Guy Neill

Priming compounds were early on, fulminate of mercury that destroyed the brass casing. Then were the potassium chlorate prim ing compounds (so called corrosive primers) that left a salt in the bore that needed to be cleaned out to avoid rust. That was replaced with the lead styphnate priming mixes, that are still in use, with the non-toxic also being used. The non-toxic, to really mean anything need to be used indoors on a range dedicated to non-toxic. If lead styphnate priming has been used previously, the NT won't reduce the shooter's exposure to lead.

Non-toxic is heavy metal free for the priming compound. No lead, no strontium or such. Federal started crimping the NBT primers as a further guard against their backing out, along with the enlarged flash hole. The NT priming compounds have more brisance than the older priming compounds. When CCI first developed their Cleanfire lead free priming, there were instances in testing where the primers dished the breech face on guns only having case hardening of the slide.

I just looked at the USPSA Approved Pistol list and it has the Echelon listed.

40 cartridges have been known to rattle down the bore and obstruct it when the next round is fired. It would take racking the slide for the new round to be loaded.

I expect the factory will fire fine. As stated, firing on a second strike has been due to primers not completely seated. Completely seated defined as the primer anvil legs being against the bottom of the primer pocket. What loading press are you using?

Essentially, the only time a primer will fire on a second firing pin strike is that the primer was not completely seated on the first attempt. Completely seated, primers are commonly 0.003" - 0.005" below flush with the case. Have you tried any factory ammunition. If so, how did it perform?

The Hodgdon data for a 147gr Hornady XTP bullet maxs out at 2.9gr with only a 123 power factor. There COAL is at 1.100", that I would consider short for that weight bullet. A lead or plated bullet with a longer OAL is likely to allow getting where you want.

I've used 700X for quite a while. Yours sounds like a hot load as I use less with lighter weight bullets.

I had expected someone to have answered this, and I was curious about the answer, but it doesn't seem anyone is forthcoming. My suspicion deals with the trigger spring and the disconnector springs since they are the ones bearing directly on the trigger. Looking on the Wolff Spring website, I see they have a "Trigger Function Pak" having reduced power trigger and disconnector springs. I've not used these, but it makes me think my thinking was on course. I hope this may be helpful. If you try the lighter weight Wolff springs, let us know how they work out for you.

Over the years I shot quite a bit of factory 40 in my STI and kept my reloads at 1.135" or such. No problems. I consider it more of a gun problem than an ammo problem if it will not feed factory ammunition.

Posible to uniform primer pockets?

I keep thinking those working on an apparatus to sort cases by headstamp should have a simplified version to sort by primer size.

10mm Auto cases are now seeing the small primers as well.

This rear sight, perhaps? Rear Sights - Sights By Manufacture - Smith & Wesson Sights - Kensight Sights

You might check the respective diameters of the firing pin and the firing pin tunnel it fits through. Since the primer is extruding into the tunnel, it may indicate the firing pin diameter is smaller than it should be. You may also try using a new HD firing pin spring.

There are a number of good makers of steel targets. I've gone with MGM.

Work on trigger control by not worrying about drawing from the holster or such. Concentrate on watching the front sight and dropping the hammer without disturbing the sight picture. Use a light switch or such across the room as an aiming point. I don't recommend using the TV as an aiming point since the picture is moving and it's difficult to really know how consistent you are at not moving disturbing the sight alignment when the hammer falls. When I first began dry firing in earnest, I did 500 snaps each evening. 200 two-handed, and 150 each strong and weak hand, I advanced my classification percentage by 26 with no additional live fire.

Add a dry-fire routine. It will give you greater trigger control. It has been said that you should do 10 dry-fire snaps for each live round fired.

The 45 Auto Rim was specifically made to use in 45 Auto revolvers to allow shooting without need half or full moon clips, Likely not to work in any other application.

Are the case lengths consistent? Is the die staying tight in the press? Case wall thickness can play a part as well.

You might check Accurate Plating and Weaponry Refinishing | APW Cogan Custom

0.38 * 0.39 is a different shot than 0.40 - 0.41

I see nothing in either video that has the slide not moving by the time the bullet exits. It can't be one way one time, and different the next time. It takes the bullet some 0.0009 seconds to traverse the bore. The slide cannot stand still for that time and suddenly start moving later. Perhaps the video time scales differ a bit, but I don't see the bullet exit until the 0.42 mark - after the slide has moved in the 0.40 - 0.41 marks.

In the second video, at the 0.40 - 0.41 second mark, you can see that the slide has moved just before the bullet exits.

Stopping the first video at the 0.11 second point, the bullet is exiting the muzzle. Backing up to the 0.10 second mark clearly shows that the slide has moved between the 0.10 and 0.11 marks. The black background isn't the best for seeing details, but examining the two marks will show the motion. Thanks for posting the vids. I still need to look at the second one.