Buffer Weight

[You'reNobodyImportant]

I don't post much.. 

 

This is for all you "experts" with the AR15.. 

 

Rifle is a AR15 Service Rifle.. I need to slow down the buffer.. when i put this together.. no one had anything in stock local or from what i could find online.. so when i installed the UBR 2 Buttstock on the rifle, it was a carbine length tube.. all i had was a rifle length spring.. through trial and error, i eventually got the carrier to lock back with the spring at 10" and the rifle buffer shortened to 3.1 inches and it weighs 3.0 ounces.. 

tested the system with Hornady Frontier 55 gr pills.. system was kicking the brass out at 330.. that's good. 

Now my new 600 yard load is lapua brass, Nosler CC 80's and 26.3 grs of 2000MR. With this load, the brass is getting sent out at 1230.. which means the system is getting over gassed. So I need to slow the carrier down some.. 

So the question is, use an H2 (4.6 oz) or should i go for the H3 (5.5 oz) tungsten buffer. The length on the new buffer would be 3.25 inches.. so i am going to presume that i should take another half inch off the spring.. 

 

What say you? 

[mike_f]

What overall length/gas system length/brand, etc. barrel are you using on your rifle? Since you're shooting 80 gr bullets, I'll assume it's a 20" barrel w/rifle length gas system. 

If you're going to get a new buffer, why wouldn't you just get the proper length/type spring to go with it? 

My UBR is first gen and takes a carbine buffer/spring.  I just run a regular carbine buffer and regular carbine spring with a 20" barrel with rifle length gas system, and haven't encountered any problems. My heaviest bullet are only 77gr though.

I'm certainly no expert (about anything), but I use the brass ejection as more of a possible indicator than a definitive diagnostic tool.  Especially if the upper has a brass deflector. YMMV

[You'reNobodyImportant]

10 hours ago, mike_f said:

What overall length/gas system length/brand, etc. barrel are you using on your rifle? Since you're shooting 80 gr bullets, I'll assume it's a 20" barrel w/rifle length gas system. 

If you're going to get a new buffer, why wouldn't you just get the proper length/type spring to go with it? 

My UBR is first gen and takes a carbine buffer/spring.  I just run a regular carbine buffer and regular carbine spring with a 20" barrel with rifle length gas system, and haven't encountered any problems. My heaviest bullet are only 77gr though.

I'm certainly no expert (about anything), but I use the brass ejection as more of a possible indicator than a definitive diagnostic tool.  Especially if the upper has a brass deflector. YMMV

i can use the A1 buffer tube i have if i have to.. since i will only be shooting it prone. Which i may do.. You "assumed" correctly that it is a 20" barrel with a rifle length gas tube. Adjustable gas blocks are not allowed. As for the barrel, it is a Shelin 7.5 twist 4  groove barrel.. 

 

How fast and what powder load are you using with your 77's? Have you shot yours at 600 yards and further with yours.. ???

As for a tool, it's pretty common thought.. that if your brass is landing 1230 to 230.. you are over gassed.. 3 to 430 is perfect, 430 to 530.. the carrier is going too slow. 

 i am not hip to all this new tech with buffers and springs..  

been told about the use of the Gissele springs, but to be honest, he just wants way too much for those. I found the company that makes the buffers for everyone that sells them.. and they sell direct.. so it is a matter of now much weight i should go for to slow this carrier down. 

I have also considered a JP Silent Captured Spring system too

Edited March 4, 2023 by You'reNobodyImportant

[You'reNobodyImportant]

oh and i once had a AR10 built.. never could get the gas tamed on that one.. it would cycle the bolt carrier so fast that it was capturing the brass before it was getting out of the port

Edited March 4, 2023 by You'reNobodyImportant

[InertOrd13]

I picked up one of the geissele springs during a black friday sale and really like it. Still pricey on sale but much better than the MSRP if that is a route you want to go. If not, I would go H4 or maybe do a sprinco spring.

