SA20 vs SA15.7 buffers.... Edumakate me....

TacticalTeacher

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Okay, so I bought a SA20 from Ellwood Epps and I'm just waiting for the CFC Miramichi folks to approve this fun. I noticed that some of you great SA20 owners posted pics on the SA20 and specifically it's buffer marked H ? or HH?

I need reading glasses and cannot figure out what is gonna arrive with my SA20 (buffer I mean) next week when things are approved and I can pick it up north of Orillia. :)

I'm used to carbine buffers for years and I know they are all marked H for Heavy. What is coming with my SA20?

Are the buffer springs different or the same? Should I buy a new buffer and spring (if I want to use a 14.5" carbine upper) down the road? Maybe I should order a carbine buffer & spring combination from Armseast or Wolverine or SFRC or Questar now before the SA20 arrives and I might start slapping on a carbine barreled upper just for poops and giggles?

What say your black rifle experts? Will my #### fall off ? :cool:

Cheers and keep helping them noobs out there! :wave:

Barney
 
They're H2 buffers marked HH. They were found to be the most reliable by DND with uppers of varying lengths from 10" to 20". Spring is standard carbine type.

I wouldn't buy another buffer or spring. You'll likely find that the lower will run just fine with any upper you throw on it. If anything your #### will fall off if you swap the buffer out.
 
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All colt canadas are HH buffers, I have very few rounds down the tube of my SA20 but I can tell you it is incredibly soft shooting.
 
Fun fact: The HH buffers were selected because the bolt-carrier group would travel so fast on the C8s that the magazine spring couldn't push the next round up fast enough before the bolt came back. The heavier buffer slows the speed of the bolt-carrier group enough for the next round to be fed and chambered. Colt Canada puts 3H buffers in their C7A3/monolithic rifles with collapsible stocks because of the extra weight in the front.

The HH buffers that comes with your Diemaco rifles are 100% good to go. Colt Canada did enough testing and experimenting that they know what they're doing and know what parts to use.
 
Mostly, I've read that the heavier buffer was to compensate for the lost tube length from the full stock to the carbine collapsing stock tube, while still running a 20 full rifle length barrel in the initial C7a2 upgrade. Then heavier buffers are used in all carbines, again because of the shorter buffer tube.
 
I see the light! (quoting the late John Belushi in Blues Brothers) :wave:

My #### is safe! My HH buffer is all I need when swapping uppers on my SA20 from Ellwood Epps. Now they are closed on Mondays and I did get a message on Saturday night about my window to pick up that rifle from Orillia area.

According to their website, they still have a bunch of SA15.7's there and in stock. :eek:

How awesome is that?

This one Colt Fan-boy is super pleased!

Cheers,
Barney
 
Fun fact: The HH buffers were selected because the bolt-carrier group would travel so fast on the C8s that the magazine spring couldn't push the next round up fast enough before the bolt came back. The heavier buffer slows the speed of the bolt-carrier group enough for the next round to be fed and chambered. Colt Canada puts 3H buffers in their C7A3/monolithic rifles with collapsible stocks because of the extra weight in the front.

This is actually a non-fact - not to pick on you as this is a fairly commonly repeated myth.

The buffer is for buffering out bolt bounce back on automatic. The heavier the upper (heavy vs light barrel, plus the IUR vs conventional upper, plus optics, plus accessories like lights, GL, laser, etc) the more the bounce back. It is the same principle a newtons cradle operates on.

It still buffers bolt bounce on semi-auto - it just doesn't matter. Bolt bounce only causes light strikes at high cyclic rates.

The velocity of the BCG is determined by the gas system. Adding extra weight behind the carrier may slow it down, but if you need to do this, there is a gas problem or your spring is worn out.

All the SA models would work fine with standard or H buffers. They would even work empty. We shoot hundreds of rounds on armourer course with empty buffers and they work great until you try to fire a burst.

For interchangeability conventional rifles have HH buffers (works for C7A2 with a GL and eclan on auto) and all IURs are issued with HHH buyers (they are heavier and have more room for junk to make bigger bounce). The IUR will work just fine on an SA with HH buffers. You don't have auto guns.

We have tested these with tens of thousands of rounds. We use high speed video and lasers. We know exactly what the velocity of all the moving parts are - with different gas systems, with different buffers, with different ammo, and so on. There is no need to change your buffers.
 
It's alright, good info is always welcome. :d I'm surprised because the person who passed on that info to me is very high up there but he also talked about the bolt bounce on automatic weapons and the HHH buffers in the IURs and such.
 
This is actually a non-fact - not to pick on you as this is a fairly commonly repeated myth.

The buffer is for buffering out bolt bounce back on automatic. The heavier the upper (heavy vs light barrel, plus the IUR vs conventional upper, plus optics, plus accessories like lights, GL, laser, etc) the more the bounce back. It is the same principle a newtons cradle operates on.

It still buffers bolt bounce on semi-auto - it just doesn't matter. Bolt bounce only causes light strikes at high cyclic rates.

The velocity of the BCG is determined by the gas system. Adding extra weight behind the carrier may slow it down, but if you need to do this, there is a gas problem or your spring is worn out.

All the SA models would work fine with standard or H buffers. They would even work empty. We shoot hundreds of rounds on armourer course with empty buffers and they work great until you try to fire a burst.

For interchangeability conventional rifles have HH buffers (works for C7A2 with a GL and eclan on auto) and all IURs are issued with HHH buyers (they are heavier and have more room for junk to make bigger bounce). The IUR will work just fine on an SA with HH buffers. You don't have auto guns.

We have tested these with tens of thousands of rounds. We use high speed video and lasers. We know exactly what the velocity of all the moving parts are - with different gas systems, with different buffers, with different ammo, and so on. There is no need to change your buffers.

Is there any downsides to using a HHH buffer in case say I pop say my 20inch upper on a different lower equipped with a HHH buffer?
 
Vltor A5 is the cat's meow.

Personally I don't get it. One of the biggest benefits of using an adjustable stock is the ability to change the length of pull in order to accommodate different shooters using different equipment (ie armour). The A5s shortest length of pull is 11.5" and the longest is 15". If I'm wearing armour this means I have to run it fully collapsed. If someone with much shorter arms is wearing armour then they'll have issues with the LOP.

They claim it has the widest range of adjustment (7 positions doncha know), which it may have but most of them are useless to the majority of users. Who needs a 15" LOP?? I get a much more useful range of adjustment out of a run of the mill four posn tube. IMHO this stock has the least useful range of adjustment out there.
 
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