Beeman RS2 velocity fix! UPDATEMarch 8 2008 at 4:54 PM
|Russ (Login Guru1atl)|
In my last posted I explained the results of some transfer port adjustments. Before making these changes permanent I did a bit more tinkering including a closer look at the breach seal which had given me trouble earlier.
The original breach seal was producing 177 velocities around 400-500fps. I installed the spare which Beeman provided and the velocities increased to 750fps with CP's. The new seal wasn't much thicker than the old one and the old one had no signs of damage either. Decided to fabricate a better seal before messing with the transfer port since it was easiest to do and less permanent.
With the improved breach seal the gun shoots CP's at 870fps and Superdomes at 920fps. Still prefers the Superdomes but at least it will shoot other brands as well. Decided not to go with the transfer port mod until I can do more testing in 22 caliber.
Mods so far...
Thread lock all screws
Trigger polish and lube
Cut chamfer at breach for better pellet fit
Installed foam slider to eliminate loose cocking link
Installed tighter safety spring and re-cut safety detents
Polished the stock
One of the best shooting guns in my collection now and it doesn't look bad doing it either. Trigger is real sweet with a little work.
It is a keeper.
|This message has been edited by Guru1atl on Mar 8, 2008 7:49 PM|
you might take a look at the cylinder face(where the seal contacts)
|March 8 2008, 11:57 PM |
it should be mirror smooth.I've seen gouges,burrs,grooves...on various springers over the years.
There is an issue with the tollerances...
|March 9 2008, 1:02 AM |
and the seal must bridge too large a gap. The seals that came with it would do it but didn't have enough pressure to provide a good seal. Installing a shim behind the seal would be another way of correcting this but there isn't enough material on the breach side for this.
I did polish the mating surfaces though and applied a bit of a beveled edge to the transfer port to prevent gouging the new seal.
maybe an ecentric bushing in the pivot hole?
|March 9 2008, 5:27 PM |
that would move the breech face closer to the cylinder face...
|March 14 2008, 9:12 PM |
did you use for the seal?I`ve had similar issues.
|March 14 2008, 9:21 PM |
two of these guns.The 1st would only shoot 570-625 in 22cal,and around 850 with cpl`s in 177.I didn`t detect a breech seal issue with gun.The second will only do 710 in 177 cal with cpl`s.Putting some dental floss behind o-ring showed a gain of 110fps in 177 cal.Putting more floss caused seal damage,but no further gain.This gun has some real seal issues.
as to the transfer port,the RS-2 has same size hole as my Spanish Norica GS-950,that is the parent to the RS-2(actually the GS-1000,but almost same gun)and it will do 650 in 22cal with RWs Superpoints.I was hoping to get closer to the speed of the RWS 94,or around 725.I`m thinking these guns also have piston seal issues.
Yep, breech seal needs some help
|March 16 2008, 12:37 AM |
Guys, I put some really thin shim in the seal cavity and lubed up the oring with silicone oring grease. This simple mod gave me a gain of ~50fps. Now she shoots Hobby .22s at 790fps! That was quite a wollup, and explains my inconsistent velocities.
Also, I think a #011 oring might seal up a bit better...
|This message has been edited by davee123 on Mar 16, 2008 12:41 AM|