My RTI Prophet Compact muffler, without lengthening the gun

Here's what I did to make my loud Prophet Compact a LOT quieter, without additional outside help. This is not a glue in "fender washer" or two as baffles deal.

I like short guns. A Prophet or even the Compact...with a silencer, LDC, moderator, muffler, suppressor, or any other device hanging off the end of the barrel/shroud to make it a bit less noisy, is not my idea of short.

After getting my Prophet Compact the other day, and was very disappointed at the sound level, I wanted to figure out a way to make it quieter without the extra length hanging off of the far end.

After removing the shrouds end cap, I noticed the disk full of small holes screwed to the end of the barrel. After some though, I figured to remove the disc, and cut it into a triangle, so much more air would pass into the large plenum area behind it. After finally getting the shroud off, I found that the "disc" was also attached to the barrel...VERY tightly. I could not get it to budge. (either rifle). So I figured that I'd just carefully remove "some" material to open the air passage and still support the barrel.

The next day as I was waking up, I started wondering about the baffles in the Daystate Renegade. What's the tube outside diameters ? I measured them, they are within a few thousandths. I removed the baffles from the Renegade (5) and put one into the Compact shroud. A little loose a fit. I put a wrap of aluminum tape around it so it would fit a little tighter and still move in the shroud.

THAT"S part of the key here. The baffles NEED to move to do their job. I had a short spring of the correct diameter handy, and I cut it so that with the shroud, just touching the threads in the body of the frame/receiver, and all five baffles in place, I put the end cap on the shroud, and the shroud fully in place on the gun. This light spring load would hold the baffles in place, but will also let them move quickly upon seeing shot pressure. I put a coupla pellets in the magazine, pointed it at my indoor target and pulled the trigger. It put out about one half of the sound than the gun did as with either the 0dB or the Tatsu silencer (muffler ?) in place. VERY notably quieter than with even add-on silencers

Sometime back, I made up my own moving chamber baffle system in the "can" of my BP17. I had tried three or four different YouTube methods with no success. Then using RC car gears and some other parts, I had a moving chamber baffle system that did a decent job of cutting the sound level of the BP17. The same basic thought for the RTI guns.

Back to today. I called a noted Daystate dealer to see if they had any Renegade, Pulsar baffles. They did. I needed enough to refill my Renegade and fill my Prophet. Interesting thing, the guy I was talking to told me that the Daystate baffles screwed up the accuracy. I mentioned that I hadn't noticed that in my Renegade or my Pulsar, we'll see. But this is now a different beast I experimenting on...so...I need to check this carefully.

FX, 18.1 pellets filled the magazine, 100 bar in my regulator adjustment, I put the cats in the bedroom and opened the back door so I could get a little longer shot than normal. I stood back about 20 yrds. After four magazines full, off hand shooting, at a "cent" (NOT a penny!) coin sized black target, 10 rounds each magazine, I saw no signs of any baffle influence on the accuracy. I shot four magazines (10 ea) through the gun (at different times, the neighbors you know), opening a single hole just a hair larger than a quarter. The same thing happened with all four magazines.

Maybe today was just my day. The other day, I was shooting my Ocelot (single shot pistol) and was doing terrible. A gun I normally shoot well ! Today...all good...and quiet. I need to do some checking, but it's one of two of my quietest guns now. I'll keep close watch on the accuracy during future shooting sessions to see if the baffles hurt the accuracy.

The Daystate baffles are staying in my RTI Prophet Performance Compact.

That's my two and a half day experiment that ended well.

MIke
 
P.s. - A little sound info from above.

No, my sound comments are a perceived by my ears only. I do not have a very high dollar acoustic chamber where I can get accurate sound readings like I could when I was still working. Nore, do I have any mostly useless (my opinion) $20 hand head decibel meters.

Just a perceived sound level, shooting about 10 minutes apart, same location to the target, same adjustments in the gun.



Mike
 
No, I did not modify the disc at the end of the barrel. I just inserted the Daystate like spring and five baffles (same quantity that Daystate uses). No modification were done to the shroud or barrel. Overall, a pretty simple, but great working change.