[You'reNobodyImportant]

34 minutes ago, InertOrd13 said:

I picked up one of the geissele springs during a black friday sale and really like it. Still pricey on sale but much better than the MSRP if that is a route you want to go. If not, I would go H4 or maybe do a sprinco spring.

might try the orange spring.. thanks for the tip on the Sprinco Springs.. 

[mike_f]

16 hours ago, You'reNobodyImportant said:

i can use the A1 buffer tube i have if i have to.. since i will only be shooting it prone. Which i may do.. You "assumed" correctly that it is a 20" barrel with a rifle length gas tube. Adjustable gas blocks are not allowed. As for the barrel, it is a Shelin 7.5 twist 4  groove barrel.. 

 

How fast and what powder load are you using with your 77's? Have you shot yours at 600 yards and further with yours.. ???

As for a tool, it's pretty common thought.. that if your brass is landing 1230 to 230.. you are over gassed.. 3 to 430 is perfect, 430 to 530.. the carrier is going too slow. 

 i am not hip to all this new tech with buffers and springs..  

been told about the use of the Gissele springs, but to be honest, he just wants way too much for those. I found the company that makes the buffers for everyone that sells them.. and they sell direct.. so it is a matter of now much weight i should go for to slow this carrier down. 

I have also considered a JP Silent Captured Spring system too

I use Ramshot TAC and IMR 8202 XBR with the 77's. I've only shot out to 400 with it in informal target shooting.

I agree a lot of people use brass ejection direction as a diagnostic tool. I just think people put too much emphasis on it. If my rifle is working, no feeding or reliability problems, nothing is getting beat up, etc.; then I tend to just use it. YMMV. I'm also not sure how valid it is if you're not using a standard milspec forged upper. The brass deflector sizes, angles, etc. appear to vary quite a bit on all of the various non-milspec uppers.

I'm certainly not up on all the various springs & buffers.  My very basic understanding regarding the various springs is that is you're going with a relatively standard spring rate/weight the more expensive ones (Geissele, Springco, etc.) just last longer. Springco offers a bunch of different weights to solve problems (they can also cause problems). I think the standard carbine recoil spring is usually under $10 and supposed to last ~5,000 rounds.

I have a JP silent spring system in a carbine, but those start at well over $100 and get even more expensive if you start adding addition tungsten weights and/or additional springs.

One relatively easy way to experiment with different carbine buffer weights is to take a standard carbine buffer with 3 steel weights and buy a set of 3 tungsten weights from a place like Midwest Tungsten. For about $50 you can make standard through H3 buffers a see which one you prefer. Put whatever number of tungsten weight(s) you want to use in first (toward the receiver when installed in the rifle), with steel in the back.

https://shop.tungsten.com/tungsten-h3-recoil-rifle-buffer-weights-3-pack-1-43-oz-each-ar-15/

If I wanted the "easy button" solution, I'd use a rifle length recoil system and just use a standard rifle buffer/spring. To me the recoil impulse on on rifle system seems to be the smoothest and seldom has reliability problems.

[You'reNobodyImportant]

15 minutes ago, mike_f said:

I use Ramshot TAC and IMR 8202 XBR with the 77's. I've only shot out to 400 with it in informal target shooting.

I agree a lot of people use brass ejection direction as a diagnostic tool. I just think people put too much emphasis on it. If my rifle is working, no feeding or reliability problems, nothing is getting beat up, etc.; then I tend to just use it. YMMV. I'm also not sure how valid it is if you're not using a standard milspec forged upper. The brass deflector sizes, angles, etc. appear to vary quite a bit on all of the various non-milspec uppers.

I'm certainly not up on all the various springs & buffers.  My very basic understanding regarding the various springs is that is you're going with a relatively standard spring rate/weight the more expensive ones (Geissele, Springco, etc.) just last longer. Springco offers a bunch of different weights to solve problems (they can also cause problems). I think the standard carbine recoil spring is usually under $10 and supposed to last ~5,000 rounds.

