Edgun R3 .22: Shot String, Air Efficiency, & Trigger

This will be a long post, sorry about that. Ran into the dive shop to fill up the scuba tank yesterday. The shop owner put on a pressure gauge to show me how much the tank was filled, because I was “hinting” at him that I could only fill the gun to 180 bars (~2610 psi) last time with a full tank. The tank was indeed filled to the maximum pressure around 3100 psi in this new fill. Interestingly, again, I only could fill the gun up to ~180 bars based on the gun gauge; but the gauge in the fill adaptor showed 3050 psi (~210 bars). It seems that the pressure of my Edgun was somewhat under measured by 440 psi or 30 bars. 🙄

I tested a shot-string using Combro Chronograph, which is a very small and handy chronograph installed at the end of the muzzle area. The starting pressure was 180 bar (based on Edgun gauge) and JSB Heavy (18.1 grains) was used. The first shot was low in speed (878 ft/sec), but the subsequent 35 shots were consistent with average 916.5±4.5 ft/sec (minimum 910 ft/sec and maximum 926 ft/sec). The regulator came off around 130 bars (I think) because of a little rise in speed for several shots and then the speed dropped to around 840 ft/sec for about 13 shots in parallel with pressure drop. The POI (at 30 yards) started to drop slightly (~0.2”) at shot #37 (or the regulator was off at this point?) The POI didn’t further drop until pressure went below 105 bars. I got 35 good shots consuming ~800 psi (from 180 bar to 125 bar) from a 289-cc air tube with average 33.8 foot-pound muzzle energy, which is about 13.1 bar-cc/ft-lb efficiency of air usage. If using Zoco’s data – green-line shot string, 220 bar to 130 bar for 57 shots, ~32.5 fpe (http://talonairgun.com/forum/viewtopic.php?t=19488&postdays=0&postorder=asc&start=520), I got the number 14 bar-cc/ft-lb efficiency.

Based on the data from a shot-string of Royale 400 (without regulator; average 868 fps with 37 fps extreme spread) (http://www.network54.com/Forum/79537/thread/1318702313/FX+Royale+400+.22+-+90+shot+string+with+chart-target), which consumed 0.94 bar/shot (220 to 135 bars for 90 shots) with ~30.3 fpe from a 400-cc bottle, the air efficiency is 12.4 bar-cc/ft-lb. Using another shot-string (http://airgunadvice.net/viewtopic.php?t=12183), from 220 bars to 179 bars with 36 shots (average 954 fps with 28 fps spread) at ~36.6 fpe, I got the same number (12.4 bar-cc/ft-lb) for air efficiency. Using the data from the FX Royale 400 review video of Ted in Youtube, average 33.53 fpe and 20 fps extreme spread with high power, I got 11.1 bar-cc/ft-lb efficiency. If the medium power is used (884 fps with 31.4 fpe and 13 fps extreme spread), the efficiency will be higher at 9.6 bar-cc/ft-lb. It seems Royale is a little bit better than Matador R3 (standard length) in air efficiency without much sacrificing speed variation in the un-regulator gun.

I think Edgun can be optimized by adjusting the combination of regulator and power to reach max efficiency, but it will need a lot of trial. Or this is already at the optimal condition when Ed designed and set up the gun. What do you think?

p.s
I also installed a Harris bipod BRM-S model 6”-9” in late afternoon, and ran a few shots under high-gust wind (>20 miles/hr) before dark. It seems to improve the unstable sitting of the gun and increase the shooting accuracy. 😛 Will test more tomorrow if weather is good.

titeuf007

Participant

July 31, 2018 at 11:15 pm

i have this same barrel on my airfoce clone

very good job

darryl

November 11, 2015 at 2:40 pm

me too. I hope the winds a re fair and the skies are sunny for your test. take pictures! maybe a video? :smilen:

endothelium

November 11, 2015 at 4:16 am

Yeah, MIT (Made in Taiwan) has a good name.
I am more confident with MIT than MIC.

I am happy with the barrel and Dman’s work.
Hopefully I can shoot more groups this weekend.

November 10, 2015 at 5:25 pm

What?! A Chinese barrel?!!! :suprisedn: Just kidding. I hear negative refrains about Chinese products so often… Well, I’m just flat JEALOUS. Start selling these, and you’ll be rich in no time (if not already). Mighty fine shootin’ there, pard. Well worth your wait, I’m sure.

secoda

November 10, 2015 at 3:19 am

Cool. Taiwan is producing a lot of high quality products these days. I wish they had more scopes being manufactured there.

November 10, 2015 at 2:57 am

This is to update my R3 0.22 LW barrel, which is very picky and only likes JSB Heavy head size 5.50-5.51 mm (18.1 grain). Anything outside of 5.50/5.51 mm, the gun shoots like crap (this may be exaggerated, but the accuracy is significantly compromised). This has bothered me for some times because it is difficult to source the head size that my R3 likes. The pellets I got from PA are always less than 5.50 mm (around 5.46-5.49 mm in past 3 years), and the style is very inconsistent.

I have been thinking to replace the barrel like Tedd (Oldgoat) and Robert (Veerkracht) did in their R3. They replaced LW with BSA barrel, which is less picky and also improves accuracy. Robert has consistently ranked top 3 in 100 m competition with BSA barrel in his R3. The BSA barrel has 15 mm OD and it needs to be turned down to 12 mm OD. I have purchased BSA barrel two years ago and was trying to find someone who can machine the barrel down to 12 mm OD and cut/thread to fit to R3. This project has been stalled for more than 2 years and the bugs kept biting me to have the barrel replaced.

