AR10 stiff buffer spring question

[Joesmurf]

I have a 6.5CM Aero Precision (Aero buffer, carbine buffer tube) that cycles perfectly, but is way harder to rack the slide compared to AR15’s. Having not shot any other AR10’s before, I didn’t know if it’s normal to need two hands to rack an AR10 slide?

 

[krunchnik]

I have a Ruger SFAR that has a very stiff recoil spring-
I know it's not a real AR10 but very close in .308 Win-

 

[LRRPF52]

Every AR-10/SR-25 I have worked with or owned is noticeably-more difficult to charge than an AR-15.

Action spring is stronger, BCG is much heavier, and stroke length is much longer. The combination of all these plus a generally-heavier rifle contribute to more muscle being required to charge them.

 

[bfoosh006]

Is your buffer tube and spring lubed ? And the BCG as well.

Consider a Tubbs 308 recoil spring, it has a different "weight" profile than a normal round wire spring.
Also, are you using a USGI charging handle ? Something like the Radian Raptor affords a better grip on the CH.

 

[Joesmurf]

Is your buffer tube and spring lubed ? And the BCG as well.

Consider a Tubbs 308 recoil spring, it has a different "weight" profile than a normal round wire spring.
Also, are you using a USGI charging handle ? Something like the Radian Raptor affords a better grip on the CH.

I use the radian charging handle. I lubed the BCG and charging handle, but haven’t tried the buffer assembly.

 

[msgriff]

AR-10/308 buffer springs are definitely stronger than an AR-15, but there are other things that I might also check out. What to look for has a lot to do with where in the charging cycle that you perceive unusual force, and if you're cycling with an empty chamber or not. Slightly mistimed barrels can cause binding between the bolt lugs and barrel extension. Look at the cam pin cut-out in the upper for wear/damage due to cam pin interference. Check for a rough cam pin track on the carrier. Some of these things can occur even with a factory built weapon. An AR-10/308 usually needs a break-in period, more than an AR-15, and many of these issues, if minor, will self resolve during that.

Also, make sure and remove the bolt from the carrier and lube the gas rings well.

 

[papershredder]

^^^^^ adding to above post^^^ Pull out the buffer and spring and look for drag marks inside the buffer tube and look for wear marks in the receiver channel for the charging handle. Is it hard to rack with an empty chamber with no magazine installed or just hard to rack with a loaded/full mag?

 

[Joesmurf]

AR-10/308 buffer springs are definitely stronger than an AR-15, but there are other things that I might also check out. What to look for has a lot to do with where in the charging cycle that you perceive unusual force, and if you're cycling with an empty chamber or not. Slightly mistimed barrels can cause binding between the bolt lugs and barrel extension. Look at the cam pin cut-out in the upper for wear/damage due to cam pin interference. Check for a rough cam pin track on the carrier. Some of these things can occur even with a factory built weapon. An AR-10/308 usually needs a break-in period, more than an AR-15, and many of these issues, if minor, will self resolve during that.

Also, make sure and remove the bolt from the carrier and lube the gas rings well.

I finally remembered to check inside the upper and buffer tube and didn’t really see any wear marks. As I was pulling the charging handle, it does not make a difference whether there is a magazine, or round, or nothing. Resistance is the same either way. I also noticed that I don’t have the Radian charging handle. I have the breach by aero. it seems like the charging handle is sticky, so I will that as well and just went back-and-forth a lot, and that seem to make a difference. After doing some oil and cycling the charging handle many times, that seem to help. I feel like I have about 500 rounds through it, so I feel like it should be in by now.

Thanks for the help!

 

[Rocketvapor]

Try it without the hammer installed.