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3gunnuts

JP jumps on the short stroke bandwagon

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Not everyone agrees with you and there is certainly nothing glaring about the statement.

If what you say were true then spring tubes would only need to be five or six inches long. But they aren't.

 

I'll tell you what. I just now took my PCC out of the safe and put in in the vice.

I opened it up, removed the buffer and spring, and installed a NFA polymer spacer.

The spacer is 3/4 inches long so I have effectively shortened the stroke by that much.

The bolt will lock back, but only by about an eighth of an inch.

I'll take it to the range tomorrow and if I find the dot bounce to be as you say, I'll be happy to apologize. 

Edited by MikieM

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22 hours ago, 3gunnuts said:

I tried my same setup with the bolt weight removed and got more dot movement so I put it back in

With  Armaspec there was no choice. The rod in the center of the buffer protrudes into the bolt carrier, so you have to take the weight out so it doesn't crash. As I said before, there was more weight in the gun this way than with the bolt as designed and the 7.5oz buffer.

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5 hours ago, MikieM said:

I'll tell you what. I just now took my PCC out of the safe and put in in the vice.

I did just that very same thing, albeit without the vice.

 

I wanted to see how much extra the bolt has when it bottoms out. Pulling the charge handle back all the way, there is less than .125" between the bolt face and the bolt catch,( more like  but that is the charge handle bottoming out, not the bolt.

 

Take the bolt out of the upper, lock the hammer back and push the bolt into the tube. When the buffer bottoms out, there is a bit more than .125" clearance between bolt and catch, maybe .150/.175 max. If I had the vice handy, I could have measured it. I use a standard Kaw Valley 7.5oz buffer with a piece of delrin on the back side of it to take up the metal on metal hit.

 

So I wonder, that isn't a whole lot of room to shorten it up, no matter what system I would use. On any loaded start, I lock the bolt back before inserting the mag, hit the bolt release and go. I wouldn't want to change that.

 

Any thoughts? And I do appreciate this discussion, I have picked up quite a bit.

Edited by SJMPCC022
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Quote

 

So I wonder, that isn't a whole lot of room to shorten it up, no matter what system I would use. 

 

 

 

I can measure my spacer when I get home, but I too found there wasn't MUCH room to play with. I would guess my spacer is only 3/8" wide. That said, it was enough room that I bent a Seekins bolt-catch to the point where it locked up the entire gun before using the spacer.


 

Quote

 

On any loaded start, I lock the bolt back before inserting the mag, hit the bolt release and go. I wouldn't want to change that.

 

 

 

 

I do exactly the same. I face-sanded my spacer until I could JUST lock the bolt back manually, but it's not enough space to function during live-fire. So I can still lock-back manually for loading on stage start, but no risk of locking open, bending/breaking bolt catch, etc. It's the best of both worlds IMO. Would be easy to do with a normal spring/buffer setup too. I'd have to measure, but I assume a 3/4" OD delrin rod would do the trick. 

 

 

Edited by Acer2428

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Just like I said, de-stroking my PCC by 3/4 of an inch did increase felt recoil. Watching the dot while I pulled the trigger showed a slight increase in movement, as well.

And why wouldn't recoil increase? Because I took away some of the action spring's ability to absorb the energy of the bolt/buffer as it traveled rearward. Eighth grade science.

 

Sorry, Memphis. No apologies forthcoming.

Edited by MikieM

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21 minutes ago, MikieM said:

Just like I said, de-stroking my PCC by 3/4 of an inch did increase felt recoil. Watching the dot while I pulled the trigger showed a slight increase in movement, as well.

And why wouldn't recoil increase? Because I took away some of the action spring's ability to absorb the energy of the bolt/buffer as it traveled rearward. Eighth grade science.

 

Sorry, Memphis. No apologies forthcoming.

A spacer is not reducing the action of the spring.  It is pre-loading it.  The same amount of resistance is still there it is just being applied over a shorter difference. It simply increases the initial resistance  the bolt must overcome before it can move rearward.  The same amount of resistance is still there it is just being applied over a shorter difference. It has ZERO effect on the max compression weight of the spring. Since the spring in my system never goes solid whether I use a spacer of not I am not losing anything.

