multi-variate conundrum


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antsi
January 26, 2003, 12:11 PM
I have been working up a load for .45 ACP using AA#5 and West Coast 230 gr. plated RN.

After numerous trials, I am close to minimum charge - 7.6 gr

Now, suddenly I throw a new pistol and a chrony into the calculus.

The new pistol is a 1911 and it is having some "break-in" issues, but I do seem to get more misfeeds with my loads than with factory ammo. Stovepipe jams, and rounds that don't quite chamber all the way into battery.

The SIG is no help on this. It never malfunctions no matter what I feed it.

Yesterday, I chronoed my load at 7.6 grains. Velocity was low - average 804 fps. This is at or below minimum velocity depending on whose data you believe. Then again, it was 25 degrees yesterday - how much difference would the temperature make?

When it does feed and function, I like this load. It shoots nice.

But I am hesitant to load up a great massive pile of it, before I sort all this out. I am tempted to notch up the charge a little bit, if it could be a reliable function issue.

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Jim Watson
January 26, 2003, 12:57 PM
A velocity of 804 fps is not bad with a 230 grain bullet. I have chronographed factory loads everywhere from 748 fps (USA econo-ball in a Commander) to 912 fps (Hydra-shok in a GM.) It should have plenty of recoil to function a normal .45ACP. The last batch of 230 RN reloads I chronographed, the starting load was 806 fps and is plenty for me. Powder burn is bound to be temperature sensitive, although some of the newer stuff minimizes the effect.

"Breakin" after a couple of hundred rounds is the company or dealer's way of telling you "go away and leave me alone."

I suspect stovepiping to be an extractor fault.
Failures to chamber can be oversize or uncrimped ammo, undersize chamber, or a sharp edge at the chamber mouth.

Do a search here, TFL, 1911forum.com and m1911.org for tests of extractor tension.

Do you taper crimp?

Have you chamber checked your ammo in the clean barrel out of the gun? If it won't go in FREELY and even rattle around a bit, either the load is big or the chamber tight. Compare vs your S-S.

Inspect a malfunctioned round for a crescent shaped ding in the brass about .10" back from the casemouth.

WESHOOT2
January 26, 2003, 05:41 PM
What KIND of 1911?

What components?
OAL?
What do you want this ammo to do?

BTW, load manual data is based on the test gun used; may have zero bearing on the performance from YOUR specific launch platform(s).

antsi
January 27, 2003, 12:19 AM
WS2: The 1911 is a Springfield Mil-Spec. OAL is 1.125 Bullets and powder already mentioned; primers are Winchester. Intended use is range ammo, so I'd prioritize 1) reasonable accuracy, 2) reliability, 3) pleasant-to-shoot-ness.

JW: I tried chamber-fitting the rounds in the 1911 - I had set the dies up before I had this pistol, so although they fitted the SIG chamber perfectly, they were a little tight in the 1911 chamber. Adding just a skoshe more crimp helped a lot.

I also tried the extractor tensioning trick as described in the 1911 tech info. By the "shake" test, my extractor is too loose. However, I was not able to make it much tighter using the adjustment method they described. I will try again. Any tips?

Didn't see any of the crescent-shaped dings in the case. However, I have ocassionally seen dings in the bullets from rounds that didn't feed. Those plated bullets are very soft - it is the first time I have used them.

Thanks guys for the help.

Jim Watson
January 27, 2003, 12:51 AM
OAL of 1.125" is way short for a .45ACP RN.
Do you maybe mean 1.250"?

Are the marks on the failed bullets the same, indicating they may be hitting the same on the way up? Or they just the soft plated bullets getting beat up in general?

Are the failed rounds shorter OAL than they started out? Bullets setting back can cause all manner of trouble.

You might try some real jacketed bullets instead of plated.

Otherwise, I am out of ideas.
I would be on the run to my FLG (Friendly Local Gunsmith) because I am classified NRA Mechanically Inept.

WESHOOT2
January 27, 2003, 01:04 AM
If using 230g RN suggest 1.245-1.265".
LEE Carbide Factory Crimp die.
Different magazine(s).
Not the first Springfield I've heard of (or handled, so you others just hold yer water) with feed woes, but FIRST confirm your ammo.

antsi
January 27, 2003, 03:35 AM
Oops, you're right, 1.250, little brain fart there.

I think the extra skoshe of crimp will be helpful. Stupid; it never occurred to me that the SIG and the 1911 would have different chamber dimensions. Duh.

Even before, my bullets were passing the "repeated chambering set back test" and the "thumb pressure set back test."

We will see about extraction/ejection. I can't make my extractor act like the 1911 tech info suggests.

Re; mags -- the factory Springfield mag is a troublemaker. I have a Kimber 8-round mag, and two Mec-Gar 8-rounders, which all behave about the same; about 2-3 misfeeds per 50 rounds.

The dings on the bullets appear to be where they are hitting the top of the chamber on the way in. Now, with more crimp, they seem to chamber more smoothly without so many dings.

WESHOOT2
January 28, 2003, 06:43 AM
Might try: 1.262" OAL; 1.245" OAL; Kimber :D

mec
January 30, 2003, 12:34 AM
you're velocity is within expectations for .45 ball. I've seen the same basic velocity ranges Mr. March describes with factory ammunition in full size .45s. Seating depth can make a difference. Speer recommends 1.270 for their lead rn but they didnt get to 100 percent functioning until I loaded them to 1.280.
Springfield likes to use inferior extractors and then fail to tension them before shipping the gun. Mine relaxed and quit working at under 1,000 rounds and I replaced it with a wilson extractor from Dillon. If you have one of their stupid titanium firing pins and are getting occasional misfires, throw it away and get an Ed Brown heavy duty from Dillon.

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