SteelCityShooter

Unlike standard pressure and +P 9 mm ammo there is no SAAMI specifications for 9 mm +P+ so how do you know what you are buying or reloading? No firearm manufacture sanctions the use of +P+ ammo since they have no idea what it is.

I fully agree with all of the above. I have a 510C on my AR9 and it works wonderfully. I also run the circle and dot together. That said, it's too big and heavy for handguns and I have a Vortex Venom on my S&W 686 and a Leupold DPP on my M&P9 2.0. These are smaller, lighter and more suitable for handgun use.

Not owning either but having a fair bit of experience with both MkII and MkIV Rugers I would always go for the Mamba since it's built on the MkIV frame. Unless you enjoy learning an intricate and fussy disassembly/reassembly procedure for cleaning, the MkIII frame (Scorpion) should be avoided.

My cure/preventive for compensator fouling is not to have one. For my modest PPC loads (124 gr bullets at pf of135-140) I've found the compensator does almost nothing for recoil or muzzle climb and the lack of a compensator means I can shoot any lead, coated or jacketed bullet with no serious cleanup problems.

I'm sorry if this sounds insulting but are you sure you had the correct battery? CR batteries come in a bewildering range of sizes and it's easy to buy the wrong one.

I had a case of 1000 115 gr Blazer TMJs and the box clearly stated "Don't shoot these in compensated or ported barrels". I called CCI to ask why and they told me these are really plated, not true jacketed bullets and the plating could flake off when passing through the comp or ports. I guess they were concerned the fragments could spit out of the ports and possibly injure the shooter or a bystander. I don't think coated bullets have the same hazard but frequent cleaning is a good idea. I removed the comp from my GMR-15 to avoid the issue and because I never noticed any benefit from it.

It's possible that you still had water drops caught in the base of some of the brass, even with that extended drying period. I once had a bunch of reloaded shotshells give a high percentage of failures to fire after washing the empty hulls and drying them but not adequately. Try oven drying the brass at low heat, say 200º, for a couple of hours and see it that ends the problem.

Yes, 2.5 mm is made and actually very common. All four of my metric Allen key sets (two folding types and two individual key sets) have one.

Same and same. It works very well.

Micrometer seating dies, like Redding's or Hornady's, make changes in OAL predictable and reproducible.

If you want an aluminum back plate, Springer Precision will gladly sell you one for $35 that includes a built in slide racker handle. Your choice of right handed, left handed or symmetrical extensions.

I expect that is just the M&P 45 kit relabeled for the 9 and 40 2.0s

Ah, yes it does. I should have checked but, since the battery loads from the bottom I guess there is more room for a larger one.

How about this: https://www.amazon.com/Leapers-MT-RSX5L-Super-Picatinny-Height/dp/B01CKYYH9S/ref=sr_1_17?dchild=1&keywords=Picatinny+risers&qid=1573583866&sr=8-17 It's available in 0.50 and 0.75 heights.

I expect the problems with .40 S&W are that it relies on the moon clip for headspacing while the 10 mm headspaces on the cartridge case mouth. So the 10 mm can tolerate a loose fit in the moonclip while a sloppy fit .40 S&W causes mis-fires.

That's correct, the Apex kit for the M&P9 1.0 will not work in the M&P9 2.0. You have to get the kit made for the M&P45. When you go onto the Apex web site, the link to the DCAEK for the M&P9 2.0 takes you to the M&P45 site. And, no, you don't have to use the Apex trigger with the kit. I have that kit in my 5" M&P9 2.0 and it made a world of difference. I agree that the 2.0 factory trigger isn't much better than the 1.0 factory trigger.

As you have discovered, not every red dot takes a 2032! The Vortex Venom and Viper, Burris FF3, Nikon P-Tactical Spur and I assume other similar size sights all take the 1632. I'm surprised no one else had one.

You guys may be correct but the dealer told me they did fill out the 4473 form listing it as a handgun even though it came in rifle form. This is a big, well established and respected dealership and I assumed they knew the legalities. That said, I just checked the 4473 form (I keep everything!) and there is no mention of a handgun, just a rifle, so who knows. I no longer have it so the issue is moot.

DT's understanding is correct. Several years ago I bought a T/C Encore Pro Hunter in rifle form (28" barrel, rifle stock). My LGS registered it on Form 4473 as a handgun telling me I could then legally convert it to a "pistol" (<16" barrel, pistol grip) and back to a rifle at will. Since the Encore takes a wide range of replacement barrels and stocks this was a good recommendation.

What footprint do those Sigs use, a proprietary one or one the common types like a Vortex, RMR, DPP, etc.?

Well, how much "accuracy" is needed? If you want 1 MOA, of course you won't get it with nearly any pistol bullet in a handgun or a PCC. What level of accuracy do you expect and require?

Sorry for the thread drift but Precision Delta JHPs have been mentioned and recommended a few times in this thread so I'd like to get some thoughts about them. I have a fair bit experience with Montana Gold 124 gr Gold JHP in a 9mm 1911, and an S&W M&P9 and their 125 gr JHP in a .38 Sp. S&W 686. All of these are loaded to minor power factors and in non-compensated guns and all work well. I have also used Blue Bullets in the same guns and a couple of 9 mm PPC's with good results. Now I notice the PD's are priced a bit above the Blue Bullets and a bit below the MGs for the equal quantities and all three offer free shipping so the price comparison is valid. Are PD's worth the upcharge over the Blues and are they as good as the MGs?

You made two changes: 1) different gun and 2) different bullet. One or both of these may be the cause of the problem and you have to sort out which it is. As noted above, try the new reloads in a proven gun and try a proven load in the Walther.

If, and it's a big if, your gun(s) are compatible with it, the MagnetoSpeed chronograph is highly recommended. It's completely independent of the amount and type of ambient light or even no light at all. It can be set up and used without going downrange and requires no tripod or other remote sensor mount or long connecting cables. It is also unaffected by muzzle blast and the readings are true muzzle velocity. Finally, no other shooter at the range is going to shoot the sky screens accidentally since there are none. However, it's not usable with all types of guns, particularly some semi-auto handguns since the "bayonet" has to be fixed below the barrel. It works wonderfully with rifles, PCCs, shotguns, revolvers and most .22 LR semi auto pistols like the Ruger Mk-series and S&W Victory with exposed barrels. It will also work (with an inexpensive adapter) on most centerfire semi-autos with a Picatinny rail on the dustcover. Also, the fact the bayonet is hung on the barrel may affect accuracy while in use so you can't reliably zero and chronograph your loads at the same time. If your guns are suitable, give it a real good look.

One more question; is the guiderod for the 5" M&P any different from the one in the 4.25" gun? I have a 5" M&P9 2.0 and when I bought a spare factory recoil spring/guide rod the part number was the same for both lengths.