Short stroke bolt w/ LRBHO..?

[ck1]

So, I haven’t gotten into the short stroke game yet with my PCC, but since I’ve begun itching to play with my buffer setup to maybe improve recoil impulse characteristics and follow up shots, figure I might as well... Thing is, LRBHO works 100% in my gun and I wanna keep it that way (nothing to do with gaming, I know I don’t need it, just prefer it for a few reasons), and until recently SS + LRBHO was a no-go.

 

From what I’ve found, looks like JP and Taccom both now make bolts that’ll support LRBHO with a short stroked system, anyone have any experience with these or know of any others..?

 

They’re close in price so that’s not really a factor as far as the bolts (of course the JP is more $$$ lol ), but I’ll more than likely pair whichever one I go with to either Taccom’s new delayed blowback buffer setup or JP’s short stroke SCS setup. If they’re apples to apples, in the end the JP stuff ends up about $150-200 more, but that’s not a big deal if it’s worth it... so it’d be helpful if anyone could chime in if they have experience with either of these bolts with either of these buffer setups too..?

 

One thing I did notice is that the Taccom bolt says it comes with spacers to short stroke a conventional buffer setup, which might be good to try out before I decide on which buffer setup I want to go with, and I also appreciate that the Taccom folks are regular contributors on here, but idk...

 

Thanks.

 

Edited to add: I don’t reload and generally shoot whatever brass-cased 9mm is cheapest in bulk at the given time (usually Blazer Brass or Magtech, 115gr more often than 124gr)... no idea what power factor I’m getting out of a 16” barrel, but guessing it’s middle of the road, above 130pf but not too hot...

Edited July 27, 2019 by ck1
Ammo

[rowdyb]

i ordered a new enhanced bolt for my JP, I'll let you know how it works with my short stroked gun

[mveto]

I recently switched to the new enhanced JP bolt, I’ve been running the JP SCS short stroke since it came out and noticed a big difference in recoil impulse and dot bounce. While I don’t use the LRBHO in the gun I like being able to lock the bolt back at the make ready command, just makes insetting that fully stuffed mag easier.

[ck1]

Cool, thanks for the responses guys! I’m looking forward to trying the short stroke thing out, just still on the fence... Honestly, I’m just happy to have a gun that runs, and haven’t been able to make a match in forever due to work/life, but I’ve got a good trigger in it and can already see how it could be a benefit because I can sometimes feel like I’m “waiting” on the gun to cycle, and feel like I’d prefer it to cycle faster...

 

*That said (and this could probably be another topic): any reason I might NOT want to SS it to cycle faster, or does anyone prefer that..? 

*(I ask because years ago I went from shooting CZ/Glock pistols to a 9mm 1911 w/ like a 10lb recoil spring for a summer that felt like it cycled in slow motion, but I put up some of my fastest classifier times even though the gun felt slow AF...)

 

 

Edited July 28, 2019 by ck1

[Darqusoull13]

Stroke it, big increase in performance. The LRBHO bolt is solid and just as reliable as a standard bolt. 

[ck1]

12 minutes ago, Darqusoull13 said:

Stroke it, big increase in performance. The LRBHO bolt is solid and just as reliable as a standard bolt. 

 

Awesome! Think I might, thanks!

[dthomas1003]

I run the JP short stroke bolt and LRBHO does not work and JP states this on their website. It will manually lock back though, so no problem there.

 

To answer your other question, I tried pairing it with JP's SCS short stroke buffer and it was a no go. It would not reset my trigger and would not feed. I currently have an X buffer at 7.5oz and a regular carbine spring and it just runs and runs. 

Edited July 28, 2019 by dthomas1003

[ck1]

11 hours ago, dthomas1003 said:

I run the JP short stroke bolt and LRBHO does not work and JP states this on their website. It will manually lock back though, so no problem there.

 

To answer your other question, I tried pairing it with JP's SCS short stroke buffer and it was a no go. It would not reset my trigger and would not feed. I currently have an X buffer at 7.5oz and a regular carbine spring and it just runs and runs. 

 

Huh? That defeats the whole purpose of the new SS bolt? Sure it’s this one? https://www.jprifles.com/buy.php?item=JPBC-9SL-SP

 

Says it “provides reliable last-round lock back with any compatible receiver...” What Receiver are you running?

