Tuning RAW .25 -- Leak (air *PUFF*) around probe? [SOLVED]

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bambuino

bambuino

Member
Aug 13, 2020
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HI, United States
Hello --

Am experiencing a *PUFF* of air exiting the mag well, pretty much every shot when mag fed. Can't track it when finger feeding. Seems to be channeled out the magazine recess, indicated in photo. Cleaned the barrel today, went out for leading in and check POI change at 50YD zero, and shot this. Two dots for sighters and two mags through the sticky. That's about what I shoot at 50, sometimes better, sometimes not.

What adjustment can be made to probe to tune this out? Do I need adjust for a particular pellet? Am shooting the JSB King Hvy mkII.

Thanks

IMG_9463.1629090336.JPG

 
It looks like the probe has backed off a bit. They rely on a mechanical seal (far superior) vs o-rings. Depending on the model, it is adjustable for length by threading longer or shorter to the breach. You should have moderate pressure required to close the bolt. I wish other manufacturers would use this approach.
Click to expand...

From what I been reading this could be an easy fix or a hard fix. Just some prelim reading. I wanna say that the effort to latch the cocking handle with a pellet in there has been fairly consistent, but was not something I had been keeping track of.
 
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Hello --

Am experiencing a *PUFF* of air exiting the mag well, pretty much every shot when mag fed. Can't track it when finger feeding. Seems to be channeled out the magazine recess, indicated in photo. Cleaned the barrel today, went out for leading in and check POI change at 50YD zero, and shot this. Two dots for sighters and two mags through the sticky. That's about what I shoot at 50, sometimes better, sometimes not.

What adjustment can be made to probe to tune this out? Do I need adjust for a particular pellet? Am shooting the JSB King Hvy mkII.

Thanks

IMG_9463.1629090336.JPG
Click to expand...

It has adjustable probe. Further you may loosen the barrel screws and push the barrel into the action a very little. Then see if your magazine will sit into the slot. 

Basically by any of these two options you have to increase the binding pressure between the prove abdvtge breach.

This will help.

O ring seals are much easy to stop air puff further if O rings breakers its very easy to put new O rings.

I am a fan if O rings sealing and have converted my RAW guns to O ring seals.
 
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After plying my way through some of the "RAW Report", reading Sean's View attachment 1524077856_13076287715ad79520d63e56.94903022_RAW Caliber Change Guide, Rev 2c.pdf, and figuring out just what particular pellet probe I have on here...and then jumping down a rabbit hole or two...ugh.

I checked what was going on with the magazine before getting out any wrenches. Appears that when outer probe enters magazine it is deflected upward maybe a millimeter, and figure maybe by time outer probe proceeds forward to arrive at barrel is held upward enough to not make good seal. I sure hope it is something easy like that, something requiring just a bit of light sanding of the opening in the magazine. Perhaps someone can confirm for me that this is normal or not.

Still though, I cannot quite wrap head around how to adjust outer probe seating pressure. Referring to below photo, the only way I can figure out how to lengthen outer probe, for greater sealing pressure would be if label B & C were threaded together...fix in place label B part then turn label C part CCW and makes longer, greater sealing pressure. Of course that is only if C is threaded into B. I don't get the part about the grub screws (A), as looks like they just keep probe ass'y from falling out the bolt housing (A) (ref). Mine has the spring inside the outer probe. There is no single grub screw on outer probe (part label B) (ref)(ref).

PelletProbe_9465.1629114310.jpg


edit: Needless to say I know A LOT MORE about this gun now than I did yesterday. Certainly not everything for sure.
 
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I think in some guns they stopped putting the tiny screw and just lock tightened the adjustable threads of probe.

So a little heat will help
Click to expand...

If that's the case, it doesn't make sense to me. Depending on what bonding agent was used, if the probe assembly is removed and held solidly, it might turn without heat, and it might retain the new adjustment also.
 
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I think in some guns they stopped putting the tiny screw and just lock tightened the adjustable threads of probe.

So a little heat will help
Click to expand...

