45acp too hot (pics)

[wigz]

Hi guys im new on the site I have been reloading 4 years or so, Im in france so use mostly vectan powders for the 45acp I use vectan A1 0.35g (5.40gr)
and normally fmj 230gr RN with cci 200 primers, A friend of mine recently sold me some 230gr LRN as he no longer uses this caliber for my colt 1911 gold cup 70 series, using the plunk test I found the OAL to be around 31.55mm (1.242 inch) using my load table I saw that with the LRN I could use same charge of powder which with the FMJ feeds and shoots great but with the LRN im getting primer crater and the slide seems to cycle way to fast and v the cases before they eject but they do not stove pipe. Im going to use my puller and pull all the LRN (about 150 rounds) and drop the load down a fair bit and try 10 or so to see what that's like. anyone else had the case mouth v from hot loads?

Thanks.

[Jim243]

Have no idea about the powder you mentioned. But it is hard to tell from the photos you posted, but it looks like those cases are blackened that would be an indication of a under-power load (too little powder). Also your slide is cycling faster might be because it is not fully going back (for the same reason).

Like I said have no idea what your powder is or where it's made. If you could post some lighter pictures we may be able to tell more.

Thanks
Jim

[BuckRub]

Never heard of that powder either. But the pics don't really show high pressure to me.

[MR_X]

According to the load data I can find, you are fine on your charge (4.9-5.9gr). I only see some cratering on one of those cartridges. Is that the only one? How accurate is your equipment? What pistol are you shooting? What are you crimping too? Maybe your crimping is to light and you might be getting bullet set back?

[WESHOOT2]

Suggest backing off .4g and test.

[stubbicatt]

To me the primer cratering in the example at the top suggests perhaps you had an overloaded charge, or a circumstance where the cartridge immediately before this one had a light charge, and the remainder of the undispensed powder was dispensed into this case. The remaining empties look normal enough to me. I am curious why the case mouths are as dinged up as that?

[Shootest]

Welcome aboard, nice to have members form other countries. I can’t comment on your powder either. Your brass looks really beat up, both the mouth and case head, maybe time for some new stuff?

[Martys]

I use 300 MP for some of my 357 loads. Those primers look ok to me. However as previously recommended might back off .5 gr and check again. The only thing I don't like about the powder is how "fine" it is and sometimes snows a bit on my 550b. I even called Dillon but didn't get much help although he was nice and tried to resolve my issue.

[Brian Pfleuger]

Considering that you could use the same primers in 45acp (traditionally large but now also small primer) at about 18,000psi as you would in .357sig, 9mm +p (small primer) or 10mm (large primer) (all at roughly 37-44,000psi) I would not expect to see any pressure signs in the 45acp except the gun coming apart and my hands bleeding.

[Unclenick]

Curious photos. I'm not seeing any black on the cases; just shadow from being a back-lighted photos. In the first photo, the top primer is the one that is cratered, but the outer edges are not flattened a lot, much less mushroomed out into the primer pocket perimeter, as usually happens along with cratering. Plus the crater is broad, as if the firing pin tunnel were chamfered, which can cause cratering at normal pressures.

Can you get two close-up photos of the breechface on the slide; one with the firing pin held out by its spring, the other with you forcing the pin to protrude using a toothpick or ball point pen? I want to see how well the firing pin fits the hole. Occasionally, for repair, someone will accidentally put a Springfield Armory firing pin into the Colt. The SA pin is narrower for double duty in their 9 mm version.

My next question is how the seating depths of your two bullets compare?

Seating Depth = Case Length + Bullet Length - COL.

To get the same pressure, ideally you'd want the same seating depth for both (assuming identical case length; just use 0.898 inch (22.81 mm)

Occasionally lead bullets will produce higher pressure than jacketed bullets. This used to be commonly reported in revolvers because base pressure would upset the lead to fill out the forcing cone during firing. But if the lead is soft enough and if, as is unfortunately not uncommon, the chamber is long enough to let the cartridges headspace on the extractor hook rather than the case mouth, lead could be upset by pressure to fill that space hard. Do you get leading in the end of the chamber or excessive lead build-up in the bore?

That said, I have a Series '70 Goldcup that would occasionally bite cases like that. I solved it by replacing the ejector with a Commander ejector to start the case out of the ejection port earlier in the cycle. Both slow and fast cycling can cause this problem, though by different mechanisms. Trying a reduced charge it the safe place to start your diagnosis.

[BuckRub]

Plus one for UncleNick

[wigz]

thanks guys ill sort out some more pics and stuff tomorrow eve when I get in from work.

[steve4102]

Originally Posted by Brian Pfleuger

Considering that you could use the same primers in 45acp (traditionally large but now also small primer) at about 18,000psi as you would in .357sig, 9mm +p (small primer) or 10mm (large primer) (all at roughly 37-44,000psi) I would not expect to see any pressure signs in the 45acp except the gun coming apart and my hands bleeding.

Well said.

