Thanks all. I'll put this stuff to work and post back.

This is a p320 story I've told here before:

Back in 2018 I went to Front Sights 4 day defensive handgun class for the forth time. I had bought a P320 compact with Romeo sight just for this jaunt.

On about the 3rd day I went up to the gun shop with a buddy who was looking to change the sights on his Glock and while there I asked the head gun smith about my Sig. this guy had a big Glock tattoo on his arm... and he showed me how the slide on my Sig wiggled and the gun could not be made accurate no matter what...
The next day we had to shoot for qualification:


So much for 'expert' advice.

Thought about something...

I installed SIG flat triggers on this gun as well as my P365. I had yet to shoot either pistol since I installed the triggers. Thought they felt good during dry fire, but noticed a bit extra reach vs. stock triggers.

Today I swapped the stock SIG triggers back into both pistols, and did some dry-firing with the P320. WAY less dot movement. Way less. I've yet to get back out to the range, but I'm HOPING this is the fix...that somehow the flat trigger was, in conjunction with the newness of the RMR experience, causing me to do funky stuff with my trigger finger placement and trigger press.

I'll post back once I get to confirm or debunk this theory on the range, but I'm hopeful.

I zero my RDS by using a bore laser and use a reflective target at 17 meters.
Simply adjust the red dot to the laser dot.
Works for me. My nephew and me have shots a few thousand rounds at 10 inch steel targets.
Also I buy a bad of cheap yellow tennis balls at
Walmart and we shoot at those.
Never had a dot, once zeroed give us any problem.
Most of our sights are Shield sights
My P320 has the Sig Romeo 1 on it. Has stayed zeroed for months.
Poli Viejo

quote:

You can hide a lot of flaws on iron sights that will be glaring on a RDS. Also, my trigger control went to complete crap the moment I saw the little red dot. I slapped the crap out of the last 1/3 of the trigger as soon as the dot appeared. It took a good deal of practice and a huge serving of humble pie to fix.

This.
2 weeks ago I was sighting in an AR and tossed my 229RX in the bag as I hadn't shot a red dot pistol in quite awhile.
This is a pistol I've shot matches before with, so I knew it was zero'd, accurate, etc.
First mag - the target looked like I'd hit it with buckshot. Definitely a "WTF" kinda moment.
Did the RDS get knocked in the safe? Screw loose? Something with the pistol off? Lots of questions start going through my mind.
I turn the dot off and run a mag with BUIS. One ragged hole. Ok, it's not the gun.
Turn the dot back on but made a conscious decision to slow down a tad and focus on trigger control.
Next mag - one ragged hole again.

quote:

Originally posted by Snake207:

quote:

You can hide a lot of flaws on iron sights that will be glaring on a RDS. Also, my trigger control went to complete crap the moment I saw the little red dot. I slapped the crap out of the last 1/3 of the trigger as soon as the dot appeared. It took a good deal of practice and a huge serving of humble pie to fix.

This.
2 weeks ago I was sighting in an AR and tossed my 229RX in the bag as I hadn't shot a red dot pistol in quite awhile.
This is a pistol I've shot matches before with, so I knew it was zero'd, accurate, etc.
First mag - the target looked like I'd hit it with buckshot. Definitely a "WTF" kinda moment.
Did the RDS get knocked in the safe? Screw loose? Something with the pistol off? Lots of questions start going through my mind.
I turn the dot off and run a mag with BUIS. One ragged hole. Ok, it's not the gun.
Turn the dot back on but made a conscious decision to slow down a tad and focus on trigger control.
Next mag - one ragged hole again.

Thank God. Seriously. I was wondering if I'd just lost years of ability. Lasik? Some disease? NSA radio waves finally getting to me?

Sounds like it's back to the fundamentals. I'm relieved. Thanks all. Should get to shooting this again mid-week and see how I can improve.

Okay, I'm kinda at a loss. I thought maybe part of my issues with this setup was the flat SIG trigger I installed, how it interfaced with my trigger finger and changed the geometry of my trigger press, so I removed and sold both the P320 and P365 flat triggers I purchased. Returning to the stock, curved triggers improved (reduced) dot movement during dry fire, yet there is only marginal improvement during live fire.

Shooting my P320 today from a kneeling rest at 50' in an indoor range, slow fire, using only iron sights (RMR off), gave me about a 4" group using 115gr WWB 9mm. Before I had the sights/RMR installed and the slide Cerakoted, I'd easily shoot that type of group standing offhand through Truglo Tritium Pro iron sights. Kneeling off a rest, that group should definitely be better.