[Darqusoull13]

1 hour ago, ck1 said:

 

Huh? That defeats the whole purpose of the new SS bolt? Sure it’s this one? https://www.jprifles.com/buy.php?item=JPBC-9SL-SP

 

Says it “provides reliable last-round lock back with any compatible receiver...” What Receiver are you running?

 

My GMR-15's all lock back with the new bolt designed for last round bolt hold open and short stroke SCS.

[rowdyb]

ups tracking says mine will arrive tuesday. so tuesday night i will install 2 tungsten weights to make my short stroke gun with 5 tungsten.

 

i'll also throw on my extended mag release and the new enhanced bolt inside. range opens at noon on Wednesday so you'll get a post from me that afternoon.

[dthomas1003]

4 hours ago, ck1 said:

 

Huh? That defeats the whole purpose of the new SS bolt? Sure it’s this one? https://www.jprifles.com/buy.php?item=JPBC-9SL-SP

 

Says it “provides reliable last-round lock back with any compatible receiver...” What Receiver are you running?

Yes, that is the one I have unless they released a new one in the last month. I was mistaken about the LRBHO for the bolt, it says that for the SS SCS. I have the Quentin Defense ARQ 9mm receiver set that I am running it in. I'm not really concerned with LRBHO. I am more concerned that they advertise the SS Bolt and SS SCS buffer as working together and they do not for me. A 31 round Glock mag with a TTI +10 extension will absolutely not feed until 10 rds are gone. I put in the X buffer and it runs like a sewing machine.

 

The biggest heartburn I have over the whole situation is that JP has not responded in a month to the two emails I have sent with questions about this issue. My work schedule and being on AZ time makes it almost impossible to call them. 

Edited July 28, 2019 by dthomas1003

[ck1]

14 hours ago, dthomas1003 said:

Yes, that is the one I have unless they released a new one in the last month. I was mistaken about the LRBHO for the bolt, it says that for the SS SCS. I have the Quentin Defense ARQ 9mm receiver set that I am running it in. I'm not really concerned with LRBHO. I am more concerned that they advertise the SS Bolt and SS SCS buffer as working together and they do not for me. A 31 round Glock mag with a TTI +10 extension will absolutely not feed until 10 rds are gone. I put in the X buffer and it runs like a sewing machine.

 

The biggest heartburn I have over the whole situation is that JP has not responded in a month to the two emails I have sent with questions about this issue. My work schedule and being on AZ time makes it almost impossible to call them. 

 

Wow, sorry, that stinks that JP hasn’t gotten back to you...

 

I looked up Quentin Defense, looks like pretty trick stuff for sure, but they don’t show a pic of inside your receiver... I’d be willing to bet their LRBHO is proprietary though and that might be your issue, if you feel like posting a pic of inside the top of the lower maybe we can help you troubleshoot it..?

 

From what I can tell, I think JP might have licensed the Foxtrot Mike LRBHO design...

Paul FM’s owner/designer has stated publicly that PWS, Wilson Combat (who of course made it trickier/more proprietary than it needs to be turning 1-piece into 3 w/ a couple roll pins ) and “a few other companies” have licensed their LRBHO design. I have the Foxtrot Mike, and the receiver’s LRBHO looks just like a JP GMR-15’s... Before I buy I’m hoping either FM or JP will let me know if my receiver is compatible with the JP stuff, but from comparing pics of each it looks like it should be GTG.

 

 

 

Edited July 29, 2019 by ck1

[4mike]

this is my solution, hope it will will help someone (for Glock magazines)
my SS are defined by 4.75 " OAL of compressed buffer + spacer

Edited July 30, 2019 by 4mike

[4mike]

second part
useful when the slide stop does not capture bolt just 0.02 "
realised by laser weld-on
 

 

Edited July 29, 2019 by 4mike

[4mike]

third part is about trigger reseting by cancellation of the bolt ramping  

 

Edited July 29, 2019 by 4mike

[ck1]

4mike, thanks for your replies, but I’m confused st what you’re getting at? Think you’re showing how one can machine their bolt to lock open when short stroked which is cool, but that’s beyond my skill set, the most advanced tool in my garage is my zero-turn lol!

