Rate of twist M&P 9C

[scattershot]

Anyone know the rate of twist for aM&P 9c?

Reason I ask is, yesterday I was shooting mine, and it was doing fine with 124 grain bullets. When I switched to 147 grain, accuracy went out the window.
Other 9s I have don’t do that, and I was wondering if the rate of twist has something to do with that.

 

[dajogejr]

I am “somewhat” certain it’s 1:10.
What was the distance? Irons or red dot?
Same type/brand of target ammo.. or mix of JHP and FMJ?
How so in accuracy? high, low, L/R, scattered, larger groupings?

In any of my previous M&P 9mm, including an older 9c, 115 to 147 didn’t make much of a difference out to 10 yard shooting.
I doubt it’s the weight of the ammo.
Could be the “manufacturer” of it…though.

 

[Saudade]

Depends on how old your 9C is. Early 1.0 models had a 1:18.75 twist. That changed around 2012 to a 1:10 twist. My 2013 9 full and 9C have 1:10.

Are the 147s keyholing in the target?

Here's a quick way to tell.

Smith & Wesson M&P9, Version 1, What to Look For – Scattered Shots

 

[Saudade]

I just noticed the link above uses a similar name to you.

 

[scattershot]

Thanks for the replies. This is a mod2, so fairly recent manufacture, shooting handloads pretty close.( 7 yards) with. Xtreme bullets. No keyholing, just poor accuracy. Like one hole with 124s, 3” or so with 147s.

 

[Saudade]

Ah, it's a 2.0, sorry for my confusion. It's 1:10.

Is yours the 4" or 3.6" barrel?

My 9C is a 1.0 which is the same size as the 2.0 Subcompact.

 

[scattershot]

Sorry to be so long in getting back to you. It’s a 4” barrel.

 

[agksimon]

Sorry to be so long in getting back to you. It’s a 4” barrel.

I had a 5" barrel M&P Pro (1 in 10 twist) that at 25 yard, would benchrest 6" groups with 115 grain and 2.5" with 124 grain ammo.

 

[scattershot]

Guess they just like the 124s.

 

[WR Moore]

Could be a couple of factors. That particular batch/brand of 147s might be off or the lower velocity is showing that you have poor follow through in your technique.