If that's the case, it doesn't make sense to me. Depending on what bonding agent was used, if the probe assembly is removed and held solidly, it might turn without heat, and it might retain the new adjustment also.
Click to expand...

Yeah, wish had the grub screw on the outer probe assembly (part label B), one which locks that (part label C) in place. That makes sense to me. I started picking around base of outer probe and there is a viscous substance like beeswax. So don't know if this is heat labile ( @mubhaur ) or thixotropic ( @elh0102 ) thread locker. Either way thinking this requires removal of outer probe assembly in order to affix and adjust probe length, then re-assemble and test.

Can someone confirm for me whether it is easy enough for newb like me to remove that outer probe assembly without having to remove barrel?

And on topic of adjusting bbl to rear...that is a no-go, as the magazine is already pretty tight in there when inserted.

Looking at that first post, that guy really doesn't know much about his gun. That guy being me.


 
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If it has grub screws you can only see them when cycling the action c is threaded into b when mine was leaking found the grub screws were both gone ended ordering a whole mess of them on the net you shouldn't have to pull out the outer probe or assembly to adjust it. But you can disassemble the whole action with the barrel left in place I just did this tonight and decided to pull the barrel which I did last to check port sizes 
 
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I am going to refer to a photo in a post from @bucketboy .

RAW HM1000xLRT Pellet Proble [shift + click]

In the top photo is depicted outer probe that has small grub screw. I do not have this type of outer probe in my HM1000X .25. Mine is grub screw-less.

So could be couple reasons getting this puff of air on a shot...chamfered nose of probe not seating squarely and with sufficient pressure on breech, and/or air is leaking past the rubber washer on the inner probe behind spring. Adjusting the outer probe forward I think will solve both of those possible issues.

What I gather is, if there WAS a small grub screw present, then the procedure is pretty straightforward --- tighten two small grub screws on bolt, loosen the grub screw on the outer probe, adjust CCW, test, re-tighten grub on outer probe and finish by backing out the two grubs until flush with outer dimension of bolt. The easy fix

In this particular build that I have, what is the amount of torque need be applied to outer probe forward sub-ass'y to break free of the threadlocker compound, and once done, will that probe stay put? That is, considering I want to adjust pellet probe in situ, rather than go through the disassembly, removal of barrel, &c, which to me sounds like major headache. The hard fix.

Thank you folks for your patience with reading this and for any assistance, shared experiences...
 
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Yeah I suppose it would be mark it turn it all the way out and apply more loctite and reinstall just alittle out from your mark. It's not hard to pull apart just alot of set screws and most of the stuff has to come out of the action . I took mine our tonight for the first time in under a hour about 45 mins but I took all the parts out including valve and regulator I'm going to do some polishing inside the action and hammer area and a couple other mods 
 
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If not wanting to fiddle with the probe seating adjusting ???? ..... Lightly loosen the 3 barrel clamp screws and with bolt OPEN ... very gently Tap the barrel rearward, tighten 1 screw and check bolt closure SNAP. Repeat if wanting it tighter. Once you have a firm and solid SNAP snug up all 3 screws and your done.

If it moves TOO FAR simple close bolt while screws are loose and push barrel forward then repeat above.



I too AM NOT a fan of inner barrel O-rings for probes and try to place o-ring ON THE PROBE of which the RAM HM guns you can not do ... so IMO stay with what you have being correctly adjusted it works just fine.



Scott S
 
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Scott and all, thank you for your input and support.

I did get the probe adjusted forward for a better seal, rotating the forward sub-ass'y about 20deg. Not a pleasant experience, choke on heart in throat.

Applied heat to the probe to soften the threadlocker and grasped the proboscis with a pair of channellocks (seriously?). There was some marring of probe when teeth bit through the leather patch. A pair of small wrench flats on the probe would have been great to have! Better yet, the previous version with grub screw would solve all this headache. Maybe this new design is to prevent any bit of blow-by around threads of two-piece outer probe ass'y?

Anyway, few rounds into the ground and no blow-by detected from mag well. Job done.

Again, thanks folks!
 
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