GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: imadunatic on December 20, 2016, 11:11:08 AM

Title: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on December 20, 2016, 11:11:08 AM
Read through Bob's posts (http://www.gatewaytoairguns.org/GTA/index.php?topic=16616.20) as well as many others on the Hammerli (yes I know it's fallen out of favor, but stumbled into a Refurb .22 for $180 shipped) and most of what I find is max FPE tunes. I don't use my airguns for hunting, but I do enjoy long range (NUAH) shooting every chance I get so the stock 12 FPE needs a boost, but I'd still like to be fairly easy on the bottle.

In bone stock form on this gun, 700 PSI air is slower than 700 psi  CO2, so I know this thing is not breathing well as is. I have collected all the information on porting, flow modding the valve and what not, and I'm not afraid to open things up, but I want to make sure I don't go too far.

So, Bob or anyone else listening, what would you recommend to get the most efficient tune at or near 16-20 FPE? I don't really need adjustability and I haven't bought the HPA bottle for it yet, the one caveat I'd like to maintain is being able to pull the bottle and install a 9 OZ CO2 for maximum summertime plinking fun, which means I really need to leave the pin in my Baker long adapter; if this is a major hang up in my quest, then I'll pull the pin, bore it out and install an extension on the regulator (tho I don't think I'll need that much volume for the power I'm looking to get).

Thanks in advance.
Kevin
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on December 20, 2016, 02:00:54 PM
Common 850's tuning can reach about 32FPE with a 1900psi regulator and uses a 22ci bottle.A good tuning can give 60-70 shots.
If your goal is about 20 fpe,i think you can squeeze out 40-50 shots with a 13ci bottle around 1600psi.
A long adapter bored out without the rod is a great gain of regulated air and a big improvement in efficiency,but you can run bi fuel milling a flat on the adapter rod to allow better air flow.
If i am not wrong,Robert (rsterne) had a similar setup some years ago (without rod) and can give you more exact numbers.
Check for accuracy before touch the rifle,some bad .22 barrells around.
I am in the 850 resource too  ;)
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on December 20, 2016, 02:51:51 PM
Quote from: Tucobenedicto on December 20, 2016, 02:00:54 PM
Common 850's tuning can reach about 32FPE with a 1900psi regulator and uses a 22ci bottle.A good tuning can give 60-70 shots.
If your goal is about 20 fpe,i think you can squeeze out 40-50 shots with a 13ci bottle around 1600psi.
A long adapter bored out without the rod is a great gain of regulated air and a big improvement in efficiency,but you can run bi fuel milling a flat on the adapter rod to allow better air flow.
If i am not wrong,Robert (rsterne) had a similar setup some years ago (without rod) and can give you more exact numbers.
Check for accuracy before touch the rifle,some bad .22 barrells around.
I am in the 850 resource too  ;)

Accuracy is good at 15 meters, single hole groups out of JSB exact's and heavies (didn't like the monster's so much or the CPHP's though). It's almost dead of winter here, so I need a calm day for longer range testing; but it was very impressive at my indoor range.

Would it be more efficient to open up the valve and ports and run lower PSI or just leave it and crank the PSI? To be honest, I'd like to tune the gun for max efficiency on low pressure (under 1000 PSI) so that switching back and forth between HPA and CO2 is mostly painless. I was surprised when the HPA ran slower than the CO2 at the same pressure, but I have another rifle that does the same thing (the plastic M14 runs about 50% slower, it's just not designed for HPA flow).

Quote from: Tucobenedicto on December 20, 2016, 02:00:54 PM
I am in the 850 resource too  ;)

I did notice you were a MOD over on the yellow, that is where I gathered all the info on flow modding the valve, barrel, etc. I will most likely still end up flow modding everything when I have it apart to smooth the barrel inlet (action is a little harsh right now, I'd like to smooth it out) and possibly add an extension just to increase my volume of regulated air, but I really don't want to hot rod this, I have other rifles for hunting, I don't need another! LOL
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on December 20, 2016, 03:00:57 PM
Paintball regulators have a low flow rate compared with a 88grams CO2 bottle,this is the main reason you need around 1200psi on hpa to obtain the same performance.You can try a 1400psi setup without touching the valve and adapter and see the results.
Keep in mind you need a strongest hammer spring to run over 1100 psi,the 850 valve become very hard to open raising the work pressure.
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 18, 2017, 06:50:39 PM
Ok. Finally tore the 850 apart, lightened a few components to get the flow more in line with what HPA needs and gained almost 100 FPS at the same pressure.

