Loading the 40 S&W : I NEED some help !!!


March 8, 2008, 05:08 AM
I started loading up 40 S&W recently and have 4 loads through the Chrony. My velocities are wild, getting differences of 100 fps or better in each loading. Last batch was from 881 to 991 fps. They averaged 917 fps over 22 rounds fired. Not sure if the problem is the used brass, it is fired brass from a range. Cleaned it and sorted it. If bulged or otherwise Glocked it was tossed. I have now seperated 2 different headstamps, *I* and Winchester. Not sure if the case volume or length is different. Possibly some of the brass was already reloaded and stretched. I have checked the press and scale and both are working correctly. All rounds are to spec with OAL a little on the long side but they all check out the same. No apparent variation in the loaded rounds. 5.5 Gr of Power Pistol on an RCBS 550. Anyone have any ideas of what is causing my Chrony readings to be spread wildly ?

If you enjoyed reading about "Loading the 40 S&W : I NEED some help !!!" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
March 8, 2008, 07:24 AM
It could be any of that which you listed. Winchester brass seems to have some distinct properties, one of which is thicker walls than CCI or Independance. This will obviously change your pressure, and could result in the velocity spread you're looking at.

To get consistant loads, you need consistant variables. Same lot cases that have been under the same amount of wear, exact powder charge, crimp, exact seating depth, and exact length of bullet. These last two are the easiest to miss. Unless you're using match grade bullets, the odds of any five bullets you pull from the box being the exact same are slim to none.
If you measure your COL from head to bullet tip, you're going to get a varying depth, as the only exact way to measure is from just behind the bullet's tip to the head. If you measure from the tip, and if the bullet is longer than the previous one, you'll think your seating depth is different. The reality is that the depth is the same since the seating die pushes on the bullet from below the tip. Er...got that? :confused:

So....your velocity is probably being varied by inconsistant bullets, inconsistant seating depth (in the 9mm and 40cal, volume change drasticly changes pressure), and case thickness (which also affects crimp). Start dealing with those variables individually and I think your numbers will flatten out. The case issue is the most easily solved. Also, measure and sort your bullets.

March 8, 2008, 08:17 AM
I never measure handgun bullets and find the OAL variation doesn’t matter. I bet you need more powder. What bullet weight are you shooting?

March 8, 2008, 10:15 AM
My vote is to get some "new" brass--with range pickups, there's just too much variation in its history.

And, double check your recipe....

You might consider buying some starline brass--even just 100 pieces--and load twenty rounds with your current recipe and see if you get the same kind of ESs. If you do, then you could consider tweaking your crimp slightly.

You don't mention your charge-metering hardware and procedure--but given PP meters pretty well, charge weight variation is not likely the problem.

So, the overall procedure would be to narrow down your variables--I would start with new / consistent brass, and if the swings still occur, try different bullets as well. Have you random-checked your bullets to see how they vary in LOA and dia?

Jim H.

March 8, 2008, 10:22 AM
I don't use PP but from my experience you have to go up and down the scale to find a load with any given powder that tightens up extreme spreads like you are encountering. Take a look at your loading manual for the high ad low loadings for PP. You likel will find that the tightest velocity ranges will come at the lower end of the scale but not always.

I use Titegroup and try to makje 125 PF for IDPA. 2.8 gr comes in consistantly at just over 125 in my guns with my Lyman cast bullets. Guess it depends on what you are trying to achieve. Power Pistol may not be the best powder to meet your particular requirements.

Take Care


March 8, 2008, 11:13 AM
+1 for tightgroup. I tried power pistol and had the same variation even with new brass. I think it is the nature of the powder. Even with that variation the accuracy was good but I did a lot better with tightgroup in 40 and have been using it ever since.

March 8, 2008, 12:44 PM
Forget the "get new brass" advice.

If you have sorted it by head-stamp, it is all the same for all practical purposes.
Just because it is once-fired doesn't make it any worse then new Starline brass for uniformity. Thats why you resized it.

If you are still concerned, weigh them and sort them that way.

I would have to guess your problem is too light a load of Power Pistol for it to burn correctly.

You didn't mention the bullet weight, but 5.5 grains is not even a starting load with a 155, and barely a mid-range load with a 180.

I would bump it up, or change to a faster powder for light loads.


