Blue vs clear bumper

[flyingpootang]

Anyone use the blue bumpers vs the clear ones on a L10 with a X/E/RT type valves and a L10 bolt without any long term affect? I'm just tired of the clear ones getting eaten away even though they're glued to the valve. I measured the thickness of both and they are the exact same thickness....

[MournBlade]

The blue bumpers can bounce the level 10 bolt out of the sear catch and can damage the bolt.

[Mechanic79]

The clear ones are more pliable.
The blue ones are less pliable.

I've used both and prefer the blue ones because they hold up better/last longer. I use them on all my AGD guns. Emag, RT ULE, previous DevilMag,

[ljpiller]

Mine has a black rubber-like bumper in it, how does that stack up?

[Hilltop Customs]

The clear ones are more pliable.
The blue ones are less pliable.

I've used both and prefer the blue ones because they hold up better/last longer. I use them on all my AGD guns. Emag, RT ULE, previous DevilMag,

+1

originally had a clear one on my x valve that held up for a case before it was ate up. Got 2 more clears, tried the glue trick with no benifits. Switched to a blue and havent changed it in 4 years or so.


Ive never heard of a black one? Did you get it second hand or something? maybe someone replaced the bumper with a rubber washer?

[WickedKlown2]

Not to long ago a bought a E-Mag valve w/lvl 7 and it came with a black bumper on it... I have since replaced it with a blue bumper and a lvl 10 kit... No worries here so far...

[DevilMan]

From AGD site..

"The clear urethane washer sits at the base of your power tube. When the bolt returns, it hits this to decelerate. This bumper is a little softer than the standard blue bumper for the higher firing rate of the Retro Valve. The bumper should be replaced about once a year."

:D

Hope it helps...

And nooooo no mention of the black one yet...

DM

[Ruler_Mark]

my friend bought an emag and the clear oring was cooked onto the gun and turned black, that could be what you have, it was stuck to the bolt and valve. Spend a few more $$ a year and stay 'CLEAR' of any problems.

[athomas]

I wouldn't worry about using a blue bumper, especially with the level 10 bolt. The level 10 bolt doesn't return quite as fast as the level 7, therefore the impact force on the front of the valve is less than the level 7 bolt. The clear bumper is softer and absorbs impact when in new condition. The blue bumper is harder but will spread the impact force out over a wider area. The shreading of the clear bumper plus the smaller area at the base of the level 10 allows more impact force per square inch to be applied to the front of the valve when using the clear bumper anyway. I think the benefits of the longevity of the blue bumper merit some thought.

[Ruler_Mark]

I wouldn't worry about using a blue bumper, especially with the level 10 bolt. The level 10 bolt doesn't return quite as fast as the level 7, therefore the impact force on the front of the valve is less than the level 7 bolt. The clear bumper is softer and absorbs impact when in new condition. The blue bumper is harder but will spread the impact force out over a wider area. The shreading of the clear bumper plus the smaller area at the base of the level 10 allows more impact force per square inch to be applied to the front of the valve when using the clear bumper anyway. I think the benefits of the longevity of the blue bumper merit some thought.


I beg to differ. the forward force is less on the lvl X because of the spring, in the same respect the spring pushes harder on a lvl X bolt to return it vs the lvl 7 because of the spring. with all the air down the barrel the only horizontal force on the bolt is the spring. the lvl X springs have a higher spring constants vs the lvl 7 spring therefore yielding a higher force.

[athomas]

I beg to differ. the forward force is less on the lvl X because of the spring, in the same respect the spring pushes harder on a lvl X bolt to return it vs the lvl 7 because of the spring. with all the air down the barrel the only horizontal force on the bolt is the spring. the lvl X springs have a higher spring constants vs the lvl 7 spring therefore yielding a higher force.
Because of the reduced differential pressure, the exhaust air tapers off more gently than with a level 7 bolt. There is more retained pressure in the chamber. This results in less acceleration towards the reset position, even with a stiffer spring.

[ajnin]

i have a black bumper on one of my mags. it even cameon the mag with the reg capped. odd gun.

[Ruler_Mark]

Because of the reduced differential pressure, the exhaust air tapers off more gently than with a level 7 bolt. There is more retained pressure in the chamber. This results in less acceleration towards the reset position, even with a stiffer spring.

Is this a vacuum pressure?

[snoopay700]

If i recall correctly, isn't the black bumper for a pump mag, and it was smaller in diameter and everything?

[AGDRetro]

If i recall correctly, isn't the black bumper for a pump mag, and it was smaller in diameter and everything?

Yes, typically the black ones are found on Pump Mags and have a smaller diameter (so the wave spring fits around it).

Tunaman has suggested Loctite 380 aka Black Maxx to adhere the clear bumpers to the valve, but I have had little success with that stuff. I ordered some Loctite 4851, which is a clear but flexible instant adhesive, through work at Fastenal (part number #0682683). I'm hoping that the 4851's flexibility will finally give us solid solution for the RT bumper!

I have to purchase a minimum of 10 to meet the minimum order requirements for this item, even with my Fastenal employee discount I'm still paying $15.51 per bottle! If this stuff is the miracle glue we've been searching for I will gladly get the other 9 bottles to any intrested AOer's! I'll let you know my results when I test the stuff!

If 4851 doesn't work, I'm just gonna chew up my clear bumpers and use the blue ones till my X-Valves explode! :eek:

[athomas]

Is this a vacuum pressure?That question doesn't even make sense.



The bolt works much like a regulator. It has a piston (bolt stem) that is forced out by air pressure. There is a spring that pushes back against the bolt to limit the amount of air that gets out. On a level 10 bolt setup, the smaller stem allows less force against the bolt spring than a level 7 bolt, which is why the level 10 is easier on paint. Unfortunately, it also results in less air flow. Less air flow results in the chamber being dumped slower, especially as the pressure reaches the value equal to the spring return force. This is how a regulator works. Once the spring force is greater than the chamber force exerted on the larger part of the stem (since the bolt is now forward), the bolt is forced back to its reset position. Because the level 10 air is flowing at a reduced rate through the smaller carrier opening, the regulation is more precise and closer to the spring rating than the more quickly dumped level 7 air. This results in more air remaining in the chamber of a level 10 equiped valve, which slows the rate of the returning bolt.



The shredding of the clear bumper has nothing to do with the rate of acceleration of the bolt towards the back anyway. If the back to the level 7 bolt was machined to the same dimensions as the level 10 bolt, it too would tear the clear bumper. The clear bumper being softer squishes as the bolt is returned. The inner part of the bumper is tight against the valve stem and can't go anywhere. The inner edge of the bolt holds it from moving anywhere when the impact occurs. The remaining bumper material squeezes to the only place it can, which is towards the outside edge. The movement of the bumper material with the inner part held tight creates a tearing action on the material. Eventually it fails. The fix is to glue the bumper down. This prevents the migration of the bumper material towards the outer edge and prevents the tearing action and thus, saves the bumper. The blue bumper, which does not compress at the same rate, does not suffer from this affliction.

[garbageman705]

My E-mag has had a black bumper on it for like 5 years.

[PhoenixWolf]

I seem to recall that AGD later stated that it doesn't really matter (this was years later). They originally thought that they would need the softer bumper for use with higher performance guns. However, they underestimated the quality of their engineering, and underestimated how quickly these new bumpers would wear out. End result is that most people just use whatever they have on hand, and don't worry about which bumper they have. Given that people use the blue bumpers on E-Mags for years with no sign of wear, it's pretty obvious at this point that it doesn't matter.