Right up front, this is the last string I shot before I took it apart, regulator was set to 700 PSI, bone stock everything with Baker Long Adapter (also stock):

Description: Hammerli Tethered Hpa 700 psi
Notes 1: jsb exact heavy 18.13 gr
Bullet Weight (gr): 18.300
Temp: 7 (outside!!! Was 56 in the basement) °F
BP: 29.91 inHG
Shots
# FPS FT-LBS PF
8 566 13.02 10.36
7 566 13.02 10.36
6 565 12.97 10.34
5 551 12.34 10.08
4 553 12.43 10.12
3 563 12.88 10.30
2 562 12.84 10.28
1 570 13.20 10.43
Average: 562.00
StdDev: 6.63
Min: 551
Max: 570
Spread: 19

Was fairly anemic, and even slower than CO2.

Did lots of stuff, this is the result on the same air pressure:

Description: Hammerli 850 after flow mods. 700 psi JSB exact heavy 18 gr
Bullet Weight (gr): 18.130
Altitude (FT): 0.0
Temp: 34 °F
BP: 29.98 inHG
Shots
# FPS FT-LBS PF
8 ERROR 2
7 651 17.06 11.80
6 658 17.43 11.93
5 656 17.33 11.89
4 654 17.22 11.86
3 653 17.17 11.84
2 656 17.33 11.89
1 661 17.59 11.98
Average: 655.57
StdDev: 3.31
Min: 651
Max: 661
Spread: 10

Gained almost 100 FPS at the same pressure. Once I replace the coil spring in this regulator with a belleville stack and bump the pressure to 850-900, I should be right near the 18-20 FPE I want to be at with this set up. I'm still running the stock CO2 spring, so I'm guessing the air usage won't be much higher now than it was, I am trying to work out a way to incorporate a twin spring system like Travis has been playing with because there is no room for even one of my internal SSG's in this setup.

So, the list of mods is as follows:

Opened the throat (exhaust port on this design???) to .265"
Removed the screen and drilled 3 1/8" holes in the inlet side of the valve. Not sure why this doesn't respond well to a hogging like the QB or Crosman valves, but I'm guessing it has something to do with the design of the wide, flat poppet (Roald and others all recommended the 3 hole method, I am not one to argue).

(http://i.imgur.com/9QnzOrI.jpg)

Drilled a mini plenum into the adapter, .516" x 1.4" deep (I couldn't bring myself to bore it out as far as Bob did with his build years ago (2010 I think?) plus, this isn't a power build, it's a get the maximum power and efficiency out of 850-900 PSI build (I hope).

(http://i.imgur.com/HAxM5DA.jpg)

Opened the other end of the adapter to 21/64 and countersunk to help feed the 3 holes I machined into the valve:

(http://i.imgur.com/cyw9nmm.jpg)

Opened the bottom barrel port to 5/32 and touched up the leade on the back to try and smooth out the action. I kind of wish I would have knocked that corner off further, but I didn't want to go too far and risk a leak around the bolt:

(http://i.imgur.com/AlPfg7g.jpg)

I also wanted to maintain the option to run the airsource cylinders, as well as remove the HPA bottle and fit a 9oz CO2 bottle in the summer months when it's 80 degrees around here. In order to do that, and bore out the adapter, I needed another solution. That solution was an inline ASA that acts as a shutoff as well as a pin depressor for any attached tank. They work very smooth and this one popped up on ebay for $13 shipped:

(http://i.imgur.com/xbneuMV.jpg)

Next step is to re-stack the regulator to bump the pressure about 150 lbs and retest. It may not even take that much to get where I want. If it ends up above 20 FPE at 900 PSI I'll back it off. This is strictly going to be a long range plinker (other than the occasional Starlings that show up in the spring).

I'll post back with what restacking brings when I get to it.

