Misfires are very common with the TC break open guns, but easy to cure if you know what to do.
Misfires do not need to be a problem at all.
In spite of all the information on the website and my best efforts, hardly a day goes by without calls or email regarding misfires with the break open TC guns. It is chronic, one of the major problems you folks have shooting Contenders, Encores, and G2s. I
f it has not been a problem to you yet, sooner or later it will be. Count on it if you shoot these guns much at all, but be prepared to deal with it without much more than a hiccup.
Encore and G2 misfires are usually due to:
1) Excess Headspace and/or
2) Inadequate hammer spring tension.
Assuming the primers are good, Encore and G2 misfires and inaccuracy related to inadequate or marginal hammer spring tension are aggravated by the weight of a hammer extension added to the mass the spring must move to fire a primer and to excess headspace, especially with rimless and belted mag cases.
Bellm Stronger Hammer Springs.
Our stronger 41 pound and 51 pound hammer springs replace the marginal 30 pound factory issue hammer spring and are a MUST if you use a hammer extension!
Failure to be able to pull the hammer to the rear to cock it is
caused by either the locking bolts not going into the frame far enough or cases sticking out of the barrel too far interfering with complete closing of the barrel and the locking bolts moving the interlock far enough back to unlock the hammer so it can rotate.
With the Contenders
it may be simply that the lockup is too tight, preventing the hammer block from dropping freely as is often the case. The locking bolts must adequately engage the frame to rotate the interlock plate and allow the hammer block to drop freely. If the hammer block drags on the interlock, the hammer block does not clear the falling hammer. The hammer dings the top of the block and loses enough inertia to fail to fire primers. The remedy is to lower the locking bolt surface that engages under the locking table in the frame. Stone down this top surface just enough that it can travel adequately into the frame, but do not alter the slight rear to front "draft angle" of the engagement surface. Inking the top surface then opening and closing the barrel should show the ink marred well forward of the "U" notch in the locking bolts.
EITHER excess headspace or the case sticking out of the barrel too far, meaning no space at the case, cause misfires. If the case sticks out of the barrel too far, it prevents the barrel from closing all the way and allowing the locking bolts to fully engage the frame. Thus the gun will not fire. Inadequate hammer spring tension is also common to the Contender. The high stress design of the Contender hammer spring makes it more susceptible to losing tension and becoming too weak to fire primers.
I have also seen instances where the vertical arm of the sear that holds the hammer block up when the hammer is cocked drags ON THE BACK SIDE of the hammer block as it is released. This slows the hammer block with the result the hammer dings the top of the block and loses enough inertia to fail to fire primers.
Click Here to View Our Contender Firing Pins!
All springs take a set and weaken to some degree over time. Simply installing a new factory Contender hammer spring periodically is highly recommended. The factory Contender hammer springs are already about as strong as can be made for this application.
Do primers either fire all the way or fire in varying degrees? Here is an example of what happens.
Pulled bullet and clumped powder from a misfired .45/70. The powder was heated enough to clump it together, but not enough to sustain combustion. Note how the powder is clumped together, indicating the primer fired, but not with enough intensity for combustion of the powder to be sustained.
This is an instance where the gun simply did not fire. But what if combustion had continued enough for the bullet to make it out the barrel? And at what speed? And impacting where on the target? The point is that primers do in fact fire with varying degrees of force depending among other things on how they are struck by the firing pin. If primers fire consistently with full force igniting the powder the same way each time, we can expect good accuracy if everything else is right. But when primers fire with varying degrees of force, eratic ignition results, and often shows up as vertical stringing of shots on the target.
How to fix the problem? Correct the headspace, ideally to about .001 to .002," minimum headspace, but NOT cramming a too long case into the chamber either. Either install a new factory fresh hammer spring in Contenders or in G2s and Encores, our heavy duty 51# hammer spring.
The Encore and G2,
which both use the same exact hammer springs, need to have a much stronger hammer spring than the factory installs in them. Our Bellm Custom Heavy Duty Encore and G2 Hammer Springs have been a great help in alleviating this problem, but if excess headspace is the issue, a stronger hammer spring is a band-aid covering the sympton and not treating the cause, excess headspace.
The main cause of misfires in Encores and G2s
is having to move the entire mass of the cartridge and extractor forward until the cartridge comes to a stop so the firing pin can dent the primer, then not having enough energy left to fire the primer. This is especially true with rimless and belted mag cases where the spring loaded extractor holds the case back against the breechface while closing the barrel.
The firing pin then must move the case and extractor forward until the case comes to a stop and is supported so the firing pin can dent the primer sharply with all its energy. If too much energy is lost moving the case forward, even our strongest hammer spring may not be strong enough, (Our 51 pound spring is about the absolute maximum force that can readily be obtained with a spring this size.), and the issue of headspace will ultimately still have to be dealt with.
One beauty of the TC break open system is the ease with which the user can make his own headspace corrections
by either correctly adjusting the size die or shimming the firing pin bushing forward. Correctly adjusting the size die requires taking two simple measurements. First, the barrel-to-frame gap is measured with a feeler gauge set, and then the location of the case head relative to the end of the barrel made to determine if it is dead flush with the end of the barrel, sticking out of the barrel and by how much, or falling below the end of the barrel and by how much. This measurement compared to the barrel-to-frame gap tells you exactly what the headspace is with any cartridge. Click Here to View the Bellm Headspace Indicator!
If you don't want to get involved in headspace issues
as easy and simple as it is, and prefer to have someone else fix it for you, contact Kurt Michael Bellm and make arrangements for him to make the correction for you.
What he can do in addition to installing a heavier hammer spring:
1) Shim the firing pin bushing forward to close up headspace on factory ammo or new brass. This is especially needed with the belted mag cases.
2) Face off the end of the barrel if there is not enough room to shim the firing pin bushing forward and/or if the barrel itself is hitting too hard on the firing pin bushing, but the headspace is ok.
3) Lower the tops of the locking bolts to get full engagement in the frame to move the interlock the required amount for the frame to function.
4) Not directly related to headspace: Fit oversize hinge pin, do forend bedding, or do a trigger job.
What he cannot do:
1) Correct lockup if the present locking bolts give a lock up that is too loose. (Has to go back to the factory or to a TC "authorized repair station," which neither of us are.)
2) Hold your hand while you continue to make the same mistakes resizing cases without taking the required steps to assure correct/minimum headspace yourself. He or I can coach you on what needs to be done, but ultimately if you reload, sooner or later you will have to pay close attention to size die adjustment. If you don't, you will have problems, no matter how much experience you have reloading for bolt actions and fixed barrel single shots
The TC break open guns are a different breed of cat,
easily tamed with some understanding, but best gotten rid of if not dealt with accordingly. That is the cold, hard truth that has been born out time and again throughout the history of the Contender and continues to be the case with Encores and G2s. Our approach to TCs is driven by education and "self-help," but if you want someone else to do it for you, here is a solution that may help many of you. Between Jim "SHOTS" Hendershot and Bellm TCs, we can make any of the misfire problems go away