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Posted: 3/10/2011 2:13:58 PM EDT
| Can someone enlighten me as to what benefit they provide? I am shopping for triggers and have seen this term. What is lockup time in regards to an AR15 trigger? Thanks |
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I'm sure I couldn't say it any better than the company that manufacturers them. This is from the JP site: The JP Speed Hammer is the perfect compliment for our trigger system. This low mass hammer gives a 50% reduction in lock time for improved accuracy and ignition reliability. Hammer fired ignition systems are notorious for slow lock time and the torque effect of the hammer accelerating through its arc is transmitted through the whole rifle. Try dry firing your rifle as you look at a 100 yard target and see how far the scope moves off point of aim. The JP Speed Hammer minimizes the effect for a significant improvement in accuracy potential. This hammer is so fast you can hear the difference when you dry fire. It's as close as you can come to the lock time and torque free function of a linear striker system in this type of mechanism. The JP Speed Hammer is not compatible with standard M15 trigger parts. The new design in made from laser cut cryogenically treated A2 tool steel, hardened to 58 Rockwell all the way through, not just on the surface like conventional hammers. It also features a precision pressed in stainless pin boss for accurate alignment. Improved metallurgy, precision geometry and notch preparation result in a durable high performance part. Now supplied with a "D" spring to retain standard grooved trigger pins. |
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In bolt action rifles, the striker moves less than 1/8". It has a high spring force. The AR15 hammer moves a good deal through its arc. Lighter hammers move faster. Since the energy required to set off a primer is from the spring, changing the hammer does not reduce the firing pin energy. But lighter hammers reduce lock time because they accelerate faster. Yes, lock time in an AR15 is very long. |
| Only noticable on the top end of the accuracy scale. The standard AR hammer has evolved from the "hooked" hammer that was designed to be caught and delayed during full auto fire. The extra mass is not required for semi auto rifles. For a standard combat type rifle, limited returns, if your trying to squeeze the best possible accuracy out, might be worth the trouble. I pruned the spur off mine when I added the JP springs..... |
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I am just trying to get a better trigger for my target rifle. I only use it out to 200 yds and it isn't a top of the line rifle rifle but it is good enough for my needs, but the trigger really sucks. I am thinking about sending the trigger group to Bill Springfield and getting the 2.5 lb trigger job does anybody have any reviews?
ETA: I think I am going to try to do a trigger job myself. I did a quick search of the archives and found this. I just need to find a FCG on the EE and buy some JP springs. I like to try new things, I'll see how it turns out and post it. |
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The energy a hammer imparts to the firing pin is a product of its mass and its spring power. Lightening the hammer reduces inertial mass, so the spring is more important in providing enough energy, but it also reduces "lock time"-that's the time between sear disengagement and the hammer striking the firing pin. That is where the accuracy part of the equation comes in; with less time between the final slip off the sear notch and impacting the firing pin, external forces (like breeze and shooter movement) are minimized.
I haven't used a lighter hammer, but I'd be cautious to ensure that if I did, I had an appropriately strong spring moving it. |
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Quoted:
Can someone enlighten me as to what benefit they provide? I am shopping for triggers and have seen this term. What is lockup time in regards to an AR15 trigger? Thanks snake oil IMO, the time it takes for the hammer to drop is instant for all intents and purposes. making it fast will not help your shooting, unless maybe, youre shooting benchrest or something. But for 99.9% of ars out there, dont bother. I would not do it on a combat weapon. FWIW, titanium fireing pins are definitely a no-go, they have a habit of breaking IIRC. |
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