Tuning Hw50s vortek HO kit

[luckybuckeye]

Newish guy here I rejoined the forum after a few months hiatus. I love the forum and have found so much useful information here.

I installed the vortek kit today and I only fired 3 pellets so far and it’s dieseling pretty bad. I cleaned and deburred everything really well prior to the install. However, during the install I had to remove the piston and I didn’t degrease the tube again before I reinstalled it. Did I squeegee a bunch of grease up the tube? 

Could this be why it is dieseling and if so should I tear it back down and start over or keep shooting it to see if it quits dieseling. This is my first springer rebuild any advice would be greatly appreciated. 

 

[Michigander]

I would guess you did end up with grease in front of the piston. Some would recommend to keep shooting until it stops dieseling, but I don't like doing that. For one thing, it can take a long time to get rid of all that excess lubricant. Then there is the possibility of spring damage. If it sounds like a 22 rimfire going off, definitely tear it down.

After pulling the piston, thoroughly wipe the entire length of the compression tube to remove excess grease. There is no need to degrease with solvents, the little grease that is left should only cause a little smoke in the bore, and that should disappear after a few dozen shots. Wipe off the outside of the piston and seal, then reapply a very thin coating of fresh grease using your fingers. Do not grease the front of the seal! If you added grease to the spring, you may want to remove some of that as well, leaving only a light coating.

That should fix the dieseling, and after 50-100 shots the rifle should settle into a stable velocity with ES in the teens or better with its preferred pellet.

 

[luckybuckeye]

Thanks Michigander, I’ll strip it back down tomorrow. I did shoot it about 30 more times and it was still pretty loud. It did tame a little bit but I don’t want to risk a broken spring. I put a fair amount of grease on the spring so I’ll definitely take some off some of it. On the bright side my homemade spring compressor worked like a charm. The second time around should go a lot quicker and smoother. Thanks again. 

 

[Jlowe]

Your not going to break that spring. Taking some off will speed up the FPS some and it will still shoot smooth. The HW50S is a really great springer. My son used to have one with a custom green stock. 

 

[Jayson]

Yeah, you will not break that spring, dieseling is part of springers, most of the AA or HW’s have dieseled out of the box for me! And always after a rebuild. I would stay calm and shoot the hell out of it

 

[luckybuckeye]

Thanks for the replies. After it breaks in I can post the before and after velocities if anyone is interested. This gun has been a challenge from the get go to say the least and I probably should have rebuilt it shortly after I bought it last year. I enjoy tinkering so it’s no big deal. 

 

[boscoebrea]

I am interested as I will rebuild mine ,leaning toward the JM kit;I do have the Vortek kit in my R-7,I am open to which one to install.

My HW50 was rough new,it has since become a lot better,I will properly go down in power...

 

[jusanothajoe]

Both my 50's have Vortek kits tuned to around 11 fpe, to me that is the sweet spot.

 

[luckybuckeye]

I think the only low power vortek kit for the hw50 is 7.5 foot pounds. I put the HO kit which is up to 12 fpe and I think they have a 12+fpe SHO kit as well. I would love 10.5-11 foot pounds. I wasn’t able to rotate the adjustable top hat to the lowest power level on my kit. I might try it again if I tear it back down. Another weird thing with my gun is the factory piston seal was kind of loose and the piston fell out on to the floor own when picked up the compression tube after the tear down. I figured it would have been tighter than that as I only have around 1000 pellets through the gun. 


HW50s .22 when new last January:

rws hobby 645 fps 16 extreme spread

rws meisterkugeln 628 fps 12 es

FTT green 731 fps 56 es

FTT 5.53 535 fps 23 es

GTO 692 fps 24 es (most accurate)

 

[luckybuckeye]

Fifty shots into the break in before and after chrony summary.

 

[luckybuckeye]

