Edgun R5M, my well-intended mistake

[JWilson]

Anxiously awaiting your results. I have settled on 127 BAR, 890 fps at muzzle. These pellets are very interesting. There is little to be gained by speeding them up further. In fact they begin to open in the wind if I push them any harder. In perfect conditions they are stable... or appear stable up to 930 fps but with any wind they seem better below 900. The more you shoot the more you learn.

 

[kiba]

No long range paper results yet. It was 105F on Friday, 108F Saturday, and 102F and breezy right now. No fun to be outside shooting. I did zero the rifle at 50Y this morning and shot 3 ground squirrels with it before I got out of the heat... the 34gr pellets sure hit hard compared to the 25gr pellets, a nice satisfying thump... there is no doubt if you hit one. If the breeze dies down tonight I'll go back out and test on paper at 75Y-150Y to verify long range drop and figure out a BC number.

Going from 25gr JSBs @ 915 to 34gr JSBs @ 895 only changed the 50y zero down by 0.1 mils and left by 0.7 mils, but the windage difference may be from the breeze today because I was shooting crosswind.

Time to go jump in the pool for a bit and cool down!

 

[Alejandroo]

Hi to all!

There's been a while since I last comment, by now I've shot around 400 pellets on my R5M Long .25.

My current setting is this: shooting JSB 25grs @ 920 (HST peak was at 945) the HUMA is set between 105 and 110BAR (using the sticker as a guide), I've also tried lowering the FPS to 880 to see if the groups get tighter but at 55 yds there's no big difference so..........

I'm getting like 60+ shots on the reg from a 235BAR fill (Pmin on the EDMU is set at 106BAR), I also plan to try the MKII 34grs setup to see how much it changes at longer ranges, I also want to tryout the NSA ammo but my only concern is that they don't shoot as accurate on the R5M, Coolhand your rifle is the R5 standard with single shot/rear bolt model so It could be different.

As standard groups my gun is doing 1/2inch at 55yds full mag, I shoot only taking the pellets strait out of the tin NO weighing and NO sorting !.

I'll try to upload some pics of the groups and other stuff, If anyone needs more info just let me know, glad to help and contribute.

Alejandro

 

[Ronin001]

Alejandro,

Those numbers look good thanks for the input. For the NSA ammo it won't be the barrel if anything it would be the magazine and If That's the case single load insert Would solve that.

Looking forward to your pictures!! 

 

[Alejandroo]

 

Hi to all I started a new round of tests with a few pellets that I have, so I'll post my findings and data for all of us, It would be great if someone else could upload results with NSA ammo and 50 yard or more paper targets.

Just a story of this past weekend......I made the inaugural hunting trip with my R5M and shooting with the 25gr kings at 880FPS what can I say..........the rifle exceded my expectations when hunting and I if this thing shoots this well with the 25grs Kings I can only imagine what it will do with the 34grs or the NSA ammo out to 100 meters.....WOW !!!

I'll keep you posted

 

[kiba]

The 34gr JSBs are shooting very well out of my R5M at 895fps... more accurate than the 25gr pellets, especially at longer ranges. I shot out to 150Y last weekend to verify drops and was very happy with them. Had a couple 125Y 5 shot groups that were about 1". It was the first time I've ever shot the 34s, I've been using the 25gr pellets for years with my previous R3 and R3M.



While the 34gr JSBs shoot great, the higher muzzle energy and regulator pressure compared to the 25gr pellets has revealed another problem... occasional bolt blowback when firing, maybe 4 shots in 10. The bolt doesn't blow completely out of battery and dump air on your cheek and drop velocity when it happens, but the cocking carriage does come unlatched and the bolt and carriage moves back about 1/2". When it happens accuracy isn't effected and the Labradar doesn't show any velocity loss so there isn't any air loss, but it is an annoyance.



I took the rifle apart on Sunday to see what the problem might be and what could be done. Step one is adding a secondary spring to the pivoting latch in the cocking carriage to hold the latch more firmly in the closed position. That's done, but unfortunately I nicked an o-ring on the brass breech adapter when sliding it past the transfer port in the frame and am waiting for replacement o-rings. The original o-rings measured to be 13.1 x 1.6mm; I had 13 x 1.5mm o-rings on hand but they slide into the frame with almost no resistance so they may leak.

Once I get the correct replacement o-rings we'll see if the second latch spring fixes the blowback issue or if I'll have to start looking for another fix… I have two more ideas in mind that may help if the spring alone doesn’t solve the issue, one is easily reversible with no permanent mods to the rifle, the other would require modifying the pivoting latch in the carriage and the fixed latch in the frame.

