MAGNUM RIFLE ADJUSTERS for Discovery, Maximus & 2260

$30.50

This item is out of stock

 These adjusters are listed in 6061-T6 aluminum, black anodized 6061-T6 and 360 brass. The full-size version has a locking collar and tick marks on the back of the knob to help gauge and maintain adjustments. The compact adjuster has no knob or collar, it requires a 3/16 hex wrench to adjust it which is not included but is listed separately in the TOOLS & SUPPLIES section. The striker spring can be removed by backing the adjuster knob/guide-screw all the way out. The adjustment range is wide enough to produce maximum power, maximum shot count or the precise level of performance you want anywhere in between. These will also fit 22XX, they are the same adjusters but include the shorter rear trigger frame screw described below.

 Discovery, Maximus, 1760 and 2260 models require a shorter rear trigger frame screw. The original screw is too long and will hit the adjuster knob threads. A length of 3/8" works best. One 3/8" alloy-steel socket screw is included. It requires a 3/32" hex wrench to install which is not included but is listed in the TOOLS & SUPPLIES section.

 The Maximus striker spring will not fit on these adjusters, a Discovery or Magnum striker spring should be used instead. I have those listed separately. 

 The following chrony test results compare a standard Discovery .22 to one modified with a combination of this and other custom parts I have listed. 14.3 Grain pellets were used for both tests. Testing was stopped at 100 FPS below peak power. Fallowing that are more dramatic results produced by replacing the original Discovery valve with a Magnum Valve. 


Unmodified Discovery .22 starting at 2000 PSI :

1)      888.1   muzzle velocity in FPS (feet per second)
2)      901.0   peak power
3)      899.8
4)      878.8
5)      877.7
6)      871.5
7)      855.6
8)      854.9
9)      849.6
10)    843.0
11)    837.1
12)    836.0
13)    827.6
14)    819..7
15)    813.4
16)    797.1   100+ FPS below peak power

.22 Discovery with custom valve screws, Magnum Adjuster, .045 Magnum Hammer Spring, wide-bore gauge port or bypass cap, 26" Maximus barrel and a starting pressure of 3200 PSI. 

1)     958.8
2)     965.9
3)     971.2
4)     973.4
5)     977.2
6)     978.9
7)     984.5
8)     991.6
9)     994.7
10)   989.3
11)   997.6
12)   1000
13)   1007
14)   1002
15)   1005
16)   1009   peak power
17)   998.8
18)   1002
19)   990.1
20)   982.7
21)   977.8
22)   965.2
23)   958.3
24)   949.4
25)   938.3
26)   918.7
27)   907.6   100+ FPS below peak power

 The following chrony results were produced with an upgraded Discovery .22. It had a 26" Maximus barrel, wide-bore gauge port, 3500 PSI gauge, .045 Magnum Hammer Spring, Magnum Adjuster, Magnum Valve with a short cap and custom valve screws for higher pressure. The transfer sleeve and barrel port were both deburred and polished which enlarged each by about .003".


PSI     PELLET   FPS     FPE

3200   10.03 g    1288    36.9

3200   14.3 g      1142     41.4

3200   18.21 g    1086     47.7

3200   25.39 g    1000    56.3

3200   33.95 g     905     61.7


  The following chrony results were produced with the same gun as above but with the Custom Bypass Cap instead of the wide-bore gauge port. The adjuster was set  3.5 turns back from full spring compression. The starting pressure was 3200 PSI. JSB Jumbo Monster 25.39 and Jumbo Beast 33.95 produced the best consistency and groupings of about a dozen types and weights tested. Heavy pellets work best at these extreme power levels.    

1)    817  FPS    33.95 g    50  FPE

2)    833

3)    837

4)    843

5)    845

6)    850

7)    853                             54  FPE

8)    849

9)    838

10)  824

11)  816                            50   FPE