9mm AR15 Buffer

[easy]

A 9mm, AR15 bubber weighs 5.6oz. A 5.56 CAR buffer weighs only 2.9oz.

Why is such a heavy buffer needed for a blowback system. I tries an H buffer in my 9mm AR and it functioned perfectly. If anything, I think it ran better. Faster maybe? The H buffer weighs 3.75oz.

Should I keep the H buffer in the 9mm, or is there a reason for the much heavier 9mm buffer.

 

[Paulinski]

I think its mostly for F/A 9mm AR. The rate of fire is extremely high with car buffer.

 

[twocold]

A 9mm, AR15 bubber weighs 5.6oz. A 5.56 CAR buffer weighs only 2.9oz.

Why is such a heavy buffer needed for a blowback system. I tries an H buffer in my 9mm AR and it functioned perfectly. If anything, I think it ran better. Faster maybe? The H buffer weighs 3.75oz.

Should I keep the H buffer in the 9mm, or is there a reason for the much heavier 9mm buffer.

The reason for heavy buffers in all carbines with short barrels 11.5 and under .223 and blow backs,is to slow the bolt down. Yes this does reduce the rate of full auto fire that most people will never need. But it also serves a very important purpose. Of keeping the bolt closed a fraction of a second longer to allow chamber presure to drop, to insure smoother extraction and keep the case in the chamber a bit longer to avoid case ruptures.

I run . 9mm 5.7 oz. in .223 shorties and I have seen huge improvements in smooth operation of extraction.

In my 9mm AR's I run a 8 oz, as I found the 9mm 5.7 oz worked but the heavier buffer just felt was smoother.

Try a heavier buffer and you will see a more constant ejection.

 

[TRG-42]

You NEED the heavier buffers in the 9mm since its blowback operated ( unlike a locked breech )

If you ever shoot in a indoor range you can see a huge difference when you watch the ejection port. With a heavy buffer you most likely won't see any flash. With the light buffer I can see a good flash out the ejection port.

With the light buffer, bolt is moving before pressure drops and ( depending on load ) all the powder is consumed. Worst case, I have bulged the base of cases when running hotter loads in my 9 AR

With the heavier buffer there is less bolt overtravel, so much so that wussy 9mm loads won't lock back the bolt . On the other extreme with 9 major loads the buffer bottoms out hard

If your 223/5.56 does not function well with the heavier 9mm ( some of mine don't ) then a good comprimise is the Enidine Hydraulic buffer

 

[pc9]

Sorry to hijack your thread but where would one get one of theese buffers?
I just ordered a RRA 9mm from Questar.

 

[FPembleton]

Sorry to hijack your thread but where would one get one of theese buffers?
I just ordered a RRA 9mm from Questar.

You get it from Questar. A complete rifle should come with one.

 

[banger]

What buffer springs do you use? Is a car buffer spring sufficient?

 

[Questar]

You get it from Questar. A complete rifle should come with one.

When we sell 9mm lowers or 9mm rifles they do come with 9mm buffers... not sure why this fellow doesn't realize that...

Mark

 

[P0WERWAGON]

the problem with 9mm buffers are that they are too short. on the last round the bolt goes too far back and slams against the bolt catch bending it. yes even the colt bolts do this. the 9mm buffer offered by Slash on AR15.com solves this problem.