If you look at the locking bolts for any of the Encore, Contender, or G2 barrels from the side, you will see that the top surface of the locking bolts where they engage the frame are slightly angled. Thus, the more strength there is in the locking bolt spring pushing the locking bolts in under the frame's "locking table," the more firmly the barrel is locked up. The farther in the locking bolts go, the tighter they get.
Contenders are particularly sensitive to an inadequate engagement of the locking bolts. If the locking bolts do not engage far enough into the frame, the hammer block safety mechanism is such that it often interferes with the hammer fall enough to cause misfires or eratic ignition. A stronger locking bolt spring forces the locking bolts farther into the frame and helps insure an adequate lockup for more reliable functioning and better accuracy.
However, stronger locking bolt springs are not a substitute for properly fitted locking bolts of the right height. This is a subject we will be addressing here on the store in the near future.
Encores and G2s do not have the hammer block related issues that plague the older Contender design. Instead, if the locking bolts are not engaged far enough, you simply cannot cock the hammer. So with the Encore and G2 it is not a "misfire" issue, but rather an accuracy issue that our Heavy Duty Locking Bolt Springs address.
It is interesting to note that when TC designed the Encore barrels with their wider barrel lugs and wider locking bolts, they failed to increase the strength of the spring that pushes the locking bolts into engagement. Thus the same Contender size spring is also expected to be sufficient for the greater size locking bolts and the greater forces found in the higher intensity Encore barrels when the stock Contender locking bolt spring needs to be stronger even for the Contender. I find this quite interesting.
With any of the vintages of frames, locking bolts that are only marginally engaged into the frame put more force on a smaller area and tend to round the locking table. This has been particularly true of Contenders where the combination of firing hot loads continuously and the locking bolts just barely engaged eventually results in the barrel flying open when fired.
Applying more force to engage the locking bolts helps ensure more contact between locking bolts and the frame and helps reduce wear on the frame.
Supplying my oversize hinge pins over the years has proven the accuracy benefits a tighter, more secure barrel lockup provides. While a tighter fit at the hinge is essential to best accuracy, the rear of the barrel must be secure also.
If you click back one page to the picture of the barrel, spring, locking bolts, and locking bolt retaining pin, you can see a bare spot in the bluing on the round part of this used barrel where it seats in the frame. Look directly above the retaining pin on the round part of the barrel.
This contact point acts as a fulcrum or "teeter" point. If there is any play at all at the hinge pin, the barrel actually teeters downward at the rear. Of course our oversize hinge pins remove the play at the hinge area, but applying more force to the locking bolts also puts more pressure on the hinge area, effectively making it tighter on a loosely fitted pin. So if you opt to not use oversize hinge pins, at least tighten things up with Heavy Duty Locking Bolt Springs for more securely engaged locking bolts.
The stiffer springs do make unlocking the barrel more difficult as would be expected. This is less of a problem with the "Easy Open" Contender frames whose trigger groups pivot at a point just above the trigger. However, the older frames that pivot at the front of the frame are often hard to open with just the stock spring.
In the event an easier unlocking is desired, you can shorten the spring a little while still having a stronger spring than the factory issue spring. Just grind some off the end or clip some off with a good wire cutter.
Our Heavy Duty Locking Bolt Springs are carefully engineered to apply optimum force to the locking bolts over an extended period of time. They are "pre-set" at the factory to make them easier to install.
Get the best performance you can from any of your Contender, G2, or Encore barrels with a secure lockup using our Heavy Duty Locking Bolt Springs.
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Tip: Print this page out so you have the disassembly/reassembly sequence and safety function checks handy. No printed detailed instructions come with the springs or pliers. Purchase our Bellm Trigger Job Instruction Manual Separate.
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