VISUAL differences in PDI 150% springs

[CDN_Stalker]

Ya, I know ther was a thead about this at one point, couldn't find to bring back up again, so I am starting a new one.

Ok, I've tried two different PDI springs in my MP5, both push a .2g BB about 360fps W/O hop up. One teammate had a PDI 150% spring put in his SR-16, it shot about 415fps WITH hop up on! Another, I was the one who installed the PDI 150% spring, it now shoots about 390fps with hop up. People have been wondering WTF is going on with the PDI 150% lately, and while I CAN'T explain, I have found out the way to tell what is a real 150%, and what isn't.

The real PDI 150% spring measures 6 3/8" long. It puts out (as said, 360fps in my MP5 without hop up, and set for .2g, 340fps). I have a TM G36 apart now, ready to put in a PDI 150% spring the owner bought, and check it out, it's longer than the spare one I have. I measured it, it's 7" long. Compare the two, and there is a visual almost 1" difference in length!!!!!

This is the ONLY reason I am posting this, is because I just found out how to ID "HOT" 150% springs (which could put one over the field limits of most fields for an AEG) and how to ID a true PDI 150% spring.

Thought that might help out those that want a reasonably mild upgrade, to roughly 350fps, yet end up with field "illegal" guns.

As far as I know, a stock spring (~280fps) is what PDI might consider to be a 100%, am I correct? And a 150% spring would in theory, add another half on top of that, aka 140fps. So in theory, a PDI 150% spring would add up to roughly 420fps, NOT 350fps. Looking for added info from the experienced in this area. I feel this is a pretty important topic/observation!

yah, good observation.
On a bad day my SR pushes 415fps...from time to time, much higher.
For the longest time I thought it was my piston head or my tightbore that was giving me the huge fps boost.

but, these hot PDI 150% springs are acting like 190% or just under....yet, they dont look like 190% springs.

Perhaps these hot 150% springs are actually pushing their advertised fps.

[CDN_Stalker]

As I said bro, my understanding of the % system leads me to conclude exactly what your SR is putting out. Like, maybe the perceived idea that the PDI 150% sometimes get mislabelled having higher % springs in the bag, well, I think the recurring thing her is the HOT springs are 150%, the not as hot springs are 130%ish. Seriously, I've dealt with enough PDI 170% springs to know they are much easier to compress to get inside the mechbox, and run roughly about 390fps, but these 150% springs............... Christ, I can't sort it out, just know the spring is going into a G-36 now and it's gonna be hot! Hopefully just under 400fps. Will let know what the fps is on this 7" spring when I find out.

[Sgt_Lynch]

Be aware, PDI made what was called a 150 Pro.

You may have stumbled across one or they may have mispackaged a bunch. A few years back we were wondering the same thing when a few of us got them and our guns were hotter than 170% guns.

Read the packaging carefully to see if anything designates the spring as 'Pro'.

[CDN_Stalker]

Oooh, good call! My original PDI 150% said PID 150 Pro on it, yet it shot 340ish. It came in a clear plastic box. Since then, all springs have come in a bag. Have to look & see, but my experience so far has most of the bagged springs being hotter.

Damn PDI!?!?!?!?!

[ILLusion]

How about this as food for thought:

PDI springs are cheaply made, mass produced and have very little to no quality control.

Consistency is non-existent and is the main reason why I refuse to suggest high powered PDI springs to anybody. I can't even begin to give them velocity estimates for their springs before the install because PDI springs are so unpredictable.

There are TONS of better choices out there, but people continue to choose PDI because they are the most well known.


Something else to take in to consideration:
Short 6.08mm inner barrels are very limited in performance. There are instances where a longer tightbore barrel can provide HUGE velocity gains.

For example, I just upgraded an AK Beta that had a stock inner barrel in it. A SystemA M120S was installed in the gun, yet it shot only 355fps w/ 0.20g KSC Perfect BBs.
Disappointed with the result, the owner took my suggestion to install a 407mm 6.03mm inner barrel. The resulting velocity was 392fps. That is almost a 40fps gain (over 10%). When comparing your gun to another gun with similar upgrades, consider the other parts they have in there.

But back to the original post - I don't like PDI springs. Prometheus and SystemA springs are always my top choices. Their performance is also MUCH more consistent than PDI, giving you more shot consistency (accuracy.) Consider these other springs, especially since they are at the same price point as PDI springs.

[vondnik]

I recently installed a PDI 150 in a gun and with hopup the velocity was around 480..... yeah that is not a typo... 480... Bruce also got the same type of results... PDI springs are about the cheapest spring you can buy... stick with systema or guarder....

[CDN_Stalker]

Am glad I decided to post this thread up, there is a LOT of great info coming out now. Thanks guys, that really helps me (and am sure everyone else who reads this). Will consider the other choices next time, and suggest to others that ask me not to get the PDI springs.

[Kwokwai]

Remininscent of the old PDI 120% mystery springs anyone? The ones that seemed to be behaving like PDI 190% for those who don't remember.

[Ridiculous132]

I tried to put a PDI 150% in my ICS m16a3, the gun wasn't even able to crank it... I installed a friend's PDI 150% in it and now it shoots 360 fps just fine... I'll never buy from PDI again...

[Greykin]

I have a handmade 150 PDI spring and it works fine for me. I get around 390fps with it.

[Wolfgang]

I get 390fps with a PDI 130 with .20s

[Tankdude]

Had a G36 that couldn't crank a PDI 130%. Ruined the batteries.

It is for sale right now

[Sgt_Lynch]

As far as my personal feelings towards illusions statement about PDI, Prometheous & Systema.

I'm not big on Systema, I've seen alot of smashed mechboxes with their M120 springs. I find them to be way too rigid. The M120S he's refering to.. I have no experience with, so I can't comment on those.

Prometheous... no experience so I can't say either way, but I'll probly pick one up to test it in the short future.

PDI, I've got a fair bit of experience with. Just about every upgraded gun I have is using a PDI 170% spring, and they seem to be very close to eachother regardless of barrel length. The thing I like most abut them is they are less rigid then the Systema M120 spring, but produce similar velocity numbers. The result of this is that I can honestly say... I have never broken a mechbox.

With that aside, I have noticed (as stated) the rest of PDI springs are all over the map with regards to performance. I've experimented with a few, and knew others using different PDI springs and it's a roll of the dice at best. So, obviously something ain't right over there at PDI.

[royal marine]

shit i hope my g36 is ok ive had a pdi 150 put in. still waiting for my battery & charger. oh well can always downgrade it i spose.