308 Carrier bounce info request

[Lallop]

Hi everyone, been playing with my 308 trying to figure out the best configuration for the buffer & spring in order to reduce carrier bounce,

made this because ive noticed that with a standard carbine spring + 308 carbine buffer, the carrier bounces back enough to literally start unlocking the bolt even when chambering a round.

I ended up buying a CAR XH buffer from heavybuffers that is 6.5 oz, and his springs.

at first glance i tought the problem was solved because when loading soft point bullets they slide on barrel extension so hard it chew them increasing friction and slowing the carrier down.

but when loading FMJ the carrier still bounce slightly back, just enough for me to dont sleep at nights lol. Mainly because ive bought two of them and they costed me quite a good amount of money...and not being able to totally solve the bounce is

a little annoying. Now, im a little concerned going with a heavier buffer because i already had couples of failure to lock back on last round plus im not really willing to trade an adjustable buttstock for a fixed stock on such an already heavy gun..

the barrel im using is a spike tactical 308 which have a slightly longer gas system too.

anyone here have been experiencing other solutions like springco orange springs with a standard carbine buffer? is there any other manufacturer making stronger 308 springs?

is anyone using a heavier buffer? i guess the spikes barrel must have a fine tuned gasport in order to not overgas the gun.

seen quite a few videos online of pretty much "stock" guns with no modified buffers or spring having completely 0 carrier bounce LOL

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[georgeib]

You can get a JP or Tubbs spring for your 308. I've tried those two, and the Sprinco Orange, but I ended up using the Tubbs. The Sprinco is just too heavy.

The best way to reduce your carrier's velocity is to get an adjustable gas block, as this solves the reason for adding the heavier springs/buffers in the first place. I ended up trying almost every combination of buffer and spring weight available, and ended up settling for a 5.5 oz short carbine buffer from Heavybuffers.com, and a Tubbs flat wire spring with a SLR adjustable gas block.

[georgeib]

You can get a JP or Tubbs spring for your 308. I've tried those two, and the Sprinco Orange, but I ended up using the Tubbs. The Sprinco is just too heavy.

The best way to reduce your carrier's velocity is to get an adjustable gas block, as this solves the reason for adding the heavier springs/buffers in the first place. I ended up trying almost every combination of buffer and spring weight available, and ended up settling for a 5.5 oz short carbine buffer from Heavybuffers.com, and a Tubbs flat wire spring with a SLR adjustable gas block.

[MegademiC]

The spring should push the carrier back closed. Sounds like a really weak or too short of a spring.

Are you sure you have the right spring for your setup? Ive only heard of carrier bounce being an issue for FA and every semi I used closes itself after pulling the ch back any amount when clean and lubed.

Esit how long is the spring when laying on a table?
https://forum.308ar.com/topic/597-bu...buffer-spring/
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Just saw below post... so it is closing - disregard above.

[Lallop]

Okay so,

i was waiting to receive the second 6.5 OZ and spring from Heavybuffers.com and i

when compared this spring with the one i received earlier, this one (other than is a different color) appears to be one coil shorter.

tested again releasing the bolt from the bolt catch while chambering a round, and the carrier bounce is now near zero....

what have gone wrong? the previous heavybuffer spring have been used only for about 30 rounds or so, i think is not enough to wear down a spring (or is it)

other option could be that the other spring is too strong causing the bcg travel faster and hit the barrel extension with more energy ---> causing the carrier to bounce?

i have upload two quick videos,

https://youtu.be/2UFlwlVQC0c this one being with the just arrived Heavybuffer spring

https://youtu.be/9qo4-9XuJ6g this one being with the other Heavybuffer spring

it is a little bounce even on the second video i know, but considering theres zero to noone on the first instance, there must be something wrong on the second setup.

[mic2377]

Getting these to run optimally is tough with the CAR length buffer tube. I think it is tough to fit enough buffer and spring to tame the heavy weight of a 308 BCG in such a small tube.

I had tried at length to get one of the 308 AR's I worked on to run reliably with the the "stubby" 308 buffer. I also tried different springs in addition to an adjustable gas block. It had a very narrow window of operation - while it would run fine with standard 147 grain ball, but then with heavier bullets would act over gassed and occasionally fail to eject, and lighter bullets/faster powders would sometimes not lock back.

After some experimentation, I found that the 2 best combos were either a rifle length tube and rifle buffer/spring, or a A5/AR-10 carbine tube, an AR-10 carbine spring, and a H3 carbine buffer. These allowed a heavier buffer weight but more importantly the spring rate is more constant across the length of operation.

I think the really heavy Springco orange springs generate too much forward carrier velocity and need a VERY heavy buffer to control bolt bounce, which I don't think exists.

The benefit of using the A5 or AR-10 buffer tube (which is DIFFERENT than the LR-308 carbine tube that is the same as an AR-15) is that you get to keep your adjustable LOP, albeit when collapsed it is about 1.5 inches longer than the short tube. Not a big deal in my mind.

[Lallop]

very unfortunately i learned the existance of the Armalite/A5 buffer tube lenght a little too late ;((

i would have otherwise gone with a 8.5 oz buffer weight.

i want to point out that both of my rifles work exceptionally fine, except for that little bounce back that im having (that is more a OCD thing lol) however since the rifle is probably not designed to have the carrier bouncing around, thats what i would like

to accomplish..