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KingAcquisitions 05-04-2010 04:30 PM

Important Bolt / Power tube / spacer test results
Alright, I had some serious leaking down the barrel out of all three of my classic valve'd automags recently. I tried putting new orings in the on/off and powertube that ended up doing nothing, plus I tried using different power tube spacers to no avail. So, I was left to changing out individual pieces on the guns until I found a culprit, which I finally did: the bolts. I always wanted aftermarket automag bolts, but now I realize some bolts have a serious problem, they cause the mags to leak. So, I did some testing comparing each of 5 bolts with various powertube spacers. Here are the results:

The testing was done on a classic valve automag with freshly lubed o-rings using dow 33 grease. Here are the bolts:

Here is a layout of the results I found when I used each bolt with the .215 and .220 spacers.
If you guys can't read what I wrote on the paper, just let me know and I will type it out.

A couple things are important to point out. Firstly, bolt 1 (venturi 1) does NOT have the slight inner collar on the end of the bolt shaft. Secondly, changing spacers didn't seem to make any difference with any of the bolts.

Questions I have are these:
1) What does the inner collar do on the bolt shaft do?
2) Why would an automag bolt NOT have the inner bolt shaft ring?

Let me know what you guys think....

secretweaponevan 05-04-2010 06:21 PM

It is recommmended that you use only autolube or airtool oil.

If you have a powertube leak, move to a shorter spacer.

minimag03 05-05-2010 02:07 PM

Has there ever been an internal "upgrade" that actually performed better than its stock AGD counterpart?

secretweaponevan 05-05-2010 06:06 PM


Originally Posted by minimag03 (Post 1291976)
Has there ever been an internal "upgrade" that actually performed better than its stock AGD counterpart?


Scott Hudnall 05-06-2010 05:07 AM

My personal choice on my 'mag bolt is the level 7 stock foamie bolt. 'nuf said.

KingAcquisitions 05-06-2010 11:09 AM

Here are some photos of the bolts' inner bolt shaft groove, I did the best I could with zooming in. The only one that does not have the inner groove is the first one (venturi 1).
Bolt 1
Bolt 2
Bolt 3
Bolt 4
Bolt 5

Anyone have any idea why Bolts 3 & 4 (which are both 'stock bolts') have different bolt heads? One is recessed and one protrudes out a bit..... thanks

minimag03 05-06-2010 11:14 AM

There are a few different types of stock bolts. The extended one, the recessed one, and the foamie. IIRC The foamie bolt was first. The short one was next and gave people the option to not have a foamie. The long one is the newest and helps cut down on blowback.

KingAcquisitions 05-06-2010 12:28 PM

ah, ok. Another question is this: What is the point of the power tube spacer kit if the inner shaft on the bolts is just a piece of metal? Wouldn't they all be the same size? I have never noticed a difference between the various powertube spacers.....I just use .220. What about you guys?

Greenmtnphantom 05-06-2010 12:34 PM

IIRC they are to account for possible fluctuations in the machining. if foe some reason you get a bolt that is .001 off from what it should be you switch spacers rather than needing a whole new bolt.

KingAcquisitions 05-06-2010 12:44 PM

Hm, well I would have to see how the larger spacers do with the bolts that leak. I also would like to know if there are any upgrades to the mag (other than the obvious: lvlX, RT valve, a good paint to barrel match, compressed air...) that legitimately improve performance.
I have found a parabolic powerfeed plug to make a noticeable difference. I have a couple of the ANS X-flow on/off pieces, but haven't noticed anything with them, but I will conduct some tests to see.....

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