Sumatra 2500R in .20 Caliber has arrived

Thanks Sluggo I’ll have to try it out! Sounds simple enough 😉 😆

Jim.

Hey Sluggo, can you take that shroud/bracket thing off while the gun is charged? I have been pondering some ideas for the guns but havn’t figured out how to get that part off? I took the “nut” things off that seem to hold it on maybe I just need to use some more force????

I NEED to shoot that .25 tonight and see how it does at low power of maybe 500 fps? that would be devistating on the Starlings and Crows at 10-15 yards 😈 I bet they will literally flip when hit with a MCM!

Jim.

Hey Sluggo! I JUST read your post…I didn’t realize it was your gun I got! cool!!!! I haven’t shot it yet 😕 been working on the house/shop/.177 Field Target project. I did pull it out today and showed the wife what it looks like 😆 she said “looks nice, what do you need all those guns for?”.

How is it working for you? have you gotten to shoot it much?

Man I just looked over those numbers this .20 gun shot again and wholly crap that sucker is consistant!!! not sure where this .177 project is going to end up but I might have to get another one of these in .20!

Jim.

I swapped this gun out for a full length .25 Career II with a guy on the Yellow Forum…looking forward to testing out the .25 thumper!!!

He did some shooting with the Eun Jins already and said he was getting fantastic accuracy from the .20 so the accuracy stuff was all on my end 😆 looks like I need to do some more target practice!

Jim.

Hey Cygnus, 24″ barrel…cranked up 900fps’ish it is “booming” a bit 😆 compared to 700’ish fps…I shot some water tonight and it was louder than the gun when the pellet hit it! HUGE “POP” when it hit the puddles 25 yards away. I’m excited to see how it does at 12’ish FPE (Med -1 click?) as so far it has NO curve and fired full power right from shot #1….

LOVING this gun!!!! been a lot of fun to shoot/mess with so far. I am VERY anxious to get inside this thing and smooth out the trigger and see how the power wheel works??? I would like it to be a little less of a jump but it is definitely useful as is…

Would REALLY like a LDC on this sucker!!! it’s loud but not enough to ring my ears and I’m WAYYYYYYY spoiled from the .22 SS fully baffled gun I also brought with me…trigger is f’ing up so I’m not shooting it right now…never taken it apart and it will fire itself 3 out of 4 times if you are not REALLY, REALLY gentle pulling the slide back 👿

Got some quick shooting in tonight…from 4:30-5:30(pretty dark) upped the power to try and keep it around 850-900 fps with the 14.3 Grain Crosman Premiers. When it hit 850’sh I turned the power wheel a notch…I should have turned it up around shot 30 but it didn’t occur to me until shot 42 😆

Going to do some more testing with the power wheel and also shoot for some groups…850-900 the Premiers should be shooting about their best but we’ll see how they do in this gun????

3 point sling has been a serious pain in the ass so far…it has actually been useless on this gun as of yet…I need to sit and play with it and try to make it work…might have to put in a sling swivel? when I let it hang the belt slips some and the muzzle heads towards the ground…when I pull it up for a shot it gets hung/wadded up at my shoulder and makes aiming nearly impossible. I need to mess with it some more and also try it as a conventional sling and see how that works????

Starting PSI 3,045(210 BAR) ending PSI 1,435 (99 BAR)

