Which spring is better - Gsmith or CHerokee

[sam 47]

Thanks, polishing , lubricating, placing stainless steel washer in front of the rear guide and placing shims made out of plastic pet bottles placed inside piston solved the problem.
Basuda, not only does stronger mainsprings but I also find too long mainsprings reduce power and increase cocking effort only. Is it normal or what I got was a fluke?

[Basu]

Dear sam47,
Perhaps you meant to put sleeve inside piston.
This sleeve does neutralize the transverse vibration of the spring thus fetches better accuracy.
Too hard and long spring causes piston bounce and so there is drop in peak pressure, resulting in less energy.
My experience says the set length of the spring should be max 28 cms to get optimum energy.
However again that depends on the internal size and space of the gun.
Most Kolkata made guns are inspired by old Diana35 made in Germany.
Diana 35 being a classic of all times , known for its accuracy and not power.

Basu

[sam 47]

yes sir that is what i meant. accuracy is what i am after ,not power. the full length cherooke spring could not keep 10 shots under 3.5 inches at 50 feet.
and it produced about 7-7.5 fpe with aimco round head. the 30 coil spring produces 8 - 8.3 fpe. and a coke bottle cap can be hit at 50 feet with it & the gun is much more pleasant to shoot now

[Basu]

I have similar experience with SDB45.
I destroyed the setting of the AR by deliberate chamber dieseling.
Now having put a new spring , I struggled to get back to earlier power setting.
Finally reduced the length of the spring then got back deadly accuracy as well as 10.3 ft/lbs energy.
Moral of the story- "Never fiddle a set gun"

Basu

[broadway]

Visited a local store and bought an IHP spring. It is a soft spring and bends easily(compared to cherokee or ak stock spring) but it is long - a little more than 360 mm; maybe needs to be set in a nut bolt setup for a few hours?. Wire gauge thickness looks identical to cherokee; maybe slightly slim. IHP has its ends sanded flat and looks well made.

IHP at top. Broken cherokee at bottom

P61013-230527.jpg

Added in 13 minutes 40 seconds:

Was the spring under heavy preloaded? Did you set it before firing?

No it wasn't set. It went straight from the packaging and into the tube. Spring was harder than the stock spring that came with the agni 500. It was well lubed. If you look at the broken ends(the camera doesn't capture the details), it looks brittle.

Was it canted/too loose on the guide?

Snug fit. Maybe a mm gap just enough for it to fall down the guide.

Added in 11 minutes 15 seconds:

BTW , I must tell you that harder spring does not increase power always ,it may go other way as well.

Yes, I found this out.

The power level of cherokee and the stock spring was about the same, maybe a 50fps diff at the most as per my estimate. The cherokee also made the trigger pull unnecessarily heavy. It had become an effort and I mistook it for power.

You can use the longer part of the broken spring after grinding the end properly.

Here is the bizarre part...

The broken cherokee spring gives about the same power performance as it did when it was not broken. The power limitation appears to be at the rifles side - the bottleneck is in the design itself. I think the mod 35 design peaks at ~600 fps range and stronger springs are unlikely to change its performance further.