How do you work up a pistol load?

[Pkspawn]

Exactly as the title states.

Currently. I will load a bunch of rounds, starting at or below the recommended min. Making about 5 rounds each stepping up .2gn each upto the max recommended.

I looked for any function issues and grouping. If no feeding/ejecting issues, I look at which ones grouped the best. Then I will load up 20-50 rounds and again check for issues.

I now have a chronograph. So I can see the speeds of my bullets. For IDPA/USPSA, I'm figuring, find the min speed needed to make power factor and then start looking for grouping.

My real issue comes with my Cowboy action, which doesn't have any power factor issues.

This past weekend I ran a bunch of rounds through the chrono. I have a progressive press. When I set the charge, I will weigh 10 charges until I get the avg of the throw I want.. So if I was 2.2gn I will keep adjusting until I get a 22gn 10 throw weight.

I dunno if these readings are normal, or what..

Factory PMC FMJ 132gn 38 Special
871, 864.1, 858.2, 869.9

WST Powder, 125gn LRNFP 2.4gn powder
474.1, 516.3, 516.3, 604.3, 574.3

Now there is almost a 100fps difference there.. And I can see that in the other loads as well. Is that normal on a progressive? Should I be adjusting my powder measure in a different way?

What are you looking for when loading it up? Just grouping? I can see some grouping with my 4-500fps rounds that barely kick and I think I can go lower .. Whether they will knock steel down is another story.

Trust me, if I didn't see a reading after a shot, I was checking the barrel to be sure .. Cowboy Action is basically goes from Clear the barrel to not blowing up the gun..

[Jim8300]

I looked up WST on the Hodgdon site and the recommended load data. They did not show a load for 125G, only 148g and 158g. The minimum powder charge for those slugs is 2.5g for the 148's.

You should try another powder. I shoot Clays 3.0g under a 125g, 147g or 158g lead bullet. All three work fine for me.

Your load could be too low and unstable. One thing that can happen with light loads is variation due to the location of a small amount of powder in the case.

Try another powder and loads within the specs of the load chart. When shooting through the chronograph raise the muzzle to bring the powder towards the primer prior to shooting each round. That should give you more consistent values.

I would not go outside the data charts with the loads.

[Pkspawn]

Ohh, I was using the Data for Clays with 125gn bullet.

I found Clays to be very similar to WST when I was using it in my 45acp rounds. Haven't chrono'ed them though.

But from what you are saying.. You think I should go with a powder that might fill up the space/void between bullet and primer to get a more consistent FPS.

I will look into tilting the gun back after each shot to see if I notice anything.. I've heard of that happening with other powders.

[Jim8300]

Ohh, I was using the Data for Clays with 125gn bullet.

I found Clays to be very similar to WST when I was using it in my 45acp rounds. Haven't chrono'ed them though.

But from what you are saying.. You think I should go with a powder that might fill up the space/void between bullet and primer to get a more consistent FPS.

I will look into tilting the gun back after each shot to see if I notice anything.. I've heard of that happening with other powders.

3.0g of clays is still a low volume load, you do have to be sure your press is set up correctly. Your Dillon has a fail safe rod on the powder measure and when set properly can prevent a double charge unless you do not move the shell plate, then you could get a double charge.

If you want a safer load that has higher volume in a light charge than I would recommend trying Trail Boss. It was designed for a light load while taking up much of the room in the case.

I am also using Trail Boss 3.1g with a 125g lead flat nose. Another shooter I know said it nets about 700fps out of his Rugers with 5 1/2" barrels.

[DucatiRon]

Another thing that can make your fps jump around is case length and brand. If your case length differs between rounds a different amout of crimp will be applied to each case. A longer case will have more crimp than a shorter case as long as te die position remains constant. The longer case will travel farther into the die and there for have more crimp. Powder will burn different based on said crimp.

Different brass manufactures may make their brass harder or softer and this will also effect crimp tension.

Also careful in lower than starting charges. Not that I've seen it happen but as reported on the Internet an undercharged round can effectively detonate and explode instead of burning. It's said that the resulting explosion can kaboom your gun in your hand.

[knight0334]

You are going to get inconsistencies when you measure powder with a dispenser. About the only thing you can do is use a powder that fills the measure a bit better if you aren't going to weight it on a scale.

You're doing good though about taking an average sample, but you will still have the problems associated with volumetric measurements.

Fine flake and ball powders are more consistent than larger flake and extruded(rod shaped) when using volumetric means. A couple small things that helps is keeping the powder hopper full to allow the mass of the stored powder to help fill the measure, and giving the hopper/measure a couple taps when it is filling the measure.

[Brick]

OK so we're talking .38 Special right?

For IDPA you only need to make a 105,000 power factor (that's down from used to be a 125,000 power factor. The change came through last year. You'll notice that your factory PMC cartridges didn't make the PF.) Personally I like 158 gr. bullets and I've had very good results with Accurate #5. (158 gr. bulets only need to make 665 fps)

But if you want to stick with 125 grainers that's up to you. You'll need to get them going an average of 840 fps. So start looking at the manuals and find a powder that has you in that velocity range at about mid-weight. But, bear in mind you shall never reach the speeds they show in the manual! More than likely when you chrono your loads you'll find they run 100 fps or so slower than book.

[762xIan]

Currently. I will load a bunch of rounds, starting at or below the recommended min. Making about 5 rounds each stepping up .2gn each upto the max recommended.

That is how I do it also, but I usually make 10 or more per test batch, that's just me being anal I guess. Then again I actually like doing load developement.

WST Powder, 125gn LRNFP 2.4gn powder
474.1, 516.3, 516.3, 604.3, 574.3

Now that is some variation.

Your load could be too low and unstable. One thing that can happen with light loads is variation due to the location of a small amount of powder in the case.

I agree with this, that is my opinion also.

[Pkspawn]

Thank you very much for the info.

I really don't want to get to specific to the 38 loads.. But more on how you work up any load for a pistol..

Do you look at the speeds you want and the volume that the powder is taking up? Like my 38 rounds. I want a low recoil which might be slower speeds. So I should go with a powder that I drop a bigger charge of (like the TRail Boss) but doesn't build as much pressure as quickly as others??

LoL, if you think 3.0gn is low.. I started at 2.2gn All the different test rounds I fired all grouped in about a 2" circle, I was only about 10-12 yards from the target.

The rounds for the Games are a little easier I guess, since I know there is a MIN power factor to look for before I even start looking at grouping/gun function..

I had a great load for 155gn SWC and 13# recoil spring in my 45.. Problem was when shooting paper you could tell the bullet was tumbling .. Shooting steel challenge, it went bang then ding and that is all that mattered..

edit: didn't know about the low charges blowing up.. googles says that occurs wit fast burning powders. I don't think WST is a fast burner, but is something to be aware of.. Thank you

[Jim8300]

Thank you very much for the info.
edit: didn't know about the low charges blowing up.. googles says that occurs wit fast burning powders. I don't think WST is a fast burner, but is something to be aware of.. Thank you

WST is high on the chart of fastest burning powder.

http://www.hodgdon.com/burn-rate.html