147gr bullets, wimpy ejection and recoil spring?

[DIYguy]

I loaded several hundred rounds of 147gr FP bullets to run in my 5" Pro M&P. Starting at 910 FPS and average PF of 134 and up to 970 FPS and 141 PF I get a really wimpy ejection. Even at 141 PF casings are traveling two to three feet max. At the 135 PF level I start getting stove pipes. I really like the soft feel of 147 but even around 138 PF I've had some jams. Not good to be clearing jams while on the clock.
Any experience with changing the recoil spring when running heavier bullets?

 

[TAROMAN]

I just tune mine for sane, reliable ejection.
Springs are cheap.
Try a 13# for starters.
I shoot 147s at 950 f/s in my 5" Pro with the stock spring.
Every gun's a story unto itself, however..

 

[DIYguy]

Any idea what the factory default weight is for the Pro 5" recoil spring? SSS shows 11, 13, 15, 17 and 20# springs available

 

[TAROMAN]

I have read it's 16#.

 

[DIYguy]

Just ordered 13# from SSS

 

[rwsmith]

Indicated....

Very low loads and weak ejection = New Spring

I don't know what the make of your target gun is or the strength of the spring, but try one a few lbs weaker.

Brownell's or Wolff Springs can fix you up.

 

[PPCSHOOTER]

OR WHAT IS YOUR OAL? I RUN MINE AT 1.142. WHAT POWDER? JP

 

[DIYguy]

New 13# spring showed up and did the swap with my existing guide rod. Taped two pieces of wood in my vice to clamp the rod, pulled the spring back to clamp it. Rod still kept twisting no matter how hard clamped using the wood.
Ended up (shudder) using vice grips. Got the nut loose and holding the spring back with my other fingers was carefully removing the nut and just as I was almost clear the spring slipped. Think air rifle firing that small bolt across my shop. Two ricochets then silence. Not a chance of finding that one.
Stole the recoil assembly out of my other M&P9 and was more successful saving the bolt this time. Next day put about 120 rounds through the gun no issues. Ran my second match last night (previous match rained out) no issues.
Had go go through Brownells for a replacement OEM recoil assembly and with shipping $20. Damn expensive itty bity bolt to drop.

JP: I tested my OAL doing the barrel plunk. FP 147gr bullets so COL is 1.075 to 1.083
Power Pistol 4.4 gr Getting an average of 940 FPS and PF of 138

 

[OKFC05]

New 13# spring showed up and did the swap with my existing guide rod. Taped two pieces of wood in my vice to clamp the rod, pulled the spring back to clamp it. Rod still kept twisting no matter how hard clamped using the wood.
Ended up (shudder) using vice grips. Got the nut loose and holding the spring back with my other fingers was carefully removing the nut and just as I was almost clear the spring slipped. Think air rifle firing that small bolt across my shop. Two ricochets then silence. Not a chance of finding that one.
Stole the recoil assembly out of my other M&P9 and was more successful saving the bolt this time. Next day put about 120 rounds through the gun no issues. Ran my second match last night (previous match rained out) no issues.
Had go go through Brownells for a replacement OEM recoil assembly and with shipping $20. Damn expensive itty bity bolt to drop.

JP: I tested my OAL doing the barrel plunk. FP 147gr bullets so COL is 1.075 to 1.083
Power Pistol 4.4 gr Getting an average of 940 FPS and PF of 138

Wish I had seen this sooner. I use the 15# spring for PF130 in the M&P I use for beginners to try (loose grip).
The secret to changing the spring is to put the HEX HEAD of the bolt into the vise so it cannot turn. Then compress the spring and put a little vise grip on it to retain the spring. The take a socket and remove the nut (store carefully). Now you can use both hands to remove the little vise grip and control the spring. Reverse the process to install the new spring.