 

[Alejandroo]

Hi Kiba, I have to say that at when I just got my rifle the regulator pressure was set at 120BAR and I suffer form the same issue but I got air dump on my cheek and the subsequent velocity drop of near 40FPS, after I drop the reg pressure to 105BAR never happened again I'll report if the problem comes again once I tune the rifle to shoot the 34 grains.

Now I did the tests and here are the results with corresponding pics and explanation, there's not much scientific procedures on some of them but I'm just starting if any of you have suggestions or ideas please be my guest !!!

Pic Nº1: 6 shot groups at 50mts of the pellets that I showed on the previous post, I didn't measure speed because I just wanted to see if the barrel like them or not, as point of reference I shot them with my initial setup of the JSB 25 grains, reg at 105BAR so can get an idea.

 

Conclusion: Barrel liked the Edguns (of course), Barracuda Hunter Extreme and surprise surprise !!! the Benjamin Domed, maybe more test is required.



Pic Nº2: 100mts groups at 2 different velocities with the JSB 25gr, unsorted, 8 shots each.

Conclusion: just as JWilson said, the 25 grainers shoot better at longer ranges at 880FPS avg at the muzzle.



Pic Nº3: Here I sorted the JSB 25 grains, visually inspected and head size diameter with the pelletgagewith 3 sizes 6.36, 6.37, 6.38, vast majority was 6.37mm then 6.38mm. After that I left one group lubed (L)and another unlubed (N.L.), 7 shots per red bullseye. 

Conlusion: Seems that the 6.37 are more consistent and no real difference between lube or not lube pellet.



Pic Nº4: After head size diameter sorting I re-shot at 100mts to see the difference, 9 shots per group.

 

Conclusion: Again the 6.37mm group better at 100.

So after all this testing the night settle in so I had to leave the range ?. 

What comes next.......???

With the 25grains pellets that I have let I'm going to weigh both batches the 6.37 and the 6.38mm and shoot them again to see if the rifle likes a particular weight and post the results.

Hope you like this and that helps all of us to get know the gun a little better, remember........any ideas let me know!.

Bye bye

 

[kiba]

Just a quick report... finally had a chance to reassemble and test fire the rifle tonight after adding the secondary spring under the pivoting latch.

Factory spring on the right, new secondary spring on the left. The secondary spring fits inside the factory spring, then you reassemble the latch.

You have to size the secondary spring carefully. Too tall and it coil binds and won’t let the pivoting latch open enough to snap over the fixed latch in the frame. Also, you have to make sure it’s short enough to let the pivoting latch open enough so that the 2x cocking levers can pivot rearward fully and hit their stop pins; if you leave the spring too tall it will coil bind and stop the rotation of the pivoting latch before the 2x cocking levers hit their rearward stop pins and all the cocking effort will be put into the ramps on the cocking levers and the pivoting latch that’s bottomed out against the fully compressed and bound spring. Took a couple tries of trimming ¼ coil at a time until everything worked as it should without coil bind. Once the 2x cocking levers can pivot all the way rearward to their stop pins, the new secondary spring is trimmed short enough.

The good news: 2x fills (80 pellets or so) at 63 ft-lb with zero instances of bolt blow back. We'll see how it holds up long term, but for now it looks like the second spring was a simple and easy fix.

One lesson learned from disassembly/reassembly...when removing or reinstalling the barrel, you need to insert something about .230" diameter into the transfer port in the frame to keep pressure on the front o-ring on the brass breech extension on the barrel, or else the front o-ring bulges/extrudes into the transfer port and gets cut. The brass breech extension o-rings are metric, 13.1 x 1.6mm... I would not suggest removing or reinstalling the barrel without having spare o-rings on hand, it is very easy to cut the front o-ring in the transfer port.

 

[koomassa]

Anybody have any results on r5m standard? 

 

[Alejandroo]

Just a quick report... finally had a chance to reassemble and test fire the rifle tonight after adding the secondary spring under the pivoting latch.

Factory spring on the right, new secondary spring on the left. The secondary spring fits inside the factory spring, then you reassemble the latch.

Did you tried to change the original spring with a stiffer one to see if it works ?,do you have the specs on the secondary spring, like length, diameter hardness or tension?

Thanks again.

 

[kiba]

The factory spring is 0.218" OD x 0.325" tall (uncompressed) with 0.014" thick wire.

The cocking carriage has room for a spring with a max OD of 0.235"

The secondary spring I added was .175" OD x 0.014" wire. No known specs other than it came out of my "assorted spring bin" in my bin organizers. I grabbed the highest rate spring from the bin that would fit inside the factory spring.

