DWX compact (4" barrel) load work-up

[Clint007]

Building up loads for idPA CCP division with my DWX Compact. This is a 4" barrel.

Interesting to note that my 124 gr RMR match winner flat point FMJ, with 4.0 gr 231, which are dead on in my SP01 Shadow Custom at 50 feet, shoot less accurately in the DWX Compact and consistently about 2" lower using the stock sights whereas some hot SD loads are dead on with tight groups. No matter, I know all guns are different. That's part of this fun.

IDPA CCP allows a power factor of 105 for competition. So, in general we'd like as soft a shooting gun as possible that still makes 105 power factor.

Are there accepted truths about shorter barrels and preferred load features (bullet weight, powder burn rate selection) for optimal accuracy and ES and SD but striving for as close to 105 pf as possible (actually I always end up wanting 5 above, so 110 pf, for safety at the chrono station)? 

Like, oh you have a compact pistol barrel so you'll find 115 gr bullets and fast powders to be generally better....etc etc.

One of the problems I noted with 'light' loads like this in general is temperamental accuracy and high SD and ES b/c we are perhaps (is this right?) flirting with incomplete pressure seal at these loads.

thx

C

[Clint007]

My struggle continues to be getting good accuracy and good SD while keeping the PF around 110. This is somewhat embarrassingly light and I’m finding that most loads Lose a lot of accuracy when loaded this softly.  I noticed that the accuracy tightens up about the time of the standard deviation of velocity tightens down, assuming this is when a full pressure seal is being made in the chamber. So that means some of my lighter loads are generating inconsistent pressures.  Is that right? Asking help from all the wisemen here… would it help looking for high volume but slower burning powders, compared to 231 or n320 or titegroup?

C

[tdogg]

I've never tried to load that slow.  I would assume a faster powder will hit pressure sooner and help with consistency/pressure seal.

I would assume a slower powder would just not burn clean enough at that low end.

Just because you can load that low doesn't mean you should or need to load that slow.  I'd find the load where the cases are not showing blow by and the accuracy is good.

Cheers,
Toby

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[tdogg]

And yes I'd opt for a lighter bullet to require more velocity and hopefully get you out of the blow by regime.

Cheers,
Toby

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[Clint007]

Thank you. Yes, this is a little unusual, in fact, the power factor requirement for this division is 105, because these are compact pistols.

I’ll try some fast burning powders and lighter bullets, but I’m suspecting an ideal load (one that is making good but not dangerous pressure for a full seal, but not egregiously over the necessary power factor goal to keep recoil competitive) are probably not popular published loads. And of course, I hesitate to load things that are not validated by reputable sources.

C