GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => China/Asian AirGun Gate => Topic started by: nced on February 21, 2015, 10:21:52 AM
-
Just shot another 18 yard target and my Remmy groups like my old Crosman Quest of years ago with vertical stringing!
Here is the latest target where most of the 10 shots go into a tight one hole group and others "have a mind of their own".
Groups shot Feb 20.....
(http://www.snapagogo.com/uploads/source/512015/1424525835_122533712_RemTargetFeb21_2015.jpg) (http://www.snapagogo.com/photo.php?id=67113)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Groups shot Feb 18.......
(http://www.snapagogo.com/uploads/source/482015/1424287410_735543189_RemTargetFeb182015.jpg) (http://www.snapagogo.com/photo.php?id=67018)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Group shot Feb 16........
(http://www.snapagogo.com/uploads/source/472015/1424134394_272303561_RemExpTargetFeb16_2015.jpg) (http://www.snapagogo.com/photo.php?id=66930)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
This group actually showed some promise that I could make the Remmy into an accurate shooter.
Target shot with Remmy straight from the box Jan 1 after a bore clean with the factory chipped up piston seal.......
(http://www.snapagogo.com/uploads/source/282015/1422566509_1771287605_RemExpTargetJan292015.jpg) (http://www.snapagogo.com/photo.php?id=65595)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Yesterday I tore the Remmy apart and inspected the components of the barrel pivot mechanism..........
(http://www.snapagogo.com/uploads/source/292015/1422624753_1346838234_RemmyDiagram.jpg) (http://www.snapagogo.com/photo.php?id=65606)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
I found that sleeve "Part #11 was a rather sloppy fit to both the receiver forks of "Part #24", the barrel pivot block of "Part #1", and the barrel pivot tension bolt "part #12" which wouldn't hold the barrel tension once adjusted.
IMHO, there are already too many issues with MY PARTICULAR REMMY to make it a good (well, good to me) shooter without a lot of custom work! Definitely NOT a good low cost option for a cheap hunter class field target rig, but perhaps MY Remmy is just a lemon like the Quest I owned and PERHAPS it's an isolated example. The hope was that a deburred Remmy with replaced piston seal, a 4-16x40 Center Point scope, and a UTG scope mount would yield a $200 hunter class field target rig.....but no dice with my sample.
Anywhoo.....The Remmy looks nice and the fit/finish really isn't that bad so I'll be modifying the barrel pivot geometry to a single pivot bolt through the bore in the barrel pivot block that's secured with a lock nut similar to the HW95/R9 geometry to see if this solves the "vertical stringing issue". I'll also try to deal with the rather heavy cocking effort by replacing the factory spring with a light wire Maccari spring and reducing the power to 12fpe ish. The pellet stringing is indeed a curiosity since the velocity variation is "single diget" with the JSB Exacts and the pellets are indeed engraved consistently around a pushed pellet. I'm hoping that a modified pivot bolt geometry solves the vertical stringing issue, but who knows, there may be other issues!
-
Not an isolated example, I'm afraid. Mine had the same issue. Lacking the tools and the skills to use them, I returned mine. Seems to me the Chinese can't seem to take their manufacturing to the next level and attend to some of the finer details.JMO. :(
Scotty
-
I will look into the loose pin for the barrel, also look at how the breech seal is seating...not enough or too much will make it sloppy, if you have polished the pin then that could be the problem also. Most of the rifles do seem to have a snug fit but...a barrel swap might cure the problem also. Check velocity to see if it is consistent also...if you have a leak at the breech seal that will make it string ... could also be you just need to replace the cross pin...
-
Ed,
My barrel lock-up seems just fine to me. The pivot bolt and nut do not loosen at all. I just screwed it tight and now it just rotates as the barrel does. Check it last night and just as tight as before.
My gun hits right where I aim it when I'm shooting it right LOL - Haven't had much experience with a springer, but when I squeeze, and think "that one should hit the bullseye", it usually does. When I feel it jump I know I missed, and usually do. Part of this is due to my "botched" trigger mods, but I have a B26 one coming from Mike this week.
I think maybe production changed at some point. You may have gotten parts from different guns. My "catch" spring (#46 in your diagram) matches the diagram. The spring "rests" against the same pin that the Latch spring rests on. (Inside the center of trigger housing)
(http://www.snapagogo.com/uploads/source/292015/1422624753_1346838234_RemmyDiagram.jpg)
In the below pic yours is different. Your spring rests against the outside rear of the housing
(http://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=83884.0;attach=100172;image)
-
Just shot another 18 yard target and my Remmy groups like my old Crosman Quest of years ago with vertical stringing!
Here is the latest target where most of the 10 shots go into a tight one hole group and others "have a mind of their own".
Looks familiar. ;) My Air Hawk, basically the same air rifle, was doing the same. Five out of ten shots touching and the rest off in the next county. I couldn't find anything wrong with the barrel pivot or lockup. I shimmed the breech seal. It was higher than I thought it needed to be and thought it might make the problem worse. Surprise, it fixed the vertical stringing.