Many thanks to Tucobenedicto as well as Fivestar45 for the suggestions. I know that for many this gun is simply old news so they don't even bother reading the posts....  :-[
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: anti-squirrel on January 18, 2017, 09:27:15 PM
Quote from: imadunatic on January 18, 2017, 06:50:39 PM
Ok. Finally tore the 850 apart, lightened a few components to get the flow more in line with what HPA needs and gained almost 100 FPS at the same pressure.

~[Did some awesome stuff]~

I know that for many this gun is simply old news so they don't even both reading the posts....  :-[
Hush.  This was a good "how-to", and if nothing a great refresher on tuning for a purpose.
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Horatio on January 19, 2017, 01:43:35 AM
Quote from: imadunatic on January 18, 2017, 06:50:39 PM

I know that for many this gun is simply old news so they don't even bother reading the posts....  :-[

Thanks for posting.
I've thought about getting one for a couple years, just haven't ponied up yet.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 19, 2017, 02:49:53 AM
It seems to me a perfect job Kevin,i doubt a twin spring system can be useful,but if you can fit it in the 850,i whant to see how  :D
With the standard  spring the 850 hammer is free flight,have you noticed hammer bounce on your setup?
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 19, 2017, 06:26:44 AM
Quote from: Tucobenedicto on January 19, 2017, 02:49:53 AM
It seems to me a perfect job Kevin,i doubt a twin spring system can be useful,but if you can fit it in the 850,i whant to see how  :D
With the standard  spring the 850 hammer is free flight,have you noticed hammer bounce on your setup?

I haven't noticed any hammer bounce, and some of the efficiency numbers others have posted at higher FPE leads me to believe it's a fairly efficient design to begin with. I'm glad you confirmed the negative preload on the hammer spring, I didn't have my valve complete when I reassembled the receiver the other night to confirm it, but it did seem to me that the spring was shorter than the stroke. It's easy to forget when you're working on this gun that it's a 10+ year old design. They really were ahead of their time, it's no wonder they were (are) so loved.


Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 19, 2017, 06:32:15 AM
Quote from: Horatio on January 19, 2017, 01:43:35 AM

Thanks for posting.
I've thought about getting one for a couple years, just haven't ponied up yet.

If the build quality on the Gauntlet is anywhere near as nice as this 850, I think that is definitely going to be the way to go.... I wouldn't be surprised to see the 850 end production at some point, especially considering that the production costs on the 850 have to be driving the high normal price tag (so many little moving parts and pieces).

Oddly enough, I made my to do list on this rifle about a month ago, and then they announce the Gauntlet and it's almost a dead ringer for my plans on this rifle. Go figure.  ;D
Title: Re: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 19, 2017, 06:34:54 AM
Quote from: anti-squirrel on January 18, 2017, 09:27:15 PM
Hush.  This was a good "how-to", and if nothing a great refresher on tuning for a purpose.

Thanks Peter. Many of the builds you can find documented around the net are definitely aging and usually for max power; I figured it was time to document a different purpose build, might light a spark for someone else.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 19, 2017, 01:25:30 PM
I bought my 850 about eight years ago,this rifle was very popular for PCP conversions at that time.
Now there are many more options around,but is still an enjoyable rifle to shoot due to the accuracy of the barrells.
If Umarex will put on the Gauntlet a good barrell too at the price claimed we have a very interesting new option.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 19, 2017, 09:39:23 PM
Well, as amazed as I was last night, I'm equally amazed tonight, but not in a good way. Restacked my reg so that it was putting out ~850 psi, hooked it up and lost about 10 FPS, which tells me the stock CO2 spring isn't strong enough to bump the valve even at 850 PSI (with the valve face opened up).

Created: 01-19-2017 07:57:53 PM
Description: Hammerli 850 after flow mods. 850 psi JSB EH
Bullet Weight (gr): 18.130
Shots
# FPS FT-LBS PF
7 636 16.29 11.53
6 645 16.75 11.69
5 649 16.96 11.77
4 639 16.44 11.59
3 641 16.54 11.62
2 634 16.18 11.49
1 653 17.17 11.84
Average: 642.43
StdDev: 6.92
Min: 634
Max: 653
Spread: 19
Shots/sec: 0.19


This leaves me at a bit of an impasse. I think the first thing I'm going to do is start shimming the spring to see how much it needs, and then I need to decide if I just want to leave well enough alone, buy another bottle and run it at 700 PSI. At 700 PSI, it's dangerously close to my target power (17.4ish foot pounds) and knowing that it's barely enough spring leads me to believe it's going to be fairly efficient at this pressure as well (thirdly, I fill from a standard SCUBA tank, so being able to shoot down to 650 PSI on the bottle is also nice).