# FPS FPE Wt. Power setting
1 663 14.0 14.3 Med/Blue dot
2 663 14.0 14.3 Med/Blue dot
3 1075 36.7 14.3 High/Red dot
4 1003 31.9 14.3 High/ -1 click
5 892 25.3 14.3 High/ -2 clicks
6 894 25.4 14.3 High/ -2 clicks
7 892 25.3 14.3 High/ -2 clicks
8 892 25.3 14.3 High/ -2 clicks
9 890 25.1 14.3 High/ -2 clicks
10 892 25.3 14.3 High/ -2 clicks
11 897 25.5 14.3 High/ -2 clicks
12 886 24.9 14.3 High/ -2 clicks
13 881 24.6 14.3 High/ -2 clicks
14 885 24.9 14.3 High/ -2 clicks
15 882 24.7 14.3 High/ -2 clicks
16 882 24.7 14.3 High/ -2 clicks
17 874 24.3 14.3 High/ -2 clicks
18 874 24.3 14.3 High/ -2 clicks
19 872 24.1 14.3 High/ -2 clicks
20 874 24.3 14.3 High/ -2 clicks
21 874 24.3 14.3 High/ -2 clicks
22 865 23.8 14.3 High/ -2 clicks
23 862 23.6 14.3 High/ -2 clicks
24 862 23.6 14.3 High/ -2 clicks
25 870 24.0 14.3 High/ -2 clicks
26 855 23.2 14.3 High/ -2 clicks
27 855 23.2 14.3 High/ -2 clicks
28 853 23.1 14.3 High/ -2 clicks
29 849 22.9 14.3 High/ -2 clicks
30 851 23.0 14.3 High/ -2 clicks
31 842 22.5 14.3 High/ -2 clicks
32 841 22.5 14.3 High/ -2 clicks
33 841 22.5 14.3 High/ -2 clicks
34 844 22.6 14.3 High/ -2 clicks
35 839 22.3 14.3 High/ -2 clicks
36 838 22.3 14.3 High/ -2 clicks
37 827 21.7 14.3 High/ -2 clicks
38 828 21.8 14.3 High/ -2 clicks
39 831 21.9 14.3 High/ -2 clicks
40 833 22.0 14.3 High/ -2 clicks
41 824 21.6 14.3 High/ -2 clicks
42 820 21.3 14.3 High/ -2 clicks
43 903 25.9 14.3 High/ -1 clicks
44 902 25.8 14.3 High/ -1 clicks
45 900 25.7 14.3 High/ -1 clicks
46 906 26.1 14.3 High/ -1 clicks
47 911 26.3 14.3 High/ -1 clicks
48 894 25.4 14.3 High/ -1 clicks
49 888 25.0 14.3 High/ -1 clicks
50 884 24.8 14.3 High/ -1 clicks
51 880 24.6 14.3 High/ -1 clicks
52 879 24.5 14.3 High/ -1 clicks
53 874 24.3 14.3 High/ -1 clicks
54 875 24.3 14.3 High/ -1 clicks
55 870 24.0 14.3 High/ -1 clicks
56 867 23.9 14.3 High/ -1 clicks
57 871 24.1 14.3 High/ -1 clicks
58 873 24.2 14.3 High/ -1 clicks
59 865 23.8 14.3 High/ -1 clicks
60 861 23.5 14.3 High/ -1 clicks
61 857 23.3 14.3 High/ -1 clicks
62 915 26.6 14.3 High/Red dot
63 926 27.2 14.3 High/Red dot
64 928 27.3 14.3 High/Red dot
65 919 26.8 14.3 High/Red dot
66 917 26.7 14.3 High/Red dot
67 918 26.8 14.3 High/Red dot
68 916 26.6 14.3 High/Red dot
69 919 26.8 14.3 High/Red dot
70 915 26.6 14.3 High/Red dot
71 914 26.5 14.3 High/Red dot
72 915 26.6 14.3 High/Red dot
73 913 26.5 14.3 High/Red dot
74 908 26.2 14.3 High/Red dot
75 908 26.2 14.3 High/Red dot
76 905 26.0 14.3 High/Red dot
77 907 26.1 14.3 High/Red dot
78 904 25.9 14.3 High/Red dot
79 904 25.9 14.3 High/Red dot
80 898 25.6 14.3 High/Red dot
81 898 25.6 14.3 High/Red dot
82 890 25.1 14.3 High/Red dot
83 890 25.1 14.3 High/Red dot
84 886 24.9 14.3 High/Red dot
85 882 24.7 14.3 High/Red dot
86 887 25.0 14.3 High/Red dot
87 877 24.4 14.3 High/Red dot
88 872 24.1 14.3 High/Red dot
89 869 24.0 14.3 High/Red dot
90 870 24.0 14.3 High/Red dot
91 864 23.7 14.3 High/Red dot
92 857 23.3 14.3 High/Red dot
93 893 25.3 14.3 High/ +1 clicks
94 894 25.4 14.3 High/ +1 clicks
95 884 24.8 14.3 High/ +1 clicks
96 882 24.7 14.3 High/ +1 clicks
97 875 24.3 14.3 High/ +1 clicks
98 869 24.0 14.3 High/ +1 clicks
99 861 23.5 14.3 High/ +1 clicks
100 868 23.9 14.3 High/ +1 clicks
101 858 23.4 14.3 High/ +1 clicks
102 857 23.3 14.3 High/ +1 clicks

SUM 2503.3 FPE

NOTES: 26 NOV 2007 New stock Sumatra 2500
14.3 grain Crosman Premiers

My left shoulder was frigging BURNING at about shot 50 as I was actually shouldering and shooting at a plastic bottle to make these sessions a little more fun…I was shooting about as fast as is possible reset, cock, write, shoulder, aim, fire, reset, cock, write, shoulder, aim, fire…..102 times 😮 in 60 minutes plus about 10 minutes of walking around/taking a wizz 😆

So far so fun! Jim.