I think they do a pretty good job of copying the Diana style ball detent breech lockup. Like the Diana's, the pivot bolt is kinda thin and can't apply much squeeze to the barrel forks. It seems to rely mostly on how well the pivot washers (#8) and pivot bushing (#11) are fit. If the bushing is sloppy then the lockup will be sloppy too.
Regarding the Quest, I've seen weak lockup issues with all air rifles with the Crosman chisel type of detent. I found that increasing the angle on the alive jam makes the latching on the detent much tighter. In fact it's very easy to go too far and get a detent that won't open at all. (Ask me how I know) I like it so a slap on the barrel is needed to open.
Jon
-
nced, is pin#11 supposed to be long enough to fit inside washer #8 and be flush with the outside of the washer or does the pin just butt against the inside of the washer?
-
nced, is pin#11 supposed to be long enough to fit inside washer #8 and be flush with the outside of the washer or does the pin just butt against the inside of the washer?
#11 goes through both #8s, but it's short enough so tightening the adjustment screws can draw the receiver forks together a bit to adjust the barrel tension.
-
thank you. It seems as if the washer OD was tight in the receiver#1 and the washer ID was tight with the OD of the pin then a proper washer would keep it tight until the washer wore. if the nut was adjusted right and stayed snug Is it the washer that wears and causes the slop?
-
Just shot another 18 yard target and my Remmy groups like my old Crosman Quest of years ago with vertical stringing!
Here is the latest target where most of the 10 shots go into a tight one hole group and others "have a mind of their own".
Looks familiar. ;) My Air Hawk, basically the same air rifle, was doing the same. Five out of ten shots touching and the rest off in the next county. I couldn't find anything wrong with the barrel pivot or lockup. I shimmed the breech seal. It was higher than I thought it needed to be and thought it might make the problem worse. Surprise, it fixed the vertical stringing.
I think they do a pretty good job of copying the Diana style ball detent breech lockup. Like the Diana's, the pivot bolt is kinda thin and can't apply much squeeze to the barrel forks. It seems to rely mostly on how well the pivot washers (#8) and pivot bushing (#11) are fit. If the bushing is sloppy then the lockup will be sloppy too.
Regarding the Quest, I've seen weak lockup issues with all air rifles with the Crosman chisel type of detent. I found that increasing the angle on the alive jam makes the latching on the detent much tighter. In fact it's very easy to go too far and get a detent that won't open at all. (Ask me how I know) I like it so a slap on the barrel is needed to open.
Jon
I messed with the Remmy some more fabricatind a hardened home made "part #11" with modified "4mm cabinet screws", 5mm flat washers, and 4mm spring lock washers in an effort to provice some "spring loaded barrel tension". Here are a couple pics......
The home made "part #11" was turned from O1 tool steel, sized for a SNUG slip fit with the bores in the receiver forks, then the bore in the barrel pivot block was lapped for a close slip fit with the #11 OD......(http://www.snapagogo.com/uploads/source/522015/1424638811_891429404_RemCustomPBb.JPG) (http://www.snapagogo.com/photo.php?id=67227)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
(http://www.snapagogo.com/uploads/source/532015/1424720403_1438258111_RemCustPivotTension1.JPG) (http://www.snapagogo.com/photo.php?id=67274)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
LOL.....it even looked pretty good after assembly......
(http://www.snapagogo.com/uploads/source/532015/1424720539_212460283_RemCustPivotTension2.JPG) (http://www.snapagogo.com/photo.php?id=67276)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
After the mods I still got vertical stringing, then I read that a badly fitting breech seal oring can give vertical stringing so I "shimmed up" the breech oring by packing some PVC threaded fitting tape in the bottom of the oring groove and then replaced the oring. The result was a more solidly sounding barrel latch-up, plus vertical stringing was minimizes a lot. Here is a target shot at 18 yards......
(http://www.snapagogo.com/uploads/source/542015/1424799756_260559521_RemTargetFeb34_15.jpg) (http://www.snapagogo.com/photo.php?id=67302)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Seems that the most accurate pellet has changed with my mods from the JSB Exact to the 4.52mm Air Arms Diablo Field. LOL....I was a bit taken back by the two groups shot using cheap Crosman wad cutters!
I'm beginning to also think the Remmy is very hold sensitive since there is a LOT of gun motion when shot using the heavy factory piston and spring. Seems that the cocking effort is also rather stiff but perhaps this is due to the articulated cocking lever.
Well.....the beat goes on!
-
I shimmed the breech seal. It was higher than I thought it needed to be and thought it might make the problem worse. Surprise, it fixed the vertical stringing.
After the mods I still got vertical stringing, then I read that a badly fitting breech seal oring can give vertical stringing so I "shimmed up" the breech oring by packing some PVC threaded fitting tape in the bottom of the oring groove and then replaced the oring. The result was a more solidly sounding barrel latch-up, plus vertical stringing was minimizes a lot.
Great! That makes two of us. I got a supply of the breech seal shims from Mike Melick at FDAR. They fit most Dianas and clones like the Air Hawk and your Remmy. It looks like he punches them out of a aluminum soda pop cans. He sent me an envelope of shims and breech seals gratis, just because he's generous and a great guy.
