BAT Machine Co., Inc. | 11550 N. Bruss Rd. | Rathdrum, ID | 83858 CALL US TODAY: (208) 687-0341
Bat Machine Co. precision rifle actions, machining and tooling


What is your lead time on actions.

  • Our AVERAGE lead time is running at 6-8 months.

How do I go about ordering an action?

How to choose an action



Material and hardness of major action components:

  • Bolt: 4140; 40 or 44 RC depending on action
  • Bolt Handle: 17-4 SS
  • Firing pin: 1144-fatigue proof
  • Shroud: 303 SS
  • Cocking Piece: 1018 Carburized
  • Body: 17-4 SS; 36-38 RC
  • Body: 4140 CM; 36-38 RC

Action body to bolt clearance:

  • Benchrest actions: .0015 inch
  • HR, VR, BTA, BTLA & TR actions: .0025 inch

Firing pin info:

  • Firing pin travel: .210-.230 inch.
  • Firing pin tip diameter: .070 inch
  • Firing pin protrusion: .054-.056 inch

Action bolt diameter:

  • 2 lug actions: 0.719 inch    Bore: .720      Bolt: .7185
  • 3 lug actions: 0.900 inch    Bore: .900      Bolt: .8985

Lock time:

  • 2.2 milliseconds


How to remove firing pin assembly from bolt

On all bayonet style bolts you just need to twist the cocking piece & shroud AWAY from the cocking ramp. When the cocking piece lines up with the edge of the bolt handle it will pop out in your hand. To reinstall the assembly line up the ears of the shroud with the slots in the bolt and push together, when fully inserted twist TOWARD the cocking ramp making sure NOT to fall into it. Just before the ramp you will feel the cocking piece fall into the small detent that holds it in place.

How to fully disassemble the firing pin

Remove firing pin assembly from bolt, see instructions above. With the firing pin assembly out of the bolt the first thing you may want to do is measure the location of the firing pin in relation to the shroud so you can go to the same dimension when you put it back together. Next you will need to remove the TWO (2) set screws holding the cocking piece to the firing pin. These screws are installed using Loctite 222MS (low strength) and it often helps to heat up the cocking piece with a torch or even a cigarette lighter, it only needs heated up to the point you don’t want to touch it. Then using a GOOD sharp 1/16” allen wrench remove the first set screw, then put the wrench back in the hole and remove the second screw. Now the firing pin can be removed from the cocking piece. To do this we have found that it is quick and easy to use a ½” cordless drill to grab the firing pin, put the firing pin into the chuck so that the jaws are close to the large flange (you will be clamping on the .17” portion of the pin not the .070” tip) now put the drill in reverse (counter clockwise) so that you are unscrewing the firing pin. Unscrew the  firing pin until the shroud and cocking piece come apart.

When you are ready to put it back together do everything in reverse. We find that when screwing the firing pin back into the cocking piece it is easiest to put the back of the shroud against the side of a table or door frame and hold the cocking piece against the front side of the slot, this allows you to compress the firing pin spring easily and the firing pin can quickly begin threading into the cocking piece (the drill needs to be turning clockwise as it is a right hand thread). Thread it back to the dimension you took before taking it apart or use the instructions below on how to adjust the firing pin fall, when done install the two setscrews using the Loctite 222, do not use anything more aggressive or you may not be able to get it apart in the future.

How to adjust the firing pin fall on .250 diameter firing pins 

First note that the firing pin protrusion is set from the factory but the firing pin travel distance can be adjusted slightly on actions produced before 2014. With our new large diameter firing pin the travel distance is preset from the factory and can not be adjusted. The new pin measures .280” diameter (area under the spring), the old pin is .250” diameter.

If you have a model DS or one of our actions that has an adjustable trigger hanger you can turn the hanger 180 degrees, or install a different hanger for a total change of .030”. Standard position of the hanger is to have 0 forward and 30 at the rear of the gun. If you want .030” more firing pin fall take out the hanger and trigger and install with the 30 forward, this moves the trigger rearward by .030”. Doing this may cause the bolt to not close smoothly and so you may want to use the 10-20 hanger to fine tune to get the best closing feel along with the most firing pin travel. Again on the 10-20 hanger whatever number is forward is the amount of additional firing pin travel you have from the 0 position.

The other thing you can do is make sure that the firing pin is in the correct position within the cocking piece. This can move over time if someone has taken the firing pin apart and not assembled it correctly. To do this you need to have a firing pin tool. What you are looking for is that when the cocking piece/shroud is twisted and the cocking piece moves to the bottom of the ramp there MUST be some free play, it should be between .010” and .020” gap from the end of the cocking piece to the bottom of the cam. (See photo below). NOTE: As noted above this dimension is preset and is not adjustable on firing pins produced for new actions beginning mid 2014, these pins measure .280 diameter under the firing pin spring.

If there is less distance between these surfaces you will need to unscrew the firing pin from the cocking piece (NOTE: REMOVE BOTH SET SCREWS BEFORE TRYING TO TURN THE FIRING PIN. Go ¼ turn at a time until you get to the numbers listed above (each ¼ turn equals .009” change). If you have more play then listed, screw the firing pin INTO the cocking piece, go ¼ turn at a time and re check until you get in the range listed above. Once you have it where you want it, reinstall the set screws using Loctite 222. Also make sure the bolt handle is NOT touching your stock, if it is it will limit the firing pin travel and will cause the cocking piece to hit the bolt body resulting in a loss of accuracy and will damage the components.

General questions:

Will my scope fit using your short or tall rings? 

  • Fill out our spread sheet and get your answer!!

What barrel size do I use? For more detailed information see specific action Prints above.

  • Model EX with 1.500 x 16tpi thread requires a minimum of 1.75 diameter barrel.
  • Model L with 1.25 x 16tpi thread requires a minimum of 1.45 diameter barrel.
  • Model CT or L (1.55 dia) with 1.187 x 16tpi thread require a minimum of 1.35 diameter barrel.
  • Model M & HR with 1.125 x 16tpi thread require a minimum of 1.25 diameter barrel.
  • Models SV, S, SB, B, DS, MB, VR & TR with 1.062 x 18tpi thread require a minimum of 1.20 diameter barrel. On SB & MB actions see tenon print for maximum barrel size

How much torque do you need to put on the barrel?

  • If your machine work is good 75 ft/lb will be sufficient. Range 75-125 ft/lb.

Small screw torque spec (ALL in INCH POUNDS)

  • 8-40 scope base screws that screw into the action between .040 and .100 can be torqued between 18-20 in/lb.
  • 8-40 scope base screws that screw into the action .100 or more can be torqued between 35-40 in/lb.
  • Scope ring cap screws (6-32): Use scope manufactures torque specifications, if no specification are given 20- 25 in/lb should be sufficient.
  • Picatinny ring cross screw (10-32) can be torqued to 45 in/lb.
  • Action screws that are ¼-28 can be torqued up to 70 in/lb. Recommend 50 in/lb.
  • Front trigger guard screw (10-32) can be torqued to 30 in/lb

How much weight does a dual port remove from action?

  • 1.6oz on a 1.5 round 2 lug action.


BAT Machine Co., Inc. | 11550 N. Bruss Rd. | Rathdrum, ID | 83858 CALL US TODAY: (208) 687-0341