I think I need to sleep on it for a day or 2 before I make any rash decisions. More than likely I'll be pulling it apart this weekend to shim the mainspring and see what I can do with the stock setup. I've set a goal for 18 FPE, and since I'm this close I'm likely going to see it through and decide what I want to do.

My wife and I are taking a class to get our concealed carry license this weekend, that will slow down my tinkering...

Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 20, 2017, 01:37:39 AM
You can shim the spring up to 1/4 without coil bind.
Another option is to shim hammer side with a little brass spacer like this.
http://i1379.photobucket.com/albums/ah127/Benedictoremirez/850/WP_20150206_002_zpso6b0d3tr.jpg (http://i1379.photobucket.com/albums/ah127/Benedictoremirez/850/WP_20150206_002_zpso6b0d3tr.jpg)
This add some weight to the hammer too,worked for me when i ran CO2.
The spring rate is about 10lb,but the 850 valve is hard to break open compared with common plastic poppett valves like crosman's.
Don't think the valve locks at your pressure,maybe you need simply a bit more dwell.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 20, 2017, 06:13:41 AM
Thanks Tuco. I think for testing purposes I'm going to tether this so I can more closely monitor plenum/line pressures with my 2 1/2" gauge to make sure I'm not having another issue. It appears to me by nearly all accounts, this spring setup should be plenty up to 1000 PSI, so I'm wondering if I have another issue (like my inline ASA is causing issues...?)

In the meantime, I'm going to make a couple spacers like you mentioned, worst case I'll order a dominator spring and clip it to get where I want to be.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 20, 2017, 08:51:47 AM
The Dominator spring is very stiff and don't work well on the plastic guide,the dominator has a long metallic guide and a specific hammer drilled to accept the guide.
Thrust me,you don't need that spring,is designed to work about 1900psi.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 20, 2017, 09:06:09 AM
You're right. That is exactly what I don't want. I do have some 14 lb spring stock in my stash, that might be pretty close (especially with negative preload) if the stock spring is 10 lbs. Just need some shop time now to work through it!!  :-\
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 20, 2017, 12:29:21 PM
You are so close to your target power i think the spacers are an option to try to keep low the cocking effort.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 23, 2017, 09:10:06 AM
Rejoice! Rejoice! I had a few minutes after our class yesterday to play with this. I reshot a string tethered so I could monitor line pressure and sure enough it was slower on the 850 PSI than it was on 700 PSI, everything else being equal. So I pulled it apart, added .040" (1mm) of shim, reassembled and shot this string:

Created: 01-22-2017 04:23:22 PM
Description: Hammerli 850 850 psi JSB EH
Notes 1: .040" shim
Ballistic Coefficient: 1.000
Bullet Weight (gr): 18.130
Temp: 45 °F
BP: 29.62 inHG
Shots
# FPS FT-LBS PF
8 675 18.35 12.24
7 685 18.89 12.42
6 675 18.35 12.24
5 684 18.84 12.40
4 683 18.78 12.38
3 666 17.86 12.07
2 676 18.40 12.26
1 672 18.18 12.18
Average: 677.00
StdDev: 6.59
Min: 666
Max: 685
Spread: 19
Shots/sec: 0.16

That is pretty much spot on where I want to be with respect to power. I was able to get just over 14 clips (112 shots) from a 2000 psi fill before I had a substantial drop in POI. When the weather warms up this spring, I plan to do a full string through the Chrono so I can see exactly what it's doing and when it's doing it. But for now with our January thaw (it was almost 45 yesterday) I'm keeping it short.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 23, 2017, 09:23:39 AM
This mean a ton of shots at 3000psi fill. :D
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 23, 2017, 09:43:40 AM
I also took a few minutes to take care of a couple more creature comfort/accurizing issues:

First up, my grand plan inline ASA turned out to be a real pain, could barely get needle nose pliers on it, and even then it wasn't good.

