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Tuning AW-93 for RapidFire

Posted: Sun Dec 18, 2005 8:54 am
by Mark Briggs
It seems to me the AW-93 has a long, slow recoil impulse as a result of its three different internal spring mechanisms. I find recovery for followup shots in rapidfire to be quite slow as compared to the MG-2 and Pardini. After scratching my head a little bit and pondering how best to make adjustments to the recoil rate I thought I would put the question to this forum in hopes there have been others who have experimented and come up with a solution to this problem. Has anybody played with the internals of the AW-93, and if so, what were your results?

Thanks for sharing your positive thoughts and comments.

AW-93

Posted: Sun Dec 18, 2005 9:38 am
by Ernie Rodriguez
Before considering internal solutions for your AW-93-have you considered using higher speed ammo?? In the range of 1080-1140fps??Sight recovery should be a little faster.Ernie.

Posted: Sun Dec 18, 2005 4:44 pm
by Walter
I remember Fortitudo Dei had posted being able to adjust the 2 screws in the front of the buffer, but on my gun they are tight in place.
Thomas Rink was also mentioning on http://www.sportschuetzen-forum.de/ that these screws are not adjustable.
I know that when I tried moving the screws, they wouldn't budge.
Maybe Fortitudo will post on this for more info.

Posted: Sun Dec 18, 2005 5:34 pm
by Fortitudo Dei
Walter wrote:I remember Fortitudo Dei had posted being able to adjust the 2 screws in the front of the buffer, but on my gun they are tight in place.
Thomas Rink was also mentioning on http://www.sportschuetzen-forum.de/ that these screws are not adjustable.
I know that when I tried moving the screws, they wouldn't budge.
Maybe Fortitudo will post on this for more info.
Now that is odd. My screws were definitely movable right from the time I purchased the pistol. Initially I had them as they were when I received the gun (i.e. more or less flush with the front of the moving barrel weight), but found that as the gun cycled, they gradually started to unwind and work their way forward. During one match when I had not checked them for a couple of weeks, I came very close to launching one set of the threaded screws, springs and buffer pins out onto the range as one screw was hanging on by just a single turn of thread. At this point I decided to experiment and eventually turned both screws into the barrel weight as far as they could go and locked them into place with a little clear nail varnish. I found the effect to be subtle but noticeable i.e. the recoil sharpened up a little. If yours have been locked in place, see if they can be loosened after dabbing in a little acetone or similar
However I suspect that the amount of recoil soaked up by the two smaller adjustable front buffers is considerably less than the main internal buffer inside the moving barrel weight. Just a thought - one option worth considering could be to disassemble the main buffer (making sure that the bits don't fly across the room) and insert some kind of spacer (say a short length of brass rod of the correct diameter) to increase the tension of the main buffer spring. This might decrease the recovery time.

Posted: Mon Dec 19, 2005 7:50 am
by Mark Briggs
Thanks to all for your considerate replies!

I have examined my pistol and found the two screws in the front buffer to be chemically locked in place. They're getting a little acetone soak right now in hopes of loosening them. Unfortunately the previous owner of this pistol burred the screw heads so I must be doubly careful in removing them.

After closer examination of the main recoil buffer assembly I believe this is where I'll be concentrating the majority of my efforts, perhaps with a stiffer outer spring or through the use of spacers to provide additional pre-compression on the spring.

Once again, thank you for your assistance.

Posted: Tue Dec 20, 2005 4:49 pm
by Mark Briggs
Just a quick update on tuning the AW-93...

My front buffer screws are indeed set in place with a threadlocking compound. A curse upon Feinwerkbau for having used so much threadlocking compound on such a large screw with such a small screwdriver slot.

That's just plain dumb, and well below my expectation of build quality on the most expensive standard pistol on the market.

They could have used a service-removeable strength screw retainer like Loctite 242, or used only a little bit of locking compound, and milled a great big slot in the screw head or used a hex key. I've been soaking my lower cover in acetone and now have one of the two screws removed. So far two of my SnapOn screwdrivers have bit the dust trying to remove the second screw.

On a positive note, I'm beginning to believe that a switch to hotter ammo and/or stiffer springs will improve return-to-target performance.

Posted: Tue Dec 20, 2005 7:00 pm
by Pär
Mark Briggs wrote: On a positive note, I'm beginning to believe that a switch to hotter ammo and/or stiffer springs will improve return-to-target performance.
I do not think so. My opinoin is based on fundamental physics (increased energy and increased "someting-that-I-do-not-know-the-correct-english-word-for" which is measured in kgm/s) even if I can see your argument about faster cycletime.

Posted: Tue Dec 20, 2005 7:03 pm
by Pär
Pär wrote:
Mark Briggs wrote: On a positive note, I'm beginning to believe that a switch to hotter ammo and/or stiffer springs will improve return-to-target performance.
I do not think so. My opinoin is based on fundamental physics (increased energy and increased "someting-that-I-do-not-know-the-correct-english-word-for" which is measured in kgm/s) even if I can see your argument about faster cycletime.
Btw, I use a Sako Triace that definetly cycles a lot slower than many other pistols but I do not feel that that is a problem, did a few 579-586 scores this summer with that setup.

Name

Posted: Tue Dec 20, 2005 9:10 pm
by Mike T.
Pär-
The English word for the property having the units kgm/s (kilogram.metre per second) would be "momentum" (mass X velocity).

mass and speed

Posted: Wed Dec 21, 2005 6:29 am
by The outfitter
To Pãr, "Le Suede":

In english: mass x velocity (actually speed) = momentum

In swedish this is: "rørelsesmãngd" or "massfart".

There is often some confusion here, ´cause in swedish "momentum" rather means "torque".

Posted: Wed Dec 21, 2005 8:15 pm
by Walter
Mark,
try heating it with a hair dryer.

Posted: Thu Dec 22, 2005 10:49 pm
by Mark Briggs
Finally got the front buffer screws out - it took several hours of complete immersion in acetone before the second one would move. It was completely (and I do mean completely) covered in thread-locking compound. Obviously the folks in the FWB factory didn't read the label on the thread locking compound bottle or they would have known that it only takes a small amount of the compound to lock a screw in place...

Anyhow, I've now got the screws out, have cut new heads into them with WIDE screwdriver slots, and have re-installed them, tightened in all the way to compress the buffer springs the fullest amount. This might make some difference. Been too busy at work to get out shooting the pistol...

There was a suggestion above to put spacers in the rear buffer. I tried that and it may work, but probably not nearly as effectively as installing stiffer springs.

And yes, no matter what language, I tend to agree with Par that hotter ammunition generally goes against what we're trying to achieve in rapidfire. Using hotter ammunition to speed up the cycling of the AW-93 will perhaps fix the cycle time problem, but increase my bodies recoil recovery time. I might just have to stick to using my MG-2 for rapidfire because it does shoot very nicely...

Re: mass and speed

Posted: Fri Dec 23, 2005 3:34 am
by Funny guy
The outfitter wrote:To Pãr, "Le Suede":

In english: mass x velocity (actually speed) = momentum

In swedish this is: "rørelsesmãngd" or "massfart".

There is often some confusion here, ´cause in swedish "momentum" rather means "torque".
Massfart !!! :-D

Posted: Fri Dec 23, 2005 4:28 am
by Pär
Ahh! Momentum, yes ofcourse!

The swedish word for torque is "moment" or "vridmoment", so yes, there might be some confusion. The word for momentum is as informed "rörelsemängd", but the word "massfart" have I never heard before!

Bwt, fart is not what ju believe ;-) Its the swedish word for velocity!