GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Spooner on February 12, 2021, 09:48:57 PM

Title: 1077 detent mod question
Post by: Spooner on February 12, 2021, 09:48:57 PM
i have the o-ring for the detent but having trouble picking the spring. my local hardware store was out of the one i think will work so i am stuck with finding it online. i really just need to know what those of you who have done this mode used... wire diameter more specifically. i know the outer spring diameter is about 1/4" and the length is about an inch, so if i can find out the correct wire diameter... i can find one online.

my LDC from Geo will be here tomorrow and that will help greatly with getting rid of the barrel slop at the end. im very optimistic that with the detent mods and the LDC... i can finally resolve the accuracy issues, i hope.  ;)

thanks!
Title: Re: 1077 detent mod question
Post by: wll2506 on February 13, 2021, 10:32:35 AM
i have the o-ring for the detent but having trouble picking the spring. my local hardware store was out of the one i think will work so i am stuck with finding it online. i really just need to know what those of you who have done this mode used... wire diameter more specifically. i know the outer spring diameter is about 1/4" and the length is about an inch, so if i can find out the correct wire diameter... i can find one online.

my LDC from Geo will be here tomorrow and that will help greatly with getting rid of the barrel slop at the end. im very optimistic that with the detent mods and the LDC... i can finally resolve the accuracy issues, i hope.  ;)

thanks!

I'm folling as I want to see your accuracy increase with the LDC.

wll
Title: Re: 1077 detent mod question
Post by: Gippeto on February 13, 2021, 11:44:57 AM
Let's think this through for a second;

The oring seals the "detent" and develops force during the shot cycle to seal against the magazine, but does not have any effect at any other time.

The spring pushes the detent against the magazine during the double action trigger pull.

Do you see a problem here?

If you look at the force developed by sealing the detent, it's HUGE (in the order of 93+lbs of force) compared to whatever spring you could put in there.

Adding a heavier spring only serves to make an already atrocious trigger pull that much worse.

JM .02

edit; If you're looking to improve accuracy, two areas that were in poor shape from factory were the forcing cone and crown on the barrel. (had three 1077's and a Nightstalker come through my hands over the years, and they all needed tidying here) Re-do the crown and polish the forcing cone into the rifling.

Al
Title: Re: 1077 detent mod question
Post by: wll2506 on February 13, 2021, 12:25:40 PM
i have the o-ring for the detent but having trouble picking the spring. my local hardware store was out of the one i think will work so i am stuck with finding it online. i really just need to know what those of you who have done this mode used... wire diameter more specifically. i know the outer spring diameter is about 1/4" and the length is about an inch, so if i can find out the correct wire diameter... i can find one online.

my LDC from Geo will be here tomorrow and that will help greatly with getting rid of the barrel slop at the end. im very optimistic that with the detent mods and the LDC... i can finally resolve the accuracy issues, i hope.  ;)

thanks!

I'm following as I want to see your accuracy increase with the LDC.

wll
Title: Re: 1077 detent mod question
Post by: Spooner on February 13, 2021, 02:52:35 PM
i took a chance after hours of looking at springs and ordered a pack of 4 from ebay. no idea if its correct but it looked like the dimensions were close enough to work with. we have been getting hammered with winter storms here. it will be in the spring before i can get the 1077 and my new 2400KT out for sighting in but will post a new thread for the 1077 once i do. i am hopeful.  ;)
Title: Re: 1077 detent mod question
Post by: Spooner on February 13, 2021, 04:10:14 PM
Let's think this through for a second;

The oring seals the "detent" and develops force during the shot cycle to seal against the magazine, but does not have any effect at any other time.

The spring pushes the detent against the magazine during the double action trigger pull.

Do you see a problem here?

If you look at the force developed by sealing the detent, it's HUGE (in the order of 93+lbs of force) compared to whatever spring you could put in there.

Adding a heavier spring only serves to make an already atrocious trigger pull that much worse.

JM .02

edit; If you're looking to improve accuracy, two areas that were in poor shape from factory were the forcing cone and crown on the barrel. (had three 1077's and a Nightstalker come through my hands over the years, and they all needed tidying here) Re-do the crown and polish the forcing cone into the rifling.

Al
its a very valid point Al and thats probably why they took the o-ring out of the original design? i took my old valve and added this o-ring to the detent this morning to see how it works using the original spring. even with oil added to the o-ring it struggled to return back out. not a "heavier spring", just a longer one of the same wire size, but yes... more tension none the less on a trigger that is already rough.  im not gonna spend a lot of time on this mod, searching for the right spring. i will test it using my old valve with the spring i have coming. i can already see where the detent sticking will be an issue if the longer spring doesnt solve that and i may not go with that mod in the end? shoring up the slop in the barrel at the end is the thing that i think will help my gun the most, time will tell?

