Different brands of springs

airsoftjunky · May 19th, 2013, 19:51

I put an SHS M120 spring into my BW15, which yielded me about 375 fps. Then I put a Lonex M130 in, which only brought the speed up to about 380 fps. I should mention that my air seal is perfect, I did the flashlight test and everything, I have a Lonex cylinder head, piston head, and one of those heavy duty red Lonex pistons installed. Does the SHS M120 and Lonex M130 typically yield the same fps? My expectations were that the M130 should yield 400 fps or more but I'm thinking that the heavy piston might be dropping the fps somewhat. Are different brands different strengths? What are your recommendations to achieve 425 fps?

ThunderCactus · May 19th, 2013, 20:37

When it comes to springs, the number is just a label, not an actual indication of FPS.

audi_bhoy · May 20th, 2013, 00:01

Some springs numbers are related to M/S, while others are a % of 1 joule (330fps), so a M120 from 2 different companies may yield very different fps.

I'm also curious about the flashlight test for the compression ??! I usually block the nozzle end and try to push the cylinder in it, if it stops right away then the compression is good, if it does move forward a little it does have a small leak. Even saw some that the piston was moving freely in it !!

ThunderCactus · May 20th, 2013, 00:58

flashlight test is for air nozzle to hop rubber only. It doesn't test hop rubber to barrel or mechbox compression

audi_bhoy · May 20th, 2013, 01:01

Yeah I was thinking only into the mechbox, tought of the barrel after posting actually

I mostly rely on chrony to see if there is any leaks when I know that the gearbox is sealed perfectly :P

airsoftjunky · May 20th, 2013, 02:41

I feel confident I should have a good airseal all around. With the new components in the. Mech box I had VERY good compresion. (Unless the cylider head O ring has wore out after 5000 rounds?) I have a new pdi W hold hop up rubber installed wich, when assembling, went together nice and snug.... So should I try a Lonex M140?

airsoftjunky · May 20th, 2013, 02:44

Also, any experience with heavy VS light pistons? Do they drematicaly decrease fps?

cetane · May 20th, 2013, 07:54

A heavier piston assembly can help you get some joule creep but you should not really loose much fps from it. Over volumed cylinders can lower your fps with 0.20's on chrono but if you run heavier bb's it will be higher than expected.

What barrel length & cylinder size do you have? Did you adjust hopup settings between chrono of the 2 different springs?

airsoftjunky · May 20th, 2013, 14:40

I'm really not sure what size cylider I have. Its just whatever came stock. And my barrel is a 509 mm madbull tightbore.

Styrak · May 20th, 2013, 15:50

It would be a full cylinder because it's a M16 length gun. Heavy vs light piston will only affect rate of fire, if at all.

pestobanana · May 21st, 2013, 16:41

Piston weight has no noticeable effect on FPS. 375fps on any brand of M120 seems extremely low. I was getting 360fps at one point with a mad bull M120 when I had a leaky setup. After I did a million mods and made sure there was actually a perfect air seal, I got a consistent 455 FPS. Sounds to me like you don't actually have a perfect air seal.

Con Murder · May 21st, 2013, 17:23

Those are my thoughts as well, pesto. You could test with a spring you know has been chrono'd at a certain speed and go from there. Really though, if I were you I would open and recheck all of my air seal points and not wait to verify if the chrono'd spring matches up.

airsoftjunky · May 21st, 2013, 18:43

Yea, I'll do that. Back into the mech box I go. On a positive note, I'm getting really fast at this!

I DID notice, however, that the M130 didn't feel any harder really to install than the M120. Perhaps this is normal though.....?

pestobanana · May 21st, 2013, 18:55

Quote:

Originally Posted by airsoftjunky

Yea, I'll do that. Back into the mech box I go. On a positive note, I'm getting really fast at this!

I DID notice, however, that the M130 didn't feel any harder really to install than the M120. Perhaps this is normal though.....?

I find that springs don't get that much harder to install as long as the spring guide has a hole for you to stick a screwdriver in the back. When they don't, even a M100 feels impossible to install.

I think the best way to increase FPS is to improve air seal. That way you can maintain your rate of fire, and you don't increase stress on the gearbox parts. Your goal of 425 FPS is easily achievable on a M120 as long as you have an above average air seal, it can even be accomplished on a M110 if you know what you're doing. The reason I think you're gun is not sealing properly, is because I'm getting 370 FPS on a Modify S100 spring, using a gun that I know IS sealing properly.

airsoftjunky · May 21st, 2013, 21:47

Well, as usually happens, the problem ended up being something completely other than what I originally expected. Turns out you were all right though, I had a very bad air seal. So after getting some advice from the wonderful guys at Airsoft Store Canada, I tried blowing down the muzzle of the barrel while plugging off the ports on the hop up unit. Not to my surprise, I could blow air through. So as per my newly received advice I wrapped a few wraps of Teflon tape around the hop up rubber and reassembled it. To my delight I now have 423 fps. I'm sure this can be improved on yet, and I still haven't done any accuracy tests, but at least I know without a doubt what the real problem was.

