Do you change your buffer springs for different types of ammo?

MarkCO said:
Yes, but then I know what I am doing too.
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If you ever feel like spilling some of that knowledge into the page, I'll read it eagerly.

Is the inherent problem with a carbine length system just that it will always unlock too soon when pressure is too high, or is it just more finicky to tune?

Is a very low recoil SBR possible, or does all the hot gas pushing forward mask most of the recoil reduction involved in gas, bolt and spring tuning?
 
zukiphile; (Is a very low recoil SBR possible, or does all the hot gas pushing forward mask most of the recoil reduction involved in gas, bolt and spring tuning? )

there are ways.
1, suppressors, they generally eat a lot of the hot gas and thus reduce felt recoil. (highly governmentally regulated)

2 muzzle break, they redirect the hot gas and let you eat it (not good without hearing protection), thus reducing felt recoil.

3. special loads, one can load with a very fast burning powder and somewhat reduce the felt recoil, (not for the faint of hart) but this is not as much help as the first two.

probably the best way is add a break if you really need to reduce recoil.

that is strictly academic, not a suggestion.
 
zukiphile said:
If you ever feel like spilling some of that knowledge into the page, I'll read it eagerly.

Is the inherent problem with a carbine length system just that it will always unlock too soon when pressure is too high, or is it just more finicky to tune?

Is a very low recoil SBR possible, or does all the hot gas pushing forward mask most of the recoil reduction involved in gas, bolt and spring tuning?
Click to expand...

The closer the gas port is to the chamber, the larger the gas port needs to be. But then we get way over gassed. Powder choice is a thing to consider as well. The shorter the barrel (at least in .223) the lighter the bullet and the faster the powder (for shootability at least).

If you will recall the 3GN pro-tour, I built several of the pros uppers that were short barrels. 10" barrels with Carbine gas ports and 6.5" of pinned shroud. Running 40 grain bullets at 2200 fps. Silly soft. If you put a normal .223 load in it, it was pretty rough on the case. It's all just trade off and tunes. Being a barrel maker has some perks...I try all kinds of odd things. Some just work out really well, others, not as much.
 
tangolima said:
I thought smaller gas port hole diameter when it is closer to chamber, no?
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Yes, but there is pressure and volume. If you make the gas port larger, and fill the tube the chamber pressure drops faster, but you push more gas into the BCG. It's a dance that most folks only see one way, but it can be used to mitigate pressure if you have a way to bleed of excess gas (like a Superlative Arms or a Gas Key bleed off).

I should have been more specific as to what I was actually saying.
 
MarkCO said:
Yes, but there is pressure and volume. If you make the gas port larger, and fill the tube the chamber pressure drops faster, but you push more gas into the BCG. It's a dance that most folks only see one way, but it can be used to mitigate pressure if you have a way to bleed of excess gas (like a Superlative Arms or a Gas Key bleed off).
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Before your post above, I hadn't considered the variable of pressure as separate from volume, or the utility of the bleed off feature, for which I found no good use on my 20" rifle.

Am I thinking about this in reasonable terms if I imagine that a 16" carbine barrel using the bleed off feature, along with a lighter carrier and spring, could result in modest bolt speed despite the system being under pressure for the last nine inches or so of barrel?
 
zukiphile said:
Before your post above, I hadn't considered the variable of pressure as separate from volume, or the utility of the bleed off feature, for which I found no good use on my 20" rifle.

Am I thinking about this in reasonable terms if I imagine that a 16" carbine barrel using the bleed off feature, along with a lighter carrier and spring, could result in modest bolt speed despite the system being under pressure for the last nine inches or so of barrel?
Click to expand...

Yes. I must admit I am not a fan of gas key bleed off, but there are a few times where, given the barrel and ammo, it was the best solution to a good tune.

Magnetic and mono material high durometer buffers have shown some benefits in testing I have done over the last year, but gas volume and pressure are still the two biggies before the fine tune of the system.

And, FWIW, the Stretch16 was the original Intermediate gas length 16" AR barrel. The fact that a lot of folks have copied the configuration attests to it's benefits. But, yes, sometimes it's better, economically, to spend say $50 on parts as opposed to a whole new barrel.
 
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