Shooting the P320 using just the RMR kneeling off a rest gave me a similar spread, yet with a lone 4" flyer off high and to the right. I remember seeing that hole appear in the paper, KNOWING I held the dot on the center and had a clean, smooth trigger press, and immediately thinking "What just happened?"

Is it possible that Cerakoting the slide would change the barrel/slide interface and cause the pistol to group poorly/inconsistently?

This is super frustrating, as this gun USED to be the pistol I shot most accurately. I'm holding out hope that it really is my inability to shoot through this optic, but it's odd I'm having issues with irons and with the red dot.

I drifted the rear sight (group with irons was about 3.5" left) and will re-check zero tomorrow if I have time. Any suggestions are appreciated as this is really frustrating. If I cannot shoot a firearm accurately then my inclination is to ditch it and find one that I can, yet this platform is my favorite one and I don't want to give up on it, especially as I had this P320 Carry and my P365 setup nearly identically.

Okay, something has to be wrong with my pistol.

Shot from 25yds, outside, PERFECT conditions, sun at my back, seated, from a rest. 17 total rounds today.

Irons: First three rounds of WWB 9mm touching each other, about a half inch above the 3/4" diameter center dot of the target. That's what I'm talking about! This is how this pistol can shoot. However, the next round was about 4" high at noon, and the last round was about 4" right at 3 o'clock. WTF? Smooth, slow trigger press, follow through, good grip. I don't get it.

RMR: Optic on. Two rounds about 1.5" apart and about 3" left of center. Three rounds about 1" apart and now about 4" right of center. Smooth, slow trigger press, follow through, good grip. I'm about to throw this pistol into the river.

Next group of five with RMR after adjusting the dot about a notch to the left...two rounds about .5" from each other about 1" left of center, third round 5" left of center, 4th round about 4" left of center, fifth round about 6" right and about a half inch low. What is happening?

Adjust RMR slightly to the right (about half a notch), next round lands about 1.5" left almost level with center, and the last round is about 5" right about a half inch low. I give up.

This makes no sense. I know how to shoot. I know when I'm screwing up. I was hydrated, relatively relaxed and rested, seated comfortably and resting my arms on a good flat surface that stabilized my dot wonderfully.

I'm going to run this by my gunsmith and see what he says, as I've shot enough to know when it's me, and when it's the gun. No way does this gun go from printing a max 5" spread at 25 yards offhand to printing randomly left to right in nearly an 11" spread. I have pics to prove I have put 50 total rounds in a 4.5" circle going backwards from 5 to 25 yards with this thing, so I know what the pistol can do.

If anyone has any ideas, please pass it on, as my next step is to buy a whole new slide/barrel assembly and start from there.

Don't know if this applies to your situation, but somehow I have lost the ability to shoot consistently from rest. It is a technique issue that surfaced after I got back into reloading. I am a decent off hand shooter and lately can regularly shoot tighter groups off hand than what I get from a rest. Even with known accurate pistols and loads I can get large groups and weird fliers.

I suspect the cause is different shot-to-shot movement of the pistol in recoil during the time the bullet is still in the barrel. I know this can be a factor since, even when I was getting good groups, the point of impact was different than when off hand.

I am making progress by concentrating on keeping everything consistent - grip, how the pistol contacts the rest, and trigger control. One thing I learned early on in shooting from rest (back when I could get good groups). I could never get good groups if the butt of the pistol came in contact with the rest during sighting or in recoil.

quote:

Originally posted by dehughes:
Okay, something has to be wrong with my pistol.

Shot from 25yds, outside, PERFECT conditions, sun at my back, seated, from a rest. 17 total rounds today.

Irons: First three rounds of WWB 9mm touching each other, about a half inch above the 3/4" diameter center dot of the target. That's what I'm talking about! This is how this pistol can shoot. However, the next round was about 4" high at noon, and the last round was about 4" right at 3 o'clock. WTF? Smooth, slow trigger press, follow through, good grip. I don't get it.

RMR: Optic on. Two rounds about 1.5" apart and about 3" left of center. Three rounds about 1" apart and now about 4" right of center. Smooth, slow trigger press, follow through, good grip. I'm about to throw this pistol into the river.

Next group of five with RMR after adjusting the dot about a notch to the left...two rounds about .5" from each other about 1" left of center, third round 5" left of center, 4th round about 4" left of center, fifth round about 6" right and about a half inch low. What is happening?

Adjust RMR slightly to the right (about half a notch), next round lands about 1.5" left almost level with center, and the last round is about 5" right about a half inch low. I give up.

This makes no sense. I know how to shoot. I know when I'm screwing up. I was hydrated, relatively relaxed and rested, seated comfortably and resting my arms on a good flat surface that stabilized my dot wonderfully.

