question for bullseye pistol reloaders:

[taliv]

i have reloaded tens of thousands of pistol rounds but only optimizing reliability, never loading for accuracy like i do in rifles, but now i am having trouble keeping 8" groups at 25 yards with a production pistol. I've tried three different bullets (125g LSWC and 124g plated RN and some mystery 115g JHP) with similar results.

my BEST 3 shot group of the day was roughly 6" at 25y shooting off a bench with the gun rested on a bag!

i'm thinking 80% chance i just have a crappy barrel/gun vs 20% chance i could fix this by changing my load. i'm not willing to change bullet or powder type, only the charge weight. brass is mixed, fired


Sooooo....in your experience tuning handloads in a pistol, what's been the largest variation? e.g. "x grains of powder gave me a y-inch group and changing to z grains of powder improved that to ..."

 

[slinkster111]

Has this pistol previously grouped better? Have you tried factory loads as a baseline? Could the muzzle be damaged? These are just some things that come to mind.

 

[taliv]

no, only if you count remanufactured ammo, and doubtful but definitely possible

 

[sexybeast]

Only shot bullseye a few times. One thing I picked up from the "real" shooters is the bullet diameter can really matter. Many of the .45 shooters liked a very soft lead that was oversized.
You may wish to experiment with some different bullets although you said you wanted to keep the same bullet/powder combination.
You also did not mention the powder you are using. Don't know any that used slow powders.

 

[taliv]

titegroup. loads ranging from 4.0 to 4.2

 

[ReloaderFred]

I was just working on this the other day and came up with a load that will put 5 shots into 1.36" at 35 yards. Four of the shots went into 1.09".

This was with a new to me Ruger Blackhawk .45 Colt/.45 acp combination revolver, with the .45 acp cylinder in the gun.

I took a bullet that I knew was a good shooter (Berry's 185 gr. SWC-Plated) and used several different weights of Winchester 231 powder. I was working the loads for accuracy, and I found the one this particular revolver likes, so now I can load up a bunch with that load. This was all with mixed brass, too.

I know you're probably working with a semi-auto handgun, and I'm guessing it's in 9x19. I would load several different loads with the bullets you have, and only vary the powder charge. When you get one that looks promising, then you can experiment with bullet seating depth, since this can have a bearing on accuracy, too.

Hope this helps.

Fred

 

[KansasSasquatch]

You don't mention what caliber. I point this out because by Hodgdon data, you're pretty much over Max if you're reloading 9mm like I'm assuming. With a fast burning powder like Tightgroup that could be your issue. Maybe not, but it probably wouldn't hurt to try a lower charge with the 124-125gr bullets.

If you were using a slower burning powder I know for sure that different charge weights could cause accuracy issues like you're describing. Powders like Unique, True Blue, and Longshot have all produced widely varying results for me in .45acp, dependent on the charge weight. I normally test my handgun loads at 20ft. And even at that relatively close distance it's easy to tell when I need to adjust my charges. Unique always performs most accurately for me in midrange loads while True Blue and Longshot have to be pushed harder before group sizes are acceptable, even for my recreational shooting. Adjust your charges, it won't take many test loads to figure out if your problem is due to charge weight.

 

[Rule3]

What gun are you shooting.? Why are you not open to other powder or bullets?

So many variables can effect accuracy

I am guessing 9mm? More info would help?

 

[taliv]

sorry, yes 9mm. S&W M&P pro core. not open to other bullets because i already bought 21,000 RMR 124g plated. at the current rate of use, i could switch to a different bullet in 6 months.

4.0g of titegroup is over max for a 124g plated bullet? i wasn't able to find that specific combo on hodgdon's site but i actually went up to 4.2 because my slide wasn't always locking back on the last round. the move to 4.2 didn't help that so i'm going back down to 4.0.

 

[USSR]

Taliv,

I load the following 9mm cast bullet load for my friends:

Lyman 358480 133gr SWC
3.3gr 700X

Seems to shoot well out of their M9's.

Don

 

[sexybeast]

Taliv, drop it down to 3.7gr of titegroup with the 124gr plated and see how that does.
I also shoot a m&p 9 pro and have found the accuracy to be a little wanting. I slugged my barrel and found it to be almost .356. Now I shoot bullets sized to .357 and the accuracy is better.
Start simple first: Drop the load and see if any improvement.
When I did my testing with cast lead bullets I adjusted the powder by .2gr incriments. With titegroup there will be differences quickly.

4.0g of titegroup is over max for a 124g plated bullet? i wasn't able to find that specific combo on hodgdon's site but i actually went up to 4.2 because my slide wasn't always locking back on the last round. the move to 4.2 didn't help that so i'm going back down to 4.0.
__________________

I just read this again and it sank in. Something is wrong if your gun is not cycling/locking back the slide with 4.0gr of titegroup! Look at hodgdon's site again for both 124 and 125gr bullets. 4.2 is slightly over max for plated!
If 4.0 won't lock back the slide you have more than one issue going on. More testing is in order.

