Gunmark air-rifles/ air-pistols

[biking3819]

hi guys,
i was talking about this rifle i bought in Pune from Gsmith who manufacture this gunmark break barrel airrifle when i had introduced myself in the forum,i guess inder had asked me to post the pic,
this is the only rifle i guess close to the national 35,even better with good accuracy and slightly better trigger feel,i cud plink and pass thru very well an empty tin of pepsi and still the gsmith pellets .22 high split was totally flat, and the high speed pointed which is heavier than the high split went quite deep arnd half an inch in a plank of wood behind the pepsi tin kept at 42 mts.since i dont have a chrono i cudnt check the fps but i felt it had good power and quite silent compared to the national.The bluing too is not damaged yet after an year.
the manufacturer claims the barrel was very accurate and the only part imported and so the high price for this one at 10k.
and specially the gurus,
please let me know if theres anyone who could guide me to tune this rifle with a crisp trigger and a piston spring with a nylon washer,since the leather one now needs to be frequently oiled for consistent power delivery...
what wud be the measurements available for a imported spring or any other kit...
thanx again,if only there was a better trigger this rifle wud be awesome.



nb-the stock was finished by myself and i had replaced the leather breech seal with a nylon o ring.
regards sanjiv
nb-still no where close to the imported ones but overall a good indian made airrifle.

[biking3819]

one more related question to the airrifle,
is there any possibility that a .22 rimfire rifle's barrel cud be used as the barrel in a .22 airrifle,
other than the difference in the alloys or steel composition wud there be any difference .just to say if it wud improve accuracy and so the question.
does walther lothar barrels of the same type used in .22 rimfire as well as some other imported airrifles??
regards sanjiv

[Rudra]

How much did u pay for it

Regards

Rudra

[biking3819]

hi rudra,...i mentioned the price already in the first post...its 10k.
Regards
sanjiv

[Rudra]

oops sorry
I think i am getting old

[biking3819]

ok...the gun shoots at 900-950fps...with gsmith high split pellets.
had called up gsmith to find out chrono results for the same.
regards sanjiv

[Mack The Knife]

ok...the gun shoots at 900-950fps...with gsmith high split pellets.

Sanjiv,

Are you sure that's the M.V. for the .22" calibre version?

I haven't seen these High Split pellets but from what I have, G.Smith pellets are on the heavier side.

If we assume a pellet weight of 16 grains and a M.V. of 900 ft./sec. we are looking at a M.E. of 28.78 ft.lbs.!

I would certainly like to chrono this rifle for myself.

Mack The Knife

[Yaj]

ok...the gun shoots at 900-950fps...with gsmith high split pellets.
had called up gsmith to find out chrono results for the same.
regards sanjiv

If those figures are correct and the rifle groups well, its a magnum powered rifle at a bargain price! Almost 30 ft. lbs! Thats as much as my Patriot is supposed to be putting out.
Regards,
Yaj.

[biking3819]

Mack The Knife the high split are the hollow point pellets and lighter than the heavier high speed and much lighter than the high impact.
but the fps that they are quoting ie gsmith needs to be verified and i am trying to arrange a chrono,as of now i cudnt arrange for one and so i called them up yesterday and got that 900-950 fps ratings which seems a lil exaggerated after yaj's comments. ,
....
i wud measure all the three pellets with a jeweller and put the wts in figs.
do u have a chrono? i may be coming next month to bangalore ,i can get the rifle,do the find and also meet u in person.

@yaj

its impossible to compare this thing to the patriot,these figs are claimed by the manufacturer,under their conditions,its only after the chrono is done by Mack The Knife with diff pellets ,wud find the truth,and yes the manufacturer do claim that its a magnum airrifle,
i cud feel it has power but 'cuz of the leather washer its not consistant,say after 50 continuos shots the pellets start falling closer,u oil it again and once the leather swells it gains its power, and i always stressed the trigger is typical indian single catch heavy wt.
regards sanjiv

[Mack The Knife]

Sanjiv,

I have a chrono. Call me just before you leave. If I am in Bangalore, we can chrono the rifle.

Get those pellets weighed and let me know the results.

Mack The Knife

[biking3819]

hi Mack The Knife,
here they are,i collected all of the patterns of pellets Gsmith produce as well as went to the local jeweller and measured each of them,the data you wanted are in grams..
from left to right in .22-
high split-1.260gm (19.44 grains)
high speed-1.390gm (21.45 grains)
high force-1.200gm (18.52 grains)
high impact-1.230gm (18.98 grains)
.177-
P10-0.530miligram (8.179 grains)
tieup-unavailable


the high speed was the heaviest and the high force was the lightest and all were at an average wt out of 3 pellets randomly selected from a box of 100,and the difference between them were +-0.5mgs.
So it seems its way beyond 16 grains u assumed,they are mostly in the range of 19-21 grains for the .22s,now
lets get the rifle thru the test.

regards sanjiv

[Mack The Knife]

Hi Sanjiv and thanks for taking the trouble to weigh the pellets.

If G.Smith even claim a M.V. of 900 ft./sec. (forget 950 ft./sec.) with even their lightest .22" calibre pellet (High Force at 18.52 grains), then they are effectively claiming a M.E. of 33.32 ft.lbs.

In effect, they are either mistaken, bull-shitting, quoting .177" calibre muzzle velocities or the ruddy rifle is dieselling to kingdom come.

I have had another look at the picture of the rifle and it simply wont support the sort of swept volume that would be required to achieve such figures.

I ask again, are you sure the quoted velocity figures were for .22" calibre?

Mack The Knife

[biking3819]

they said that even yesterday,i had called them,after weighing the pellets i came to know what was the truth,..
the possibility seems not possible anymore for the gunmark since i had seen the diana 350 magnum and the size of the cylinder was atleast 2 inches bigger than the one gunmark makes still the diana claimed a lower 900fps with .22,and .177 was truly magnum.

when people say u r the mother of airgun,how true it is, when u say the gun wud diesel heavily ,it does for the initial shots around20---and that time its power was very high,atleast wrt to penetration in a plank of wood.how wud you know that it dieseled ??...
anywaz we need to find the truth and take the chrono reads ,wud love to talk with Gsmith once i do that.

regards sanjiv

[Pran]

u say the gun wud diesel heavily ,it does for the initial shots around20---and that time its power was very high,atleast wrt to penetration in a plank

The dieseling effect lasts for well over 20 shots.Dieseling can give you inconsistent MVs and you risk snapping your mainspring.

Pran

[Mack The Knife]

how wud you know that it dieseled ??...

All spring-piston airguns diesel a bit. However, when you get the explosive variety (sounds like a centre-fire going off), the power goes up a lot (temporarily) but this is also guaranteed to scorch the piston seal, break your main-spring, create inconsistent MV's and generally make the gun a real dog to shoot.

Now I have a favour to ask. Can the platitudes and the text speak. The first I find ridiculous and the second really winds me up. Thanks.