yes, i saw a video about re-crowning and polishing both ends of the barrel. i have never done this and not sure i would be comfortable trying? i have a spare barrel and may give it a try on that one? this will be my last attempt to improve the accuracy of my 1077. the truth is, i bought my 2400KT to replace this rifle... that one will be accurate.  ;)
Title: Re: 1077 detent mod question
Post by: Spooner on February 13, 2021, 06:19:26 PM
so, i am going to take a shot at this barrel. yeah, the receiver end definitely needed smoothing out. there were ridges in the chamfer so i smoothed them out and polished it with my dremel. the crown looks pretty decent but i will give it a little more and polish it as well. its my spare barrel anyway... so if i screw it up, i can go back to my original one.  ;)
Title: Re: 1077 detent mod question
Post by: Spooner on February 13, 2021, 09:36:46 PM
barrel work is done on the backup. i think i did a pretty decent job actually. got the ridges out of the receiver end, put a little deeper crown in the exit end, polished it all up then cleaned and oiled the barrel. i took the original barrel out of my gun and i am glad i did. the exit end had nicks all around the OD. the crown didnt look too bad though. the receiver end looked pretty rough inside. the chamfer in that end was much more pronounced then my newer barrel was before i worked out the roughness. now, the newer one is pretty close to the old one, just nice and smooth. needless to say... i put the newer barrel in the gun.  ;)

the LDC from Geo came today and i got that installed. his tolerances are very accurate and the design is perfect! the barrel slips into the inner section of the LDC and the outer part of the LDC slips over the barrel tube then set by a single set screw. this barrel isnt slopping anywhere, slop is gone. the best part is that the anti-jam latch still works. it is a tight fit but i was able to work the barrel forward with the latch without removing the LDC. with or without the detent mod, and i am not sure i am going to do that one yet, the barrel is now stable.  8)
Title: Re: 1077 detent mod question
Post by: wll2506 on February 13, 2021, 09:49:58 PM
barrel work is done on the backup. i think i did a pretty decent job actually. got the ridges out of the receiver end, put a little deeper crown in the exit end, polished it all up then cleaned and oiled the barrel. i took the original barrel out of my gun and i am glad i did. the exit end had nicks all around the OD. the crown didnt look too bad though. the receiver end looked pretty rough inside. the chamfer in that end was much more pronounced then my newer barrel was before i worked out the roughness. now, the newer one is pretty close to the old one, just nice and smooth. needless to say... i put the newer barrel in the gun.  ;)

the LDC from Geo came today and i got that installed. his tolerances are very accurate and the design is perfect! the barrel slips into the inner section of the LDC and the outer part of the LDC slips over the barrel tube then set by a single set screw. this barrel isnt slopping anywhere, slop is gone. the best part is that the anti-jam latch still works. it is a tight fit but i was able to work the barrel forward with the latch without removing the LDC. with or without the detent mod, and i am not sure i am going to do that one yet, the barrel is now stable.  8)

Great, following to see how your gun performs :-)
Title: Re: 1077 detent mod question
Post by: Spooner on February 14, 2021, 10:25:23 AM
here is a pic of the installed LDC from Geo, and another pic of it showing it as a whole. i will be using a vintage Tasco 3-9x32 "Antler Angler" scope on this one... the same scope i bought for it way back when.  ;)

(https://i.imgur.com/LUiv5Da.jpg)

(https://i.imgur.com/yRnePmh.jpg)
Title: Re: 1077 detent mod question
Post by: Spooner on February 23, 2021, 08:08:12 PM
my springs came in from eBay today...
https://www.ebay.com/itm/Prime-Line-5-16-in-Dia-x-1-3-4-in-L-Compression-Spring-4-pk/371990546544?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 (https://www.ebay.com/itm/Prime-Line-5-16-in-Dia-x-1-3-4-in-L-Compression-Spring-4-pk/371990546544?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649)
... these are perfect! had to cut them down to the right length but the tension, diameter, and wire diameter are an exact match to the original. i have the detent mod now done in the rifle. this mod, i may undo? i will try it out but the detent sticks a little. it has plenty of tension, and i oiled the o-ring so i am hoping it will smooth out as its gets used. i think if i work it a few times with my finger before putting in the clip, it wont be an issue. i put the scope back on tonight.

now the waiting begins. winter... go away!  ;)
Title: Re: 1077 detent mod question
Post by: Spooner on March 02, 2021, 10:44:09 AM
for those of you who have done this mod... how is it working? i havent shot the rifle yet but check the detent each day. it does stick after sitting for even a short period of time but seems to unstick and work with a push or two from my finger. just curious if any of you have this occur in your mod?

i went to the o-ring store hoping to find this size in cast urethane but they didnt have it in this size.
Title: Re: 1077 detent mod question
Post by: Spooner on March 16, 2021, 09:51:49 AM
just wanted to update...
after testing the recommended o-ring in my old valve and checking the one i put in the actual gun valve, results were the same. after sitting for a few minutes, the o-ring was  sticking and had to be pushed free with my finger. i have a very nice kit from the o-ring store of AS568 buna's and looked through the different sizes. the 009 was just about perfect to the recommended one but the wall thickness was 1.78... just a little bit thinner than one for this mod. i can tell that it touches the wall of the detent but this one doesnt stick after sitting. it may or may not seal as well as the 2mm one recommended, but i went with it.  ;)