Help me tune my .22

[jlands]

thx for the plot. doesn't look too hot grafted out, lol. I won't be able to do any accuracy testing 'til next weekend, my yard is only a 178 feet deep. while this gives me about 60 yards, i would have too shoot in a very narrow and unsafe manner from the side of the house. i did do some more tuning since i had nothing else to do.


preload- 5 cw
stroke - 6 cw
meter- 2.5 ccw

psi- 3000
862.9
861.1
862.9
866.1
869.7

psi- 2875
872.9
868.9
877.1
873.0
873.5

psi- 2725
873.9
867.9
871.5
867.8
864.9

psi- 2525
861.5
859.6
858.0
851.8
849.1

psi- 2375

then i stopped because i didn't like how it was going. i think i will change preload to 4 0r 3.5 cw and give it another go. i beleive the a-team guide is spot on, but refilling after every 4-5 shots is a pain with a pump. i really need a regulated scuba..... at least to tune. i think i am going to shoot for the 810-830 range for the barracudas. that should give me good power and a good shot count.

820fps= 31.51 ft/lbs at muzzle and 677fps= 21.50 ft/lbs at 55 yards and still under a 2 inch hold under at max apogee. which is about about 1.5" at 35 yards when zeroed at 55 yards.

btw scott, what do you use to make your plots with.

thx
jared

[ssscottg]

Hi Jared,

I use MS Excel. Send me an PM and I can send the sheet to you.

Scott

[ssscottg]

Hi Guys,

I have this posted on a file share.

http://www.mediafire.com/?mdb2xeqbypaib4v

[jlands]

thx

jared

[jlands]

i can't put the hex wrenches down. it seems like i am always adjusting and chronying (spell check).

any way, with a 3000 psi fill, preload and stroke maxed out and meter 6 turns ccw, i have achieved what i thought was impossible. 976.5 fps with 21.14 gr h&n barracudas . yes, you read right, that's 44.69 ft/lbs . it was loud as hell .

967.2 -43.84 ft/lbs
968.3 -43.94 ft/lbs
976.5 -44.69 ft/lbs
968.2 -43.93 ft/lbs
961.6 -43.33 ft/lbs
944.3 -41.79 ft/lbs
946.9 -42.02 ft/lbs
932.8 -44.69 ft/lbs
933.3 -40.78 ft/lbs
2800ps1
922.9 -39.92 ft/lbs
916.9 -39.40 ft/lbs
910.2 -38.83 ft/lbs

i just wanted to see what the mrod can do. so after the fun, i got back to serious tuning. after tuning, shooting and pumping and tuning, shooting and pumping and on and on. these is where i stand right now.

preload- 4.5 cw
stroke - 1.5 cw
meter - 3.25 ccw
3000 psi fill
21.14 gr barracudas


849.7
867.9
860.0
878.8
873.5
forgot to check pressure after 5 like usual, so i didn,t check til end.
880.4
911.5
920.7
906.7
913.1

916.2
924.8
909.1
910.7
911.8

903.8
902.0
899.6
895.0
893.1

894.1
885.2
884.8
874.6
864.6

866.9
857.5
844.4
839.3
832.1

828.4
819.3
813.0
806.9
798.5

791.2
776.0
768.2
754.5
749.8

end pressure 1400 psi

if i subtract shot # 1 and shoot to shot # 26, that gives me 25 real good hunting shots averinging 896 fps. i plan on turning the meter cw another .25 or .5 to see if i can clip the spikes off a little bit.


jared

[Walx]

What is the accuracy like at that speed?

[jlands]

What is the accuracy like at that speed?

won't get to test over 40 yards til the weekend. but i'll keep you informed.

jared

[Walx]

Thanks keeps us posted. At 750 fps I am getting decent groups.

[jlands]

I've spent hours cruising every airgun forum i have in my bookmarks. I've even looked at older post on this forum. i have not found anything close to the type power in the mrod 22 that i have posted earlier in this post. it even beats out some of the 25 mrods i've seen. if i had not seen the chrony screen with my own eyes, i might not believe it possible. i was debating about buying a more powerful spring, but that is on hold now(at least til this one wears out). what i will get after Christmas is the reservoir extension. then i will crank it back up to the 960's. i haven't test the long range yet and accuracy is important, but if i can hit a squirrel's head at 50 yards(about a 2" circle), i am good. at 860 fps, i was averaging 1.5" at 50 yards with a leapers 8-32x56 and a bi-pod with towel under back of stock, so i would imagine that it will be close to the same at 910 fps, if not better. it's 1:30 am here and all i want to do is go outside and shoot something. well, for now, tuning is officially done. i will be posting more in the hunting thread.

jared

[avv604]

I've spent hours cruising every airgun forum i have in my bookmarks. I've even looked at older post on this forum. i have not found anything close to the type power in the mrod 22 that i have posted earlier in this post. it even beats out some of the 25 mrods i've seen. if i had not seen the chrony screen with my own eyes, i might not believe it possible. i was debating about buying a more powerful spring, but that is on hold now(at least til this one wears out). what i will get after Christmas is the reservoir extension. then i will crank it back up to the 960's. i haven't test the long range yet and accuracy is important, but if i can hit a squirrel's head at 50 yards(about a 2" circle), i am good. at 860 fps, i was averaging 1.5" at 50 yards with a leapers 8-32x56 and a bi-pod with towel under back of stock, so i would imagine that it will be close to the same at 910 fps, if not better. it's 1:30 am here and all i want to do is go outside and shoot something. well, for now, tuning is officially done. i will be posting more in the hunting thread.

jared

Jared,

At group measuring 1.5" at 50 is pretty poor for these guns. If one doubles that for 100 yards, you have a 3" group. Not good at all. You may want to try changing the FPS or pellet. You should be getting close to .5" at 50 yards.