I'm going to run this by my gunsmith and see what he says, as I've shot enough to know when it's me, and when it's the gun. No way does this gun go from printing a max 5" spread at 25 yards offhand to printing randomly left to right in nearly an 11" spread. I have pics to prove I have put 50 total rounds in a 4.5" circle going backwards from 5 to 25 yards with this thing, so I know what the pistol can do.

If anyone has any ideas, please pass it on, as my next step is to buy a whole new slide/barrel assembly and start from there.

Have another known competent shooter shoot the gun. If they get the same results look at the mounting and optic.

1) Who milled the slide ?
2) Who mounted the optic ?
3) Who supplied the screws used to mount the optic ?
4) Who told you 12 inch lbs was appropriate torque value ? (varies with the screw size but 16 inch-lbs is common for direct mill mounts).

1) Is RMR a gen 1 or a Gen 2 ?
2) Was the RMR new or used ?

Gen 1 RMR's sometimes have issues with adjustments holding zero, however, when that occurs the failure is internal and you would not see it reflected in the dot when shooting.

I’ll post a bit more later, but I always struggle shooting from a rest.

In dealing with a pistol with a mounted optic, I do all my zero work at 10 yards. I attended a class a while back that had us shoot prone in the back of a truck to zero at 10. For many factors, that is the only way I have performed well from a rest.

Aside from that, I ALWAYS perform better shooting freestyle as opposed to shooting from a rest.

Glad I read this thread as I finally got a chance to try out my p320 compact with a Romeo1. It's been almost a year since I did any shooting. Working a rd for the first time on a handgun.
The info here helped a lot.

HCM:

Thanks for the reply. Here's the deets:

1) Fabricated Arms direct-milled both this P320 Carry and my P365 slide. Their milling work appears to be excellent.
2) Fabricated Arms mounted the optic, but I re-mounted it before I initially went to the range as I wanted to verify the torque on the screws.
3) Screws are stock and came with the optic.
4) Can't remember where I got the 12 inch-lbs figure from. Had to dig through the internet IIRC as nothing is spec'd in the instruction manual, but I do remember seeing the thread here: https://sigforum.com/eve/forum...40018264&s=674608412

I'll re-torque to 16 inch-lbs and check the zero/grouping again this week. Thanks.

1) This RMR is a Gen 2.
2) I purchased this RMR (as well as my RMRcc on my P365) at the same time a couple months ago, brand new.

________

jljones:

Thanks for the input. I'll re-torque the screws as above, and re-check zero this week at 10 yds.

Interesting info about shooting/zeroing a pistol from a rest. I figured it'd work the same way as a shooting prone with a rifle vs. standing, but maybe not. Always learning, I am.

______

The plan now is.....tomorrow I'm going to pick up an entirely new pistol (likely an optics-ready version of the CZ P10F, as I really liked my non-OR P10F) and mount the RMR onto that should it still not zero/group well for me. Worst case scenario is it's something simple like the torque or just me being stupid, and then I sell the CZ (or keep it, heck...but again the goal was to simplify to the SIG P-Series and sell my other pistols). Still though, if the RMR still isn't grouping well on an entirely different pistol, then I know it's either 1) ME, which is likely, or 2) something is up with the RMR. I have a couple scheduled ranged days this month for work so I'll also get some better shooters than I to test it out, and hopefully get to the bottom of all this soon.

Thanks again, all, for the input. Appreciate it. Sorry for taking up so much virtual space with this.

This message has been edited. Last edited by: dehughes,

Went and picked up a CZ P10F OR and mounted the Trijicon RMR from my P320 onto it. First impressions...significantly less dot movement upon trigger break with the CZ. Not like there was a ton on the SIG, but on the P10F the dot hardly moves at all when the trigger breaks...so much so that at times I can hardly tell.

Maybe this is a function of ergos, but I'm curious to see how this setup performs on the range. I'll try to get to the range tomorrow after work and zero the P10F (at 10yds, thanks jljones), and then put some iron-sight only rounds through the P320 sans RMR and see what I get.

Hit the outdoor range after work today because someone was shooting at the indoor range.

91 degrees, sunny, hot, gave blood yesterday, long day at work today, so terrible conditions to go shooting...which means it's perfect.

First up, the new CZ P10F OR with the installed Trijicon Type 2 RMR I took off of my P320. Within 25 rounds I had the CZ/RMR setup zeroed and putting 10 rounds inside the 9 and 10 ring of a NRA B8 target from 25 yards standing. Piece of cake. That's more like it!