This was the stock on/off knob installed in the gun, you can see it's dang near impossible to reach:

(http://i.imgur.com/RDE5vwt.jpg?1)

So, one piece of aluminum and some lathe time produced a new knob that would actually extend up and around the regulator up to the bonnet set screws:

(http://i.imgur.com/Jd3sPiz.jpg)

Extends out beyond the forearm just enough :

(http://i.imgur.com/5uzIHCb.jpg)

Next was locking the barrel down. Looked at many ideas, but I figured 3 #8-32 SHSS (even in the white metal) would be the easiest way to lock up the barrel. Wouldn't want to get ham fisted with the allen wrench, but it doesn't even pretend to move in the receiver now:

(http://i.imgur.com/SLcVBFd.jpg)

After all this, I came up from the basement to find sunshine and hardly a breeze... so I remounted the scope, sighted it in and then proceeded to shoot this 8 shot string at 22 yards:

(http://i.imgur.com/nmxW2Po.jpg)

Turns out she can cook too!!! Just to be sure it wasn't a fluke, I backed it up with this 8 shot group:

(http://i.imgur.com/5xEeEW6.jpg)

A little wider, but, right at this point in time I am nearly ready to say mission accomplished. The only things left on the to do list are a bottle support/built in sling mount (I found this on someone else's build, I can't remember who, but I'm borrowing the idea, so thank you!) and a barrel shroud (1" aluminum is supposed to be here tomorrow for that).

Couldn't be happier with it right now. Just need a good efficiency run to see how much of a gas guzzler it is.

Quote from: Tucobenedicto on January 23, 2017, 09:23:39 AM
This mean a ton of shots at 3000psi fill. :D

I think you're exactly right Fabio... I am definitely looking forward to a full shot string just to see how much we're talking.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 26, 2017, 07:37:27 PM
Efficiency testing tonight.... For some reason my power slipped back down to 17.5 FPE, which is a little less than I would prefer. I'm going to wait until I have time to shoot it off the regulator before I decide what I want to do.

In it's current form, I'm getting 1.52 FPE/ci 1.39 FPE/ci (fat fingered a number I think) and using about 12.5 psi per shot, which means my shot count should be in the neighborhood of 175 shots from 3000-800 psi (assuming I'm just off the knee now and I can extend my usuable shots to 800 PSI).

Since this is a plinker, and now technically the most powerful airgun I own, I'm really tempted to just leave it where it's at and see if I like it. I would certainly like to bump it up closer to 20 FPE, but I can't negate the fact that my efficiency will most likely go down as I shim the hammer spring (I think it's still a little light based on a fairly wide ES), but this rifle only has about 200 pellets through it, so I'm not calling it broke in yet.

It's not over yet.

Kevin

Edit: Bumped the shim to .060" and it landed right at 18.6 FPE @ 1.32 FPE/Ci, gonna shoot it there for awhile and see what happens.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Hobbyman2007 on January 26, 2017, 08:28:08 PM
Nice work Kevin. Never had one of the 850 rifles but always wanted one. Retail up here is nearly 400$ right now . Unless I see one used for a good price ,I'll have to live through your tinkering. Enjoy the new rifle .
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on January 26, 2017, 09:16:10 PM
Quote from: Hobbyman2007 on January 26, 2017, 08:28:08 PM
Nice work Kevin. Never had one of the 850 rifles but always wanted one. Retail up here is nearly 400$ right now . Unless I see one used for a good price ,I'll have to live through your tinkering. Enjoy the new rifle .

Thanks Denis.

I feel you there. My wife paid $180 shipped for this as a refurb from airgun depot (early christmas present for me), that really is the right price; I can't see spending the full $300 (retail here) on it even as sweet as it shoots. I think it will always have it's place in the cabinet once I'm done with it though. It seems well built, and it's encouraging to hear other members like Fabio talk about having their 850 for 8 years and still loving it.

