The Vortek Pro-Guide2™ Spring Kits

By Brad Troyer
6/23/2010


Manufacturer of the worlds premier airguns
click the ad to visit this advertiser, View All Advertisers On This Page

Over the past few years most of the major spring gun manufacturers have started using more advanced materials in their production rifles to help reduce vibrations and improve the firing cycle. Many of the materials and techniques used by the manufacturers were pioneered by airgun smiths in an effort to extract the utmost power and accuracy out of their spring guns. Even though the manufacturers are doing better with their production rifles, there is still a demand for aftermarket tune kits. Most of these kits are comprised of a quality spring, spring guides, and dampening compound. The key to reducing the vibration and spring noise is are the spring guides. Most kits use a guide that is inserted inside the rear of the spring and prevents the rear of the spring from vibrating during the firing cycle. The front of the spring is managed by the inside diameter of the piston (sometimes with the help of a piston sleeve).


Figure 1: Standard Tune Kit (above) and a Pro-Guide2™ kit (below)

Vortek Products Inc out of South Lyon Michigan has developed another approach to the tune kit with the release of their Pro-Guide2™ Spring Kits. Instead of using a single tight fitting spring guide that is inserted inside the rear of the spring, the Pro-Guide2 kits uses a proprietary “Dual Guide” that made up of a guide that fits over the outside diameter of the spring along with a shorter internal spring guide, see figure 1 below. The Dual Guide doesn’t use as tight a fit as the traditional single spring guide so the spring is free to expand with less resistance. The dual guide is made from materials that help to reduce the vibration and dampen the transmission of spring noise.

I first read about the Pro-Guide2™ kit on an airgun forum and decided to give the kit a try in my TX200 MkI rifle. The MkI is the original TX200 12 ft. lbs. design using a shorter cocking stroke. When I received the Pro-Guide2™ kit I followed the simple instructions and had the new kit installed in under 30 minutes. The longest part of the install was cleaning the inside of the piston. After applying a bit of lubricant to the new spring, the Pro-Guide2™ slide right into the piston and the installation was complete. I fired a couple of rounds down range and the rifle fired like a 10 meter match rifle. After shooting a couple of rounds across the chronograph I found out why, the rifle was only shooting around 580 fps!

I contacted Tom Gore at Vortek and he informed me that he Pro-Guide2™ 12 ft. lbs. kit is designed for a FAC TX200 which has a longer compression stroke. When installed in an original MkI, the kit would only generate around 6 ft. lbs. and that is what I saw with my rifle. Tom also told me that Vortek has developed a new kit for the TX200 called the Elite series and he offered to send me a kit to evaluate with my rifles. I reluctantly had to accept his offer and an Elite series kit showed up at my door a couple days later.


Figure 2: Pro-Guide2™ Elite Series (above) and Pro-Guide2™ 12 ft lbs kit (below)

The new Elite series kit uses a similar exterior spring dampener as the original kit. The difference is that the Elite series uses symmetrical spring guides on either end of the spring with power spacers installed. On one end the power spacers are steel while the other end uses a synthetic material. The idea is that the user can put the weighted end forward or rearward depending on what type of pellet is to be used with the rifle. The weighted end can provide a smoother shot cycle with tighter fitting pellets like the Crosman Premier 7.9 pellets while looser fitting pellets like the JSB brand would benefit from the light weight end of the spring. I have had discussions with various tuners about adding or subtracting weight to the piston end of the spring to modify the firing cycle so this seemed plausible. I decided to run a series of tests with both of the Pro-Guide2™ kits to see how they performed and how the weighting affected the shot cycle on the Elite series.


Figure 2: Pro-Guide2™ Elite Series non-weight (left) and weighted (right) spring guides

To start the test, I recorded the baseline performance of both rifles with a factory spring kit. Table 1 shows the test results. The factory springs that were installed in both TX200s had steel top hats (front spring guides) and they made the shooting cycle a bit choppy or chunky feeling. That is typical with extra weight added inside the piston. The factory spring was smooth and had no perceptible spring twang but the shot cycle seemed loud.