The breech seal problem is well known on these clones and there are "kits" you can buy for too much $ to fix it. The "kit" is some shims and a new o-ring breech seal.
Jon
-
I shimmed the breech seal. It was higher than I thought it needed to be and thought it might make the problem worse. Surprise, it fixed the vertical stringing.
After the mods I still got vertical stringing, then I read that a badly fitting breech seal oring can give vertical stringing so I "shimmed up" the breech oring by packing some PVC threaded fitting tape in the bottom of the oring groove and then replaced the oring. The result was a more solidly sounding barrel latch-up, plus vertical stringing was minimizes a lot.
Great! That makes two of us. I got a supply of the breech seal shims from Mike Melick at FDAR. They fit most Dianas and clones like the Air Hawk and your Remmy. It looks like he punches them out of a aluminum soda pop cans. He sent me an envelope of shims and breech seals gratis, just because he's generous and a great guy.
The breech seal problem is well known on these clones and there are "kits" you can buy for too much $ to fix it. The "kit" is some shims and a new o-ring breech seal.
Jon
Actually....you're the one that gave me the idea! Thanks a bunch!!
-
suggestion to keep rifle accurate, look inside the bore at the breech, do you have a dark area of build up from burning lubes?? Happens sometimes and will affect it...
-
suggestion to keep rifle accurate, look inside the bore at the breech, do you have a dark area of build up from burning lubes?? Happens sometimes and will affect it...
The bore has been scrubbed with a bronze brush soaked in Hoppes #9, then treated with J-B Bore Paste on several pulled patches, then pulled dry patches, and the bore is indeed "shiny clean". Here is a pic of a pushed pellet after the treatment.....
(http://www.snapagogo.com/uploads/source/402015/1423531176_336447221_FireChokedRemPellet.JPG) (http://www.snapagogo.com/photo.php?id=66644)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
There is a TIGHT constriction at the breech area that perhaps was caused by the pressing in of the barrel to breech block or perhaps the pressing in of the retaining dowel. One oddity to me is that way the breech was chamfered.........
(http://www.snapagogo.com/uploads/source/282015/1422566486_492385646_RemExpress7.JPG) (http://www.snapagogo.com/photo.php?id=65587)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Here is a pic of a Remm breech from the web.......
(http://www.snapagogo.com/uploads/source/552015/1424873921_1823190827_Express_Detail_BarrelBreak.jpg) (http://www.snapagogo.com/photo.php?id=67333)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
The breech doesn't look "wallowed out" like the breech of my Remmy.
Question, how much would a .177 Remmy barrel (only interested in .177 cal) cost to replace with good new OR used? I can find parts list for Crosman airguns but so far no good finding parts for the Remmy. Is it possible that there is another Chinese airgun than uses the same barrel?
-
Mike has barrels that'll fit the Remington. It's the same as the Air Hawk and XS25. The chamfer looks off center because it might be a bit deeper than it needs to be and the face of the breech is not square to the center line of the bore. My Diana 34 and Air Hawk breech are chamfered similarly. The breech closes tighter at the top than the bottom. You might want to try a more aggressive grit on the tight spot near the breech. Soft scrub and valve lapping compound comes to mind. These Asian barrels can be quite frustrating but are (relatively) inexpensive to replace. What have you got to loose? Sometimes they can't get any worse so you roll the dice and try a new one.
Another thought, have you re-crowned it yet? I put a square target crown on it. Not worried about it getting dinged with the plastic front sight surrounding it to protect the crown.
-
the breeches are different due to the way they are made, one is angled and one is not????? polish the inside of the angles in the breech so the pellet slides in smoothly, that helps...
-
the breeches are different due to the way they are made, one is angled and one is not?????
They are different because one is chamfered and the web photo breech is not.
-
They are different because one is chamfered and the web photo breech is not.
I think they are actually both chamfered. Mine looks like the one in web photo, but when I hold it at an angle I can see it is chamfered, but I can't get it to show in pic. Trying to download my pic but Yahoo is having technical difficulties.
Mine does not "look" anywhere near as "off centered" as Ed's looks.
-
They are different because one is chamfered and the web photo breech is not.
I think they are actually both chamfered. Mine looks like the one in web photo, but when I hold it at an angle I can see it is chamfered, but I can't get it to show in pic. Trying to download my pic but Yahoo is having technical difficulties.
Mine does not "look" anywhere near as "off centered" as Ed's looks.
Here is a pic of a pellet in the leade of my Remmy barrel........
(http://www.snapagogo.com/uploads/source/282015/1422566488_1161647084_RemExpress6.JPG) (http://www.snapagogo.com/photo.php?id=65588)Uploaded at Snapagogo.com (http://"http://www.snapagogo.com")
Anywhoo.....I just ordered a new .177 Remmy barrel from Mike at Flying Dragons along with a breech seal shim and a spare breech seal oring.
-
Just a thought, Since you have a barrel on order and coming, try cutting some off yours and recrown and see what that does
-
Just a thought, Since you have a barrel on order and coming, try cutting some off yours and recrown and see what that does
Probably will do that AFTER the replacement arrives!