Kevin
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on January 27, 2017, 02:19:09 AM
Yes,my .177 850 is still up and running and is very accurate, i love it.
Like i sayed,there are much more options around now,but if one can catch one for a good price i still suggest to buy one.
A lot of fun,even out of the box.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on February 01, 2017, 09:43:03 PM
So the permanent bottle showed up today, lo and behold, it was at 775 PSI right out of the gate with the stock coil spring in it. It just happened I wanted to try this pressure with the .060" spring shim, so I loaded up 3 clips and proceeded to shoot this string:

Description: hammerli 850 775 psi hpa jsb eh 18.13 efficiency testing
Notes 1: start 1500 psi
Notes 2: end 1175


#   FPS   FT-LBS
1   702   19.84
2   700   19.73
3   700   19.73
4   698   19.62
5   704   19.96
6   700   19.73
7   701   19.79
8   705   20.01
9   704   19.96
10   703   19.9
11   702   19.84
12   701   19.79
13   703   19.9
14   700   19.73
15   700   19.73
16   705   20.01
17   695   19.45
18   689   19.11
19   696   19.5
20   689   19.11
21   691   19.23
22   685   18.89
23   689   19.11
24   690   19.17

That is the new current record for my tune, which is 1.58FPE/CI.... That is pretty spectacular considering I also bumped the average FPE up to about 19.6 with this regulator set point. Also, my extreme spread for the first 2 clips was 7 FPS or about 1%, I need to investigate that third clip and see what is going on with that. Makes me think the pellets might be getting damaged or something.

My shot count from 3000 to 750 PSI should be in the neighborhood of 160 which is enough for me to not even bother switching over to CO2 in the summer months.

None the less. Still being amazed by what a few PSI can do to the efficiency and power of an airgun.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on February 02, 2017, 01:52:48 AM
Very nice results Kevin,maybe the last shots are close to regulator setpoint?
I would test a string starting from an higher filling pressure to see.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: stalwart on February 08, 2017, 06:45:28 AM
Quote from: Tucobenedicto on January 27, 2017, 02:19:09 AM
Yes,my .177 850 is still up and running and is very accurate, i love it.
Like i sayed,there are much more options around now,but if one can catch one for a good price i still suggest to buy one.
A lot of fun,even out of the box.

I have a magic number in mind, that will put one in my stable... even if it takes years. Did some reading, for a customer's project, and saw a *lot* of love out there.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on February 08, 2017, 09:48:25 AM
Forgot to post my print of the extended knob (for the future builder of course!)...

Edit: Apparently really slacking. I've also attached a print and pics of the wrench needed to open up the valve. I used 2 #6 SHCS for the pegs, worked perfectly, just be careful when you open the valve, the spring has a fair bit of preload and stuff goes flying everywhere.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: stalwart on February 08, 2017, 09:56:44 AM
Nice!
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on February 08, 2017, 01:00:59 PM
Kevin,want go deep in the 850? A couple of years ago i modded the valve with a different stem,this allowed me to run the standard spring with a 1800psi setup.the great advantage is a low cocking effort and a lighter trigger.
Attached a drawing (metric) and some pictures
You can get the idea.
There is another mod around made by fivestar45 (anthony) with a classic poppett and a new valve cap,but i don't have Anthony skills and tools,so this is my way  ;)
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on February 09, 2017, 01:31:45 PM
Fabio,

You are enabling the sickness. Lol.

Does the valve seal with the o ring on the washer? I've read other discussions on the tapered valve seat design, the consensus was that it took more hammer strike to crack it open, but it sounds like you're seeing the opposite?

Is it just because that stock poppet oring is so soft that it takes a ton of movement just to break the seal?
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on February 09, 2017, 01:47:46 PM
Yes,the valve seal with the o ring on the washer,you can see better on the pdf attached.
The 90° angle on the stem was an arbitrary choice but worked for me.this setup is inside my 850 and still consistent without leaks after two years or more of shooting.I thinkered about a flattest angle,but i had no reasons to do that.
A conical valve spring works better with my stem,the standard spring tend to bent a little and misalign the stem.not a big issue with the valve screwed on the rifle.
This valve works with the standard hammer spring shimmed about 2millimeters giving 21fpe at 1800 psi on my .177 850.
The rifle becomed more quiet too,i think it waste less air then standard valve.
You are correct,the standard poppet require a big strike to break the o ring seal so a very strong hammer spring is required to run 1800-1900psi
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: fsae99 on February 09, 2017, 01:51:59 PM
Kevin,
If you going to make this make 2, 1 for me.

Quote from: imadunatic on February 09, 2017, 01:31:45 PM
Fabio,

You are enabling the sickness. Lol.

