I made some plated 115g HP loaded at 6g of Unique. OAL of 1.125+/- . Slight crimp. Gun is a MP9FS. I didn't get a chance to chrono yet but they are inaccurate as all hell. I am going to back the load down a bit and try again, I am thinking maybe the load is too hot. Seems that every other bullet is a flyer. Any of you guys have accuracy issues with the RMR plated HP's? I love their 115g RN

If you have a 4" barrel, that amount of powder will be right at
the standard 9mm loading.

I have had good luck with as light as 5.2grs of Unique but I
keep the 115 FMJ at 1.12" and the 124gr FMJ (round nose plated) at
1.14" for my best results.

4.2grs of fast powder or 4.5grs of the med. fast powder around
1020 fps will also work if you have any of this kind of powder.

I didn't have any accuracy problems when I used their 115gr bullets, but I never used Unique, only 231 and Autocomp. I changed over to 124gr for reasons other than accuracy (cycling and power factor) about a year ago. (using the same powders)

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Might be a bit hot. Do you use the same load for the RN plated bullet?

I usually use 231/HP38 for all my loads but ran out (I have 8lbs of unique). I have not loaded any 9 with Unique other than the HPs I mentioned. I love Unique in my 40 and 45ACP. I am going to back down the load and see what happens this weekend when I go.

Check your crimp. That load is not too hot, but over crimping plated messes with accuracy something fierce. Pull a bullet, measure the bearing surface. If it is smaller than when it went in, too much crimp. Even 0.001" can make a diff.

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thanks ill check that, I barely put a crimp if any on all my stuff. So i doubt thats the issue.

Plated bullets are very sensitive to crimp. What I do is set the die build a cartridge and then (with hammer puller) remove the bullet. If it has a "ring" on it then I re-adjust until the bullet is "like new". If you shoot with a "ring" you will experience exactly what you are describing. Also, the barrel with start to lead up. another factor only less so, is checking the height of the case for lengthening. If you are re-loading them 20x or more than the case can grow. If it grows then your taper crimp is harder on some bullets than others accuracy can suffer. Just a thought. I'd check these items and then change the load.

I think you may be a bit too hot for thin plated bullets and you are probably on the right track reducing your load a bit.

6.0grs of Unique sends a Remington 115gr HP jacketed bullet out the muzzle of a Walther P1 at 1,257 fps. I have loaded as light as 5.2gr of Unique behind the same 115gr JHP and that chrono'd at 1,151 fps from a Glock 19 typical of about what I get from Winchester USA and S&B 115gr FMJ.

I would drop back to 4.5 gr and work up until accuracy is good. It is possible the gun just doesnt like the recipe. WW231 was my powder for most standard loads but it is hard to get right now.

If you do try just 4.5 grs of Unique with a 115gr jacketed bullet
I would just load five to eight to see if they will work your action.

My spring/weapon would not cycle this light of a load of Unique but would
go all the way down to 3.5 grs of a medium fast powder.

As another poster mentioned, plated bullets are very sensitive to COAL and crimp.

Test #1-use a bullet puller and pull a loaded round. If there is a ring or any deformation of the bullet, your crimp is excessive. If the bullet looks any different than a new bullet, you may need to adjust your dies. All you want to do is iron the bell out of the case from bullet seating.

Suggestion-Start with a COAL of 1.10 and work your way up .05 at a time to see where the preferred length is for your gun. The target will tell.

Suggestion #2-Plated bullets will work best with a medium burn rate powder vs a faster one. WSF, Unique, AA#5, Power Pistol are your friends.

Suggestion #3-115's usually perform better a higher rate of speed. Push them at least 1050 fps to see groups shrink. Look at Blazer and Federal aluminum case ammo using X Treme bullets as a benchmark for velocity.

Plated bullets can be very accurate, however the sweet spot is much more narrow than the equivalent FMJ, coated or lead bullet. It will take a little more load development and trial to find where your loads need to be. That can be tricky with reduced powder availability these days. Hope this helps. Let us know how your loading turns out.

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I've run berrys & Rainer plated to 1250fps in the 357sig w/ good accuracy. Beyond that, things start getting poor quickly, but 1200fps should not be an issue. I'm still betting crimp or undersized buckets. Ime, pated want to un like. Lead bulket. Best accuracy seems to come with bullets 0.001" over jacketed. If your plated measure smaller than 0.3555", they won't shoot well.

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NRA Cert. Inst. IDPA CSO

In a 3" 9mm I have had the plated RN 115gr bullet down to
735-816 fps with an average of 784 fps for the SLOWEST load
for this weight bullet with IMR4227 that was pretty accurate but it also had some fail to eject problems. ( Dah )

A load of Green Dot got me up to 842 fps where the action cycled and groups were just over an inch at ten feet.

A lot of loads between 1030 to 1090 fps shot well from several powders but was pretty much the limit for the faster powders.

With the little 3" barrel and my top loads at a OAL of 1.12"...
out of 170 loads I only had ONE round hit over 1200 fps !!

Good loading.