Cheapest method to add weight to rifle length buffer.

[arakboss]

I would like to add weight to a rifle length buffer so I can run a 9mm upper on my lower with A2 stock set up. Tungsten weights are not cheap. What are some cheap alternatives that I could use to add weight to the buffer? I would like to get the buffer up to 8 ounces or more if possible.

Also why is this area reduced on the exterior of the buffer.

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[osprey]

The reason it is reduced is for weight reduction I would guess. Wrap it tight with pencil lead and cover with tape for a hokey setup.

 

[USMC1911]

It's to capture the spring and to make the proper length. I would avoid using anything as soft as lead but you might be able to find some low cost steel weights or make your own out of a small piece of round bar from someplace like Home Depot.

 

[osprey]

It's to capture the spring and to make the proper length. I would avoid using anything as soft as lead but you might be able to find some low cost steel weights or make your own out of a small piece of round bar from someplace like Home Depot.

You sure about that? The shoulder that holds the spring could be the same diameter all the way to the end and function the same except for being heavier. The pencil lead/tape would be shy of the full diameter and not touch the buffer tube so I don't see a problem with lead being too soft.

 

[arakboss]

I have some 50cal Minnie ball projectiles that are around .8 ounces each. I was thinking I could powder coat them and replace the steel weights and aluminum spacer inside the buffer. I am not sure how the lead would hold up, it would likely become compacted to the point where it would not slide inside the buffer. Some of the cheap heavy weight buffers are solid steel so maybe having free sliding weight inside the buffer isn't necessary. I don't rapid fire anyways so bolt bounce wouldn't be a big concern.

 

[USMC1911]

That soft pencil lead would end up after repeated use of that buffer moving back and forth end up flattening itself out and possibly making a real mess of the buffer tube. Sorry I'm not putting pencil lead in there to save myself from purchasing a 40ish dollar buffer weight kit. It's obvious it's there to capture the spring. Generally a rifle buffer would be used in conjunction with a rifle length gas system that would not need a heavier buffer to increase the dwell time.

 

[arakboss]

You sure about that? The shoulder that holds the spring could be the same diameter all the way to the end and function the same except for being heavier. The pencil lead/tape would be shy of the full diameter and not touch the buffer tube so I don't see a problem with lead being too soft.

That is what I was thinking it, making the lead stay on there might be tricky.

 

[osprey]

Yeah, it would probably be for proof of concept fix and not long term solution. I view shooting 9mm out of an ar as a passing fad though.

 

[arakboss]

Some people have had luck just running the rifle length buffer as is. I am a bit paranoid about having the bolt open prematurely like has happened to others. The heavier the buffer the better IMHO.

 

[pnwGearhead]

Some interesting methods of adding buffer weight ive never thought of here.

 

[deadeye]

Some people have had luck just running the rifle length buffer as is. I am a bit paranoid about having the bolt open prematurely like has happened to others. The heavier the buffer the better IMHO.

Try running as is, it should be fine unless you plan on a can. Otherwise, don't waste your time and just pony up for a proper weight buffer ya cheapskate..............

Edit: go to the local golf pro shop and ask for some lead tape.

 

[arakboss]

Try running as is, it should be fine unless you plan on a can. Otherwise, don't waste your time and just pony up for a proper weight buffer ya cheapskate..............

Edit: go to the local golf pro shop and ask for some lead tape.

The proper buffer would be nice but you're right I am a cheapskate.

Heavy Buffers | Products | AR-15 Rifle

 

[deadeye]

The proper buffer would be nice but you're right I am a cheapskate.

Heavy Buffers | Products | AR-15 Rifle

Well at that price the lead tape would be a bit cheaper.......YMMV

 

[TTSX]

Unless you add a spacer in front of your buffer, you will have poor results running a 9mm blow back upper.

 

[USMC1911]

The proper buffer would be nice but you're right I am a cheapskate.

Heavy Buffers | Products | AR-15 Rifle

Odin Works has a reasonably priced buffer weight set for like 40 or 45 bucks last time I looked. I'd run it with the rifle buffer and see how it acts. I think I ended up at around 8 oz on my last 9 mm pistol build and if I'm not mistaken the rifle buffer is 5 plus ounces so you're not terribly far off. Some of it depends on what bolt you're running also because some are much heavier than others.

 

[TTSX]

Read this site and get educated. It's a wealth of knowledge.

Blowback9.com

No-BS information for the 9mm AR.

blowback9.wordpress.com

 

[arakboss]

I was thinking that a hardware bolt could be used to replace the buffer. A rifle length buffer is about 5.90 inches OAL. A 3/4" x 5.5" or 6" would fit inside buffer spring. The head of the bolt would need some contouring with a bench grinder.

The 5.5" length bolt would be roughly 12oz and the 6" bolt would be roughly 13.5oz. Cost is about $4 at home depot.

Edit: Additional weight could be added to the bolt with a combination of lock washers and or multiple nuts. I am guessing you could get to a full pound+ of buffer weight, if desired. I am going to make a new years day visit to Home Depot with my kitchen scale and a buffer spring to see what I can come up with.

https://www.homedepot.com/p/Everbilt-3-4-in-10-x-6-in-Zinc-Plated-Hex-Bolt-801266/204633341

A bumper could be placed at the end of the extension tube instead of being mounted on the buffer (bolt).

I weighed the 9mm bolt from the upper I'm working on and it's about 15.5 ounces.

 

[arakboss]

For my first effort I cannibalized a regular carbine buffer. I yanked the aluminum spacer in the rifle buffer and replaced it with two steel weights from the carbine buffer. This brings the weight of the rifle buffer up to 6.1 ounces. Supposedly 6.1oz buffers is what Colt used for their fixed rifle stock 9mm rifles.

I also added a silicone plug to the butt end of the buffer spring. When the bolt is pulled all the way back it is now less than a 1/4" from the bolt catch. Without the silicone plug the bolt traveled darn near an inch past the bolt catch.





I think my first attempt will be to use endomags in the lower. I recently bought a mag insert adapter that allows for the use of sig p320 or m&p mags but I can't find it in my mess. Honestly I haven't found the endomags either. One way or another I will get this thing running.

Digging through my mess I found an 8.4oz extended length carbine buffer, I forgot I had ordered. If rifle stock lower doesn't work out I will try a carbine lower.