Why HD carrier dog spring?
Why HD carrier dog spring?
Why is the HD spring part # F16966 considered an upgrade on a non police model 870? What does the heavier spring actually do? Does it lift the shell with more authority?
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Re: Why HD carrier dog spring?
The carrier dog follower spring isn't what lifts the carrier up; the slide assembly acts directly on the carrier dog to do that. The spring holds the carrier dog against the slide assembly so that they can engage, and it holds the carrier in the up or down position.
As far as my understanding goes, the extra-heavy carrier dog follower spring has the following advantages:
>Its extra stiffness means that even if allowed to wear out, it will ensure reliable function for longer. Obviously you should be replacing any carrier dog follower spring at appropriate intervals if you use your shotgun very heavily (and I mean very heavily, there are 870s from the 1950s that are still running reliably on their original springs), but if a shotgun regularly has lives depending on it, it's nice to have a little extra margin for error in case the person maintaining it isn't quite on the ball. Law enforcement shotguns are an obvious case where might apply.
>The extra stiffness could help keep the carrier system functioning if other parts are damaged, and not quite interacting properly. I know of one anecdote where someone used poor-quality aftermarket replacement trigger plate pins that misaligned the trigger plate assembly, causing the carrier to malfunction until they put in an extra-heavy carrier dog follower spring. Obviously, the spring wasn't actually the issue in that case, but it is conceivable that a very roughly-used combat shotgun could become similarly messed up during an encounter, and a little more force from that spring could be the difference between a mis-feed and a life-saving shot. Again, something applicable to LE/military use more than anything else, since it's hard to imagine situations outside of rough combat where an 870 would be treated harshly enough for things to start breaking inside it.
>Since an 870's carrier is held in the down position when the action is closed, it provides a measure of protection in harsh environments. If an 870 is dropped loading port-first into mud or snow, the spring-loaded carrier will help to block ingress, and even if it is pushed aside, it will try to push any debris back out once the gun is picked up (this is one reason I prefer the 870's style of carrier over retracted carriers like those found in Mossberg 500s or Ithaca 37s). Since the carrier dog follower spring is what serves this function, a stiffer spring means the carrier is better able to keep foreign material out of the action.
These advantages (as well as others that are misconceptions) sound good, and since folks like to tinker and do whatever they can to improve their toys, they tend to go for the extra-heavy spring. However, as with anything, there are also downsides to consider:
>Since the stiffer spring holds the carrier down with more force, it makes loading the gun less forgiving. A minor slip-up when pushing a shell into line with the magazine is more likely to end with the shell being flipped out of your grasp and onto the floor. This is something that should be considered by users who don't put in enough practice time to develop good muscle memory for this technique - which covers a large number of people who keep 870s for HD. Or, even if you practice a lot with it, what about when you're stressed-out and pumped full of adrenaline? Or what if you're not home, and your less-experienced spouse or kid is the one trying to use the thing?
>There's also the fact that the extra spring force increases friction in the gun's action. None of the parts involved here are realistically going to wear out or anything, but there is noticeable added resistance when working the action on an 870 that's been broken in if you replace the standard carrier dog follower spring with a heavier one. This perhaps has a slight chance of encouraging short-strokes, but I'd say it more just takes away from the great feel of a properly run-in 870 action.
So, as with most "upgrades", the value depends on your particular needs and application. In certain situations, I would agree that the extra-heavy carrier dog follower spring is nice to have, but in others, it's not necessary, and even somewhat counter-productive. It's sort of like putting tires with a speed rating of 149 miles per hour on your daily driver that never gets above 75. Are they really an upgrade? Or are you just getting lost in stats that really don't apply to your situation, and maybe even hurting your ride quality & increasing road noise in the process?
As far as my understanding goes, the extra-heavy carrier dog follower spring has the following advantages:
>Its extra stiffness means that even if allowed to wear out, it will ensure reliable function for longer. Obviously you should be replacing any carrier dog follower spring at appropriate intervals if you use your shotgun very heavily (and I mean very heavily, there are 870s from the 1950s that are still running reliably on their original springs), but if a shotgun regularly has lives depending on it, it's nice to have a little extra margin for error in case the person maintaining it isn't quite on the ball. Law enforcement shotguns are an obvious case where might apply.
>The extra stiffness could help keep the carrier system functioning if other parts are damaged, and not quite interacting properly. I know of one anecdote where someone used poor-quality aftermarket replacement trigger plate pins that misaligned the trigger plate assembly, causing the carrier to malfunction until they put in an extra-heavy carrier dog follower spring. Obviously, the spring wasn't actually the issue in that case, but it is conceivable that a very roughly-used combat shotgun could become similarly messed up during an encounter, and a little more force from that spring could be the difference between a mis-feed and a life-saving shot. Again, something applicable to LE/military use more than anything else, since it's hard to imagine situations outside of rough combat where an 870 would be treated harshly enough for things to start breaking inside it.
>Since an 870's carrier is held in the down position when the action is closed, it provides a measure of protection in harsh environments. If an 870 is dropped loading port-first into mud or snow, the spring-loaded carrier will help to block ingress, and even if it is pushed aside, it will try to push any debris back out once the gun is picked up (this is one reason I prefer the 870's style of carrier over retracted carriers like those found in Mossberg 500s or Ithaca 37s). Since the carrier dog follower spring is what serves this function, a stiffer spring means the carrier is better able to keep foreign material out of the action.
These advantages (as well as others that are misconceptions) sound good, and since folks like to tinker and do whatever they can to improve their toys, they tend to go for the extra-heavy spring. However, as with anything, there are also downsides to consider:
>Since the stiffer spring holds the carrier down with more force, it makes loading the gun less forgiving. A minor slip-up when pushing a shell into line with the magazine is more likely to end with the shell being flipped out of your grasp and onto the floor. This is something that should be considered by users who don't put in enough practice time to develop good muscle memory for this technique - which covers a large number of people who keep 870s for HD. Or, even if you practice a lot with it, what about when you're stressed-out and pumped full of adrenaline? Or what if you're not home, and your less-experienced spouse or kid is the one trying to use the thing?
>There's also the fact that the extra spring force increases friction in the gun's action. None of the parts involved here are realistically going to wear out or anything, but there is noticeable added resistance when working the action on an 870 that's been broken in if you replace the standard carrier dog follower spring with a heavier one. This perhaps has a slight chance of encouraging short-strokes, but I'd say it more just takes away from the great feel of a properly run-in 870 action.
So, as with most "upgrades", the value depends on your particular needs and application. In certain situations, I would agree that the extra-heavy carrier dog follower spring is nice to have, but in others, it's not necessary, and even somewhat counter-productive. It's sort of like putting tires with a speed rating of 149 miles per hour on your daily driver that never gets above 75. Are they really an upgrade? Or are you just getting lost in stats that really don't apply to your situation, and maybe even hurting your ride quality & increasing road noise in the process?
Re: Why HD carrier dog spring?
Thanks Sync! After reading your reply several times I think I may order the heavier spring and give it a try.
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Re: Why HD carrier dog spring?
Sure. If you can still reload the gun reliably and you don't mind (or notice) the extra slide resistance, there's not much else to say against the heavier spring. And if you don't like it, it's easy to switch back.