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1 hour ago, 3gunnuts said:

A spacer is not reducing the action of the spring.  It is pre-loading it.  The same amount of resistance is still there it is just being applied over a shorter difference. It simply increases the initial resistance  the bolt must overcome before it can move rearward.  The same amount of resistance is still there it is just being applied over a shorter difference. It has ZERO effect on the max compression weight of the spring. Since the spring in my system never goes solid whether I use a spacer of not I am not losing anything.

 

You couldn't be more wrong.

Using a spacer shortens the spring. The more you pre-load, as you say, the more the spring shortens and the more it's effectiveness is reduced.

Regardless, if shortening the bolt/buffer stroke rearward in order to improve split times causes an increase in recoil then the trade-off isn't worth it, at least to my way of thinking.

Edited by MikieM

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The JP spacer is hollow and does not affect the spring. I have a Jones arms Kronos lower and use 124gr everglades ammo hp v2 with 3.6 gr of red dot. The short stroke kit really helped tame dot bounce on my 5lb 4oz rifle. I did have issue with the trigger not resetting.


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1 hour ago, MikieM said:

 

You couldn't be more wrong.

Using a spacer shortens the spring. The more you pre-load, as you say, the more the spring shortens and the more it's effectiveness is reduced.

Regardless, if shortening the bolt/buffer stroke rearward in order to improve split times causes an increase in recoil then the trade-off isn't worth it, at least to my way of thinking.

For simplicity sake let's say a spring takes 10#'s to compress over 10 inches.  If you preload the spring 20% by inserting a 2" spacer behind it the spring is still 10# at full compression. You have not taken any weight out of the spring. It does not increase or decrease the recoil at all.  That is a physics equation. It is the same amount of energy just realized differently. Short-stroking changes the recoil impulse to to a faster, sharper, shorter impulse rather than a slower, duller, longer impulse.  Some shooters will prefer the former while some will prefer the latter. This has been hashed over in the automotive suspension world. 

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Your comment is not relative to the discussion.

Memphis stated that short stroking the AR 9 action produces less recoil, with a corresponding reduction in dot bounce. I disagreed with him.

This morning at the range I proved him wrong. At least to my satisfaction.

 

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10 minutes ago, 3gunnuts said:

For simplicity sake let's say a spring takes 10#'s to compress over 10 inches.  If you preload the spring 20% by inserting a 2" spacer behind it the spring is still 10# at full compression. You have not taken any weight out of the spring. It does not increase or decrease the recoil at all.  That is a physics equation. It is the same amount of energy just realized differently. Short-stroking changes the recoil impulse to to a faster, sharper, shorter impulse rather than a slower, duller, longer impulse.  Some shooters will prefer the former while some will prefer the latter. This has been hashed over in the automotive suspension world. 

 

^^^  That's going to depend on the spacer.  If you insert a conical spacer that sits inside the spring coils, It will short stroke your buffer by allowing it to bottom out sooner but it's not going to change anything wrt the spring.

Edited by JAFO

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3 minutes ago, JAFO said:

 

^^^  That's going to depend on the spacer.  If you insert a conical spacer that sits inside the spring coils, It will short stroke your buffer by allowing it to bottom out sooner but it's not going to change anything wrt the spring.

No one is talking about conical spacers.

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9 minutes ago, MikieM said:

Your comment is not relative to the discussion.

Memphis stated that short stroking the AR 9 action produces less recoil, with a corresponding reduction in dot bounce. I disagreed with him.

This morning at the range I proved him wrong. At least to my satisfaction.

 

Uh.  I started the thread.  Pretty sure about what is relative to the discussion. :)

 

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Can you believe that guy. He's trying to sell something that will shorten the stroke of your AR, which will increase the recoil of your gun, by adding on to a device that's supposed to reduce the recoil of your gun.

Only in America.

