AR 9 bolt travel question

[fstdraw]

I've got a flawlessly shooting AR 9mm carbine. 16 " barrel, Glock lower, I installed a heavy buffer and spring and that really helps, runs like a champ. I purchased it from a forum member who really knows his stuff. Never even a stove pipe or a missed striped round. However it does not have LRBHO. Not a problem to me. I just noticed I can't lock the bolt open even by hand, bolt won't go back far enough. I removed 3 or 4 quarters from the buffer tube and now I can manually lock the bolt open. Is this going to change the recoil dynamic and cause a problem? Or just work as usual? I do like being able to lock bolt open. I've not shot it since my change. Thank you.

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[Member 34319]

What do you mean by removing 3-4 quarters of the buffer tube?

 

[fstdraw]

Yes, I installed a few quarters originally to keep the bolt from going TOO far back.

 

[Member 34319]

Yes, I installed a few quarters originally to keep the bolt from going TOO far back.

That's a new one for me...

If it works without the quarters, you should be fine.

If anything the recoil should be less, as the spring should be allowed to slow things down longer now that it has more room to do so. It was likely more snappy before as the buffer shorts out faster with those quarters in the way.

 

[fstdraw]

I think the quarters are a well-known fix for the buffer going back too far, compensating for the shorter 9mm round. So maybe I'll need to experiment a bit and find a happy medium between the bolt going back too far and being able to lock the bolt back. I don't want to screw this excellent weapon up.

 

[Tomahawk67]

Your old buffer was a normal carbine length buffer and your new buffer is 9mm ar length buffer. You don't need spacers with the longer ar9 buffers, as they are longer to match the 9mm bolt length.

 

[fstdraw]

I'll try the buffer w/o any quarters, might work just fine. I didn't think about the new 9mm buffer being different, thank you!

 

[fstdraw]

Thanks to those that chimed in. I remember the quarters in the buffer tube were to reduce recoil. Recoil is not a problem with the new buffer and spring. Bolt locks back and gun functions perfect.

 

[VinnieBoomBah]

The only reason for the quarters is to reduce bolt over travel so that your bolt doesn't have a running start to slam into your LRBHO and break it, but you don't have one of those, so there's nothing to worry about

 

[spookshack]

I ran a KVP 7.5oz 9mm buffer with a .308 buffer spring. No issues....

I currently run a Taccom recoil system. No issues with it either.

 

[fstdraw]

You are correct Sir!
I run almost the same buffer/spring and it is great.