Bobydazzler Posted June 21, 2018 Report Share Posted June 21, 2018 Hello, A friend and I were enjoying some target plinking yesterday when he encountered a strange (to us at least) issue with his gun. We're both very new to PCP's and have just acquired .177 Walther Rm8's (wonderful rifle with amazing accuracy). He had just topped up his gun from a 7lt 300 bar cylinder....we usually shoot down to 90 bar before topping back up to 200 bar....when his shots immediately began to drop by 2 inches or more at 21 yards! The gun also sounded different (?)...more muted...and the power was definitely down! We took off the sound moderator (Weihrauch) and no sign of pellet fouling could be found, perhaps just a little bit oily so ran it through with a cleaning cloth, tried the gun again without it and the power seemed to have returned somewhat. Re-attached the mod and suddenly all of his shot were now high by about 10mm! It took some repeated dialling back down until it settled on zero where it behaved for the rest of the session. Does this sound like a regulator issue to anyone? Many thanks for any advice Bob Quote Link to comment Share on other sites More sharing options...
Dasher Posted June 21, 2018 Report Share Posted June 21, 2018 I wonder if he had over filled his gun, or filled it too quickly, and the increased pressure was restricting the mechanism until the pressure dropped to the designed working pressure. Quote Link to comment Share on other sites More sharing options...
Bobydazzler Posted June 21, 2018 Author Report Share Posted June 21, 2018 Hmmmm thanks Dasher......I too wonder if he had filled too quickly.....(I saw it was filled to 200 bar and not it's maximum 232 bar) Quote Link to comment Share on other sites More sharing options...
Guest Posted June 21, 2018 Report Share Posted June 21, 2018 Always fill slowly, if not in steps to let it settle. Also, this can happen if the moderator becomes loose. Quote Link to comment Share on other sites More sharing options...
NIGHT SEARCHER Posted July 25, 2018 Report Share Posted July 25, 2018 (edited) The early Walther RM8 is an Unregulated Rifle and will have a sweet spot where it shoots at full power. The spec on the Riflle is 150 shots in .177 and 170 shots in .22 from a 232 bar fill. But you will get around 80 to 100 shots at full power.You need to find the Rifles sweet spot. (ie) What power is it shooting at what Bar. I have a few Unregulated Rifles Logun Pro. Daystate Huntsman. Falcon FN19. All say fill to 200 bar. At 200 Bar they are well down on power. The Logun at 200 bar is shooting at 6.5 Ft lb. 190 Bar =8.7 ft lb. 180 Bar =10. ft lb 170 bar down to 80 Bar it shoots at 11.7 ft lb. So the sweet spot is 170 down to 80 Bar. You can have a Regulator fitted so all your shots are at the same power. You could do with a cheap Chronograph around £40 to check it`s power at what Bar. I have just been reading that since early 2017 That Walther have been fitting a regulator to the RM 8 has standard to get rid of a power curve sweet spot problem. Good luck. Russ. Edited July 25, 2018 by NIGHT SEARCHER Quote Link to comment Share on other sites More sharing options...
chrisjpainter Posted July 25, 2018 Report Share Posted July 25, 2018 Any update on this? overfill/rapid fill sounds the most likely - especially when shooting with mates! Sounds daft, but it's easily done. You're chatting away, not concentrating, the needle goes a bit higher than you planned and there you have it. at its worst you fill it so full the valve simply won't open and the gun won't fire. Then it's a repair job and an expensive bill! Quote Link to comment Share on other sites More sharing options...
Seadog1408 Posted July 26, 2018 Report Share Posted July 26, 2018 If you have filled to 200 instead of 232 it obviously is NOT overfill. As with ANY gas charging/decanting it's always best to be done slowly. mike Quote Link to comment Share on other sites More sharing options...
Bobydazzler Posted July 26, 2018 Author Report Share Posted July 26, 2018 Thanks guys, I forgot about this thread and forgot to update! ? We went halves on a Crombo and chrony'd it....it was indeed the regulator! The shot string line chart looked like an ECG of someone suffering a cardiac arrest! Pellpax were very good and swapped out the rifle the same weekend so all's well in the World again! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.