Motorhead LW Hammer - Non-Regged Results (w/ A2A valve)

[AlanMcD]

I purchased one of Scott's lightweight hammers to use with the new AirgunsExporter regulator that I had been playing with in my .22, but now that the reg has been sent back to Vincent for a redesign, I'm left with a new hammer that Scott says is only intended for regulated guns. Well, I thought - we will just see about that!

I figured I might as well spend some time playing around with it to find the best way to run it when the new reg shows up, so I tested both the stock hammer with an HDD and Scott's light hammer (without the HDD) at lower pressures (around and under 2000 psi, since the reg set point is 135 bar, or ~1950 psi). In the end, the lightweight hammer won out on efficiency, and gave some impressive results in terms of reasonably powerful shot strings at low pressure. Of course I do need to point out that I am also using one of Dave Rogers Addicted2Airguns High Flow valves with a .25 cal transfer sleeve in my gun, and that is helping to flow more air at the lower pressures, so a stock valve might not get as much power at this pressure level, but should still get similar shot counts and variation levels.

My best full string came off a fill of 2300 psi, shooting down to just above 1700 psi for 20 shots. These 20 shots of JSB 18.1 grain pellets averaged 903 fps for almost 33 FPE, had an ES of only 16 fps (1.8%), and an efficiency level of ~13.5 bar-cc/FPE (which is pretty good for low pressure shooting). I found other tunes that delivered more energy but also had more ES (one averaged ~920 with an ES of 30 over 20 shots). All of my test strings were done with a stock tuning configuration (non BHB), and with the Transfer Port adjustment wide open (so lower speeds and more shots are easily possible too).

So - is Scott telling the truth when he says that these hammers are ONLY to be used with regulated guns? I think not!! I think he is simply trying to make sure nobody is disappointed when buying these to use in a non-regulated gun, and is being quite conservative in doing so. But from what I have seen, if you are a hand pumper / SCUBA tanker and only want to set up your gun for lower pressure stings (like no more than 2400 psi as a max fill point), then these hammers may be worth looking into. They will not work as well as the stock hammer at high pressure fills, but I have found mine to work great at low pressure, and amazingly I could not get it to bounce and burp air at all! Hammer bounce is something that I find easy to do with the heavy hammer and no HDD, especially at lower pressures.

I hope I don't annoy Scott with this post, given that I am saying something that he has not been willing to say, but I really do want to share these findings with others - with his hammer I have found some low pressure strings with it that rival some of my best high pressure strings, and I could not do that with the stock hammer. I find that to be really impressive. I was not expecting this since Scott said it was for regulated use only, but it really does work well at lower pressures, with the added benefit of a nice shot cycle (less movement from the lighter hammer).

Here is the post on his hammer in the buy/sell section: viewtopic.php?f=21&t=5302#p30015 ,and the post on the development of it: viewtopic.php?f=28&t=4970

[Motorhead]

Lol .... that ever so Grey area of "You said so "
Honestly never wished to go about talking / advertizing the LW hammers at DISCO pressures being this a Marauder site and guns being 3000# guns in stock form.

Very cool you did some LP testing in lieu of not having your regulator
Had done a few hammers at mid weight of @ 40 grams that seemed to go HP to Mid Pressure W/O a regulator but never occurred to me as you have just tested a LW 26 gram one.

Good stuff & thank you
Scott

[Wasatch]

Could it be that the LW hammer having both lower energy and lower inertia not only allows the low pressure shooting (lower energy) but also follows the valve better without bouncing (lower inertia)?

I'm trying a LW hammer with BHB 3 in 177 mrod and am getting 45-50 shots 3200 - 3000 psi in the 855fps range. Haven't tried stock hammer yet w/ BHB.

[Garden Sniper]

Alan, I had found while using a 25 cal valve in my 22 cal that I had the same type of result and also thought of the people using hand pumps or lower pressure tanks may benefit from these mods most. Do you still need an improved air stripper for .630 OD Barrel ? Pete.

[AlanMcD]

Pete,

Shootinit made one up and sent it to me a while back, and it is working well in the stock shroud. I may be contacting you at some point for one of your 1" shrouds for it, but I do want to get the regulator in and test everything out to make sure that I am sticking with the .63" Poly - it's possible that I might go back to one of the other barrels or maybe try one of Jim's new hammer forged barrels, and then the 1" shroud would not really be necessary. This poly barrel only seems to shine with JSBs above 880 fps or so, and Baracudas above around 830, so I need to be able to get the regulator up to those speeds for the barrel to stay in the gun (that or I loose the regulator, and it was REAL nice for the short time I had it in the gun).
So thanks for the follow up, and I'll be in touch.

