M&P- best 40 bullet weight?

[Dr.Doug]

I recently acquired an M&P 40- mostly because I like the way it fits my hand. I've had good success with a 180 grain bullet load in my other 40s, but in this gun they are not as accurate as I'd like.

Has anyone had good luck with lighter bullets in an M&P 40?

Thanks,
Doug

 

[LiveLife]

I've had good success with a 180 grain bullet load in my other 40s, but in this gun they are not as accurate as I'd like.

As you posted, your accuracy issue maybe more from the pistol/trigger than bullet weight.

My M&P40 and M&P45 benefitted from trigger jobs which significantly reduced shot group sizes and improved accuracy - http://www.burwellguns.com/M&Ptriggerjob1.htm

Dry fire your pistol while watching the front sight. If it moves/jumps when the striker is released and/or if your trigger feels gritty, try polishing the trigger metal contact surfaces (see linked pdf for areas to polish) until the trigger feels smooth and front sight is steady when the striker is released.

I have tested 155/165/180 gr Montana Gold/Golden Saber FMJ/JHP and Berry's/PowerBond/Rainier/X-Treme 165/180 gr TCFP/RNFP bullets with various powders and there wasn't a significant enough difference in bullet weight to say you will see a large reduction in shot group size in a stock M&P40.

In general, I have seen more accurate loads with 180 gr bullets but depending on the powder and charge, I have gotten accurate loads with lighter bullets too. If you want to try lighter bullets, I would recommend HP bullets as longer bearing surface seem to better stabilize the bullet with rifling/in flight (BTW, 165 gr MG JHP is my preferred bullet for match shooting).

 

[1KPerDay]

What 180s are you loading out of curiosity? I think I got a bad batch of Berry's 180s. I can't get them to shoot in any gun over any powder so far. I usually have great success with Berry's stuff, the 165 HB in particular.

 

[Rico567]

I shoot nothing but 165s....but I shoot Glocks.

 

[Sauer Grapes]

I haven't had much luck with the Berrys plated 180s in either of my M&P 40's. They do work better in my S&W 4006 for some reason. I'll stick with lead.

 

[zaphar]

My normal practice loading is a Montana Gold 165gr JHP @ ~1050fps out of a M&P40c. They seem to be accurate enough that I hit what I'm trying to shoot.

 

[Dr.Doug]

thanks

Belated thanks for your responses, guys.

I've been using Hornady XTPs and also shot some Berry's- with the same (lack of) accuracy. Titegroup is my powder of choice. I've had good success with both in the past, but not with this M&P.

bds- I've dry fired like you recommended, and there is a distinct jump in the front sight as the trigger breaks. No jump at all with my tuned 1911 or my box-stock XD. I'll see about the polishing you recommended.

 

[kcofohio]

Apex Tactical has kits, whether for duty/carry or for competition that smoothed the trigger on the wife's M&P40. They have tutorial videos posted for each replacement part.
At approx. 30 ft, dry firing, I only see about 1 inch or 2 jump on the target from unsupported aim with the laser.

 

[Oldgoat03]

Good results with Berrys all sizes

I've had only good results from Berry's in 40 S&W with 155 HBRN, 165 FP and 180 RN gr. I use Win 231 / HP 38 and had to work up loads for each bullet weight/profile to find the sweet spot but they are all pretty accurate in my M& Shield. I have not done a trigger job on my Shield because it has a pretty nice pull out of the box. My son wasn't so lucky and had to do an apex trigger.

By the way I was able to get satisfactory accuracy from fairly light target loads.

My suggestion would be don't give up on Berry's without trying different loads and AOL combinations.

Hope this helps
OG03

 

[brow_tines]

I cast my own, 175 grain

 

[Wreck-n-Crew]

I too have had good success with berry's and xtremes in the 180gr. I load them to mid range load data using Autocomp. Pretty accurate load and burned clean.

If your on the high end of the load back it off a tad and if your on the low end bump it up to mid range.

 

[higgite]

I had an M&P40c which came with a scratchy, not so smooth trigger. But, it improved dramatically the more I shot it and dry fired it. My aim also improved proportionately. Your problem may be more trigger related than bullet weight related.

 

[Lj1941]

I have loaded for my son's M & P 40. My most accurate IDPA load is Berry's 155 plated HBRN /3.8 gr Clays.This is a good shooting middle of road load. I forget what it clocked but it made 125K power factor with ease.