Blast tamer results

[rkr]

As some of you may know, BSA has been equipping their import FAC models with HDD called blast tamer. After seeing a photo at BSAOG I got inspired and built one for my Gamo Dynamax. Here are the results of my first version, shotcount went from 25 to 30:



I'm building an improved version now, never thought these things would actually work that well 

[lloyd-ss]

rkr, 
That looks pretty darn good, like with one of those, "as seen on TV" endorsements.  Just joking, of course.   
But if that is the real deal, I am real curious.  Please keep us posted!  Maybe some pics, too. 
Lloyd

[rkr]

Thanks Lloyd, I'll take a photo when I get it working well. I think the "tamer" part is too light now and doesn't stop the bounce at higher psi. I'm building a heavier version right now  There's just very little room with MMC system so I'll have to think it very carefully.

[rkr]

Final version is in the photos, the bright metal colored rod. The shot count with 200 bar fill went from 25 to 32, a 28% increase. I think I'm happy with that. The BT is made from 3mm steel rod, goes through the MMC block (drilled 3,2mm hole there), threaded on one end with M3 nut and uses ball pen springs. It goes behind the hammer pin so in practice when you fire it slams the pin right after the hammer has hit the valve. Enough to stop it from bouncing it seems 

[lloyd-ss]

OK, I see the rod with the nut and small springs and a short piece of orange or red tube around it.  I am not familiar with the dynamax internals enough to really understand.  Can you explain a little more?
Thanks,
Lloyd

[DFWdude]

Can you link us to the topic/photo at BSAOG, too, please?

[Motorhead]

Some of us are fooling around with / using loosely similar idea in our Marauders .... Shot count has near doubled with them.

Nice work there !  hope you fine tune it to be even better yet. 

[rsterne]

You may find that the HDD isn't necessary at the beginning of the shot string at higher pressures as the air pressure is so high the second hammer strike can't open the valve anyway.... just a thought....

This is the first graph I have seen with actual results from a HDD.... it does appear to have some merit (which I had previously doubted)....

Bob

[lloyd-ss]

+1 on Bob's comments
Lloyd

[rkr]

Can you link us to the topic/photo at BSAOG, too, please?

http://bsaog.co.uk/forum/index.php?topic=25352.0

[rkr]

OK, I see the rod with the nut and small springs and a short piece of orange or red tube around it.  I am not familiar with the dynamax internals enough to really understand.  Can you explain a little more?
Thanks,
Lloyd

That rod goes through that aluminium block and slides back and forth as the hammer moves. Towards the rear of the gun it hooks behind the pin that connects hammer to the trigger unit. Towards front there is a spring, a spacer to give enough tension and a nut. Those ensure that the rod slams forward when the hammer is released. Only it slams just a tad bit later than the hammer strikes the valve so it reduces the bouncing effect. The aluminium block itself has the MMC system which is used to cock the hammer (those black rods). The issue with MMC BSAs is that there's very little room left for this blast tamer system unless one takes a dremel to the stock, which I didn't want to do.

[rkr]

You may find that the HDD isn't necessary at the beginning of the shot string at higher pressures as the air pressure is so high the second hammer strike can't open the valve anyway.... just a thought....

This is the first graph I have seen with actual results from a HDD.... it does appear to have some merit (which I had previously doubted)....

Bob

Bob, I've come to the same conclusion. In all my tests the major improvement comes in lower pressure. It would be interesting to test a really heavy BT unit to see if that would help with higher pressure, but unfortunately there's no room for it in my gun

[DFWdude]

Thanks for the link, rkr!

[wasatch]

Rkr, did you drill through the push bar holder for the BT rod to fit through?  Looks tight.

I'd like to try fitting a BT to either an R10 (which may be space limited due to the regulator block) or a Huntsman which has the MMC.

[rkr]

Rkr, did you drill through the push bar holder for the BT rod to fit through?  Looks tight.

I'd like to try fitting a BT to either an R10 (which may be space limited due to the regulator block) or a Huntsman which has the MMC.

Yes, I drilled through that aluminium block that holds the MMC linkage. R10 should have a shorter version of that block to mount the stock holding screw. You can just mount the blast tamer in it without drilling as those slots hold 3mm rod nicely. This photo is from my Scorpion SE where I installed the longer block but people have built these using the short block.



For Sportsman (Huntsman is daystate and has HDD in it) you can copy my approach.

[wasatch]

Sportsman HV you're right, my bad. Sorry if i confused things.

Thanks for the picture.  I'll have to get in there tonight to see if I can fit it.