 

[Rico567]

Designing a gun for reliability under all conditions, vs. designing a gun for maximum accuracy are fundamentally different processes. It does not surprise me that the S&W M&P Pro 9 does not have the best accuracy. Before I started testing this or that load, I would find several different brands of quality commercial ammo and test them out, in order to have a better idea of the capabilities of this pistol.

{Long digression; don't read if not interested}

In the old days, buying a Colt 1911 new in the box was not necessarily going to yield the best accuracy, either. The plain jane pistol was a military design, and to get the reliability, it was too loose in its tolerances to yield the best accuracy. Over the years, various talented gunsmiths addressed this issue, and the 1911 became very accurate indeed.
When I got a Colt Mk IV Series 70 NIB in 1976, I didn't even shoot it, just sent it off to Wilson's for a trigger job, Bomar sights, and a few other tweaks. Then I dropped a Bar-Sto barrel in it. That gun would shoot into a quarter at 25 yards all day (back when I was young enough to shoot that well) with a 200 gr. H&G #68 SWC pushed by 5.3 gr. of 231. But I had to develop that load carefully, paying particular attention to OAL, before it would fee reliably. Accurizing the gun meant I sacrificed some reliability.

 

[taliv]

thanks for the input guys

a little more info on slide lock on empty mag:
i'm not having any problems cycling at all. the gun is completely reliable from first to next to last round in the mag.
however,
if i load one round in the mag and shoot it, i get slide lock 100%. always.
if i load 2 or 3 rounds in the mag and shoot rapidly with .18-.23 sec split times, slide lock is about 50%. sometimes it does and sometimes it doesn't. i've tested many times making sure i'm not limp wristing. I also am making sure i'm not resting my thumb on the slide release (though sometimes i do this, it doesn't account for all failures to lock back). i'm getting A-zone hits.

i also had a few other people shoot it and it doesn't seem to be happening to them but they are not shooting quite as fast either (not that .18 is 'fast')
i'll try dropping back to 3.7.

 

[sexybeast]

Try different mags or mag springs. I bought my m&p pro in 2011 and have about 15k through it and have no mag issues. This dosen't mean you don't/won't though. Mine get dropped in the dirt and I clean them on a regular basis. Something to try. Keep it simple first.

 

[KansasSasquatch]

Didn't S&W redesign their mag followers at some point for the M&P or am I nuts? I've never owned an M&P but I vaguely recall reading something about that. Maybe your followers are the old design and that has something to do with the slide not locking back?

 

[the count]

i have reloaded tens of thousands of pistol rounds but only optimizing reliability, never loading for accuracy like i do in rifles, but now i am having trouble keeping 8" groups at 25 yards with a production pistol. I've tried three different bullets (125g LSWC and 124g plated RN and some mystery 115g JHP) with similar results.

my BEST 3 shot group of the day was roughly 6" at 25y shooting off a bench with the gun rested on a bag!

i'm thinking 80% chance i just have a crappy barrel/gun vs 20% chance i could fix this by changing my load. i'm not willing to change bullet or powder type, only the charge weight. brass is mixed, fired


Sooooo....in your experience tuning handloads in a pistol, what's been the largest variation? e.g. "x grains of powder gave me a y-inch group and changing to z grains of powder improved that to ..."

Well, shoot the same gun/distance with factory ammo and compare. There's the answer to your question.

 

[taliv]

Try different mags or mag springs

yep, bought new mags, have 5 total and same issue with all. i also ordered ismi recoil springs earlier this week but they haven't arrived yet

squatch, this gun was purchased just before christmas so i'm assuming it's all recent stuff

 

[Walkalong]

I would suggest that Titegroup isn't the right powder for your application. If you have something in the middle range of burn speed like AA #5, True Blue, Unique, HS-6, N340, 4756, etc, it may do better by those bullets. I would try that. Another thing is your gun might not like those bullet, but it should shoot a lot better than it is, which is why my first suggestion is to try a different powder. Moving the powder charge up and down with a bullet can change the group size, but most of the time it isn't going to turn a 6" group at 25 yards into a 2" group.

Shooting 3 different bullets badly would worry me as well, but I would try a different powder first before blaming the gun. Have you shot any reputable factory ammo for group?

Good news is that S&W will fix it for free if the gun is at fault.

 

[LiveLife]

taliv, not sure if you mentioned OAL used but how about trying the longest OAL to reduce gas leakage around the bullet for more consistent chamber pressure build up?

For the Herco testing in 9mm thread, instead of the usual 1.135" OAL I use with 115/124 gr FMJ/RN bullets, to squeeze out the most accuracy, I used 1.150" - 1.160". Both KKM and Lone Wolf barrels will accommodate OAL out to SAAMI max of 1.169" but I did not want to reduce initial chamber pressure build up from reduced neck tension.

M&P 9 barrel should also accommodate similar OAL so how about trying 1.150"-1.160" and 3.8/4.0 charges of Titegroup? BTW, Hodgdon's load data for 124 gr Berry's HBRN bullet used 1.150" OAL so a regular flat base plated bullet at 1.150" should have shallower bullet seating depth. If I am using shorter 1.135" OAL (as I did for the initial 124 gr HBRN testing), I would use 4.0 gr as max charge but at longer 1.150"-1.160" OAL with flat base bullets, I would test 4.2 gr as max charge.