TX200 MkI
TX200 MkII
Shot
CP 7.9
JSB 8.44
CP 7.9
JSB 8.44
1
880
862
856
856
2
871
862
847
857
3
861
862
849
854
4
864
865
848
860
5
872
867
847
854
6
856
855
842
862
7
863
863
851
856
8
867
863
855
856
9
857
861
849
856
10
863
856
841
858
Ave
865.4
861.6
848.5
856.9
Energy
13.1
13.9
12.6
13.8
StdDev
7.32
3.66
4.81
2.51
Hi
880
867
856
862
Lo
856
855
841
854
Spread
24
12
15
8

Table 1: Baseline test results using factory spring components

I decided to test the 12 ft. lbs. spring kit first. As I found in my previous installation in the MkI, the 12 ft. lbs. kit only produced less than 8 ft. lbs. but the shot cycle was very smooth, of course. I didn’t bother too much with this setup as I don’t have much interested shooting my TX200 at 8 ft. lbs.

The MkII performed nicely but a bit under powered compared to the advertised 12 ft. lbs. level. When installing he kit I noticed that there was almost no preloading of the spring since installing the breech block was very easy. The MkII was very easy cock and the firing cycle smooth with no spring twang or torque. The perceived noise level seemed lower. I didn’t seem to pick up as much noise through the stock of the rifle. The rifle was definitely easier to shoot at the lower power and accuracy was as good as or better than with the factory kit. Both pellets shot well with this kit and I was able to shoot a couple of nickel size groups with the JSB pellets. Other than the lower power, the 12 ft. lbs. kit performed as advertised and it was a snap to install.

TX200 MkI
TX200 MkI
Shot
CP 7.9
JSB 8.44
CP 7.9
JSB 8.44
1
612
648
745
743
2
591
659
738
762
3
633
669
731
751
4
622
662
731
754
5
628
664
727
758
6
631
661
733
751
7
618
665
736
765
8
621
657
723
756
9
614
653
725
756
10
625
658
736
749
Ave
619.5
659.6
732.5
754.5
Energy
6.7
8.2
9.4
10.7
StdDev
12.14
6.08
6.60
6.42
Hi
633
669
745
765
Lo
591
648
723
743
Spread
42
21
22
22

Table 2: 12 ft lbs kit test results

With the power being a bit low I disassembled the rifle again and added a spring spacer that I bought from Air Rifle Headquarters. The spacer that was installed was a .150 synthetic piston spacer so it didn’t add much weight to the piston. The extra spacer brought the velocity up to 780-785 fps which is just about right for a 12 ft. lbs. rifle. The rifle still had a smooth firing cycle with no diminished accuracy.

Onto the Pro-Guide2 Elite series kit. I decided to test the kits with the weighted end of the spring installed both forward and rearward in the rifles. The testing started with the MkII rifle this time. The kit produced the full 15 ft. lbs. of energy with both pellets tested. There wasn’t really much difference in the shooting cycle with the weighted end either forward or rearward. The feel of the shooting cycle was basically the same either way. However the power was increased slightly with the weight installed forward in the piston, as shown in Table 2 below. The overall firing cycle had more movement in it in when compared to the 12 ft. lbs. but it was definitely less than the factory spring. The firing cycle seemed a bit quicker and quieter than the factory spring with no spring twang or felt vibration. The overall noise seemed lower too.

