Buffers
Posted: Tue Dec 22, 2009 4:13 pmRecently I have been doing some experimenting with different weight buffers. At first all my load development was done with the A2 stock and standard rifle buffer. Most of most of my loads used 240, 250, 275 and 300 grain bullets. They are stout, but within Hornady's load recommendations. Pressures seemed normal and bases of the cases looked normal -- as compared to factory loads.
A year ago, I got a collapsable stock for X-mas. I purchased a carbine tube and buffer. The buffer weighs 2.8 oz and the rifle weighs 5.2 oz.. I did not pay much attention to the weight difference. However, I did notice with the 300 gr. loads that the rims of my cases were in the beginning stages of being torn (slightly bent). This really became an issue when trying to use 400 gr. bullets no matter the velocity. As long as I stayed with 240's and 250's there was not a problem.
I have now put the A2 stock back on with the rifle buffer (5.2 oz) and have added a carrier weight system from David Tubb http://www.davidtubb.com/ar15_cws.html (going to start playing with 400's again).
I used the heaviest weight set, plus the rifle buffer, that brings the total buffer/carrier weight to 9.07 ozs (I also added the recoil spring from them).
I no longer have the rim distortion. Also, the factory loads work just fine. No cycling problems. The recoil pulse seems much smoother -- not so sharp.
As a side benift -- since the carrier rearward motion has been slowed -- so has the forward movement. The slower moving forward movement has lessened the amount of bullet jump from chambering. Bullet jump with factory ammo with the Rifle weight alone as about .005 inches. With the carbine 2.8 oz, the jump was .007 to .008. With the carrier weight system added in addition to the buffer weight, the jump was .002 to .003. So, the slower the cartridge moves into battery, the less the jump. Note that no side crimp is involved and only factory ammo was used to eliminate variables associated with handloads. Also, measurements were taken from rounds loaded via actual firing. Shoot a round -- extract -- measure. All rounds started out a 2.23 inches.
The only draw back to the CWS (carrier weight system) is the both front and rear pins need to be pulled to remove the bolt group. The upper and not open just by removing the rear pin. Part of the CWS protrudes into buffer tube. Not a bid deal. The CWS can be used for add 1.54 oz, 2.79 oz or 4.05 oz in addtion to the existing buffer weight.
I have read that many users of the 458 and 50 use the heavier H2 buffer. Also a site worth visting is http://www.heavybuffers.com/reference.html
A year ago, I got a collapsable stock for X-mas. I purchased a carbine tube and buffer. The buffer weighs 2.8 oz and the rifle weighs 5.2 oz.. I did not pay much attention to the weight difference. However, I did notice with the 300 gr. loads that the rims of my cases were in the beginning stages of being torn (slightly bent). This really became an issue when trying to use 400 gr. bullets no matter the velocity. As long as I stayed with 240's and 250's there was not a problem.
I have now put the A2 stock back on with the rifle buffer (5.2 oz) and have added a carrier weight system from David Tubb http://www.davidtubb.com/ar15_cws.html (going to start playing with 400's again).
I used the heaviest weight set, plus the rifle buffer, that brings the total buffer/carrier weight to 9.07 ozs (I also added the recoil spring from them).
I no longer have the rim distortion. Also, the factory loads work just fine. No cycling problems. The recoil pulse seems much smoother -- not so sharp.
As a side benift -- since the carrier rearward motion has been slowed -- so has the forward movement. The slower moving forward movement has lessened the amount of bullet jump from chambering. Bullet jump with factory ammo with the Rifle weight alone as about .005 inches. With the carbine 2.8 oz, the jump was .007 to .008. With the carrier weight system added in addition to the buffer weight, the jump was .002 to .003. So, the slower the cartridge moves into battery, the less the jump. Note that no side crimp is involved and only factory ammo was used to eliminate variables associated with handloads. Also, measurements were taken from rounds loaded via actual firing. Shoot a round -- extract -- measure. All rounds started out a 2.23 inches.
The only draw back to the CWS (carrier weight system) is the both front and rear pins need to be pulled to remove the bolt group. The upper and not open just by removing the rear pin. Part of the CWS protrudes into buffer tube. Not a bid deal. The CWS can be used for add 1.54 oz, 2.79 oz or 4.05 oz in addtion to the existing buffer weight.
I have read that many users of the 458 and 50 use the heavier H2 buffer. Also a site worth visting is http://www.heavybuffers.com/reference.html
