Educate me about buffer and spring

[lsp408]

So I have heard if your gun kicks hard, increase the buffer spring and weight

If you use m16 bolt, increase the spring rate and buffer weight.

Any above statement true? What is the guideline here?

[peejman]

It's an AR, it barely kicks at all.

 

If the buffer is slamming into the stop, you likely have an over-gassed rifle.  

[Oh Shoot]

No fixing needed if it ain't broke and all that...

 

It's the opposite on M16 bolt carrier -- it is already slowing things down a touch as it's heavier than AR-15 carrier. The bolt  is same in either.

 

What's your ejection angle? Not written in stone, but if past 3:00 and you can fire all types ammo reliably it's probably tuned plenty well enough. Heavier buffer might or might not still run just as well and feel slightly less "snappy", but it's not a huge change. Won't change "recoil" though, which is negligible with 5.56 AR already.

 

- OS

Edited March 27, 2014 by Oh Shoot

[dcloudy777]

Adding non-reciprocating weight will help with recoil much more than adding reciprocating weight.

[mikegideon]

The various milspec buffer weights are more about taming bolt bounce for full auto fire. Can't forget that the AR-15 was designed to be a machine gun. For example, Colt doesn't ship a carbine weight buffer in their full auto M4's.

 

If you wanna manage recoil for followup shots (a legitimate goal), you use an adjustable gas system and low mass components. See JP Rifles. The gas system, BCG weight, buffer weight, and spring all have an impact.

[lsp408]

Thanks for all the replies. I just feel my 10.5 barrel ar kicks quite bit. I guess I need to shoot more and go from there.

Btw, how will I know if the buffer is bottom out in the tube? Will the end of buffer get beat up? If it's bottom out, will it cause any damage to other component?

[Oh Shoot]

Thanks for all the replies. I just feel my 10.5 barrel ar kicks quite bit. I guess I need to shoot more and go from there.

Btw, how will I know if the buffer is bottom out in the tube? Will the end of buffer get beat up? If it's bottom out, will it cause any damage to other component?

 

Again, ejection angle is a good clue. If it's before 3:00 could probably benefit from heavier buffer. Short barreled ARs do often tend to be overgassed, or perhaps more precisely the dwell time needs to be increased as there's less barrel past the gas port.

 

I have a 10.5" carbine gas pistol. Now, it worked just fine with standard carbine buffer and spring -- rims not deformed, always fed next round, ejection about 4:00,  all good. But seemed "snappier" than my rifles, which of course could have been completely subjective since was shooting with buffer tube laid alongside cheek. Anyway, just to see I did put a H2 buffer (4.6oz) in it. Moved ejection back maybe a touch, not huge change. Less snappy now? Not sure, still runs perfectly. Been meaning to swap buffers back and forth at range to see if can really tell empirical difference.

 

- OS

Edited March 27, 2014 by Oh Shoot

[lsp408]

Since mine is left handed pistol, I should be expecting ejection around 9:00 and down(maybe 8 or 7)? And if my shell eject 10 or 11, I will need heavier buffer?

[Oh Shoot]

Since mine is left handed pistol, I should be expecting ejection around 9:00 and down(maybe 8 or 7)? And if my shell eject 10 or 11, I will need heavier buffer?

 

Yeah,'bout like that. Not written in stone or anything as there are other variables, but this is sort of rule of thumb:

 

 

 

- OS

Edited March 27, 2014 by Oh Shoot

[lsp408]

Saved that pie diagram. Thanks

[KKing]

Honestly, and not to disagree with what's been posted, but heavier buffers, new springs, and the like....are bandaids. Fix the actual problem, which is likely too much gas. An adjustable gas block is the best way to do it. I'm not saying that a heavier buffer won't change your ejection pattern a smidge, but in the medical field we would say that you're "treating the symptoms, not the disease" Edited March 28, 2014 by KKing

[Oh Shoot]

Honestly, and not to disagree with what's been posted, but heavier buffers, new springs, and the like....are bandaids. Fix the actual problem, which is likely too much gas. An adjustable gas block is the best way to do it. I'm not saying that a heavier buffer won't change your ejection pattern a smidge, but in the medical field we would say that you're "treating the symptoms, not the disease"

 

Agreed that adjustable block is the way to go for over gassed heater.

 

But on the other hand if it ain't overgassed to the point where it malfunctions, I don't know that it really needs fixing at all, but a heavier buffer tweak can often gentle it down some.

