HW100 Tuning Questions for HST and regulator optimal balance

[tommyb]

I have an HW100 .22 Carbine and am doing some research on AGN before I start on a small project (after the Holidays ) to get an ideal tune for my gun. I'm actually doing this with some 'heavy lifting' Tuning assistance from a good friend and colleague, who is also an HW100 .177 owner.

Background: My gun has been sent to Air Venturi twice in the last year, to try and resolve a loud 'popping' noise when I fire pellets through it. AV has replaced the breech seal, valve seal and completely resealed all other o-rings in my gun earlier this year, but at the current velocity ( 850 FPS for the JSB 18.1 G), I am still getting this loud popping noise. I don't believe the gun is leaking and I think the seals are now all OK, in light of the above. I have tried different moderators, and still get a loud pop when I shoot. Our mutual belief is that I am shooting the 18.1g pellet too fast, and need to slow it down in conjunction with getting the correct set point with the desired velocity for the desired pellet(s). I realize after speaking to my friend, that this gun was originally built for 12 FPE in Europe and I wonder if I have the velocity too high for the 18.1 pellet. We both think this 'could' potentially be the issue for causing the loud pop for each shot. i.e., velocity too high, pressure too high causing a louder report.

In preparation for the forthcoming tuning session, I would like to get some input. I have searched and there is a lot of information on .177 versions, but I am curious to get some input on the following for the .22 caliber HW100:

1. I would like to see some tuning specs for both the 15.89 and 18.1 JSB pellets. Other pellet weights and brand also, if applicable. Specifically, I would like to know your velocity and regulator setting for each pellet listed above with your commentary on achieving best accuracy and distance shot with your HW100. As an example, if you shoot the 15.89 primarily, what is your reg setting and ideal velocity for that pellet. Same question for the 18.1

Thanks in advance for your input!

Tom

 

[MEC17670]

What's you velocity now with the 18.1 pellet.
I have a hw100 that has been highly modified, fx smooth twist, Dr Bobs Buddie Bottle conversion kit. Anyway , not the normal hw100.
I've found out of this gun, the 18.1 are a dime size group at 57 yards, no wind, off a bench. The pellets are flying at 900 fps.
Due the the Dr.Bob's conversation kit which allows for a 480cc carbon fiber bottle to be used. It allows me roughly 78 shots are that power. Unfortunately, unless you live in the UK, you can't get one.
AZ installed the barrel, and tuned it for this for this power setting. Would I convert a beautiful gun like the hw100 again, probably not. To pretty of a gun, besides I have 1 heck of a pellet shooter.

 

[MikeVV]

I've got my HW100 Carbine (Bullpup) shooting 18.1gr. and 25gr. JSB's that group nicely, at a hair over 800fps.
It's still a loud gun, but with a Huma M40, three segment suppressor on it, it's tolerable. One of my more favorite guns.

Going a little slower ISN'T a bad thing. You'd be forced to shoot slow if you lived in the UK..! And they still hit bullseye's...
If you were shooting heavier slugs, that "may be" a different situation.

Mike

 

[tommyb]

What's you velocity now with the 18.1 pellet.
I have a hw100 that has been highly modified, fx smooth twist, Dr Bobs Buddie Bottle conversion kit. Anyway , not the normal hw100.
I've found out of this gun, the 18.1 are a dime size group at 57 yards, no wind, off a bench. The pellets are flying at 900 fps.
Due the the Dr.Bob's conversation kit which allows for a 480cc carbon fiber bottle to be used. It allows me roughly 78 shots are that power. Unfortunately, unless you live in the UK, you can't get one.
AZ installed the barrel, and tuned it for this for this power setting. Would I convert a beautiful gun like the hw100 again, probably not. To pretty of a gun, besides I have 1 heck of a pellet shooter.

850 FPS was the Chrono string I requested from AV for the 18.1 pellet. I think that might be a bit fast, but as I mentioned, we have a tuning project coming up after the Holiday.

Nice gun and tune.

 

[thumper]

What length is your barrel? 410mm?

If so, 850fps is about as fast as you should expect to get from that length barrel and have any kind of efficiency left.

Carbine is not actually a "carbine" here in the USA but I'm guessing you actually have the "rifle" sized cylinder on it.

Mine stays setup happy at about 820fps with a 410mm barrel and 18gr, and my regulator runs around 120bar.

Mine has had the hammer tip shortened a little to reduce hammer bounce and adds a slight bit of hammer stroke. That helps with the noise. If yours is bouncing badly, it will definitely be louder while wasting air.

Don't know what to tell you about the loud pop, but the Weihrauch silencer is pretty damn good. But short barrel plus higher power is always going to be louder. A higher reg pressure is typically quieter or at least crisper sounding

Mine is near silent with the setup listed above.

 

[tommyb]

What length is your barrel? 410mm?

If so, 850fps is about as fast as you should expect to get from that length barrel and have any kind of efficiency left.

Carbine is not actually a "carbine" here in the USA but I'm guessing you actually have the "rifle" sized cylinder on it.

Mine stays setup happy at about 820fps with a 410mm barrel and 18gr, and my regulator runs around 120bar.

Mine has had the hammer tip shortened a little to reduce hammer bounce and adds a slight bit of hammer stroke. That helps with the noise. If yours is bouncing badly, it will definitely be louder while wasting air.

Don't know what to tell you about the loud pop, but the Weihrauch silencer is pretty damn good. But short barrel plus higher power is always going to be louder. A higher reg pressure is typically quieter or at least crisper sounding

Mine is near silent with the setup listed above.

Very helpful information Thumper.

Yeah, 850 FPS for the 18.1 is too fast. My friend Ed told me same, but you gave me the input I wanted with yours shooting that pellet at 820 FPS, reg set point = 120 BAR. We are going to tune the gun for a lower velocity ( I.e., 820 FPS range ) and I was looking for some real world experience before we started.

FYI - I get about 2 mags of shots or approximately 28 shots before it reaches the 120 BAR-yellow area on the gauge.

I just read the Users manual and it does not list barrel length. I suspect it is 410mm and has the original HW cylinder with that model. As it turns out, I looked at a YT tuning video, and it appears that the fill valve o-ring in the air cylinder might be leaking. I took the cylinder off, filled to 200 BAR and it was at 130 BAR the next morning. So, the air cylinder has a leak.

Hammer bounce - How did you shorten the tip? Mine is a bit loud “as is.” Tolerable, but louder than I prefer.

15.89 pellet ( or any other pellet weight or brand) -Did you try this and if so, what velocity and reg setting?

Thanks for the info.

 

[tommyb]

Update on leak….

I think I fixed the air cylinder leak by replacing fill valve o-ring, with great assistance from a YT video and my buddy Ed ( elh). It has been holding air at 200 BAR max fill for 2 days. Heading to the range tomorrow or Friday to test and play with HST, shooting the JSB 18.1 at lower velocity.

I am still interested in obtaining others’ feedback on my initial request, as it seems there are a fair number of HW100 .177 and .22 owners on AGN. What balanced tune of both reg set point and velocity did you observe for best accuracy with the JSB 15.89 or 18.1g pellet? Or, any other pellet?

I think this information will be helpful to the community.

Tx…Tom