Weighted Rearward
Weighted Forward
Shot
CP 7.9
JSB 8.44
CP 7.9
JSB 8.44
1
926
894
933
905
2
906
887
933
898
3
928
899
923
903
4
923
897
925
897
5
929
893
934
910
6
894
887
932
903
7
929
901
912
903
8
925
884
932
907
9
928
898
920
891
10
930
902
932
901
Ave
921.8
894.2
927.6
901.8
Energy
14.9
15.0
15.1
15.2
StdDev
12.02
6.34
7.35
5.41
Hi
930
902
934
910
Lo
894
884
912
891
Spread
36
18
22
19

Table 3: TX200 MkII test results with Pro-Guide2 Elite series kit

The shot to shot consistency was not quite as good as the factory spring in the MkII but the accuracy didn’t suffer as I was able to shoot some pretty tight groups with the kit installed. To be fair, the test velocities were measured with fresh install of the kit and with only a handful pellets shot through the rifle before testing. I would bet that after a few hundred rounds the consistency would improve as the excess lubricants would be used up and the kit would settle in.

Once the MkII was testing was complete, the Pro-Guide2 Elite series kit was installed into the MkI. According to Tom Gore, neither the 12 ft. lbs. nor Elite series kits have been tested in an original MkI TX200 so I didn’t know what to expect. I was hoping that the 15 ft. lbs. kit would produce at least 12 ft. lbs. so it would be a viable option for tuning my MkI. I was pleasantly surprised with the results shown in Table 4 below. The kit was developing an average of 13 ft. lbs. of energy in the MkI power plant. At that level, the rifle shot much like the MkII at 15 ft. lbs. It was smooth with no vibrations or twang. I didn’t feel any appreciable difference between having the weight forward or rearward in the MkI rifle even though the energy was increased slightly with the weight forward. The accuracy was spot on and I shot what was easily a dime sized 6 shot group at 50 yards. So the kit could be used for tuning a MkI and obtaining more power than the original 12 ft. lbs. configuration.

Weighted Rearward
Weighted Forward
Shot
CP 7.9
JSB 8.44
CP 7.9
JSB 8.44
1
850
844
850
851
2
853
841
845
858
3
855
845
847
856
4
849
857
848
855
5
856
855
843
847
6
850
844
849
860
7
856
849
848
844
8
852
851
840
858
9
855
849
845
855
10
850
847
849
856
Ave
852.6
848.2
846.4
854
Energy
12.8
13.5
12.6
13.7
StdDev
2.76
5.07
3.13
5.12
Hi
856
857
850
860
Lo
849
841
840
844
Spread
7
16
10
16

Table 4: TX200 MkI test results with Pro-Guide2 Elite series kit

But what if I want to make the rifle legal for Field Target shooting in the International class? Tom had mentioned that the Elite series kit had power washers installed at the factory that would produce 15 ft. lbs. in a MkII power plant. He also said that the synthetic and steel washers could be moved around or removed to obtain the desire power level and firing cycle. I decided to disassemble the rifle and remove two of the steel springs from the weighted end of the spring and to position the remaining weight to the rear of the rifle. This setup produce right at 800 fps with JSB pellets. That is right at the legal limit for international class and since some occasionally exceeded the 12 ft. lbs. limit, I decided to remove one more steel washed at the rear and add aftermarket piston power washer to the piston. This combination yielded 790 fps with a variation under 10 fps. The shot cycle was very smooth at this level and still very quick.

Both kits worked as advertised and both were very easy to install. Neither of the kits had any spring twang while the perceptible vibration and noise was lower. There was still movement in the rifle upon firing but the shot cycle was quick and the reduced vibration made follow through easier.

I didn’t feel any big difference in the weight distribution either forward or rearward but the results show that a bit more power can be obtained with the weight forward. This concurs with what I have heard from other tuners that a little extra weight in the piston can help overcome the frictional resistance of a tight pellet in the bore and make the shooting cycle a bit smoother. Well, I didn’t feel it but the extra weight did increase the energy a bit without affecting the shooting cycle.

All in all the kits performed well and made for a nice shooting rifle. I was pleased with their performance and ease of installation. The only thing I wasn’t able to test was the longevity of the kits and how they will hold up over time. That test will take a bit more time to perform.

 

Back to Review Page
Back to American Airgun Home
Top of Page

German Premier Airguns
click the ad to visit this advertiser, View All Advertisers On This Page

© Copyright 2006 by Brad Troyer & American Airguns