Tuning the Bold trigger "minimun pull"

Discussion in 'Long Range Hunting & Shooting' started by Bob the nailer, Dec 10, 2009.

  1. Bob the nailer

    Bob the nailer Well-Known Member

    Dec 9, 2009
    I'm new to the forum and thought I would share an article I wrote for a gunsmithing magazine. I am the aurthor so there will be no issues with anyone reposting this or copy/paste ect. It's good informative info and of course safe! enjoy;

    R. Coles

    Here is the article on Bold triggers.

    Bold Trigger tune – up

    Trying to find an aftermarket light weight target trigger for a M96 small ring Mauser can be very frustrating as most high quality light pull weight target triggers on the market are for M98 large ring Mausers. I am constantly fine tuning my custom built Swedish M96 small ring Mauser chambered in 6.5x55 Ackley Improved 40 degree shoulder, this is a bench rifle so a very light trigger pull weight is favorable. A Bold trigger was chosen for this project, they are of very good quality, very adjustable and proved to be quite easy to fine tune. My goal is to tune this trigger down to 1lb of pull weight and have it perform just as good as triggers costing three times as much!

    Bold Triggers can be purchased for around $40.00 (retail); they are made to fit various rifle manufactures for a drop in replacement fit and are adjustable for creep, over travel, sear engagement and pull weight. The factory minimum pull on these triggers is 2.7lb which is quite heavy for precise target or varmint work, keeping all the needed safety functions will be of high importance for this project target trigger. I will explain what I did to modify a Bold Premier Trigger model # OP – 94/96 with out side safety, available from Boyd Gunstock Industries, Inc. 25376 403rd Ave Mitchell, SD 57301 phone (605) 996-5011 fax (605) 996-9878.
    www.boydsgunstocks.com. Remember this modification will void any manufacture warranty! And your firearm must be unloaded at all times during tuning the trigger.

    Modifying trigger pull weight;
    Make certain the firearm is unloaded and remove the action from the stock. Follow the instructions included with the new Bold trigger for your specific firearm application; after trigger is installed on the action proceed with the following tuning process.
    First remove the front upper Allen screw (this is the creep and pull weight spring tension); I found this spring on my test trigger to have a slight burr on one end. Slip the spring over a small round screwdriver shaft so that the spring will spin freely. Very gently run the spring cross way on your bench grinder to reduce the outside diameter of the spring (reducing tension weight of the spring). This will be done in small amounts go slow and go by feel; a pass across a wire wheel will smooth out the roughness on the spring. Lightly lube the now reduced weight spring with a good lubricant - I use CLP by Break Free, part # 915-372 available at Midway USA 5875 West Van Horn Tavern Rd. Columbia, MO 65203 phone (800) 243-3220.
    www.midwayusa.com, reinstall spring, Allen screw and lock nut. Check pull weight with a trigger pull gauge and adjust screw tension (take several pull readings then average them), if pull is still too heavy clip ½ coil of spring from an end and retry pull weight. I found a 1lb pull weight quite easy to obtain and locked in on that setting. I also found this spring was the only one I needed to modify to reduce tension weight of the trigger pull. All other springs associated with this trigger need only adjusting to fine tune.

    Adjusting trigger overtravel;
    Now for the adjustments on the overtravel screw (this is the front lower screw) with the bolt locked in battery turn the screw in until the trigger is solid and will not move. Keeping light pressure on the trigger and turn out the screw until the trigger moves enough to release the sear, and then turn the screw out just slightly more to provide adequate clearance, tighten lock nut to hold screw position. This setting will prevent any added rearward movement from the trigger that could throw off the shot.

    Adjusting sear engagement;
    On the rear of the trigger is a very small Allen screw that will adjust sear engagement turning this screw out will increase sear engagement. Again with the bolt locked in battery turn this screw out until the bolt will not lift to open out of battery, turn this screw in until bolt unlocks – then turn in slightly more. With the sear engagement adjusted in this manner you end up with more engagement than was set at the factory. I felt the added sear engagement was not a noticeable amount due to the now lighter trigger pull; you can adjust for less sear engagement if slam fires are not an issue. Now with the bolt closed in battery and safety off rap action with a rubber or nylon mallet to try and trip “release” the trigger, also open and close the bolt with a quick hard stroke several times. If the trigger holds and will not trip you are all set, otherwise turn in pull weight screw (front upper allen screw) to increase trigger pressure slightly and retry. Apply a small amount of thread locking agent to the adjustment screws to hold everything tight when you have achieved the desired setting. I like to use “Loc tite #242” available at most hardware stores, this will hold very good and you can remove the screws with hand tools at a later time if you need.

    I installed my Bold Premier trigger on a custom M96 small ring Mauser and tested it extensively at the range; Pull weight was fantastic at 1lb with that breaking glass feel, overtravel was set to prevent any excessive trigger jerk. Safety was of major importance and was never an issue. A finely tuned trigger will only complement an accurate rifle, keeping in mind the rifle is tuned in other areas of accuracy as well and the shooter does his/her part correctly. So with a little time and tinkering a budget $40.00 trigger can perform like a winner. I understand this will not be for everyone to want to try, but with the economy today and just the fact you are reading this article will show you the cost savings of tuning a budget trigger to be a performer. This will mean profits in your pocket and you will have a satisfied customer too! Be careful, proceed slowly and excellent results can be achieved.


  2. Chas1

    Chas1 Well-Known Member

    Feb 15, 2009
    Bob, great article. Nice attention to detail and clarity. Thank you for sharing.:)

  3. Bob the nailer

    Bob the nailer Well-Known Member

    Dec 9, 2009
    Glad to hear you liked it.

    FEENIX Well-Known Member

    Dec 20, 2008
    Welcome to LRH and enjoy! Thanks for sharing your article. I'll be replacing the trigger on my old M94 soon.