Custom

[r-lad]

Lizard 13 sent his Trracer over for some low pressure mods, so I'll show what I came up with here.

First, a mini review of the stock Traccer.
This marker is a standard Nelson type with some neat features thrown in. The feed neck is removable and mounts on a weaver rail that is also handy for mounting a sight. The pump latches closed when cocked to prevent double loading, but can be released with a light pull of the trigger. I hadn't seen this feature before, and after taking the marker apart I realized it is really genius. There is just an extra notch in the sear to accomplish this function - no extra parts.
There are a lot of plastic parts on the marker, but it seems pretty sturdy overall. The only part that looked like it was going to wear out prematurely was the bolt. It is aluminum and the steel sear will likely wear a notch in it quickly.

Stock Shooting Tests:
CO2 full weight: 43g
CO2 empty weight: 31g

SPL: 91db

Shot --- Velocity
1 294
2 283
3 282
4 277
5 272
6 275
7 279
8 287
9 276
10 285
11 287
12 281
13 273
14 269
15 276
16 277
17 281
18 275
19 268
20 275
21 265
22 267
23 271
24 263
25 257
26 249
27 252
28 244
29 231
30 237
31 238
32 226
33 216
34 222
35 218
36 217
37 216
38 217
39 214
40 207
41 203
42 195
43 190
44 167
45 139
46 125
47 82
48 43
49 Fail to Recock

A CP 0.685 bore barrel was used for tests.

Here are some sample ball measurements from the bag of paint used for testing:

Seam --- 90 Deg from Seam
0.680 0.678
0.680 0.678
0.679 0.680
0.677 0.680
0.681 0.681



The low pressure upgrade consisted of the following:
*stainless bolt without velocity adjuster
*larger diameter power tube and seat
*different valve return spring
*larger volume air chamber w/o ASA, w/ regulator and gauge ports

Here are the stock parts on top and new parts on the bottom


Modified Shooting Tests:

CO2 full weight: Sorry, forgot to weigh
CO2 empty weight: 31g

Approx. Pressure: 300 PSI

SPL: 82 db

Shot --- Velocity
1 281
2 298
3 294
4 290
5 296
6 296
7 298
8 292
9 300
10 291
11 293
12 290
13 298
14 298
15 297
16 282
17 288
18 292
19 292
20 287
21 292
22 285
23 287
24 290
25 284
26 284
27 293
28 293
29 286
30 291
31 290
32 290
33 292
34 289
35 290
36 298
37 315
38 285
39 251
40 202
41 163
42 98
43 Fail to Recock

Finished LP Trracer:




Conclusion:
The Trracer now has a more durable bolt, is more efficient, and much quieter.

[-=ArchAngel=-]

Whoa. Those are some pretty impressive results

[splattttttt]

great work r-lad. I think a video would be awesome.

[russc]

Those are great results. What cupseal and powertube are you using, and did you get venting or popping when you cock the guns?

[Captain]

Would you be interested in producing some more of those steel bolts? I know that a lot of guys would like to use them.

[russc]

Also, were you running the 12 gram changer from the bottomline for the tests?

[98ssuck]

looks like someone needs a 12gram charger with a built in stabilizer

[Matt Ribble]

I appreciate the fact you took measurements across the board.

Very neat.

[-=ArchAngel=-]

tuned down to ~275fps, i bet this thing could easily get ~50 shots.

[r-lad]

Originally Posted by -=ArchAngel=-

tuned down to ~275fps, i bet this thing could easily get ~50 shots.

It might be at 275 now. I only have mini gauges that I don't entirely trust. The one I normally test with looked like 300, but each tick mark is 50 PSI. The gauge pictured only goes to 300, and is not maxed out.

looks like someone needs a 12gram charger with a built in stabilizer

Nice idea, but to be honest I really only use the 12g for testing. I'm not quite hardcore enough to challenge semis with a 12g powered pump.

Also, were you running the 12 gram changer from the bottomline for the tests

Yes, a changer was screwed into the ASA. Setup was like in the photos otherwise.

Would you be interested in producing some more of those steel bolts?

Probably. Are you interested in stock replacement? That would be different than the one shown.

What cupseal and powertube are you using, and did you get venting or popping when you cock the guns?

The parts are home made. Power tube ID is 0.234". The cupseal is a captured o-ring. My early revisions had no seals. The designs without seals work fine as long the power tube can remain perfectly straight. Unfortunately, the plastic Trracer frame allows flex, which can let the bolt push on the power tube from the side and cause leaking. With the o-ring design, slight misalignment is tolerated and there is no leaking.
The effective diameter at the seal head is also larger, giving more force to hold the valve shut and prevent venting.