Build Started: Hammerli 850 Max Efficiency Tune @18-ish FPE?

[imadunatic]

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.... 

[Nvreloader]

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

[imadunatic]

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

[Nvreloader]

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

[fivestar45]

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

[Nvreloader]

5star45

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

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

Tia,
Don

[Tucobenedicto]

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

Hi Anthony,i already posted your work in this discussion,totally agree with you.

[fivestar45]

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

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.

[fivestar45]

5star45

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

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.

[Tucobenedicto]

The 88 grams bottle thread size is metric M16 X 1,5.