To wrap this up, I decided to install the vortek kit in this gun because I could not get the scope to stop moving. Like I mentioned earlier only 1000 shots since new. I tried sportsmatch rings and the arrester pin was backing out. Next I tried a hawke one piece mount with screw in stop pin with blue loctite. There is visible damage to one of the stop pin holes from the scope base moving. Then the scope was moving in the base with everything torqued to proper spec. Long story short I done some damage to the scope tube by adding a little more torque to the top straps but it did quit moving lol. It finally held zero for me but still I knew something had to be wrong with the gun. It wasn’t loud or anything like that and the shot cycle was exactly the same since new. I let it sit for months and finally pulled the trigger on the vortek kit. The factory spring was broke and the factory piston seal was 25.85mm .35 mm smaller diameter than the new vortek piston seal and moved freely in the comp tube. I don’t know if this under sized piston seal was from premature wear or if it was made wrong. My theory is the piston wasn’t properly sealing and was slamming a little and caused all the scope movement issues and spring breakage. Anyhow this HO vortek kit is pretty consistent and pretty powerful. I’m not bashing weihrauch in any way just putting information out there that may help other air gunners. My experience with this gun is definitely not typical in any way, shape or form. The fact that it fired as accurately as it did is a testament to Weihrauch quality. I own one other weihrauch and plan on owning more, hopefully many more in the future and will never part with this Hw50 Hunter.

 

[luckybuckeye]

So I’m not putting any disinformation out there, the hw50 piston seal was the correct diameter. I just took apart my Hw97 for 12 fpe vortek and the 50 and 97 factory piston seals are the same size. The face of the 50 seal was buggered up but the diameter was not the problem. 

 

[luckybuckeye]

This is turning into a HW50 diary. The hw50 developed a little cocking noise so I decided to take it back down. I ordered some barrel shims while I was at work just in case I damaged them during the assembly process. I came across this picture on the website. 

It turns out I found something on the floor in front of my work bench that looked just like it and like a dumbass I threw it away. I looked up a schematic of the gun and I ordered the replacement fore end screw cup #9242. After a little investigating, it appears the sound is coming from the cocking slot so I’m going to clean up the slot and the cocking arm. Also there was a bunch of burnt grease on the piston seal so I’m going to clean everything up and regrease the gun more carefully this time.

 

[luckybuckeye]

I got the spring cup from dlairgun.com it’s a Canadian company and shipping was steep so I ordered extra screws and barrel washers and all the goodies to make it worth the shipping cost. They have plenty of pellets in stock also for those who can’t find them and parts in stock for a bunch of makes and models. I cleaned up the cocking linkage “tip”and cocking slot with with a dremel (very carefully I have tool room polishing experience) and cleaned up any burrs. I also removed the spring under plastic cocking guide and set the barrel tension a little looser than it was. It now cocks like a dream, no noise and very easy. 

For the newbies and rookies like myself here’s a picture of the forend screw cup in place with a spare cup for reference. 

I could be wrong but without the screw cup in place the end of the screw may rub against the cocking arm. There is not a lot of wood thickness in there so the screw cup (or washer(s) in a pinch) is definitely necessary. 

I cleaned and regreased everything and fired a couple test shots without any dieseling. I won’t have time for break in and chrony testing for a few days. 

 

[luckybuckeye]

After 100 shot break in. 

I don’t shoot nearly as often as most of the folks on here but I’m interested in see what will happen with the velocities after 500-1000 shots. I have joined a shooting range that is 10 minutes from my house so hopefully in the next couple weeks I can sight in at 25 yards and beyond. 

 

[luckybuckeye]

 Finally got the hw50 out to the range and it did pretty good with the .22 GTO pellets. My scope elevation turret was moving 1 click with every shot and it took me a while to figure that out but I was able to get pretty respectable groups with it. Then my stock screws were loose. I’m such a rookie. My scope is not the best it’s a fixed 4 power and the tube is bent from over tightening it. I really need to replace it. It’s the Weihrauch fixed 4x that came with the gun. 
Another guy was at the rifle range shooting a .22 LR and he was REALY impressed with my groups. Cool side note, he was an engineer that made his own silencer. Titanium and stainless steel and he had $700 wrapped up in it after the tax stamp. He was even more impressed with my squirrel hunting stories and the fact that I practice in my basement. Anyhow here’s my best group at 25 yards. 

 

[Jestes5]

Looking to install a HO Vortek kit in my HW50. I've read that the power could be adjusted to a degree. I would like to have my HW 50 shooting just under 12 ft lbs. Probably in the 10 to 11 ft lb range. Is this possible with the Vortek HO kit?

Also, does the ARH kit have any adjustability to it? 

My goal is cocking ease, quiet report without a buzz and most important, accuracy. 

 

[luckybuckeye]

I wasn’t able to adjust my vortek kit. The adjustable part was too tight in the spring. Maybe there is a trick to adjust it i don’t know. I’m not familiar with the ARH kit. From what I understand coils can be cut off to make less power. I have heard of people emailing vortek about a kit made to a certain power level.