I have been unable to find the reference material that I mentioned earlier on the piston ring dimensions. It was on the old Yellow forum, and has been relegated to history now apparently...

I did come across this write up though, and he measures 2 new rings and the old one in the rifle. I am gonna guess and say that you are good to go at .034 to .036.

Re-Loaded: Feinwerkbau 300S Rebuild and some rambling.........with some pics - JUNKYARDAIRGUNS https://share.google/HbfVScMek5MbOEal9

Resurrection.

Is this correct?

OK, I admit my head is hard. I thought I was starting somewhere in the middle and working both ways, but until someone challenged me, it occurred to me that I wasn't working in the upper direction far enough. I thank you for setting me straight and making me think.

As to the question of reg plenum refill, yes, I have tried all different "timings" and nothing definite has appeared. Some "quick" shots are high and some low, and the same for longer waits. So, I've adopted the 15 sec rule for the most part, even though I take one shorter here and there simply because that would be how I shoot and I want to know that scenerio also.

So, Here's my new plan based on you guys getting my head in the game.
1st reg 150 bar, 2nd reg 100 bar, FX 18.1 gr pellet. Just somewhere to start anew.
My plan is as follows
(screw turns out-power wheel setting)
0-7 shoot 10 shots
1-7 shoot 10 shots
2-7 shoot 10 shots
etc until I find the point of no increase in velocity, they go down the pw 7,6,5 etc and backward til the plateau is found.

I'm only partiall done, but can make some definite conclusions.
0-7 861 fps avg, 27 fps es, 8.0 stdev 9 shots
1-7 922 fps avg, 27 fps es, 7.5 stdev 10 shots
2-7 961 fps avg, 29 fps es, 9.2 stdev 10 shots
3-7 980 fps avg 11 fps es 4.5 stdev 17( I threw out one shot that was extremely low, and assume it was a bad pellet)
4-7 990 fps avg, 12 fps es, 3.1 stdev 15 shots
5-7 992 fps avg, 10 fps es, 2.7 stdev 14 shots

Conclusions: (updated)
The plateau is around 992 fps. This pellet in this gun is probably not a great choice, but lowing the reg might do the trick. It likes to shoot above 38 fpe, at least with this pellet.

Next up is lowering the reg pressure and repeating the full test.

This listing has been renewed

Thanks for that information. I've never seen a discussion on pellet shape or length. I have a lot to learn.

Funny nobody mentioned how the cow with her legs so close together could stay standing

Liontracks said:

Your 700mm BR impact is .22 caliber?

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.30

Have you tried to contact Huma concerning your issues with their product? I have found the customer service from Huma to be wonderful. It is interesting that their web page for the regulator states "Fitting instructions are currently not available". Hum, you are on the cutting edge.

Racer88 said:

There are similar aftermarket "big" bolt handles for PB rifles like my Ruger Precision Rifle. This one is called the "Hammerhead."

View attachment 577127

I'm surprised someone isn't making them for the Marauder.

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The mrod, at least my gen 1...is a pain to do. Lots of heat for all the loctite and a lathe were involved just to prep the original bolt handle (I turned the original ball down and threaded it 1/4-28)and the stainless monstrosity is bigger than any powder burner one ive seen in 25 years of shooting. I went obnoxious on purpose because I was so pissed at double feeding and blowing up essentially all of the delrin components after the muzzle.

Its very silly proportionally. 2" long by 3/4 Dia. It is hollow tho. The disco got a longer rod and a leftover charging handle from the aea parts I used to make. I standardized all my goofy handles to 1/4 28 so I can swap them around to test.

that's awesome, thanks for sharing.

wish i had your talent. I used to just mark areas with a semi-permanent marker in red and always ended up redoing it after each match.

i would perhaps suggest something a little quicker and easier to read.....for my eyes, less busy is quicker and easier to acquire especially if time is critical. that was true for me in local competitions.

a bold color to differentiate from the standard turret markings would d also help.