 

FM Products got back to me on whether they know if their stuff will work with JP’s SS bolt and SS SCS buffer: they haven’t had a chance to try that particular JP stuff with their stuff yet so.... 

So I’m still not sure what to go with because it’ll be a fairly expensive beta test.

That said, I may just try the Taccom SS bolt and short stroking my conventional buffer setup w/ their spacers because that’ll only cost around $200 to test drive, but idk  

 

Any replies of anyone running any of these components is welcome and helpful...

 

 

[TRUBL]

So this is something that the ESSB address's.......we've known about this and been testing for months, nothing new....but insightful. If you have a welder and a mill.....it's easy. If not....well.....we got it done already and ready to rock.

[rowdyb]

Installed extended mag release tonight. installed 5 tungsten weights on my srs. And of course the new enhanced bolt.

 

couple first impressions:

-the coating is just as slick as my other bolt

-it of course comes with firing pin, extractor and all the stuff, just plug and play.

-locked back with no mag, just manually.

-locked back on 4 different Glock mags and 3 different magpul mags just cycling the charging handle

-using dummy ammo it did the same thing, always locking back and always dropping when hitting the paddle or charging handle.

 

I'll be checking it out and with the 5 tungsten tomorrow for live fire, 6 different mags.

[ck1]

18 minutes ago, rowdyb said:

Installed extended mag release tonight. installed 5 tungsten weights on my srs. And of course the new enhanced bolt.

 

couple first impressions:

-the coating is just as slick as my other bolt

-it of course comes with firing pin, extractor and all the stuff, just plug and play.

-locked back with no mag, just manually.

-locked back on 4 different Glock mags and 3 different magpul mags just cycling the charging handle

-using dummy ammo it did the same thing, always locking back and always dropping when hitting the paddle or charging handle.

 

I'll be checking it out and with the 5 tungsten tomorrow for live fire, 6 different mags.

Cool let us know how it runs...

[rowdyb]

Perfectly w the two diff 147 loads and all my mags. No malfunction of any kind and 100% lrbho w all my mags.  I like the 5 tungsten on my scs as well.

[Darqusoull13]

1 hour ago, rowdyb said:

Perfectly w the two diff 147 loads and all my mags. No malfunction of any kind and 100% lrbho w all my mags.  I like the 5 tungsten on my scs as well.

Ifffffff anyone wants to be as happy as rowdy I'd love to be your enabler  No seriously, I love answering questions or doing demos at after match parties  

I still can't decide which weight SCS setup I like in my GMR's. Every time I play musical lowers I change my mind. The nice part is they all function no matter what combination I put together so I can shoot instead of "trouble-shoot." 

[rowdyb]

[impact]

On 7/29/2019 at 11:48 AM, 4mike said:

this is my solution, hope it will will help someone (for Glock magazines)
my SS are defined by 4.75 " OAL of compressed buffer + spacer

 

 

did the almost same thing on my short stroked built a few thousand rounds ago, and was happy to see that that secondary edge seemed to have no negative impact on feeding reliability so far. Locks back like a charm and is handy on those unloaded IPSC starts. I just didn't short stroked it that much, since I didn't tinker with the hammers cocking ramp (yet). Is that a rounded off feather key welded into a milled slot?

what buffer weight/setup do you run with such a short stroke and how do you like it?

[4mike]

just a hardened steel wedge (with radius) weld-on at original ramp (none milled slot)
380g bolt + 150g magnetopneumatic buffer (own construction) rifle spring
aluminium spacer + wave (materiál of spacer depend at PF of used ammo - higher loads works better with Delrin spacer)
love it

Edited August 2, 2019 by 4mike

[RaylanGivens]

On 7/29/2019 at 8:04 AM, 4mike said:

third part is about trigger reseting by cancellation of the bolt ramping  

 

 

So, the notch in the bolt and weld build up on the bolt catch are to enable the bolt to lock back when the bolt doesn't travel far enough back to lock normally...  Because it's been short stroked...  Great idea!

 

How does the plug you welded in help with trigger resetting?  Could you offer a little more explanation on what this actually does?  What its purpose is?  I'm curious why bolt manufacturers go to the trouble of cutting the ramp at a different angle, when it would be better to be flat?