124 gr BERB HBRN Titegroup OAL 1.150" Start 3.6 gr (957 fps) 27,700 PSI - Max 4.1 gr (1,057 fps) 32,700 PSI

I am planning another range trip to finalize my Herco testing in 9mm and I could take some Titegroup loads with plated bullets to compare. If you want me to test other powders, let me know.

 

[ClarkEMyers]

I'd start by swapping out the barrel or at least planning to swap out the barrel

I'd start by swapping out the barrel or at least planning to swap out the barrel.

Many of the M&P line have been extremely ammunition sensitive see e.g. Hilton Yam's discussion. Apex and Barsto and others (I have Storm Lake but for carry not target) have barrels on the market in the pipeline and some available real soon now. Twist rates and bullet weights have given results all over the place. I'd try a heavy bullet load with a slower powder.

Patrick Sweeney's book on Reloading for Handgunners has a useful discussion on powder speeds (too fast a powder at too high a pressure with plain base lead bullets or maybe something else see the book) and crimp. The discussion is cartridge specific.

My own experience for center fire Bullseye has been that factory loaded match ammunition is as good as it gets and that the more or less standard loads with due care can approximate the factory loads but no better. My principal gallery/indoor load was the #130 with 3.5 Bullseye and Alox/beeswax lube - chosen from a list of popular loads published by Gil Hebard. Smoky and I wouldn't use the load indoors today.

The point is that I did not think my gun(s) was so different that a unique load was necessary or even helpful.

For rifles John Barsness - Handloader magazine and many others - has list of loads that work in most rifles (updated periodically with new components). Pretty much given a load that has worked many times in many firearms but not this one maybe it's the firearm.

My own best cast loads I matched the bullets to the nearest tenth of a grain - not +/- but the nearest .01 grain on an Ohaus 1010 limit of the scale resolution - today a digital scale would make things go faster. Weighing has to be done with no lube. Cases were good fresh or annealed and so it goes. Today I wouldn't spend nearly so much time matching bullets and more time shooting but my best were square based match weighed and shot well. And yes I do have a Ransom Rest - in fact I have 2 (one is none and so it goes). My own experience has been that a faster bullet helps at the outdoor 50 yard line - but that differences at 25 yards indoors machine rested were negligible.

In sum I would be astounded given

i'm thinking 80% chance i just have a crappy barrel/gun vs 20% chance i could fix this by changing my load. i'm not willing to change bullet or powder type, only the charge weight. brass is mixed, fired

that the chance of improvement by changing the powder charge weight only is anyplace close to 20%. It's a WAG but I'd expect more like .2%.

 

[KansasSasquatch]

taliv just to clear something up, when I said you're going over Max, you probably aren't in any danger pressure wise. But you might be pushing those plated bullets faster than they like to go. Hodgdon lists a 124gr Sierra FMJ using 4.4gr, moving at 1136fps. I'd bet at 4.2gr you're pushing those plated bullets over 1200fps, which is the max velocity for many/most plated bullets. Hodgdon also lists a 130gr Berry's plated RN (which I believe is really intended for .38super). I would use their data for that 130gr bullet.

130gr Berb RN
Titegroup .356 " 1,150 " 3.5 895 27,400 PSI 3.9 1,006 32,100 PSI

 

[taliv]

but most of the time it isn't going to turn a 6" group at 25 yards into a 2" group.

It's a WAG but I'd expect more like .2%.

ok that's pretty much what i wanted to know. i will try dropping the powder but i'm expecting to need to change the barrel.

thanks all!

 

[taliv]

squatch, i will definitely try that even if it doesn't solve the problem. after all, if i can use 13% less powder and still be reliable, why wouldn't I?

 

[LiveLife]

Chances are, RMR's "seconds" plated bullets are X-Treme bullets good to 1200+ fps and even with 4.2 gr of Titegroup, taliv's M&P9 won't be pushing them faster than 1200 fps.

My experience with 124 gr plated RN bullets (Berry's/Rainier/X-Treme) and Titegroup produced accuracy at 3.8-4.0 gr range but using different pistol/barrel than taliv's. With plated bullets, I noticed shot group trend getting smaller as transitioning from mid-to-high range load data but shot group increased as I approached max load and beyond.

YMMV

 

[Rule3]

I am a SW fan and have too many of their guns. I had a "regular"
MP (not CORE)

It would not group worth a damn. I sent it back, they replaced the barrel. Still no good. It functioned fine. I had a competition shooter at my range shoot it also. All the advice out there was a APEX sear etc etc. I was not about to pay another $200 for tweaking a gun. I sold it.

My MP AR Magpul was not accurate either. Sent that back they replaced the upper (cheaper and easier than replacing a barrel) It came back and shot tight groups.

SW is not what it used to be I'll stick with their revolvers.

Shoot some factory ammo, if it's the same, Call them, tell them what factory ammo (try 2 brands) send it back get a new barrel.

I know you want to use what you have but TG is not my choice for the 9mm (just had to throw that in)

Just my experience.