .177 R9 (chronied a couple days ago) I got 844-850fps with 7.9 grain CPLs and 833-839 with 8.4 grain Air Arms domes. I could boost the 7.9 grain CPL velocity range to >880 with more spacing but I preferred the "850fps range".
Well......with my new E3650 spring fitted with TIGHT Delrin spring and top hat, after a few break in shots over the chrony I'm getting 7.9 grain CPL velocities around 910fps and 8.4 grain AA dome velocities around 890fps. The "issue" (perhaps not an issue) is that these velocities are with minimal spring spacing and the velocities can't be reduced. :-[
Another surprise is that the R9 with the late E3650 and tight guides has a surprisingly nice shot cycle at almost 14.5fpe for the CPL and almost 15fpe for the AA dome! I just shot a couple groups with both the CPL and AA pellets and at only 18 yards sitting on a bucket resting the gun on cross sticks the accuracy is "normal" for me. I haven't taken the R9 to my 50 yard practice lane so it remains to be seen what the "stretched out" accuracy will be.
I've been reading "stories" and watching videos of pellets spiraling with too much velocity so I have a question about the 8.4 grain AA pellets at 15ish fpe.........is the poi generally stable at longer distances?
LOL....I have to retract some of the above. I really couldn't figure out why replacing an old E3650 spring with a new E3650 spring would give such an increase in velocity. I just broke down the .177 R9 for a "look see" and found that there was 3/16" of extra spacing that was stuck in the piston. After removing the extra preload I found that the velocities were once again "normal" with the new spring.
The old spring was several years old with many thousand of shots so I'm guessing that I added the extra preload to increase the CPL velocity to around 850fps which is my preference.
Anywhoo.....I'm "red faced and embarrassed"!!! :-[
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LOL....I have to retract some of the above. I really couldn't figure out why replacing an old E3650 spring with a new E3650 spring would give such an increase in velocity. I just broke down the .177 R9 for a "look see" and found that there was 3/16" of extra spacing that was stuck in the piston. After removing the extra preload I found that the velocities were once again "normal" with the new spring.
The old spring was several years old with many thousand of shots so I'm guessing that I added the extra preload to increase the CPL velocity to around 850fps which is my preference.
Anywhoo.....I'm "red faced and embarrassed"!!! :-[
The ol' hidden piston spacer. One of the pitfalls of springerism.
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LOL....I have to retract some of the above.
The old spring was several years old with many thousand of shots so I'm guessing that I added the extra preload to increase the CPL velocity to around 850fps which is my preference.
Anywhoo.....I'm "red faced and embarrassed"!!! :-[
Hey Ed,
You wouldn't believe some of the embarrassing, "self inflicted dramas" I have created while tuning airguns and ..... learning how to make adjustment to get things "just right!"
I will gladly give you a big PASS on Yours 8)
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As Agent 86 said -