The primer is not smart enough to know if it should show pressure signs in the 45 ACP just about 20K, but wait until pressures are above 37K in the 10MM.

Reading primers in a low pressure round like the 45 ACP is a-kin to reading tea leaves.

Follow your load data and use a Chrony if at all possible. and forget reading primers.

[Nordeste]

Salut, Wigz. Unfortunately, as all the folks here have told you, it will be kind of difficult to get some loading data help from American shooters, since the Vectan brand is not usually imported into the US. They have, however, a wider range of powder choices than we do in Europe.

Your primers look OK to me. So do your cases except for that indentation in the three of them (recoil spring related?). The blackening looks more like it could be due to little or no tumbling and/or lack of light in the photos. I concur with Unclenick in that the crater could be due to the firing pin hole. My Beretta 92 FS does that with every cartridge I feed into her and I'm pretty sure I'm not using overpressure rounds.

Sadly enough (and you're probably aware of this), Vectan powders differ quite a bit on their burn rate from batch to batch. We've had serious issues with that and the BA-9 over here. I know BA-9 is also suitable for .45 ACP, but most of the guys who shoot .45 in Spain seem to prefer the faster BA-10 over the BA-9. It looks like this fast powder works well in the .45. Something to be considered, perhaps .

[iraiam]

Primer cratering can be a very unreliable check depending on the gun and the round. Those don't look bad at all to me, or rather I only see one with a very minor crater.

[chris in va]

using my load table I saw that with the LRN I could use same charge of powder which with the FMJ feeds and shoots great

Actually lead needs to have less of a charge than FMJ.

[Unclenick]

Needs and can-tolerate are different. Mostly, people shoot lead at lower pressures either because they are getting more metal fouling with it, or because they are shooting bullseye matches and want reduced recoil and muzzle flip. Keep in mind, we are talking about 45 Auto, whose SAAMI maximum average pressure is no greater than may still be used safely in a 140 year-old trapdoor Springfield action. That's nowhere near the pressure Elmer Keith developed the .44 Magnums with, using 16:1 lead:tin bullets and 2400.

The trick with .45 Auto has to do with the gun you use. By one gunsmith's estimate, up to 70% of the factory 1911 actions headspace on their extractor hooks before the case mouth reaches the end of the chamber. This causes the firing pin to push the cartridge against the right side of the chamber before firing, because it pivots on that extractor hook. With jacketed bullets, that is no issue, because they are tough enough to realign with the chamber as they start forward. Lead moving forward, however, tends to scrape against the right side of the case mouth step in the chamber that the cartridge was supposed to be headspacing on. This increases leading of the bore. It also puts the bullet into the chamber at a slight cant and with its center of gravity moved off the bore axis to the right. Since handgun barrels tend to have fast twists for their bullet lengths, that throws the CG at a radial tangent to the side of the bore the CG is closest to at the moment it leaves the rifling, and the drift from that stays with the bullet to the target. It also increases wobble of the bullet in flight. Both have the effect of opening groups up. So does build up of lead, which deforms passing bullets further.

Two things can be done about the above issue. One, is to stop headspacing on the extractor hook. The easiest way to ensure that, since you can't stretch your cases to find the end of the chamber, is to intentionally headspace on the bullets, instead. This means decreasing seating depth (increasing COL) until chambering stops when the bullet finds the lands of the rifling in the throat.

In the illustration below, the barrel is used as a gauge to show how to tell when you are headspacing on the bullet. I used this practice with semi-wadcutters in my own series '70 Goldcup for many years. When I first began to do it, my lead bullet group sizes off sandbags reduced about 40%, and leading was significantly reduced, and velocity extreme spread was reduced. That is due to the combination of better bullet alignment and more consistent start pressure. As always, when jamming bullet into the rifling intentionally, back the charge off 10% and work back up, watching to get back to original velocity and for pressure signs.

I've seen good evidence that most lead .45 Auto bullets are unseated by the primer before the powder gets burning, anyway, but they are then various distances from or into the lands when pressure really starts to build, so they are suffering from inconsistent start pressure when they do this. That reduces accuracy by changing the exact timing with which the bullet leaves the muzzle after the firing pin strikes the primer. With slow powders, this also causes the completeness with which they burn to vary. Again, velocity extreme spread is a good indicator of whether you are making progress improving the situation with one loading technique or another.



For some bullet shapes, like elliptical profile round noses, seating all the way out to headspace on the bullet can cause a problem with fitting the rounds in the magazine. In that instance, just seat bullets out short of allowing magazine fit and feeding to be an issue. The chances are good the front edge of the bearing surface will still get into the throat. That solves part of the problem. To improve start pressure consistency in this situation, you need a tighter crimp. If the case mouths aren't getting to the end of the chamber anyway, its not an issue to do that. Indeed, board member William Iorg reminded me that most old time bullseye shooters actually roll-crimped their .45 Auto rounds because the start pressure consistency improvement gave them measurable accuracy improvements. Again, the shoulder of the bullet was sticking out of the case enough to get into the throat when they did this.