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May 19th, 2013, 19:51	#1
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	Different brands of springs I put an SHS M120 spring into my BW15, which yielded me about 375 fps. Then I put a Lonex M130 in, which only brought the speed up to about 380 fps. I should mention that my air seal is perfect, I did the flashlight test and everything, I have a Lonex cylinder head, piston head, and one of those heavy duty red Lonex pistons installed. Does the SHS M120 and Lonex M130 typically yield the same fps? My expectations were that the M130 should yield 400 fps or more but I'm thinking that the heavy piston might be dropping the fps somewhat. Are different brands different strengths? What are your recommendations to achieve 425 fps?

May 20th, 2013, 15:50	#10
Styrak Trader rating Join Date: Jan 2007 Location: Saskatoon, SK	It would be a full cylinder because it's a M16 length gun. Heavy vs light piston will only affect rate of fire, if at all. __________________ Airsoft Sales and Repair/Upgrade Services

May 21st, 2013, 17:23	#12
Con Murder Trader rating Join Date: May 2009 Location: Lethbridge Alberta Canada	Those are my thoughts as well, pesto. You could test with a spring you know has been chrono'd at a certain speed and go from there. Really though, if I were you I would open and recheck all of my air seal points and not wait to verify if the chrono'd spring matches up. __________________ Con Murder Dark Rhino L.A. Airsoft

May 19th, 2013, 20:37	#2
ThunderCactus Not Eye Safe, Pretty Boy Maximus on the field take his picture! Trader rating Join Date: Feb 2007	When it comes to springs, the number is just a label, not an actual indication of FPS.

May 20th, 2013, 00:01	#3
audi_bhoy Trader rating Join Date: Mar 2009 Location: Trois-Rivières	Some springs numbers are related to M/S, while others are a % of 1 joule (330fps), so a M120 from 2 different companies may yield very different fps. I'm also curious about the flashlight test for the compression ??! I usually block the nozzle end and try to push the cylinder in it, if it stops right away then the compression is good, if it does move forward a little it does have a small leak. Even saw some that the piston was moving freely in it !!

May 20th, 2013, 00:58	#4
ThunderCactus Not Eye Safe, Pretty Boy Maximus on the field take his picture! Trader rating Join Date: Feb 2007	flashlight test is for air nozzle to hop rubber only. It doesn't test hop rubber to barrel or mechbox compression

May 20th, 2013, 01:01	#5
audi_bhoy Trader rating Join Date: Mar 2009 Location: Trois-Rivières	Yeah I was thinking only into the mechbox, tought of the barrel after posting actually I mostly rely on chrony to see if there is any leaks when I know that the gearbox is sealed perfectly :P

May 20th, 2013, 02:41	#6
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	I feel confident I should have a good airseal all around. With the new components in the. Mech box I had VERY good compresion. (Unless the cylider head O ring has wore out after 5000 rounds?) I have a new pdi W hold hop up rubber installed wich, when assembling, went together nice and snug.... So should I try a Lonex M140?

May 20th, 2013, 02:44	#7
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	Also, any experience with heavy VS light pistons? Do they drematicaly decrease fps?

May 20th, 2013, 07:54	#8
cetane Trader rating Join Date: Jun 2010 Location: Markham & Stouffville - Ontario - Canada	A heavier piston assembly can help you get some joule creep but you should not really loose much fps from it. Over volumed cylinders can lower your fps with 0.20's on chrono but if you run heavier bb's it will be higher than expected. What barrel length & cylinder size do you have? Did you adjust hopup settings between chrono of the 2 different springs?

May 20th, 2013, 14:40	#9
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	I'm really not sure what size cylider I have. Its just whatever came stock. And my barrel is a 509 mm madbull tightbore.

May 21st, 2013, 16:41	#11
pestobanana Squid Porn Superstar, I love the tentacles! Trader rating Join Date: Nov 2008 Location: Richmond Hill and Waterloo, Ontario	Piston weight has no noticeable effect on FPS. 375fps on any brand of M120 seems extremely low. I was getting 360fps at one point with a mad bull M120 when I had a leaky setup. After I did a million mods and made sure there was actually a perfect air seal, I got a consistent 455 FPS. Sounds to me like you don't actually have a perfect air seal.

May 21st, 2013, 18:43	#13
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	Yea, I'll do that. Back into the mech box I go. On a positive note, I'm getting really fast at this! I DID notice, however, that the M130 didn't feel any harder really to install than the M120. Perhaps this is normal though.....?

May 21st, 2013, 21:47	#15
airsoftjunky a.k.a. evaboe Trader rating Join Date: Aug 2008 Location: saskatchewan	Well, as usually happens, the problem ended up being something completely other than what I originally expected. Turns out you were all right though, I had a very bad air seal. So after getting some advice from the wonderful guys at Airsoft Store Canada, I tried blowing down the muzzle of the barrel while plugging off the ports on the hop up unit. Not to my surprise, I could blow air through. So as per my newly received advice I wrapped a few wraps of Teflon tape around the hop up rubber and reassembled it. To my delight I now have 423 fps. I'm sure this can be improved on yet, and I still haven't done any accuracy tests, but at least I know without a doubt what the real problem was.

Different brands of springs

Upgrades & Modifications