Light pf loads for M&P

[tk4]

I am planning to set up an M&P possibly 2.0 for my 105lb 13yo son and I have a few questions. 

I want to load up as light a load as possible for him to start.   I am not worried about keeping the gun or load production legal.  I plan to install an Apex trigger and barrel and run a 13lb recoil spring.  

How low of a pf will likely run the gun?  I am currently using AA#2 powder and 115 or 124 jacketed bullets.

Is it true that the 1.0s will run low pfs better than the 2.0s?

Would you suggest a 4", 4.25, or 5 inch gun?

Will the 4.25 or 5 inch slides work on a 2.0 compact frame?

 

 

 

 

 

 

[MemphisMechanic]

A good rule of thunb for ultralight loads is to run a 115gr bullet with the powder charge we’d normally use for a 147gr in USPSA/IDPA matches.

 

For example, a 115 over 3.2gr of titegroup.

 

The primary thing you’ll need to do is install a lighter recoil spring. Typically that’s an 11 to 13 pound replacement spring.

[Hi-Power Jack]

My BHP runs Very Light loads (PF110), but they don't feed well

 

thru my S&W M&P 1.0 - little too light.   But, that's with the

 

standard factory springs - lighten up the spring, and you should

 

be able to shoot PF110's all day long - and they are a real

 

pleasure to shoot - even out of my KelTec P-11     

[Rez805]

Well, I just got back from testing a couple of potential steel challenge loads. So I can tell you what DOES NOT work.

 

Velocity was recorded using a Shooting Chrony set 10 feet in front of the muzzle

 

Bayou 95 grain (originally intended for a .380 Auto, but it's the same bullet diameter).

3.8 grains Hodgdon Universal

Vel  PF

727fps 69.0 PF 

788fps 74.8 PF

I stopped there as the 11lb recoil spring did not cycle the slide at all. I mean it budged backward a tiny bit, but not enough to even stove-pipe. It felt very much like a .22 . . . that really freaked me out. I'm kind of impressed that it actually made it out of the barrel.

 

I also tested

Bayou 95 grain (originally intended for a .380 Auto, but it's the same bullet diameter).

4.0 grains Hodgdon Universal

Vel PF

941 89.3 PF

841 79.8 PF

973 92.4 PF

905 85.9 PF

893 84.8 PF

998 94.8 PF

 

Stupid light. Barely cycled (it kind of skipped off of the slide). The 841fps (79.8 PF) stove piped. I still don't feel confident that this load will work 100%. I'm using a Lee auto-disk and, as you can clearly see, the velocity spread is crazy. I think if I up it 0.3-0.5 grains or so, I'll have a light recoiling (an more importantly: reliable) steel challenge load that's around 105PF.

 

So, I'm betting you could get down to around 100-105 Power Factor with an 11lb spring. I'm pretty sure my previous Steel challenge load using a 105 grain bullet skimmed around 105 PF. Stupid light. But safe and reliable.

 

Edited September 24, 2018 by Rez805

[pskys2]

If you get a Wolff Reduced Power Recoil Spring it will come with a Reduced Power Striker Spring.  

To be effective it helps to have both, a standard striker spring with a very reduced recoil spring can actually pull the slide back as you pull the trigger and will sometimes not fully seat into battery.

I had those issues with a M&P 45 2.0 and finally went with a 14 lb set up for 130 pf loads.

[RH45]

I think I only have 4-500 rounds through my 5", 2.0, and with a tungsten guide rod, and 13# spring, I NEED to be over 130pf to get it to run reliably.

My old, 5" 1.0 Pro, with Apex, gunsmith-fit barrel, will run right down to 100pf.

I believe it's the extra friction, from the longer frame rails on the 2.0, because if I put my 1.0 top end on my 2.0 lower, I NEED hotter loads.

[superslowmo]

I ran down to 115pf on a standard 5" Pro, as well as a 2.0 (no spring modifications).  Nice and comfy to shoot, but steel just laughed at me....

[tk4]

Sounds like mixed results on the 2.0 lowers.

Thanks guys.

[OptimiStick]

I was trying to find a good common 9mm load between my guns (2011 and shadow 2) and wife’s guns (p320 and M&P core 5”).  Using 147 grain coated and VV 320 with a COL of 1.1350, the M&P wouldn’t run on anything lighter than 3.4 gr. This was with a 12lb spring. Constant stove pipes and you could feel the slide short stroking. All the others ran fine down to 3.2 grains