(i copied this photo from the internet).

dialing had become so comfortable for me over the years....its kind of like the buttons on the old SLR cameras that i used to carry all the time...i got so used to where they were located it was so easy and quick to manipulate

GerrywithaG said:

Apologies for bringing up an oldie, but a great ttuning thread imo.

I have a thought for conversation...,My .22 zelos likes 870 fps for the 18.13 pellets. I have gotten there bumping up the reg, and backing off he h.s., and vice versa with the same group sizes. What are your thoughts.

My set up with...
1. Higher reg psi, and less hammer spring feels ,and sounds sluggish compared to...

2. Lower reg. and up the hammer spring? Seems snappiier, and quiet.

let's leave shot count, sd and es at the proverbial door for now. I am more interested in finding if your rig groups better with a higher reg.?, or more H.S. Tension to get to the same fps?

Thanks for your ideas....
Gerry

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I always set up my guns more along the line of #2. Just like the second post in this thread states. Set just a tad below the max velocity the gun will produce with a given reg pressure.

Liontracks said:

I was wondering what this means about moderator? What special mod you need with 580cc and 600mm barrel??

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I think already mentioned but a 580cc bottle on a 600 mm impact does not stick out longer than the threaded end of the shroud. You can use any moderator you want.

KWK said:

That's cool, Ron. You know I would have had to make my own, right?
Should be a Weihrauch recall bulletin?
Thought about you lately, waiting to hear how you made out.
And while replacing the clutch slave and master cylinder on my son's German car. Jetta.
Shifts a little funny, 3rd and 4th. I'll replace the gear lube for him.
Nash reinstalling the clutch pedal assembly ....
Mechanical engineering student. He enjoys learning about things.
View attachment 577080Oooo

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That's a good kid!

Raccoon is delicious. Lots of trimming. The fat is a little gamey but the meat is like a rich roast beef. A 25lb hanging raccoon is only about 8lb of meat but I'll spend an hour rather than trashing then if they look like a healthy one.

jps2486 said:

I've shot 25 cal in one of my Impacts and my Wildcat MK3. Each has a 600 mm barrel and shoots exceptionally well with pellets at 100 yards. I have another impact I use for 100 yd BR competition and it has a 700 mm barrel which I recommend in this caliber. If you are leaning toward .25 caliber, I would get the Impact Standard with the 600 mm barrel. Personally, I've tried slugs and you will likely have to make some major tuning changes to shoot these well. I've never had much confidence in them and prefer to shoot pellets. They are very accurate at up to 100 yds (except .177 cal) and will satisfy your hunting requirements.

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Your 700mm BR impact is .22 caliber?

if i had the money i would strongly consider this option, they must be coming out with a new model or line as these are significantly reduced in price. i generally prefer Mil / FFP platforms from my long range rifle days (but they also offer SFP versions) .

it's not a two thousand dollar scope but it's in my opinion a pretty darn good value at $415 dollars. I just can't afford it right now.

the only major negative at least for me would be the parallax value but it sure would work well for me at the distances I tended to shoot at.

tommyb said:

Ok, an update from Wyatt and Brian at Ed Gun West.

They shipped out a brand new EzAY fill to replace my broken EZ fill which I purchased in January 2025.

I paid $150 to UA and I appreciate Brian standing behind the product. Hopefully it works once I get it.

Tips for EzAy fill users: Do not leave EZ fill on your fill tank valet open and/or pressurized over night. Also, you can safely fill guns to 250 BAR ( not greater) and it should work as designed. Do NOT leave valve open after you fill your rifle to max fill pressure. Be sure to close the valve on your big tank.

They are getting a lot of returns and repair requests because of the above issues.

My example to Wyatt today and he confirmed:

“ I typically fill or top off my guns at either the Regulator set pressure, or slightly above about 8-10 times during a 3 hour bench session. No bleeding until the ‘end’ of my session. Then I bleed tank only ONE time saving a good amount of air I believe anyway. “

Anyway, hoping this helps.

