I know there are threads on this topic but cant get the answers im looking for. My raw has been throwing some very strange velocities. And large spreads and SD,s. I put a huma reg in to see if that helped. Now my readings are much better... in a way. Half the shots are between 900-907 fps and the other half ar 865-875 fps but go back and forth between the two groups. To me, and through some research, it seems like the reg is doing its job but something is making it fluctuate between the two velicity ranges. I took the hammer assembly out and cleaned it, wasnt really that dirty though, and am preparing to lube it all with the synthetic motor oil, per martin's suggestion but havent been able to find the specific weight/viscosity of oil to use.
Tuning RAW regulator and hammer lubing
- Thread starter Stewy1412
- Start date
I used Mobil 1, can't remember the viscosity, and I don't think it's critical. As Martin probably told you, you want only a light lubrication, not dripping with it. I cleaned and lubed mine only once, and it has been fine since.
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Doubt your regulator had issues…
first thing that should be addressed when RAW is throwing bad numbers is the hammer. doesn't necessarily have to be dirty, could be some debris that got in there.
if you first shot isn’t crazy slow after your gun has sat for a while…chances are your reg is fine. (Not 100%, but good chance) this means your reg is creeping up, and your getting valve lock.
first thing that should be addressed when RAW is throwing bad numbers is the hammer. doesn't necessarily have to be dirty, could be some debris that got in there.
if you first shot isn’t crazy slow after your gun has sat for a while…chances are your reg is fine. (Not 100%, but good chance) this means your reg is creeping up, and your getting valve lock.
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If the issue persists, take some time to smooth the hammer and its runway, and then clean up everything well and burnish the surfaces with a dry lubricant (tungsten disulfide, molybdenum disulfide, or graphite).
Another possible cause of erratic velocity is a failing breech seal. In the early stages it may behave that way.
Is it adjusted to 95 – 97% of maximum velocity? If not, that should be step one. It will be less sensitive to the inevitable little variations when at this state of tune.
Another possible cause of erratic velocity is a failing breech seal. In the early stages it may behave that way.
Is it adjusted to 95 – 97% of maximum velocity? If not, that should be step one. It will be less sensitive to the inevitable little variations when at this state of tune.
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On THEOBEM / RAW ... hammer performs best when run DRY having no oils or wet lubes present. ( CLEAN and Well polished hammer )
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Nervpustrig, i have noticed that the probe is "loose" as in, without the magazine in, it is below center of bore and often catches on the barrel. Is this what you are talking about? The thing is, though, im pretty sure thats how it came to me from the distributer so i assumed it was supposed to be loose. Any ideas on how to tighten it?
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Is the probe loose, or bent? They sometimes get bent from forcing a pellet from the magazine that is not in good alignment (ask me how I know!)
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I accidentally bent my pellet probe severely, and I am guessing it was because my SST ( or magazine) was not perfectly aligned with the chamber. Martin replaced it and I have been careful ever since.
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My older raw has 2 small set screws to keep the outer probe tight which can spin in or out you want it out just enough so it seals the barrel off I found both my set screws were missing and the outer part of the probe was no longer sealing off the barrel had to readjust it and installed 2 new set screws to hold it tight if I remember correctly i believe they are 4-40 and 1/8 inch is to long so get shorter than 1/8 inch if it's same style probe
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I found two set screws on either side of the probe rider that really didnt do much in terms of tightening the probe. I do think it aligned the outer probe a little bit but the inner one is still super loose and hangs down slightly. Again, not sure if this is intended or if there are other screws i need to find to tighten the brobe up
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Those two screw just hold the probe into the probe carrier. They shouldn’t be tight. Just flush.
the probe Seating depth is adjusted by a thread on the probe assembly.
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With the action open, is this what you see, or is the smaller stem hanging out the front? If so, it is bent or broken.
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There is the tiny pellet seater, i believe, sticking out of that part. It doesnt necessarily look broken or bent, just sticks out a little
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The inner probe shouldn’t stick out at all unless the outer probe is seated into the breech. If it does, you most likely have a bent inner probe.
loosen the three grub screws holding the barrel, Remove the barrel.
Remove or loosen the two tiny grub screws on the side of the bolt carrier. (Best to remove them completely, as they will catch on your action if they aren’t flush)
this will allow you to pull the probe assembly out.
The probe is made up of outer probe, inner probe and spring. The inner probe should freely slide inside the outer probe.
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It should not. If the probe seals properly when closed (no air escaping at breech), then the probe is probably adjusted to its proper seating depth, and the problem is with the stem, which may be bent and need replacing. But, if the breech isn't fully sealing when closed, then just adjusting the probe depth in might solve the problem.
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You can straighten them.
If you have a very flat surface, (machinist plate) brass hammer….roll and tap till it’s perfectly straight again.
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No, but the new reg setting and HST might not be in a very balanced state of tune, which could be related to the shot count. But, I suggest you first finish cleaning the hammer assembly and see what happens.
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