Brought the Combro cb-625 Chrony back with me from the trip home and with a little rigging got my first shot string in… normally this rubber bands to a normal barrel but the Sumatra only has a nub 😆 so I had to rig up a piece of 1/2 inch copper pipe with a slit cut in it it is a tight press fit on the thread protector. Worked perfectly so far and didn’t try to come loose at all.

#1 I was on crack with the FPS in the previous posts… the “crack” I heard must have been the big jump in air/muzzle blast from Med to Med +1 click(about 120’ish fps jump) but still way below supersonic.

#2 I noticed something odd that the first shot after reloading the clip was almost always a few fps lower then the last or following shots…spring getting a little fatigue from being cocked for 60-70 seconds before I shot again? subsequent shots were made in approx 5 second delays for me to write down the #, reset the chrony and cock the gun

#3 none of these shots were aimed as it started raining and I shot all these from inside my truck out the window.

# FPS FPE Pellet Wt. Power setting
1 683 14.8 14.3 Med/Blue dot
2 685 14.9 14.3 Med/Blue dot
3 690 15.1 14.3 Med/Blue dot
4 690 15.1 14.3 Med/Blue dot
5 695 15.3 14.3 Med/Blue dot
6 683 14.8 14.3 Med/Blue dot
7 685 14.9 14.3 Med/Blue dot
8 689 15.1 14.3 Med/Blue dot
9 691 15.2 14.3 Med/Blue dot
10 690 15.1 14.3 Med/Blue dot
11 687 15.0 14.3 Med/Blue dot
12 692 15.2 14.3 Med/Blue dot
13 687 15.0 14.3 Med/Blue dot
14 678 14.6 14.3 Med/Blue dot
15 690 15.1 14.3 Med/Blue dot
16 688 15.0 14.3 Med/Blue dot
17 691 15.2 14.3 Med/Blue dot
18 690 15.1 14.3 Med/Blue dot
19 679 14.6 14.3 Med/Blue dot
20 687 15.0 14.3 Med/Blue dot
21 689 15.1 14.3 Med/Blue dot
22 685 14.9 14.3 Med/Blue dot
23 694 15.3 14.3 Med/Blue dot
24 686 14.9 14.3 Med/Blue dot
25 678 14.6 14.3 Med/Blue dot
26 690 15.1 14.3 Med/Blue dot
27 683 14.8 14.3 Med/Blue dot
28 688 15.0 14.3 Med/Blue dot
29 691 15.2 14.3 Med/Blue dot
30 688 15.0 14.3 Med/Blue dot
31 677 14.6 14.3 Med/Blue dot
32 678 14.6 14.3 Med/Blue dot
33 680 14.7 14.3 Med/Blue dot
34 687 15.0 14.3 Med/Blue dot
35 685 14.9 14.3 Med/Blue dot
36 687 15.0 14.3 Med/Blue dot
37 675 14.5 14.3 Med/Blue dot
38 684 14.9 14.3 Med/Blue dot
39 684 14.9 14.3 Med/Blue dot
40 684 14.9 14.3 Med/Blue dot
41 684 14.9 14.3 Med/Blue dot
42 684 14.9 14.3 Med/Blue dot
43 678 14.6 14.3 Med/Blue dot
44 677 14.6 14.3 Med/Blue dot
45 681 14.7 14.3 Med/Blue dot
46 681 14.7 14.3 Med/Blue dot
47 681 14.7 14.3 Med/Blue dot
48 677 14.6 14.3 Med/Blue dot
49 667 14.1 14.3 Med/Blue dot
50 680 14.7 14.3 Med/Blue dot
51 682 14.8 14.3 Med/Blue dot
52 680 14.7 14.3 Med/Blue dot
53 679 14.6 14.3 Med/Blue dot
54 684 14.9 14.3 Med/Blue dot
55 671 14.3 14.3 Med/Blue dot
56 675 14.5 14.3 Med/Blue dot
57 674 14.4 14.3 Med/Blue dot
58 675 14.5 14.3 Med/Blue dot
59 678 14.6 14.3 Med/Blue dot
60 673 14.4 14.3 Med/Blue dot
61 666 14.1 14.3 Med/Blue dot
62 679 14.6 14.3 Med/Blue dot
63 675 14.5 14.3 Med/Blue dot
64 673 14.4 14.3 Med/Blue dot
65 669 14.2 14.3 Med/Blue dot
66 677 14.6 14.3 Med/Blue dot
67 662 13.9 14.3 Med/Blue dot
68 663 14.0 14.3 Med/Blue dot
69 666 14.1 14.3 Med/Blue dot
70 672 14.3 14.3 Med/Blue dot
71 669 14.2 14.3 Med/Blue dot
72 666 14.1 14.3 Med/Blue dot
73 661 13.9 14.3 Med/Blue dot
74 651 13.5 14.3 Med/Blue dot
75 667 14.1 14.3 Med/Blue dot
76 666 14.1 14.3 Med/Blue dot
77 666 14.1 14.3 Med/Blue dot
78 671 14.3 14.3 Med/Blue dot
79 653 13.5 14.3 Med/Blue dot
80 661 13.9 14.3 Med/Blue dot
81 666 14.1 14.3 Med/Blue dot
82 663 14.0 14.3 Med/Blue dot
83 662 13.9 14.3 Med/Blue dot
84 661 13.9 14.3 Med/Blue dot
85 654 13.6 14.3 Med/Blue dot
86 652 13.5 14.3 Med/Blue dot
87 656 13.7 14.3 Med/Blue dot
88 658 13.7 14.3 Med/Blue dot
89 654 13.6 14.3 Med/Blue dot
90 661 13.9 14.3 Med/Blue dot
91 649 13.4 14.3 Med/Blue dot
92 655 13.6 14.3 Med/Blue dot
93 651 13.5 14.3 Med/Blue dot
94 658 13.7 14.3 Med/Blue dot
95 660 13.8 14.3 Med/Blue dot
96 655 13.6 14.3 Med/Blue dot
97 644 13.2 14.3 Med/Blue dot
98 642 13.1 14.3 Med/Blue dot
99 647 13.3 14.3 Med/Blue dot
100 651 13.5 14.3 Med/Blue dot
101 648 13.3 14.3 Med/Blue dot
102 650 13.4 14.3 Med/Blue dot
103 637 12.9 14.3 Med/Blue dot
104 753 18.0 14.3 Med + 1 click
105 826 21.7 14.3 Med + 2 click
106 878 24.5 14.3 High/Red dot
107 927 27.3 14.3 High + 1 click
108 963 29.4 14.3 High + 2 click
109 921 26.9 14.3 High +1 click
110 908 26.2 14.3 High +1 click
111 901 25.8 14.3 High +1 click
112 900 25.7 14.3 High +1 click
113 902 25.8 14.3 High +1 click
114 884 24.8 14.3 High +1 click