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4 minutes ago, MikieM said:

Can you believe that guy. He's trying to sell something that will shorten the stroke of your AR, which will increase the recoil of your gun, by adding on to a device that's supposed to reduce the recoil of your gun.

Only in America.

 

Some of our guns really run a lot flatter with a short stroke. So much so, it’s downright obvious.

 

There are a lot of different ways to build an AR, and not everyone’s is going to behave like yours.

 

I believe you when you say it doesn’t work for you. In my funky little guard build, removing the wave spring and spacer will double how much the dot moves in recoil.

 

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8 minutes ago, MikieM said:

Can you believe that guy. He's trying to sell something that will shorten the stroke of your AR, which will increase the recoil of your gun, by adding on to a device that's supposed to reduce the recoil of your gun.

Only in America.

Yeah John Paul, Tim and Max are all idiots.  You need to show us the way.

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26 minutes ago, 3gunnuts said:

Yeah John Paul, Tim and Max are all idiots.  You need to show us the way.

 

Calling those guys idiots is no way to get a discount on your new short-stoke kit.

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31 minutes ago, MemphisMechanic said:

 

Some of our guns really run a lot flatter with a short stroke. So much so, it’s downright obvious.

 

There are a lot of different ways to build an AR, and not everyone’s is going to behave like yours.

 

I believe you when you say it doesn’t work for you. In my funky little guard build, removing the wave spring and spacer will double how much the dot moves in recoil.

 

 

Memphis, you've posted some good stuff on this forum. No doubt about it. But, I had to call you on this one.

When I say my felt recoil increased you have to realize it was not by much. And the increase in dot bounce was equally small. 

Nevertheless there was an increase and the guys here need to know that there is always two sides to every story. Especially the newbies like our OP friend here.

Nothing is etched in stone, especially when it comes to these damnable PCCs.

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8 minutes ago, MikieM said:

 

Calling those guys idiots is no way to get a discount on your new short-stoke kit.

 

Kit? They make kits?!!!!

 

I had to put mine together from indiviual parts... :( 

 

:D 

Edited by MemphisMechanic

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33 minutes ago, MikieM said:

 

Memphis, you've posted some good stuff on this forum. No doubt about it. But, I had to call you on this one.

When I say my felt recoil increased you have to realize it was not by much. And the increase in dot bounce was equally small. 

Nevertheless there was an increase and the guys here need to know that there is always two sides to every story. Especially the newbies like our OP friend here.

Nothing is etched in stone, especially when it comes to these damnable PCCs.

Yes I am a newbie.  from the guy that has been registered on here 2 months after I did. :)

 

Edited by 3gunnuts

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3 hours ago, MemphisMechanic said:

 

Kit? They make kits?!!!!

 

I had to put mine together from indiviual parts... :( 

 

:D 

AS soon as I got the 3 stage kit I tried he wave spring in that forward buffer position. I didn’t like it as it gave a double spring effect. 

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On 8/8/2018 at 1:34 PM, MemphisMechanic said:

 

Some of our guns really run a lot flatter with a short stroke. So much so, it’s downright obvious.

 

There are a lot of different ways to build an AR, and not everyone’s is going to behave like yours.

 

I believe you when you say it doesn’t work for you. In my funky little guard build, removing the wave spring and spacer will double how much the dot moves in recoil.

 

 

On 8/8/2018 at 8:49 AM, MikieM said:

Just like I said, de-stroking my PCC by 3/4 of an inch did increase felt recoil. Watching the dot while I pulled the trigger showed a slight increase in movement, as well.

And why wouldn't recoil increase? Because I took away some of the action spring's ability to absorb the energy of the bolt/buffer as it traveled rearward. Eighth grade science.

 

Sorry, Memphis. No apologies forthcoming.

 

On 8/8/2018 at 12:54 PM, MikieM said:

Your comment is not relative to the discussion.

Memphis stated that short stroking the AR 9 action produces less recoil, with a corresponding reduction in dot bounce. I disagreed with him.

This morning at the range I proved him wrong. At least to my satisfaction.

 

Just reading through this thread, I noticed that one uses a wave spring, and the other doesn't.

Could be something there?

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