March 8, 2008, 01:00 PM
Lots of 40S&W at the range. Hard to find .45ACP at the indoor place I patron.

March 8, 2008, 03:58 PM
Check your powder charges. With a small charge like that a little bit of difference in the charge can make a big difference in the downrange performance. Easy way is to hand measure and charge 10 loads to exactly the same weight and see how they do.

March 8, 2008, 07:15 PM
Are you getting good groups? If so I would not worry unless you are seeing other worrisome signs.

I reload using the fired brass from my GLOCK's and have had no problems, always check brass everytime I handle it. I don't check with a crony, use recoil feel and brass inspection plus I load to no more than medium power.

I use Longshot and have found it to be clean and give good velocity within the pressure limits.
I like 7.3gr of Longshot with 165gr JHP's as a starting load and 7.3gr of Longshot as a medium load for 180gr JHP's.
I shoot GLOCK models 23 and 27.

March 8, 2008, 09:24 PM
Using a Dillon 550 setup for loading. Crimp is light, just enough to straighten out the case bell. Load is currently 5.5 Gr of Power Pistol. Weighed it before 2x, during and after loading. It is throwing a steady charge so I know its not the powder charge. I am loading 180 gr Berrys plated double strike bullets. They look beautiful and measure up the same. Soooo, I am thinking that the brass MAY have something to do with it as some in the bucket were obvious reloads and when checked had a longer OAL. That is the reason that I now have 2 batches. or of 1x fired Winchester and on of *I* brass. Will be sorting through the rest of those 2000 cases and then the next 3000 cases to see what I have the most of. Have lots of Winchester, some R-P and *I* and a little GFL mixed in and a couple hot reloads here and there. I have no idea on accuracy yet. Have been trying to get a load that can make major for IPSC first, then will concern myself with accuracy. Need someone to make the range trip and record from the Chrony. One thing at a time. Need to get consistent speed first. If the speeds are wild the groups will also not be so good.

March 9, 2008, 11:55 AM
I had the same problem as you with 4 different powders, PP, HS6, WSF, and Unique; and a variety of quality jacketed bullets and brass - it didn't matter. I am a very meticulous reloader too. Here is what I discovered. Neck tension. I dry cycled several magazines through the pistol and then measured their length. It was all over the place and always less than the initial COL. Apparently the force of the bullet hitting the barrel's ramp was pushing it into the case.

I thought my expander might be too large and honed it down on a lathe. That didn't help. Varying the crimp, of course, didn't help as has been discussed myriad times in this forum. Then I measured the case forming die. It was too big by at least 0.002 inches!! Talked to RCBS and told them about the problem. They sent me a new set after receiving mine. Problem solved. Muzzle velocity differrences are quite small and acceptable now.

March 23, 2008, 05:55 PM
Instead of starting a new post will bring this one back to life. If anyone cares to share their 40 S&W loads please do. i will assemble them and put them into a datebase. Include enough info as you have and I will put it on the sheet. BTW still trying to decide on something better than power pistol. Me thinks with VV 340

March 23, 2008, 08:44 PM
I've burned several pounds of Power Pistol, nearly all of it in the 40 SW, and I think your load has too much airspace to be consistent. My standard load (these days) is 6.0 grains under a plated 180-grain bullet, which I use for speed drills in an EAA Witness. I've run this load as high as 7.5 grains, but it got too snappy for rapid fire. I'm at work so I don't have my Bible handy, but I think I've even shot a load hotter than that one, though I don't remember the bullet weight I was using. Stick with the load data from the powder maker. A lot of it is pretty conservative, but the last couple pounds of PP I bought seemed to be a bit hotter than the first few. It seemed to give more muzzle flash, too. Fluctuations DO occur, even in canister-grade powders.

Reloading is a fascinating hobby, but if you want consistent loads, you have to eliminate all the possible variables you can. Using pick-up brass is not advised for building accuracy loads. Start with cases of known history, measure your powder charges, make sure all crimps are the same, along with OAL. I don't think it's the powder, I think it's the variations in the brass and crimp and the airspace factor. Make up some PERFECT ammo, the best you know how, with good components, and chrono those. Then you'll know a lot more.


If you enjoyed reading about "Loading the 40 S&W : I NEED some help !!!" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!