SUM 1760.2 fpe/114 shots

NOTES: 25 NOV 2007 New stock Sumatra 2500
14.3 grain Crosman Premiers

Starting PSI 2,900 ending PSI 1,624

I also put a UTG 3 point sling on it today I got off EBAY for $15/shipped… need some fiddling as it wasn’t designed to fit a gun with these dimensions.

Oh yea pics are taken with my “AT&T Tilt” phone…I think they look pretty good for a cell phone.

Jim.

Got some great target shooting in today and I’m kicking myself in the nads for not bringing my Chrony with me…

Cleaned the barrel last night with the fishing line and paper towels.This morning I got a .177 cleaning kit and some crazy barrel cleaning stuff called “Remington 40-X Bore Cleaner” using a .177 swab and a patch cut long wise. With the patch on the swab it worked great. Man that stuff pulled a good 20 pure black patches out! I cocked the gun and fired it so the pellet probe thing kept the cleaning stuff from getting into the air hole or o-ring as well as kept the rifle upside down. I ran some cleaner back and forth in the bore then ran 5-10 dry patches through it then some more solution…after about an hour I finally got clean patches out and started doing some target shooting…

30 yards groups were going 1-3″ with the average going just over 1.25″ for 6 shots.

50 yard groups around 2.5-4.5″ with the average around 3.5″ for 6 shots.

Thoughts on improving accuracy: A bench with sandbags would help (I’m using a foldup chair and Camera tripod), the trigger for sure pulled a few shots and I had to use a damned kung-fu grip on the gun to keep it from moving/jerking as I pulled the trigger. It still jerked badly on a few of them.

Should be some pretty close? FPS estimates using trajectory and Chairgun…
3,000 psi fill Crossman Premiers look to be going 1,000 fps at mid power/6 clicks(blue dot)…zeroe’d at 30 yards I was shooting roughly 1/2 inch low at 50 yards and about 3 feet low at 100 yards. 7 clicks made a definite “crack” and shot 2.5″ higher than 6 clicks at 30 yards and grouped 2.5″ for 6 shots…that was after 42 shots.

After 150 shots velocity was down from approx 1,000 fps to approx 600 fps and pressure was down to 1,700 PSI from 3,000. 36 of those shots were 4 or 5 clicks, 6 shots at 7 clicks the rest were Med(6 clicks)…4 and 5 clicks seemed like it might be inconsistant but without my cheony I don’t have any good idea how FPS is really averaging.

I’m going to re-zero at 20 yards and according to chairgun should give me a much better trajectory/point blank setup.

I’m really kicking myself for not bringing the Chrony…wife is going to mail it out tomorrow!!! WOOT!

Jim.