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Lee Undersized Sizing Die

MikeT124

Silver $$ Contributor
I have a new 1911 that has what I believe to minimum sized chamber. Factory loads will chamber, however many of my reload will not (about 15%). I've measured the ones that don't and generally they are only a couple thousands of an inch bigger diameter than factory. I was wondering if anyone has used one of these dies with success. The problem area is just above the base of the case, that is where the cartridge refuses to enter the chamber.
 
is your die set correctly to get to the base of you cases?
 
I'm not saying that this is the case in your situation, but this is a common occurrence. Many pistol barrels have a very short throat - in some cases it is nonexistent. I would suggest this - take some of your loads that will not fully chamber. Either seat the bullet deeper or pull it with an inertia bullet puller, and see if the case will chamber completely and allow the slide and barrel to lock. If it does, you have your answer.

In this case, the barrel needs to be throated to allow it to chamber all ammo. I can recommend someone to address this issue if you're interested. I encountered this with an aftermarket barrel from a well known company, and it is not at all uncommon throughout the industry. It is arguably much more common than a too-tight chamber.
 
i ran into this problem with a box of 500 cast bullets... they measured .452... when seated you could see a slight bulge in the case where the base of the bullet was in a loaded round... some would chamber and some wouldnt... i ended up pulling them all and running them through a .451 bullet sizer... loaded them back up and the slight bulge went away and they chambered and cycled like they should... may not be whats going on with yours but something to look for...
 
I have used a Lee 'U' die for .40 and 38 Super, SuperComp, etc. Never needed one for .45. All worked fine with a Dillon 550B press, but I did have to modify a locknut. With the newer 'stepped' toolheads, this may not be necessary. I'm assuming you've tried unloaded, sized brass in the actual barrel?

To answer your specific question, yes, they worked for me to get rid of the bulge at the head. Throating is a different issue.
 
The primary need for the undersize die is for compeditive shooters who use range pickup brass. They do not know how many times the case has been fired and how hard the brass has become. Meaning well used brass becomes hard and springs back more after sizing. And the undersize die decreases the case diameter .002 to .003 and increases bullet grip.

Two things pistol shooters do not do.
1. Trim their cases to the same length, and the longer cases can bulge when crimped.
2. Or anneal their brass. ;)

Below a 9mm cartridge that was sized with a undersize die and the case is wasp waisted. Meaning the case has good bullet grip and it will not move under recoil or feeding. Normally if you can see where the base of the bullet is inside the case you have good bullet grip.

MfcwIQB.jpg




And one of the biggest causes of chambering problems is case bulge below the taper crimp. Lee makes a Factory Crimp Die with a carbide ring in its base. And the carbide ring will size any crimp bulge, "BUT" it can also size any oversized cast bullets and cause leading and accuracy issues. This depends on case wall thickness and bullet diameter and if the carbide ring squeezes the case enough to reduce the bullet diameter.

I'm a cheap bastard and I use range pickup 9mm and .40 S&W brass and use a bulge buster die and a under size die. The bulge buster will bring the entire case back to minimum SAAMI diameter. And the the FCD will size any bulged crimps from longer cases.
 
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WOW lots of responses thanks, I'll try to answer as many as I can remember. First off we (my wife and I) have two of the same model 1911's consecutive serial numbers purchased at the same time (I know it really doesn't mean allot). Her gun chambers and fires all the rounds that mine fails to go into battery on. I have a .45ACP case gauge and these failing rounds also fail in the case gauge, like in my gun about the last 1/8" to last 1/4" sometime I'm able to push the back of the slide and make it go into battery, they then fire fine. If I push too hard and it still fails to go into battery it's a real PITA to get the slide open again so I don't use excessive force. The loaded cases do not show a bullet bulge, but the area just slightly above the solid base of the case is about 2-3 thousands of an inch larger diameter than the base, this is the area the the cartridge fails on both on the firearm and the case gauge. I've ordered the Lee undersized sizing die and hope that it will solve the problem. I use a Dillon taper crimp seating die in my 650 to load .45ACP so there is hardly ever a bulge at the crimp. I do occasionally get a bullet bulge but those end up failing inspection and are not fired. I pull the bullets and save the powder and primer and toss the brass. The bullet bulge is generally caused by the bullet going slightly off center before being seated. I have tried sized brass in both the 1911's mine sometimes fails my wife almost always works those also went through the case gauge and again the failures failed. The current sizing die is a Dillon sizing die and in trying to solve this issue I have set the as far down as possible while still getting a full stroke of the reloader handle. Like I said earlier I've got the Lee die on order and I'll report back when I get a chance to try it out.

Thanks everyone for your thoughts, suggestions, information and ideas.

Mike
 
Just a couple of thoughts here - both guns are assembled by the same manufacturer right ? For shits and giggles get a case that loads in the one and not in the other - take the barrel from the one that it does not go into and swap it with the barrel from the good gun if it loads - your issue is most likely the extractor in the non loading gun - and do you have a case gauge to check your sized brass/loaded rounds dillon make one - if the round fits in there it will chamber .. full disclosure I load about 5k of 45 ACP a year.
 
Just a couple of thoughts here - both guns are assembled by the same manufacturer right ? For shits and giggles get a case that loads in the one and not in the other - take the barrel from the one that it does not go into and swap it with the barrel from the good gun if it loads - your issue is most likely the extractor in the non loading gun - and do you have a case gauge to check your sized brass/loaded rounds dillon make one - if the round fits in there it will chamber .. full disclosure I load about 5k of 45 ACP a year.

Yes both guns made by same MFG. I haven't done exactly what you suggest, but I did remove both barrels and a factory load will drop into both, a failing reload drop one into one and not the other and that load will not go into my case gauge either. I have measured the case diameter just above the base (this is were they usually stop) and failing ones run just a couple of thousands of an inch greater diameter than ones that load into both barrels. My case gauge is out in my shop right now, but I believe it's a Wilson, I have several Dillon gauges but not in .45ACP Yes any round that fits my case gauge does fit both the the barrels/guns and fires. My full disclosure at one point in time 5k of reloaded .45ACP was an average month for me. Both wife and shooting bowling pins and NRA Bullseye (now called NRA Precision Pistol). Thanks for your thoughts

Mike
 
The Lee undersize sizing die has arrived and been installed. Yesterday I loaded 35 round using the die. One round has a slight bullet bulge it does not load into the chamber, the other 34 load fine, this is using the barrel that had previously been giving me fits shambering reloads. In my opinion the experiment with the undersize die is a complete success.

Mike
 
Mike,

I have a buddy in the process of testing the Lee die and the Redding dual ring die. I'll let you know the results when I have more information, but preliminary results show the Lee die working as advertised.

HTH,
DocBII
 

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