Alternatives to vltor a5

[Motivated1]

One of the issues with running the "green" spring that comes up over the conventional Colt rifle action spring is the L2 loading. The time duration in bolt over travel to the case head can drop quick. That's not in a place we want to be. With increased reciprocating mass the "green" spring can be okay with the A5H4, sometimes with the A5H3, but rarely if ever with the A5H2 or lighter.
There are some gains possible with the Tubb .308 spring on an A5 action, but they can have their own list of issues.
The Tubb .308 A5 combo can be another discussion altogether.

Could you elaborate?

[opngrnd]

One of the issues with running the "green" spring that comes up over the conventional Colt rifle action spring is the L2 loading. The time duration in bolt over travel to the case head can drop quick. That's not in a place we want to be. With increased reciprocating mass the "green" spring can be okay with the A5H4, sometimes with the A5H3, but rarely if ever with the A5H2 or lighter.
There are some gains possible with the Tubb .308 spring on an A5 action, but they can have their own list of issues.
The Tubb .308 A5 combo can be another discussion altogether.

Please elaborate on Green spring vs flat spring. The Green spring/A5H2 has been my go to with 16"bbl uppers, and Green spring/A5H3 with 18" uppers.

[MQ105]

The flat spring gives more force than a standard spring when the bolt is closed (L1), and similar/same force as standard spring when the bolt is to the rear (L2). Both of those characteristics are desirable. The increased power round wire springs have increased L1 and L2 compared to a standard spring. Increased L2 force is not desirable because that decreases BCG open dwell; the time the bolt is clear of the next round feeding from the magazine.
Enough reciprocating mass (heavy enough buffer) can slow the return of a stronger (green) spring. I'm not a fan of -3 or -4 buffers because they cause the muzzle/sights to nose dive when all that mass slams home.
Everyone has a different take on how their gun feels, and many folks run H3 or A4H4 buffers. Personally, though, I have found that the H2 or A5H2 with a flat spring and appropriate gas drive are they way to go.

[hk_shootr]

Tons of great info here....thanks. I have a Tubbs spring in the bin, may have to try it with the A5H2 buffer I have in one carbine

[tom12.7]

The green spring has some more L1 tension compared to the Colt rifle action spring. This can benefit some, but not all. It is an available option. The green spring has more L2 tension compared to the Colt rifle action spring. Having extra tension in L2 will allow more energy to be available to function the forward action cycle for that portion of the stroke. The negative associated with the extra L2 tension is that the BCG will spend less time in total cycling rearward behind the cartridge case. With less time available, you can run into issues with the magazine having the capability to consistently present the case for optimal feeding.

It's not that adding a green spring to an A5 is terrible, its not. The baseline A5 adds a generous improvement in timing over a carbine system. With the A5H2 green spring combination, you can lose some of the timing gains in bolt over travel that you gained with the baseline. The higher mass A5 buffers can increase the timing benefits further, so as you increase mass, you increase time overall in the stroke. That can bring the bolt over travel time into a more comfortable time duration with a green spring.

This is provided that the porting supports a satisfactory cycle for the combination. When comparing the cycle of a standard A5 setup to another with different mass and spring loadings, more mass=lower bcg velocities, higher L1=more initial time delay to initiate the stroke and more forward velocity back into battery, higher L2=less time in bolt over travel with more stored energy to function that portion of the cycle. High velocities decrease timing for events, we are looking at distance over time.

The Tubb flat wire springs are a topic of their own, they can be beneficial in both carbine and rifle actions, but they can add quite a few secondary issues that normally would not be considered for this system with a normal Colt action spring.

[MQ105]

Tons of great info here....thanks. I have a Tubbs spring in the bin, may have to try it with the A5H2 buffer I have in one carbine

With an A5 RE, try the SR-25/AR-10 spring. (The carbine spring will also work with carbine or A5 REs.)

[Motivated1]

The green spring has some more L1 tension compared to the Colt rifle action spring. This can benefit some, but not all. It is an available option. The green spring has more L2 tension compared to the Colt rifle action spring. Having extra tension in L2 will allow more energy to be available to function the forward action cycle for that portion of the stroke. The negative associated with the extra L2 tension is that the BCG will spend less time in total cycling rearward behind the cartridge case. With less time available, you can run into issues with the magazine having the capability to consistently present the case for optimal feeding.

It's not that adding a green spring to an A5 is terrible, its not. The baseline A5 adds a generous improvement in timing over a carbine system. With the A5H2 green spring combination, you can lose some of the timing gains in bolt over travel that you gained with the baseline. The higher mass A5 buffers can increase the timing benefits further, so as you increase mass, you increase time overall in the stroke. That can bring the bolt over travel time into a more comfortable time duration with a green spring.

This is provided that the porting supports a satisfactory cycle for the combination. When comparing the cycle of a standard A5 setup to another with different mass and spring loadings, more mass=lower bcg velocities, higher L1=more initial time delay to initiate the stroke and more forward velocity back into battery, higher L2=less time in bolt over travel with more stored energy to function that portion of the cycle. High velocities decrease timing for events, we are looking at distance over time.

The Tubb flat wire springs are a topic of their own, they can be beneficial in both carbine and rifle actions, but they can add quite a few secondary issues that normally would not be considered for this system with a normal Colt action spring.

If it's not too much of an imposition, it would be great for you to elaborate on the Tubbs flat wire spring.

[1168]

If it's not too much of an imposition, it would be great for you to elaborate on the Tubbs flat wire spring.

I’m interested, also. Particularly as pertains to the A5 and A1/A2 type systems.

[tom12.7]

How about starting a new topic for the Tubb flat wire springs? Advantages and disadvantages, or compare and contrast to more conventional springs?

[everready73]

How about starting a new topic for the Tubb flat wire springs? Advantages and disadvantages, or compare and contrast to more conventional springs?

Sounds good to me. Learning a ton. That's why I like this site more than the others. Less BS, more facts, and knowledgeable members