Does the valve seal with the o ring on the washer? I've read other discussions on the tapered valve seat design, the consensus was that it took more hammer strike to crack it open, but it sounds like you're seeing the opposite?

Is it just because that stock poppet oring is so soft that it takes a ton of movement just to break the seal?
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on February 09, 2017, 01:56:03 PM
Quote from: fsae99 on February 09, 2017, 01:51:59 PM
Kevin,
If you going to make this make 2, 1 for me.


LOL. I've stuck it in my notes, not quite to the point of modifying the valve innards like this. That will probably be stage 2 for me depending on what kind of performance I'm seeing out of my current setup. I am guessing I could finish hogging the front of the valve out with this as well since this poppet is much easier to crack.

Fabio,

Again, thanks for sharing. I've saved your print and pics, no guarantees I won't have questions if I start down that road!.

Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on February 09, 2017, 02:06:21 PM
No problem,i am around.You can also try to convince Anthony-fivestar45 to make a new cap and stem for you  ;) his mod is great.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on February 09, 2017, 02:11:37 PM
Quote from: Tucobenedicto on February 09, 2017, 02:06:21 PM
No problem,i am around.You can also try to convince Anthony-fivestar45 to make a new cap and stem for you  ;) his mod is great.

I can definitely make the parts, it's just a matter of deciding how far down the rabbit hole I want to go.... Looks like the hardest part of Anthony's is the new threaded cap, not too terrible, but admittedly it's been about 10 years since I cut a thread in the lathe!

I'm almost where I want to be power wise now, but having a more efficient poppet with a lighter hammer/spring couldn't hurt a thing in my quest for efficiency.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on February 09, 2017, 02:20:21 PM
My first itention was to replicate Anthony work,but my lathe is not equipped for thread cutting,so i reversed the design looking at a theoben and an hatsan valve.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Snaptrap on February 09, 2017, 11:36:10 PM
Getting ~20 fpe @ 775 psi boggles my mind.

Congratulations!
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on June 15, 2017, 08:35:14 AM
Well, the .177" 850 showed up last night. Pretty much going the same path I did with the .22. Initial velocity with no other mods (775 psi HPA and CO2) on the .177 is about 650 FPS with JSB 10.34. My goal is closer to 800 (16 FPE) for this build, curious to see what it takes to get there.

I did notice this trigger is slightly different than my .22, I think some adjustment is in order, or possibly the pseudo 2-stage mod. I can really find the break point like I can on my .22 (it's a little creepy) so I'm guessing this is what everyone talks about when they say it needs some work in stock form.

Still, happy to have a little sister to the .22, thought I was partially wasting my time during the .22 build, but the trigger time since has made me realize it's well worth the time investment; one of the nicest rifles I own.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on March 17, 2018, 08:58:28 PM
Well, after a year, 7 red squirrels and 2 chippers I decided to turn this up a little. I ended up going to an 8lb spring to keep the cocking effort reasonable and it maxed out about 870 fps with JSB 15.9gr. I raised the PSI to 1400 and it dropped to ~860fps, I figured this was probably the sweet spot since it was also a fair bit quieter at this level. Still shooting single holes at 40 yards and the reds will have to be a little quicker now if they're gonna jump the pellet.

I still really love this rifle, we'll see where it lands when they finally release a .25 cal gauntlet and I add that to my collection....  ;D

(https://i.imgur.com/85UcyfO.jpg)
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Nvreloader on March 18, 2018, 12:27:00 AM
Kevin

Thank you and Fabio also, for all the info,

I just got a .177, 850, was box part gun for $100 shipped, got some new parts, 17/22 bolts and extra valve,
mags etc, that tiny ball bearing/spring in the firing pin/bolt is a BEAR to get into place etc,
and have been reading all info I can find on it etc.

Never fired a shot thru it, so far...
Making a 6" long adapter, so I can run 12g Co2 cylinders for testing etc,
so I can change them out, without headaches etc,
I don't want to use up the stash of 88/90g cylinders, until I positive that I have no leaks etc.

I have been making a proto type SSG for the 850, which I think will work,
not lots of room inside, if you know what I mean....LOL.

Question for you,
Have to weighed the OEM hammer?

Tia,
Don
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: imadunatic on March 18, 2018, 09:01:18 AM
Quote from: Nvreloader on March 18, 2018, 12:27:00 AM
I have been making a proto type SSG for the 850, which I think will work,
not lots of room inside, if you know what I mean....LOL.