The aluminum tape is there to make the baffles larger to better fit the interior of the RTI shroud, to help insure that no pellet clipping would happen. After 40 shots, no damage to any of the baffles has happened.

I'm going to try a lighter and heavier pellet (than the 18.1 tested) later today to see how well they travel to the point of aim.

DSC00711.1625160990.JPG


Mike
 
Sorry, no Norcal.

The full sized Prophet's barrel is longer in the shroud than the Compact is within its shroud. Therefore, the is only room for two baffles, and no spring. These two baffles did almost no good at all. Just the very smallest amount of noise reduction.

I did mention this in another post somewhere. Sorry that you missed it.

RTI Compact = Yes, five baffles and the spring fit and work well (see above).

RTI full sized = no, not enough room in the shroud.



Mike
 
Mike,

I wonder if you milled a few length wise grooves and through holes around the baffles to allow air to somehow be directed back into the shroud might work? I think that is what the disc (with holes) on the end of the barrel is doing.

Sounds like a thought. Those baffles aren't in any way thick enough to put grooves in the outer diameter without breaking them. They are very light weight. I do have some thicker walled baffles that I might try that with. Gotta see what their outer diameter is first.

The first "chamber" will already have a leak path to the back of the shroud past the disc.

Most of the way that I believe this system works is the "expansion" of each chamber (baffle) by the air pressure pushing on each chamber (spring) as it enters that section. It then expands that chamber buy pushing on the spring. So each chamber will expand "X" amount by the air pressure, I know that this is happening by the scratches on the two baffles that have the aluminum tape. The rear baffle has a much different scratch pattern than the outer baffle. It has a lot less of a scratch pattern than the one closest to the barrel.

I made up an expanding chamber system on my BP16. The big "can" on that gun is hollow. I tried several things to act as a suppressor. Nothing worked very well. I then thought of the expanding chamber. I have no idea why ! Anyway, it has three discs that move on pieces of all thread, and have ballpoint pen springs between each baffle. So the baffle or walls, can move where they want to move. That idea...quieted the gun way down. Still in there today.



Mike
 
thanks mike! you might have opened up a can of worm for a newb like me, but i only got into this pcp thing to see if i could shoot indoors without bothering the neighbors (i don't even have a back yard). i didn't want this new hobby to turn into a tinker job, but depending on how quiet i can get with off the shelf options, i may be following your lead. some are suggesting i may have wasted money on the mod40 (i don't have yet) and i don't believe that design is going to allow for this kind of modification.
 
@mikevv I really appreciate the detail you went into explaining what you did. Can you buy that spring commercially or just see what works from the local hardware store?

Blackpaw -

I got my spring from Airguns of Arizona when I got the Daystate (Pulsar/Renegade) baffles from them. I also used the Daystate spring that I cut by about 1/3 the length, then flattened the last coil. I made the spring about one baffle length longer, than the full stackup as assembled into the shroud. That is, with spring in place, the baffles in place, one baffle sticks out of the shroud, before reinstalling the RTI cap. This is a lighter spring pressure than Daystate uses on the Renegade/Pulsar. It also ends up being a quieter gun than either of those two. After than, I ended up shortening my Pulsar spring to about the same pressure. It helped their too.

.039" wire diameter, about .800" coil to coil dimension, .800" outside diameter, and about a 2.75" overall length after cutting and flattening the cut coil. As I say, flatten the cut coil so it puts even pressure on the baffles. You may be able to buy something close from a McMaster Carr, Grainger or an actual spring manufacturer.

And yeah, before you ask, I looked, I'm not sure what I did with the remainder of the spring that I cut !

Mike

Do you have calipers to measure what the inside diameter of the shroud is? I have extra Marauder baffles maybe those would fit. Easy to get them.

BlackICE -

You should be able to measure your own gun, just in case the inside dimension is slightly different. The Daystate baffle is slightly small for the RTI at .817" dia. I used "one" layer of industrial aluminum tape to make the two end baffles slightly larger. Is that necessary... don't really know, but I did it to help keep the baffle stack centered to help keep any possible pellet clipping from happening.

The baffles NEED to slide smoothly to work properly, but not so much to be too loose and cause pellet clipping.

Mike