I didn't have a suitable single heavier spring to replace the factory spring; they were all too big for OD, so I added the secondary inner spring. Going to a single heavier spring (thicker coils) means less travel before coil bind, and that's something you need to test for. If the 2x cocking levers won't rotate all the way back to their stop pins before the pivoting latch runs out of travel and the spring fully compresses, you need a shorter spring. Easy to test for with the cocking carriage out of the rifle.

Just shot another 2x fills (80ish pellets) through the rifle and zero unlatch/blowback events.

 

[JWilson]

I took a different route and arrived at a place where the rifle has no blowback or unlock issues. My route very simple to try and very simple to remove. I simply placed a 6X2.5mm ORing on the pellet probe. It is a very good and convenient fit as it bottoms on the probe shoulder and simply ensures there is no slack or clearance in the lock latch. By eliminating the clearance my lock functions perfectly.

Kiba shared with me he found there is an ORing in the frame that is sort of an anti-rattle device. I am not clear if this ORing could serve the same purpose or not, but it is very likely. It is a terribly inconvenient location to service or adjust.

First picture shows the ORing with the probe forward. Second shows how the ORing stays seated on the probe shoulder when cocking. Note the pellet is out of the magazine long before the ORing contacts the back of the magazine.

I am tuned to 59 FtLb and this is an amazing rifle. It is so good I am probably going to sell some others to fund a Lelya 2 in .22?

 

[Alejandroo]

The factory spring is 0.218" OD x 0.325" tall (uncompressed) with 0.014" thick wire.

The cocking carriage has room for a spring with a max OD of 0.235"

The secondary spring I added was .175" OD x 0.014" wire. No known specs other than it came out of my "assorted spring bin" in my bin organizers. I grabbed the highest rate spring from the bin that would fit inside the factory spring.

I didn't have a suitable single heavier spring to replace the factory spring; they were all too big for OD, so I added the secondary inner spring. Going to a single heavier spring (thicker coils) means less travel before coil bind, and that's something you need to test for. If the 2x cocking levers won't rotate all the way back to their stop pins before the pivoting latch runs out of travel and the spring fully compresses, you need a shorter spring. Easy to test for with the cocking carriage out of the rifle.

Just shot another 2x fills (80ish pellets) through the rifle and zero unlatch/blowback events.

Thanks for the specs on the springs Kiba!!!, As soon as I start my tests with the 34 grainers I'll give you an update on the blowbacks and the solution route that I took, thanks to all of you for the inputs. 

 

[Crank]

Well, I will be paying attention to where this discussion goes. I just received a used R5M from another forum member (no complaints towards him). I was able to sit down with it at the range for several hours on Saturday and it looks like this one has some need for tinkering. I was told it was set up with a Huma regulator for a power tune with the 34gr. pellets, but it was running low and erratic velocity with the 25gr. JSB's. Prior to going to the range I had it out of the stock and adjusted the HST to get it running at 910fps and the velocity seemed to become more consistent. I didn't chrono at the range, but trying several weights up to the 31gr Barracuda (I didn't have any 34's to test), I just kept having issues with the groups suddenly opening up at 50yds. I was settled in firmly on the bags and had adjusted the trigger for a cleaner and consistent break, but I would send one downrange with confidence that I made a clean shot and I would see the pellet land well outside what was more or less a group. There was a consistent wind and it didn't affect my shooting of my other rifles other than doping for the drift. My plan is to tear it down to parade rest and carefully check all of the components, I may even re-install the factory regulator to establis a baseline. It was a bit vexing to have this rifle show poorly against a tired Theoben Rapid, a de-tuned Leshiy and a Chinese P15. I put somewhere north of 400 pellets through it and functionally it was a pleasure to shoot, but for some reason it was erratic and needs a bit of love. This will be an interesting learning experience.



JWilson: My rifle is most likely from the same batch as yours since the serial number is slightly lower, so I will be paying attention if mine shares any similar quirks.



Mark

 

[Alejandroo]

I'm buying the Huma tester to make the 34gr tune for my rifle,I'll order it from Brian at EdgunWest, as soon as I have it on my hands I'll let you know how everything goes but until then I still have the rest of the tests with the 25gr, now just finish sorting them head size and weight, I have to shoot them to see if there's any difference.

 

[JWilson]

Mark,

There are lots of great folks willing to share all they know on this forum. I am very happy with mine and honestly speaking... the lock letting loose is the only issue I have had of significance. It is now a dream to shoot and lights out from 0 to 125. That’s about the end of my range when it grows up with underbrush.

Happy to chat about what I think I know Send a PM if you want to chat or discuss on the phone.



Joe