Re: Curious about your open M&P

[Whoops!]

Question: What did you do internally to make your M&P run on 9 major?

My answer:

First I'll throw in the generic I accept no liability for this.

The most important aspects, in this order, are the barrel, the powder used, the oal of the cartridge, the recoil spring, and the compensator. A KKM or Stormlake barrel is mandatory for case support and barrel life. A relatively low pressure powder such as HS6 is needed. A long oal is also needed to minimize pressure, I use 1.155-1.16 in my Stormlake and so far function has been great.

A recoil spring from 15 to 17 pounds is needed on a fully compensated M&P platform so that the rounds don't eject while there is still too much pressure in the chamber. With an efficient compensator and spring controlling slide velocity, the only component(s) that should prematurely wear out with 9 major are the barrel and possibly the firing pin and breech face.

Good luck. Dan Burwell has more experience than I do with this, but I would guess he'd tend to agree with a lot of what I've said.

Anyone have anything to add or disagree with?

[NoSteel]

Great info, I've been thinking about going this route myself with my 5" Pro model. Did you have a custom comp designed?

[Whoops!]

No, I used a Jager compensator on a 1/2" 28 tpi Stormlake barrel. There's a small gap between the barrel and comp when in place, but it still looks good imo.

On the pro model with a slide mounted burris fastfire, standard American factory loads can not cycle the slide with an 11 pound recoil spring and the Jager comp. It seems to need about a 135 power factor to reliably cycle with the 11 pounder.

On a side note, the Taylor Freelance 170 mm mag extensions did not work with my stock mag followers. The followers always hung up at the 19th round where the stock mag body met the extension. To fix this, I shaved the edges of the followers with my Dremel to make an outward slope on the bottom which would thereby slide inside the extensions. I also cut off about 1/3rd of the plastic from the bottom of the follower to make a 28 round capacity instead of 27. No spring modification required.

Edited June 25, 2010 by Full Race

[DocMedic]

Here's a pic of Julie's Open M&P that she uses for Steel challenge

Julie Golob's Open M&P link

[Whoops!]

I like myne better.

[DocMedic]

I like myne better.

Looks good, Have you shot it in competition yet?

[Whoops!]

Just local, unsanctioned stuff. The loads I'm settling on with the Jager comp are 115-121 gn with 8.6-9 gns of HS6 at 1.156-1.1605. Autocomp seems to have too much side to side play in recoil with the Jager where as HS6 is straight up and down.

[Team Amish 1]

Cool looking gun. Not sure I'd be down with the slide mounted red dot.

BTW, is that Julie Golob shooting the gun in that picture?

[caz41]

BTW, is that Julie Golob shooting the gun in that picture?

You are correct sir

[recovering19A]

Nice boomer you got there!

[Whoops!]

Cool looking gun. Not sure I'd be down with the slide mounted red dot.

BTW, is that Julie Golob shooting the gun in that picture?

Yeah, it takes getting used to. There will always be a competitive disadvantage with a sideways mounted C-more since it will always be easier to lose the dot. That being said, with practice, it's very hard to not get the dot immediately. It's also more necessary with the M&P since it would be quite difficult to frame mount.

[Gimpy_ak]

Does anyone know who makes the Comp on her gun?