Until recently, Dman (Jaime) and I have been testing different barrels for P12 and Mutant, and came across a barrel manufacture company called Listone in Taiwan. They have 12 and 15 mm OD barrels available and Dman was kind enough to offer his skill to cut/thread the barrel for me. So, I purchased the 12 mm OD FA straight barrel from the Listone. The barrel was sealed inside a metal tube and well packed for shipping. The length is 23” and a significant choke at ~2.5” from the muzzle end. It has a label “GreenWalther work with Air Arms/FX/ED”, and I think ED = Edgun. I sent my R3 stock barrel and breech to Dman, and he cut, polished/crowned/threaded the barrel. He did an outstanding job in fitting the barrel to my R3. It is a smooth and perfect fit. Thank you Dman!

Now, how does it shoot? This is the most import part. Well, …. here are some targets I shot at different days (< 5 mph wind). Collectively, at 50 yard with 5-shot group, the smallest size was ~0.10” ctc and the worst group was ~0.40”. The red dot in the picture is 0.25” OD. The majority of the groups were in the range of 0.25” to 0.35”. The JSB head size was about 5.48-5.49 mm that my LW barrel has problem with (~0.35” to 0.6” ctc). I believe the grouping can be better at no wind condition. This Listone barrel will stay in my R3 for a long time.

I would like to thank Robert and Tedd that they have been helping me all along on the barrel specs, various mods, advising and solving all sorts of issues on my R3. And of course, Dman is the man who makes the barrel replacement possible. Thank you all!

Regards,
Endo

February 3, 2015 at 2:22 pm

Thanks Endo, I’ll give it a “spin”. Much obliged!
Darryl

February 3, 2015 at 2:37 am

Hi, Darryl:

I don’t have R3M. I still use the old fashion R3 (.25) with single shot and single trigger screw.
I like my R3 trigger with single screw. I only screwed it in just a little to lighten the trigger from the factory setting, that is it.
In your case, it may require some adjustment on the trigger linkage rod. I just found an “old” post by Clint (http://www.talonairgun.com/forum/viewtopic.php?f=34&t=26336&p=259630#p259630) that he described how he shortened the first stage on his R3. Hopefully, this is useful.

February 1, 2015 at 10:04 pm

just to be current with this thread, I’ll ask a question about the trigger on the new R3M (single-screw adjustment): how do I shorten the 1st stage? It it’s too long for me. Thanks,
Darryl

veerkracht

January 31, 2015 at 6:14 pm

Endo,

The 15,4 mm is inconsistent with my 14,9.
Your (130 bar) 15,4mm should be less then my 14,9 mm., around 14,5 mm.

Maybe the belleville washer are not consistent or our measure methodes are different.
Next time when I take Matador apart I´ll measure it again.
Well, it was worth trying.

Regards, Robert.

January 28, 2015 at 1:58 am

Hi, Robert:

It would be very nice if we have the info on the length of reg shaft vs. setting pressure.
I have a spare reg which is still in factory setting (130 bar) and the measured length is 15.04 mm.
Your 14.9 mm corresponds to 110 bar. So, 120 bar should be around 14.97 mm, in theory, if it is a linear relationship.

I don’t know if this can be generalized to all R3 regs.

BTW, it is a very professional drawing with all details. Great job!

January 26, 2015 at 5:01 pm

Hi Endo,

I’ve measured this thing, could you perhaps do the same?
This way we do not have to dis assemble the gun, just measure it for the right pressure!

September 20, 2014 at 11:13 pm

Are there any R3 .30 cal stems? I thought they had problems.

September 20, 2014 at 10:54 pm

I installed the metal valve from Ernest in my .25 R3 several months ago since I am tired of the breaking of stock plastic valve (twice). The metal valve comes with a spring and one nylon washer (now it comes with 2 washers) to fit the valve. Ernest did an excellent job of making these valves (picture 1).

My R3 reg was set at 4:00 location to shot ~900 fps with air consumption around 11 cc-bar/FPE. A fill of 200-bar can have 70-75 useful shots with end pressure around 100-bar. After installing metal valve the shot count was drastically decreased to around 60 shots with the same ending pressure and the air efficiency was low (~13.5 cc-bar/FPE) compared with the factory valve (see picture 2). The pressure drop (open square in picture 2) was faster than the factory one (closed circle in picture 2). The spring that Ernest uses for his metal valve is shorter and weaker than the stock valve. He thought that the spring he sent was too weak and the dwell time of the opened valve is too long and waste air. So, he sent several stronger springs for me to try (thank you Ernest!). Unfortunately, those springs did not bring the air efficiency back to what I expect. Then I changed different reg settings and hammer tensions trying to match the spring characters, but the best air efficiency I could get was around 12 cc-bar/FPE, and the speed was too high (~940 fps) for my liking. Through an exhausted search, I found a spring wire width that is slightly smaller than the stock spring (0.055”) and the length is shorter (lighter pre-load) but can be used for metal valve. With several adjustments on reg pressure, I found 1:00 setting is the best to match the spring and it brings the air efficiency back to “normal” and also extends the shot string a little more (speed is 10 fps lower; closed-red circle in picture 3). Now, I have 80 useful shots from 196-bar to 97-bar with air efficiency of 10.85 cc-bar/FPE, which is comparable to what I had with the factory valve (11 cc-bar/FPE). The slope of pressure-drop (closed-black and open-red circle in picture 3) is almost identical for both factory and metal valve with this setting.

Thought of sharing this with those who plan to use metal valve. You might not have the same issue as I had since the character and setting are different in each gun.

Picture 1: Ernest Metal Valve