I hope all is well - I take it your busy season is up now?

Alan

[Garden Sniper]

Alan, I have 6 more trips scheduled before the end of the year, as long as the weather co-operates. The Feds closed down our winter Sea Bass fishing so not much to fish for in jan and feb, plus there is not much help out at that time of year if their is an emergency. I have some material on the way for the 1'' OD shrouds and misc pieces. I am also interested in a regulator for my 22 cal as soon as Vincent has them ready. I am going to upgrade my new gen 1, 25 cal with an oversize shroud, air stripper, baffles, high flow gauge block and minor valve mods first, then i am back into the 22 cal. Pete.

[AlanMcD]

Just posting a little follow up to show how much Motorhead really knows about what he is doing. The following is definitely not a modification that one should do unless you either want literally nothing but irreversible maximum power from a stock gun, or you are installing a regulator . . . so I firmly believe that nobody should do the mods below unless you are going to run a regulator (because if you don't you will probably be unhappy with your gun, with no good way to dial it back down afterwards).

Motorhead has been saying that the true best way to run a Marauder with a regulator is with his lightweight hammer, but to also "open up" the air flow path to the pellet, with a larger throat in the valve and larger transfer port, sleeve, and even a larger port into the barrel. Since I am going to be re-installing the regulator later this week, I went ahead and made the changes to my gun this weekend to test them out. I started with my A2A valve that had been opened up on the high pressure side, but was pretty much stock .25 cal on the output side, but with a high flow stem (this is what I had asked Dave to make me for me then). Of course this valve (unmodified) is what was in the gun for in the original post at the top of this thread.

Here are the mods I made:
- Valve Throat - drilled out with 15/64" bit, sanded, and then polished (used a Dremel with rouge to clean up the face for the valve too) - was 6/32" or so
- Transfer port out of valve - drilled out with 5/32" bit, sanded and polished (with an adjusting screw Loctited in and drilled out too) - was 0.130"
- Transfer Sleeve - 0.165" Nylon brake line (0.470" long, ends sanded square while chucked in a drill) - was 0.130"
- Barrel port - 0.165" (drilled to 5/32" and then used a Dremel w/ stone to enlarge), sanded and polished with a Dremel - was 0.140"

Results:
Using the same hammer settings, and thus the same pressure curve, the gun is able to produce a peak of 36 FPE at the same point in the curve that the gun achieved only 32 FPE before - and it does so using less air per shot (~14 bar-cc/FPE before, vs. ~12.5 bar-cc/FPE now). Motorhead has really nailed this down.

As I said, you would not want to do this to your gun without a regulator as you would have no ability to control the pellet speed or flatten your curve, but with a regulator this will be magic. I expect to lose 3-4 FPE from the current settings with the regulator installed (due to having a restricted regulated volume of ~10cc instead of the full 215cc), but that puts me right where I want to be for best accuracy, and I expect to pick up several more regulated shots at this higher power level (32 FPE vs. 29 FPE before with the regulator). Thanks a ton, Scott! Simply brilliant!

Here is the before and after of the shot curves, adjusting the data to equalize the peak power to about the same place on the curve. The new "curve" is not as flat and thus not desirable for a stock gun, but the peak power point on the graph is at the pressure the regulator will be set to, and thus then new high flow set up will yield more power using less air than the old set up, all at the same speed +/- about 5 fps over at least 40 shots from a 3000 psi fill ( for ~32 FPE per shot with JSB 18.1s) I'll post how it all ends up.



Alan

[bstaley]

Good stuff. Those same flow mods work really well with the o-ring buffer too. Gotta get me one of Motorheads hammers.

[AlanMcD]

You raise a good point - I just wanted to share the new info I learned, while impressing on people that the mods that open the flow path up should not be done without planning how to control the energy of the gun, and in my case it will be with a regulator.

Your mod might be a way to control the speed of the gun when set up with a wide open path (I did like it a lot at high pressure with the stock hammer). But somebody would need to test it with the lightweight hammer and the open flow path to fit within the "scope" of this thread, and it probably won't be me.

[Motorhead]

Just assembled my buddies NEW .177 yesterday that was also waiting on the new regulators. Results were equally impressive

Stock rifle as running on 2500# fill set to shoot 10.3's @ 900 fps
Did the mods to valve , LW hammer etc ... installed reg ( 1850# set ) keeping spring tension the same ... 1018 fps !!!

Whoa Nelly !!! ..... dial it way down time