I recieved my Bushy 7.5" flat top upper. Here in Canada we can mount them to carbine lowers, as I have done, no prob at all. My question is this; the recoil produced by the 7.5 feels greater than my 20" or 14.5 ". Do I need a heavier buffer or will a regular weight carbine buffer work fine? I do not want to damage any components.......hinking.gif

Regards,

i thought the bushmaster pistol uppers used different bolt carriers........
if iirc then you need to find out cause the difference in length could damaged a lot of things!


but if im wrong then yeah the recoil impulse with be greater with the shorter gastube, barrel. either a heavier buffer, carrier,stronger buffer spring or pigtail gas tube will help lessen the recoil

I test fired mine (40 rounds) with my Armalite bolt assy. I now have a new Colt bolt assy for it, but I have not yet fired it.   I have not come across any info / literature that indicates a different carrier group for a pistol over a carbine ( not to say that there isn't any). The AR family is designed to be totally interchangeable so where does a different design bolt / carrier come into play? Maybe my best bet would be to fire off an e-mail to Bushmaster.....

Quoted: I test fired mine (40 rounds) with my Armalite bolt assy. I now have a new Colt bolt assy for it, but I have not yet fired it.   I have not come across any info / literature that indicates a different carrier group for a pistol over a carbine ( not to say that there isn't any). The AR family is designed to be totally interchangeable so where does a different design bolt / carrier come into play? Maybe my best bet would be to fire off an e-mail to Bushmaster.....

From what I read, the carrier on the Bush "pistol" is different so that the shorter recoil tube can be used.  The buffer assembly actually takes the place of part of the carrier, from the pictures I have seen online.

I'm leaning toward the notion that the upper rec and barrel extention and bolt are mil spec.  Only the carrier was modified (shortened).  So in theory, placing a "standard carrier" in the pistol upper wo work w/ a carbine lower/buffer system, in theory, 'should' work.

edit-
...is the upper the 'carbon' series upper (for their pistols)?  Or is it a standard aluminum one???

I was unaware that Bushmaster sold their pistol upper as a seperate part......

The upper is a standard aluminum one. The upper was purchased new, and yes it was seperate from a lower. I am just trying to prevent any situation (if indeed a situation exists) that may result in any damage to my upper components once mounted on a regular carbine lower assembly. My Bushmaster lower will arrive very soon. I just want to be certain that the carbine buffer/tube/spring is not too heavy/light for this 7.5" upper.  
http://img.photobucket.com/albums/v178/Boomer686/HPIM0418.jpg
I have since inspected all components after my range test and have found no signs of damage or excessive wear/stress.

Regards,

And where exactly did you get a aluminum Bushy upper with 7.5" bbl?  I know the Carbon pistol uses 7.5" bbl, but I don't see if offered for sale separately in their catalog.

I would use a standard carrier with it, but the added reciol that you are probably noticing would be due to the reduced weight of the weapon, as there is a whole lot less steel on there wit the shorter barrel.

Boomer -  I have a 7.5" pistol.

The regular car tube and buffer work just fine  

Quoted: I recieved my Bushy 7.5" flat top upper. Here in Canada we can mount them to carbine lowers, as I have done, no prob at all. My question is this; the recoil produced by the 7.5 feels greater than my 20" or 14.5 ". Do I need a heavier buffer or will a regular weight carbine buffer work fine? I do not want to damage any components.......hinking.gif Regards,

   

My feeling is that the shorter barrel is causing a more pronounced muzzule rise and greater felt recoil. Have you considered using a hydraulic rate /recoil reducing buffer, Enidine manufactures a buffer that will replace the standard carbine length inertia buffer as a direct drop in replacement. It will really calm down the gun.

Our hope is that Bushmaster will soon offer this buffer as an accesory in the mean time you can get it at Buffer Technologies!