9mm ar pistol, prefer to keep bolt hold open feature, buffer/spring suggestions.

[soflarick]

I really enjoy plinking with the 9 ar pistol, and it currently has a functional BHO feature.  Bolt is from Rubber City with the weight intact.  I've fiddled with buffer springs and buffers, and I'm currently using an Orange Sprinco and Taccom buffer.  Feels like if I were to remove the bolt weight, the return to battery wouldn't bounce as much, but I've noticed the cases aren't as carboned up with the heavier spring and weight.  Has anyone found a good trade-off setup?  I can tinker on my own, but thought I'd ask here in case I miss something.

[Arcrunner]

If you want less bolt travel overall you would short stroke the system. if you want to keep the LRBHO, then I would recommend the taccom ESSB, it will engage the bolt catch at a different location on the bolt and still lock open. I don't particularly need it, but I go the bolt for how quick it resets triggers, the BHO cut was just a bonus. Currently I use the taccom air piston setup with their essb, with proper stance and grip, minimal dot movement.

[TRUBL]

I'd recommend using the spring that came with the TACCOM recoil system......that one you are running is too heavy and makes your gun feel clunky. Who gives a rats butt how much carbon is on the spent cases......smooth is what you want. At most, use both pre-load rings that came with the system.

[SEB]

Does the TACCOM ESSB work with the LRBHO on Aero receiver set?  If so, what else is needed to short stroke the system?  

[Arcrunner]

12 hours ago, SEB said:

Does the TACCOM ESSB work with the LRBHO on Aero receiver set?  If so, what else is needed to short stroke the system?  

it works with the Aero's LRBHO. You may have to tune the wire that activates the bolt catch to make it fully activate depending on your mags, but it works just fine for me. You can use the taccom Air Piston and it's automatically short stroked, you can get their 3 stage buffer and it comes with a short stroke spacer, or you can just put quarters in your buffer tube if you want.

[SEB]

I was thinking of using their Adjustable Recoil Buffer System.  Other option would be KynShot.

[mitommy]

On 11/16/2022 at 1:55 PM, SEB said:

Does the TACCOM ESSB work with the LRBHO on Aero receiver set?  If so, what else is needed to short stroke the system?  

I run the ESSB in an Aero EPC9 upper. My PCC uses Glock mags. The LRBHO is reliable with Gen 3 mags only. Other gens are hit or miss. When I contacted Aero they confirmed that Gen 3 are most reliable for their LRBHO. 

[seako_916]

On 11/16/2022 at 12:55 PM, SEB said:

Does the TACCOM ESSB work with the LRBHO on Aero receiver set?  If so, what else is needed to short stroke the system?  

I recently built a EPC upper and lower with Taccom ESSB and BRBS. Shot a few hundred rounds through it and it ran fine. Went to a match with it last week and it wasn't going into battery all the time. I could see that the bold not all the way forward. Would pull the mag out and it would close. Put the mag back in and it would fire a few rounds and get stuck again. I didn't have the time to actually stop and look at it in the situation (nerves, pressure to not slow the squad down, not thinking) but the more I thought about it, it might have been related to the LRBHO feature. 

I removed the LRBHO wire and went out and shot it this weekend as fast as I could and it didn't malfunction at all.. like wasting ammo and spraying it out as fast as my finger could pull..  There didn't seem to be anything wrong with the wire but I removed it anyways.

I though I really wanted/needed the LRBHO functionality but in all honesty, it doesn't matter to me as a Glock mag with extension on it holds more rounds than any stage will ever need if it doesn't have a mandatory reload. 

[mitommy]

9 hours ago, seako_916 said:

I recently built a EPC upper and lower with Taccom ESSB and BRBS. Shot a few hundred rounds through it and it ran fine. Went to a match with it last week and it wasn't going into battery all the time. I could see that the bold not all the way forward. Would pull the mag out and it would close. Put the mag back in and it would fire a few rounds and get stuck again. I didn't have the time to actually stop and look at it in the situation (nerves, pressure to not slow the squad down, not thinking) but the more I thought about it, it might have been related to the LRBHO feature. 

I removed the LRBHO wire and went out and shot it this weekend as fast as I could and it didn't malfunction at all.. like wasting ammo and spraying it out as fast as my finger could pull..  There didn't seem to be anything wrong with the wire but I removed it anyways.

I though I really wanted/needed the LRBHO functionality but in all honesty, it doesn't matter to me as a Glock mag with extension on it holds more rounds than any stage will ever need if it doesn't have a mandatory reload. 

I had similar experience with my Aero EPC. I found that the problem was not the upper but rather the lower’s ejector.  That ejector also serves as a mag stop. The ejector is only held in place by 2 set screws that push against the side if the ejector. It’s not a positive location and if you slam the mags in, the ejector can raise over time. I inserted several mags to ensure the optimal location. I scribed a line on the side of the ejector. That gave me a visual if the ejector moved. After running a couple hundred rounds, from various mags, I confirmed flawless function.  I then removed the ejector and used a drill bit to dimple a positive location for the set screws. (Of course I installed the set screws with thread locker) I had posted a question on this site and from the responses, this was not an uncommon problem & solution for lowers  that use this style ejector mounting system. 

 

I haven’t had any further problems. And my LRBHO functions every time (with Gen 3 Glock mags)

[seako_916]

14 hours ago, mitommy said:

I had similar experience with my Aero EPC. I found that the problem was not the upper but rather the lower’s ejector.  That ejector also serves as a mag stop. The ejector is only held in place by 2 set screws that push against the side if the ejector. It’s not a positive location and if you slam the mags in, the ejector can raise over time. I inserted several mags to ensure the optimal location. I scribed a line on the side of the ejector. That gave me a visual if the ejector moved. After running a couple hundred rounds, from various mags, I confirmed flawless function.  I then removed the ejector and used a drill bit to dimple a positive location for the set screws. (Of course I installed the set screws with thread locker) I had posted a question on this site and from the responses, this was not an uncommon problem & solution for lowers  that use this style ejector mounting system. 

 

I haven’t had any further problems. And my LRBHO functions every time (with Gen 3 Glock mags)

Ah, didn't think of that. Ill take a look at it tonight as I have another match tomorrow. 

Glad to hear your LRBHO functions properly. Ill leave it out for the time being but may attempt to run it in the future. 

[SEB]

After talking with Tim, I ended up going with Taccom ULW SuperFeed 16" barrel, 3-stage air cushion recoil system, and Extreme Short Stroke Bolt.

I put around 200 rounds through mine with no issues.  I use PMAGs, so I had to bend the LRBHO wire a little so that it was ALMOST 90* (stock is visually less than 90*).  That seemed to be pretty consistent.  With it bent that way, it is possible that it will hold the bolt open on the 2nd to last round if you manually cycle it, but I had no issues under live fire.  Going back this weekend to put some more rounds through it.  So far I'm pretty happy with it.  There is more movement of the sight than I was expecting, but I think I just need to work on my technique.  Very lightweight at around 5.2lbs. Its actually about a .5lb heaver than my lightweight AR build, but because the weight is all towards the shoulder it feels lighter.