Got my ROCK to the range

[towerofpower93]

I sold my MK 1 FiveseveN back in 2014 when I wasn’t much of a pistol shooter and started regretting it almost immediately. I didn’t miss it so much as to want to pay for a MK 2 or 3 FiveseveN and the Ruger didn’t rustle my jimmies. When I saw the threaded and optics cut ROCK available for $600 though…I had to jump.

Finally got out to the range a couple hours ago with 5 x 23rd mags of handloads using the below data:

1x fired FNH brass
Winchester Auto Comp 5.4gr
Rem 7.5 SRP
Hornady 40gr VMAX
OAL 1.585"

This load gives me ~200 over FNH SS197SR (2180fps handloads, 1980fps SS197SR) in my SBR’d PS90, for reference, though I didn’t get velocity data in the ROCK today.

Started out unsuppressed and with an SF X300 and Holosun 508T on the pistol. After 10rds of total failure to eject I removed the 508T and put some more oil on the rails.

After a few more hand ejected pieces of brass started getting consistent ejection 10-15’ to the 3:30

I put the 508T back on and a fresh mag and after a couple hand ejected pieces of brass it started running again.

Put my recored Gemtech SFN-57 on along with another full mag and, again, after a few hand ejected pieces of fired brass it ran until time to reload. Two more full mags and a few more hand ejected pieces of fired brass with full mags and the last ~20 in each mag cycled just fine.

Looks like the mags are tight or the gun needs some break in to cycle with a full mag and I might run them at 20 for the next 100rds through the gun to test this theory.

I also learned I’ll need to either put some plumbers tape on the barrel threads or be sure to check the can after each mag as I ended up keyholing most of the last mag (third mag with the can on) and not noticing until I walked up to the 15yd target when cleaning up, haha. A tiny ding in the end of the can and a few pieces of jacket came out of the can when I got it home. Plan to break it apart tomorrow to clean and see if any baffles got kissed.

[panzermk2]

Did you run any factory ammo? What dies did you use?

[towerofpower93]

No factory ammo at the moment. Lee dies.

I only go 2x fired on FN brass in the PS90 and pitch it after the third firing. Thinking I’ll do virgin firing and 1st and 2nd reloading cycle in the PS90 then treat the third reload cycle as ROCK only brass that’s left/not picked up, unless others have found the ROCK to be too aggressive on shoulder movement. I thought I remembered reading how the rifle had more shoulder movement than the pistol in the past, though PSA’s offering could certainly perform differently than FN’s.

I did just receive a Lee collet crimp die.

When I got into reloading 5.7 a number of years ago Lee only made a 2 die set with no crimp die available.

My first couple of rounds into the crimp die gave a little ring of brass as it appeared to crimp too deeply and cut a piece of brass off approximately 2/3 of the case. Backed it off a 1/4 turn and no brass bits. Going to run 10rds each in the PS90 and ROCK head to head with uncrimped rounds all loaded at the same time 6mos who to see if the crimp does what Jay has mentioned in other threads and gives lower ES/SD.

[panzermk2]

I asked since Lee changed their resizing die a few years back. You can do a search here and see the posts.
Lee 5.7 dies are crap. Crimp is fucking nightmare, I made a video about the ordeal I went through,
Elite Ammunition 1st through 3rd Parts Lee 5 7x28mm Crimp Die 3 Round Battle
https://youtu.be/pz14X6uVRV8
Lee Crimp Die Fourth Time Is The Charm, very charming it works after 4 tries
https://youtu.be/J_8BEIb2ZTo


Best are CH4D 3 dies set and they are just now back instock. Pricey. I would go with the hornady 2 die set and the CH$D crimp die.

[towerofpower93]

Saw your Lee crimp die posts.

It was less than a 1/4 turn from nice crimp to cutting brass. Far more delicate than any other Lee FCDs I use for straight wall pistol or bottle necked rounds.

Hoping the crimp will bring down my ES/SD, but we’ll see.

What changes were made to the Lee dies? I got my sizing and seating dies in 2014 and the crimp did just the other day.

[panzermk2]

The angle of the case taper. Another die maker did the same thing. Not noticed as much on the pistol but in the P90/PS90 the tapper causes the rounds to jam in the mag.

[towerofpower93]

The angle of the case taper. Another die maker did the same thing. Not noticed as much on the pistol but in the P90/PS90 the tapper causes the rounds to jam in the mag.

Interesting. I haven’t fired factory ammo in years, but have had a few instances of the P90 mags being sluggish and not feeding rounds fast enough. I’d always chalked it up to the mags getting so dirty from suppressor use, but if the Lee sizing die isn’t sizing the case to the proper dims that would be good to know.

When I plunk test in my clean barrel I have no issues, but they are a few thou proud in an EA case gauge.

[towerofpower93]

Got a chance to run 50rds of Federal 40gr FMJ through two 23+1 runs and 2 random rounds.

The pistol had been cleaned and lubed and I was shooting unsuppressed with the RMR on it.

Round 1 failed to eject like my handloads. After manually cycling the action the other 23 rounds fired and ejected fine with the sliding locking back. I loaded the other mag, put an extra round in the chamber, and it ran all 24rds fine, though the first piece of brass did seem to eject less violently than the next 23. The final 2rd mag was all good.

