inconsistent combro readings..?

[Skot Ruthless Teale 1,701]

hey guys been shooting this morning and in short i got a squirrel right next to the eye at close range 20ish yds, and shot a white pigeon whilst talking to farmer at 40 yards resting on his forklift thingy! i offered to get it down but he said dont worry about it lol.

 

anywway as the topic says these are the readings i got from the combro over 35 shots with 4.52 ..unwashed unlubed straight out of the tin.. jsb exact

 

and heres the best 15 shot (quick) grouping aiming for the drawing pin at 35yds. (i did shoot a better group ((covered by the £1 coin)) after when i wasnt rushing hoping the combro didnt turn itself off)

 

a few things i will say is_

- the barrel hasnt been cleaned since i got it

- the pellets were straight out of the tin

-the rifle has so far had about 1600 pellets fired since brand new

- i had been using rws superdome pellets up until using the 35 jsb's for this 'test' so the barrel will be ''leaded'' with different lead (dont know if this will make any difference.

 

- i tried to make sure the combro was in the same place every shot, the recoil was sliding it slightly forwards by about2-3mm as seen here in the before and after pics lol

 

so .. if it wasnt for the 9 shots out of 35 that were lower than 11ft lbs i would have been very happy with a spread of 9 FPS / 0.27 FT LB

overall spread was 1.47 ftlb 53 fps.

 

so my question .. WHY one min is it 9.8 ftlb n then next min it can be 11.1 ftlb ??? surely it shouldnt be this inconsistent ? i know its still bedding in but cum on!!

 

any ideas lads?

[Phantom 631]

Easy, It's a springer, and until it's piston has been bedded in properly it will be inconsistant.

You mention it's from new, have you cleaned degreased and relubed the action? thats a starting point. Then have it tuned to perfection and your consistancy will be much better on the numbers

 

Don't get too hung up on the numbers though, as a lot of people do!

You know full well that the gun is accurate and the amount of kills you get proves your a competent shooter as well.

Put in the data into CGP and you will see that there wont be to much of a variation on POI.

 

Tony

[Skot Ruthless Teale 1,701]

see this is what i meant about not trusting my chrono tony.. lol 2 ftlb variation is a lot. what if it was 11 11 11 11 13 instead of 11 11 11 9 9 11 11 10 11 11 11 you get what i mean i dont want it going over limit either. havent ever been inside a gun lol dont think i would want to. was thinking aabout getting tune but not sure it needs one, maybe just open it an clean and polish it, but i dont know first thing about gun internals like i said. as for getting hung up on numbers im not, just want it to be 11 everytime not sumtimes 6 10 12 13 if you get me.

 

and im proper rubbish at chairgun LOL, need to figure out my 'scope height' lol is it from centre of scope tube to centre of barrel??

[Phantom 631]

Yes, centre to centre

 

I trust the Combro to keep mine on the straight and narrow. If your pellet output is consistant then the combro will show that

If it's all over the place its purely because your gun is putting out different energy.

 

The combro takes a precise measurement of speed of the pellet between point A and point B and it's processor does the math then displays it on the screen. It doesn't just take a wild guess

If you want piece of mind, take it to a smiths and get them to chrono a 10 or 20 shot string and list the speed and ft/lbs.

 

Tony

[Skot Ruthless Teale 1,701]

ok u made me trust my combro

 

stil cant believe my gun is so inconsistent most of time its 11.1 then all of a sudden bang 9.8 great stuff....

 

id actually rather it be 9 ft lbs and consistent. so you recon if i clean it out and when its fully bedded in it shouldd be a lot more consistent then? how many shots is it meant to take roughly , because some people say 500 some 1000 some 2000.. thought id fire 2500 to be sure but its taking forever LOL

[Phantom 631]

There is a lot of things that will effect the numbers bud

Try a heavier pellet such as a Bisley Magnum and compare that with say a RWS Hobby (just to really demonstrate the variation).

 

Some guns will bed in quicker than others, I was (as a youngster) told it could be as many as 5,000 :gulp:

If you've got the brass to invest, then Sandwell Field Sports seem to be the very very best for tuning springers and most of the regs here will only trust them with their springers!

I don't have a clue how much it would cost though.

 

If you feel confidant of entering your gun and breaching the warrenty then a good clean, degrease and relube with the right grease then I would say have a word with maybe Andyfr on here and see what greases he reccomends. He also a smith who may offer a good price for a strip, lube and tweek of your gun.

 

Tony

[Skot Ruthless Teale 1,701]

only thing is posting it off to get it sorted, godknows how far sfs is, is it west brom yeh? how far is that from bradford, cant just borrow a mates car an drive down can i lol..

 

plus how do you 'post' a gun? wrap it in bubblewrap and stick it in a box?!

 

+ thats what i thought, i dont want to void my warranty, its almost brand new! only had it 2 months lol.. knowing me id break it opening it up! haha

[robwelsh 354]

I stripped an underlever and still to this day its in bits lol if your not confident, dont do it..as it may need stripping again an played with cos it might go over..a gunsmith is money well spent as they work on shed loads of guns and have correct tools, grease an most importantly..knowledge an understanding of how a gun has gone over 12ft lbs and how to rectify a problem lol

[Phantom 631]

plus how do you 'post' a gun? wrap it in bubblewrap and stick it in a box?!

 

I generally seperate the stock from the action to make the parcel smaller. But yes; Thats exactly how I post guns when I need to from rifles to pistols

 

Andyfr1968 is not too far from you, drop him a message I'm sure he'll either help you out.

 

Tony