Question for you,
Have to weighed the OEM hammer?

Tia,
Don

Nice haul Don!  I personally wouldn't spend too much time on a SSG until you've had time to shoot it. These are setup with negative preload springs as well as the small forward spring that I'm guessing all works to reduce hammer bounce (I've never noticed any hammer bounce and on the previous tune I was getting 1.58 FPE/CI which makes this one of my most efficient rifles also.)

Apparently the weight of the hammer is something I never recorded. I had it out yesterday afternoon and could have easily checked it then, figures!

Good luck with your build, I also have a .177 and it's next on the "turn it up" list. I don't shoot that as often as I do the .22 but these are hard to beat for accuracy, weight and the fact they are repeaters. 

Kevin
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Nvreloader on March 18, 2018, 01:05:44 PM
Kevin

Thanks,
The reason for my question was, in my case, the hammer weight can be changed very easily,
by the same method the factory uses.

The next time you have 850 apart, take a good look inside the hammer spring hole,
take a probe and see if there is LEAD slug formed/pressed into the hole?

ON mine there is a plug of lead pressed into the spring hole.

Also when apart,
measure the hammer stem that protrudes, for it total length,
I am wondering if there is a difference in hammer weight and stem protrusion between the cal etc?

And as you stated, this model of AG seems to be NOT a popular choice any more,
so it is hard to find much info on it.

I have been playing with the Idea of making a lite weight hammer, and if needed,
lead could be pressed into the spring hole, to obtain the right hammer weight, for the SSG tuning option etc.

On both of my AG's, I plan on using both fuel types, Co2/Hpa, summer/winter use, if possible etc.

I just learned from Motorhead's post, that lite weight hammers can be used in the 79,
and it would be very easy, to add more weight via the lead plug in the spring hole,
if needed for tuning using a SSG etc.

Just some Ideas bouncing around........ LOL

Tia,
Don
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: fivestar45 on March 18, 2018, 01:23:16 PM
The 850, and the Dominator both use pretty inefficient valves. So to make them work it takes more hit force get the stem to crack open. Build a better valve and you can drop striker wt., and spring force and get better results.
Here's what I did a couple of yr's ago. (Don't know if the pic's still show)

http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630 (http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630)
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Nvreloader on March 18, 2018, 02:05:53 PM
5star45

Thank you for that info and the link to your mods etc.   8)

By any chance, do you have the tap/die size for the tube you made?

Tia,
Don
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on March 18, 2018, 02:09:29 PM
Quote from: fivestar45 on March 18, 2018, 01:23:16 PM
The 850, and the Dominator both use pretty inefficient valves. So to make them work it takes more hit force get the stem to crack open. Build a better valve and you can drop striker wt., and spring force and get better results.
Here's what I did a couple of yr's ago. (Don't know if the pic's still show)

http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630 (http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630)
Hi Anthony,i already posted your work in this discussion,totally agree with you.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: fivestar45 on March 18, 2018, 08:12:38 PM
Quote from: Tucobenedicto on March 18, 2018, 02:09:29 PM
Quote from: fivestar45 on March 18, 2018, 01:23:16 PM
The 850, and the Dominator both use pretty inefficient valves. So to make them work it takes more hit force get the stem to crack open. Build a better valve and you can drop striker wt., and spring force and get better results.
Here's what I did a couple of yr's ago. (Don't know if the pic's still show)

http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630 (http://www.gatewaytoairguns.org/GTA/index.php?topic=83664.msg802630#msg802630)
Hi Anthony,i already posted your work in this discussion,totally agree with you.


Hello Fabio..Sorry I didn't see that.  We just want to help folks to go in the right direction.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: fivestar45 on March 18, 2018, 08:14:38 PM
Quote from: Nvreloader on March 18, 2018, 02:05:53 PM
5star45

Thank you for that info and the link to your mods etc.   8)

By any chance, do you have the tap/die size for the tube you made?

Tia,
Don

I'll take a look tomorrow. It's the same as a 88g bottle.
Title: Re: Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?
Post by: Tucobenedicto on March 19, 2018, 04:39:40 AM
The 88 grams bottle thread size is metric M16 X 1,5.