I wanted to put another 100-150rds through it but the rain showed up.

Another guy on ARF is getting a similar first/cold gun FTE issue with the Ruger pistol, but he’s also using handloads and the lacquer being tumbled off might be his issue.

I’ll put at least another 100rds through it, firing 23+1 each time, and letting the gun cool so I can try to determine if mine also has a first round/cold gun FTE issue before contacting PSA for an RMA.

[MikeyS]

What type of patterns were you getting at what range. I'm having difficulty getting consistent groups with factory and hand loaded 40 gn. Not sure if its unfamiliarity with the pistol, my eyes getting worse, bullet weight, or what. Don't appear to have any problems with a Glock 19.

[towerofpower93]

I've been more focused on function over accuracy at this point, so I haven't been paying too much attention to group size or making sure my form is 100% dialed in when shooting on paper.

[MikeyS]

Function is one thing I'm pretty happy about. The Rock has eaten everything I've put through it, factory and reloads, with not one hiccup.

[panzermk2]

the Rock has the same issue as the FsN, I made a video about it a few years ago,

I can't hit sht my Five Seven is inaccurate Elite Ammunition
https://youtu.be/z80x5uAz2u8 ...

[MikeyS]

Fair enough, except that I am getting the same inaccuracy off a rest. Offhand the light weight does take some getting use too and I was sure this had something to do with it. On the rest tho there should be some improvement in the grouping. I read somewhere that the 5.7 pistols don't really like heavy bullets, so I assumed this may something to do with it. Will continue to work with it.

[panzermk2]

Anything over 40gr gets spotty. This is why I stopped using the Barnes 45gr TSX Solid Hollow point. I designed my own 36gr Solid Copper Hollow point and replaced the TSX with it on our X-terminator.

[towerofpower93]

Got the Rock back out yesterday to see if the handloads would cycle. I did another 23+1 setup and the first round failed to eject with the slide barely moving. The next 2-3rds barely cycled with me having to eject the fired cases. I then had a few that ejected the case 10-15ft to the 4oclock, but apparently failed to reset the striker. Pulling the slide to the rear while keeping the loaded round in the chamber and then tapping the rear to ensure it was fully in battery took care of the dead striker. The last 12-15rds fired, extracted, and fed without issue to slide lock.

Ran out of time to put another 50 AE FMJ through it, but I’m starting to think mine is acting like another guys who posted in ARF's Reloading sub forum. It fails to eject until a few rounds warm it up and then it’s good to go.

I’ll do another 50rds each of AE FMJ and handloads and if it’s still giving me fits I’ll plan to send it back to get checked out.

[Shotty]

There is a bit of an issue when installing an optic to the ROCK. If your mounting screws are too long they will damage the plastic firing pin holder shells in the slide. I shortened my mounting screws before mounting my Holosun HS507K-X2 but they were still too long and did some superficial damage. I doubt this is your problem but I just wanted to mention it here.

[panzermk2]

FYI The striker is not charged in the rock.

[panzermk2]

Got the Rock back out yesterday to see if the handloads would cycle. I did another 23+1 setup and the first round failed to eject with the slide barely moving. The next 2-3rds barely cycled with me having to eject the fired cases. I then had a few that ejected the case 10-15ft to the 4oclock, but apparently failed to reset the striker. Pulling the slide to the rear while keeping the loaded round in the chamber and then tapping the rear to ensure it was fully in battery took care of the dead striker. The last 12-15rds fired, extracted, and fed without issue to slide lock.

Ran out of time to put another 50 AE FMJ through it, but I’m starting to think mine is acting like another guys who posted in ARF's Reloading sub forum. It fails to eject until a few rounds warm it up and then it’s good to go.

I’ll do another 50rds each of AE FMJ and handloads and if it’s still giving me fits I’ll plan to send it back to get checked out.

What were these exact loads again?


Are you checking you loads with a go/nogo gauge?

[towerofpower93]

1x fired FNH brass
Winchester Auto Comp 5.4gr
Rem 7.5 SRP
Hornady 40gr VMAX
OAL 1.585"

They are tight in an EA gauge, which makes me want to resize some of my other 1x fired brass a bit more and try again. The fact that I've also had issues with the factory AE FMJ loads previously makes me wonder if it's a barrel/chamber issue. I plan to do another 50-100rds of AE FMJ and if there are no hiccups from start to finish I'll chalk it up to the handloads.

I sized my brass the way I did to minimize shoulder movement in my PS90 barrel. They feed and fire just fine in that, but that chamber might be on the big side of spec and the Rock on the tight end.

The odd thing is that they start running just fine after 5-10rds gets the gun warm.

[towerofpower93]

Got the Rock out again yesterday. Still failing to eject and/or reset the striker on the first round in a cold gun when loaded 23+1. This was with handloads and AE FMJ.

I've contacted PSA to get it back to them for a once over.

[panzermk2]

They should not be tight in my gauge.

[towerofpower93]

Yep, going to adjust the sizing die next time I do a run on the 650.

I used my PS90 barrel as the gauge as it was my only 5.7 firearm at that point.