Next up is the SIG P320 with an empty optic cut...iron sights only. While the group was low and right, I put the first and only five round group easily in the 9 and 10 rings of a NRA B8 target. Again, more like what I expect from this pistol. I'll gladly drift the rear sight and call it golden.

I'm at a loss...here I am tired and soaked in sweat and with range glasses starting to fog and with sweat in my eyes, and everything is fine? What gives?

I checked the torque on the CZ P10F OR mounting plate, and the RMR (I believe it was 14 inch lbs for the RMR, and 12 inch lbs for the mounting plate), and used Vibra-TITE VC3 as recommended on the linked thread above.

Is it possible the RMR is throwing off the lockup/timing of the P320 Carry slide? I did have it cut for the RMR specifically, but I don't think that's it because SIG makes stock P320 Carry slides for optics (granted, their own footprint) and I don't believe they have any weight-reduction cuts, just the optic cut, and I doubt there is significant difference in what's removed from the slide. Plus, people have been having "regular" slides milled for years and not complained of weird timing/unlocking issues.

Super confused, but at the same time happy the CZ P10F OR and RMR seem to be working dandy, at least.

One thing was interesting and is another thought about the problem: I just today was able to hear/feel the audible/tactile "click" of the RMR adjustment knobs, as I don't remember picking up on that last the first two times I shot the RMR when mounted on the P320. Granted, I had my range headphones on those times, so while it wouldn't explain the odd iron-sight groupings with the RMR mounted, is it possible the RMR groupings could have been off if I had the turrets "in-between" the click settings?

Regardless, it was a very hot, sweaty range hour in full gear, but at least I have ONE pistol/optic setup that is dialed.

I'll likely pick up another RMR and mount that on the P320 and leave the current RMR on the P10F, as that setup is DIALED IN, at least with the 115gr Blazer Brass ammo I was using today. That is, unless one of you can suggest a compelling alternative to the RMR which would mount into an RMR footprint.

UPDATE:

Received today the second RMR and sealing plate. Went to install the sealing plate on my P320 Carry and observed the screw holes weren't sliding over the raised bosses on my slide.

Huh. I don't remember this from last time. I'm pretty darn sure the other sealing plate slid over the bosses, but then a thought struck me:

I'm not 100% sure that was indeed the case, as I can see how pressing the sealing plate onto the slide one could THINK the holes had fully slid over the raised bosses, but it'd be easy to miss. This got me thinking that may have been my issue to begin with, that the sealing plate was hanging up on the bosses and ever so slightly not flush against the frame, thus shifting randomly and giving me a combination of a couple good rounds grouped, yet producing an overall huge spread.

Plus, I noticed this RMR didn't fit as tightly in the milled slide, as this one required hardly any pressure to press-fit into the slide.

Took the sealing plate off and used a small round file to increase the ID of the two screw holes until the plate was a nice press fit flush onto the slide and around the raised bosses for the screw holes.

Checked with my gunsmith that 15 inch-lbs was good for a direct mount milled slide and he confirmed. A bit of VibraTITE VC3, torqued it up, waited a few minutes, torqued it up again and got a bit more of a turn on one screw, then off to the range.

*SIDE NOTE* My gunsmith said he likes to walk up to the torque. That is, if the end goal is 15 inch lbs, then he'll go 8-10 or so, wait a sec, then bump it up to 15. Seems like that may help the parts come to rest/settle a bit better.

Five rounds at 30' kept shots in the 9 and 10 of a B8 but the zero was obviously off (quick guess zero referencing the irons at home before heading out).

Five rounds back at 60' gave me one flier out to the 8 but the group was looking a bit left so I adjusted zero to the right and a bit up.

Third target gave me a 3.5" group of five rounds at 60', with two landing squarely in the X and one landing directly on the right 9 (though I remember that shot when it broke and figured it'd be landing out to the right).

I'm good with that, as I realize some of this is me re-learning the P320's trigger after spending so much time with Glock lately. Walked back in to 15', and the X became one big hole after 17 rounds.

So I'm thinking that was it....I bet the other sealing plate (now on the P10F OR) wasn't seating properly around the raised screw bosses and causing issue, and/or I didn't get the first RMR seated properly due to the tight fit. Who knows? I looked hard at that first setup and nothing seemed visually amiss, but this sealing plate has me wondering if that was the issue all along.

Regardless, things are much better and I can tell when my "dot-jerk" reaction is causing the miss, vs. the magical hole appearing nowhere near where the dot was when the shot broke.

Hope this helps people down the road with optic mounting, slide milling stuff. Thanks all.

This message has been edited. Last edited by: dehughes,