Tom

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Thanks for the update Tommy
Only to 250 bar....hmmm
Nope...it stays in the box as a costly reminder not to buy gimmicks + i couldn't sell it in good conscious. I think it is junk
Hope the repairs hold out
Mike

Hobbyman2007 said:

Well I caved , mainly because I wanted to see what the internals of the 54 airking look like. Now I’m searching for a full power piston and spring. I got a real good deal on a 7.5J model up here in Canada. I sent hector a message asking if he had some parts. If anyone knows where I can find a piston assembly. Let me know. Thanks

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Chambers also has TO1 parts as well

This listing has been renewed

You are awesome -Thank you for doing that. Re: the slug/pellet sizes, I have the .22. 217 slugs fit the slug mag but not 218-re: pellets the ultra knockouts work well-these are 3 -3 shot groups at 25yds with iron sights while trying to sight it in-will be trying 27.5 gr 217 NSA later today

tommyb said:

Ok, an update from Wyatt and Brian at Ed Gun West.

They shipped out a brand new EzAY fill to replace my broken EZ fill which I purchased in January 2025.

I paid $150 to UA and I appreciate Brian standing behind the product. Hopefully it works once I get it.

Tips for EzAy fill users: Do not leave EZ fill on your fill tank valet open and/or pressurized over night. Also, you can safely fill guns to 250 BAR ( not greater) and it should work as designed. Do NOT leave valve open after you fill your rifle to max fill pressure. Be sure to close the valve on your big tank.

They are getting a lot of returns and repair requests because of the above issues.

My example to Wyatt today and he confirmed:

“ I typically fill or top off my guns at either the Regulator set pressure, or slightly above about 8-10 times during a 3 hour bench session. No bleeding until the ‘end’ of my session. Then I bleed tank only ONE time saving a good amount of air I believe anyway. “

Anyway, hoping this helps.

Tom

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That's crazy that they said 250 bar max - it says right on the unit 300 bar max, and they supposedly created it for field fills of their L2 which is a 300 bar gun . . . .

I've had one for at least two years now (from EdGun, not a knockoff), and I regularly use it to fill my Huben K1 and Sidewinder up to whatever pressure level is in my 9L tank, so usually in the 270 to 300 bar range based on refilling the tank at about 270 bar or so. It works great and I do like it for that use. I do leave the line charged if I am actively shooting, but close the main valve and vent it down to at least under about 125 bar or so when done if I think I'll be back to it within a day, or all the way if I know I'm done for a longer stretch. In the past I used to just close the valve but leave the line pressurized, but based on what I read in threads like this I started venting it. Hopefully it will keep working. I do have one rebuild kit on hand, based on what I read in this thread, but hopefully I won't need to use it for a long time.

If you like h&n try the 36gr HPII’s. Zan 37gr are my everyday go to hunting round. Both (.250) are capable of 3/4” groups at the distance you are shooting. Mind you, 4 out of 5 of our Uragan 2’s and 3’s were tuned by Derrick Wall with an ES of 10 or less.

My brother bought a U3 .30 700mm tuned by DW and there is zero ping compared to a U2 of the same caliber. Honestly the ping from the U2 is not bothersome to me or other animals. One night we were predator hunting there were roughly a dozen deer about 50 yards in front of us grazing when a fox came in at 100 yards. I took the shot, directly over the deer’s heads, dropped the fox, and the deer scurried off about 10 yards. In about a minutes time they were back to grazing in the same spot. They are completely unaffected by the shot cycle and/or ping from a U2. This has been tested many times and not a one off incident, no moderator used.

Thanks Jungleshooter. I prefer SFP, short range would be 15, Longest around 100. Ideally under 600 bucks.

Yes that reticle has a nice center dot and looks like it's illuminated which is even better.

I am looking at Midas 4-16X44