 

- OS

[mikegideon]

It only has to be gassed enough to (reliably) lock the bolt back on an empty mag. When it comes to felt recoil, the reciprocating mass relative to the weight of the gun is gonna be a factor, as well as the regular recoil forces. The lighter the gun, the more it's gonna kick.

[peejman]

It only has to be gassed enough to (reliably) lock the bolt back on an empty mag. When it comes to felt recoil, the reciprocating mass relative to the weight of the gun is gonna be a factor, as well as the regular recoil forces. The lighter the gun, the more it's gonna kick.

 

 

Agreed.  Seems to me that increasing the reciprocating mass in a light weight gun would tend to make for more felt recoil, if anything.

 

And what KKing said too... if the buffer is slamming into the stop and that's the jolt the shooter is feeling, the gas system needs some attention. 

[TNMTBik3r]

My last batch of reloads through my 16" were ejecting at 2:00. I had been considering a heavier buffer or adjustable gas block (although since it was a budget build wasn't sure about dumping more into it vs saving for a new build).

I may go ahead and order one or both.

 

I have noticed that different powders seem to easily overgas at least in my rifle. For example, CFE223 with a minimum load compared in 2 manuals will eject at 1:00-2:00 constantly. I dialed back 2 grains below min load to get a 3:00 ejection pattern. But Varget is usually 3:00 to 4:00 with a mid level load.

[KKing]

As an aside, I'll add this. If you're gun functions, on all types of ammo and bullet weights, don't worry about where your spent casings go. If you're having trouble with recoil that's one thing, but if you're only worried about the ejection pattern alone, you're chasing your tail IMO. Worry about where the bullets go, not the casings

[lsp408]

After few hundred rounds of 223, I can see the plastic part of buffer starting to get mushroom head and also can see bottom of buffer tube have mark from buffer bottom out. Instead of adjust gas block, can I put heavier buffer to reduce the impact of buffer against the tube?

[molonlabetn]

When I'm running my 10.5” direct impingement setup I use a standard buffer spring and carbine buffer, it eats everything, albeit a bit overgassed when suppressed. When I swap to the 12" gas piston barrel, I use an extra power buffer spring and H2 buffer to get nearly identical recoil/feed characteristics; and can turn down the gas when the suppressor is mounted. So, unless you're actually having function issues, or have changed the gas system, leave it alone.

[lsp408]

So I should leave it alone while the plastic plug on the buffer end gets beat up?
Mine is 10.5 barrel and m16 bcg. As far as buffer and spring go, they are stock. Edited April 4, 2014 by lsp408

[Oh Shoot]

After few hundred rounds of 223, I can see the plastic part of buffer starting to get mushroom head and also can see bottom of buffer tube have mark from buffer bottom out. Instead of adjust gas block, can I put heavier buffer to reduce the impact of buffer against the tube?

 

Certainly ain't gonna hurt anything to try a $20 H2 buffer.

 

http://www.ebay.com/sch/i.html?_trksid=p3984.m570.l1313.TR2.TRC1.A0.H0.Xh2+buffer+&_nkw=h2+buffer+&_sacat=0&_from=R40

 

Heck, one is selling for $16.46 delivered, guy has sold a bunch of them, no complaints. I bought probably same one (same pic) for about same price from another guy on there 9 months ago, all good.

 

http://www.ebay.com/itm/Mil-Spec-H2-Heavy-Buffer-4-5oz-Less-Recoil-223-Carbine-Rifle-Stock-Buffer-AXC-/141134942345?pt=LH_DefaultDomain_0&hash=item20dc4c5089

 

- OS

Edited April 4, 2014 by Oh Shoot

[molonlabetn]

If the buffer bumper is being destroyed, that would be considered a function issue, and I would second a heavier buffer. I thought we were just talking about reducing recoil...? Is your buffer spring worn out, perhaps? We are talking about a 5.56/.223 AR, correct?

[peejman]

If you don't care to spend the $20 and install it, go for it and let us know the results. 

[lsp408]

Yes. It is .223/5.56. I just couldn't believe that only few hundred rounds and buffer spring already worn out? I am looking into getting some h2 or 3 buffer and maybe some blue or red springs

[molonlabetn]

Worth a shot... that is really strange to be beating the buffer up so bad after just a few hundred rounds, too. If its over gassed that bad. Boosting reciprocating weight and spring tension will only hide the problem, keep an eye out for bolt/cam wear. Adjustable gas block is the true solution in that case.