I have a JP silent spring system in a carbine, but those start at well over $100 and get even more expensive if you start adding addition tungsten weights and/or additional springs.

One relatively easy way to experiment with different carbine buffer weights is to take a standard carbine buffer with 3 steel weights and buy a set of 3 tungsten weights from a place like Midwest Tungsten. For about $50 you can make standard through H3 buffers a see which one you prefer. Put whatever number of tungsten weight(s) you want to use in first (toward the receiver when installed in the rifle), with steel in the back.

https://shop.tungsten.com/tungsten-h3-recoil-rifle-buffer-weights-3-pack-1-43-oz-each-ar-15/

If I wanted the "easy button" solution, I'd use a rifle length recoil system and just use a standard rifle buffer/spring. To me the recoil impulse on on rifle system seems to be the smoothest and seldom has reliability problems.

This is where i was looking at buffers at

https://pur-tungsten.com/products/sporting-goods/ar15-accesories/

 

As for the upper.. it's a Sabre Defense forged upper. 

Do you like the JP Captured Spring system? 

Yes i have thought about putting the tungsten weights in the buffer that i have now.. 

[mike_f]

1 hour ago, You'reNobodyImportant said:

This is where i was looking at buffers at

https://pur-tungsten.com/products/sporting-goods/ar15-accesories/

 

As for the upper.. it's a Sabre Defense forged upper. 

Do you like the JP Captured Spring system? 

Yes i have thought about putting the tungsten weights in the buffer that i have now.. 

I'm sorry if what I wrote wasn't clear about the buffers. If I was doing this, I'd start with a new, standard AR carbine buffer and spring.  NOT a modified buffer and spring, just to eliminate variables.

These can be purchased from Brownells (or where ever) for about $30 total (about $17 for a standard carbine buffer & $9 for a standard carbine spring).  I'd try the standard buffer & spring first.  If it gave me the results I wanted (which it does in my 20" rifle with the UBR stock), then I'm done.

If the standard buffer/spring combo didn't get me the results I wanted, then I'd buy the tungsten 3 weights for about $30. Try out the 1-tungsten, 2-steel (H); 2-tungsten, 1-steel (H2), etc. I'd be able to assemble & test the whole range of Standard, H, H2 & H3 buffer weights for about $50. I would be shocked if I couldn't find at least one of those 4 buffer weight choices (with a standard carbine spring) that worked well for me.

The JP works great, no spring noise. Easy to install, remove, clean. I just have the standard weights/spring and use it with a 16" barrel, mid-gas upper. Have less than 1,000 rounds through that rifle, so I can't comment on the durability. I use it in a "What Would Stoner Do" KP-15 polymer lower because of the cumbersome way the buffer is normally retained with a roll pin in those lowers. Just got it on sale to see what it was like. It's nice, but I'm not convinced its worth the extra expense unless you have a special circumstance.

Edited March 4, 2023 by mike_f
typo

[DO-TN]

I am going with the pick up a correct spring/buffer combo and trial that others have mentioned. Not sure about your area, but I know at least 3 shops here in the middle/north part of the state that has them in stock. 

[You'reNobodyImportant]

1 hour ago, DO-TN said:

I am going with the pick up a correct spring/buffer combo and trial that others have mentioned. Not sure about your area, but I know at least 3 shops here in the middle/north part of the state that has them in stock. 

yeah.. it's pretty lame in this area.. 

[Smith]

I would also use a flat wire spring. Several make them Tubbs, JP, Wilson, Strike etc. They load the bolt longer.

[CMDRStormBorn]

I do all of my custom tunes with a combination of tungsten weight swaps (incrementally) & Sprinco color coded varying strength springs.  Generally this is economic and flexible enough to find your sweet- spot with minimal left over parts.