The Mini 14 and Lee’s Factory Crimp Die

I love the Ruger Mini 14 and I’ve written several blogs on it (I’ll give you a link at the end of this blog).  The Mini 14 is not the most accurate rifle I’ve ever shot, but there’s something about it that just makes it fun.  I think if Ruger had introduced the Mini 14 a few years earlier it might have been the next US service rifle instead of Mattel’s M-16.  That statement might get a few trolls’ shorts in a knot, but hey, they’re young.  They’ll get over it.

I took my Mini to the West End Gun Club a couple of weeks ago to see what impact (if any) a new Lee factory crimp die had on accuracy.  Usually when I reload rifle cartridges with jacketed bullets I don’t crimp.  Part of this is because it’s a bit difficult to get a consistent crimp if the brass is not trimmed to exactly the same length, and part of it is I often find I don’t need to trim my brass to get good accuracy.  That’s not to say case neck tension isn’t critical (it is; lube a couple of bullets before seating them and see how far out of the group they print).  But it you don’t crimp, you rely on friction between the case neck and the bullet to control the case’s grip, and friction is a tough thing to control.  Crimping should make the grip on the bullet more consistent (or so the theory goes).  Crimping is also thought to provide more complete combustion, reducing pressure variability and the inaccuracies associated with it.

Conventional reloading dies rely on a reduced diameter in the bullet seating die, which rolls the case mouth into the bullet to achieve a crimp (such a crimp is called a roll crimp).   Lee’s factory crimp die uses a different approach.  It has four collets (each forms a quadrant) that work at 90 degrees to the case to crimp the brass.  The collets are activated by the die’s base during the reloading press upstroke.

I loaded 15 rounds crimped in the Lee factory crimp die, and I used another 15 rounds without the crimp.  I shot two targets at 100 yards from a rest using iron sights, with 15 rounds for each target. The target on the left is with no crimp, the one on the right is with the Lee factory crimp die (and I used a heavy crimp). The brass was fireformed in this rifle and neck sized only to get a good fit in the Mini 14’s 5.56 NATO chamber, which (as you know) is slightly larger than the .223 Remington cartridge.  In prior load development work, I found that neck sized only brass is much more accurate in the Mini 14.

The first five shots using uncrimped reloads all went into the left target’s 10-ring, so I thought I was doing pretty well. Then I switched to the Lee factory crimp die ammo on the right target. The first shot felt weird, and it did not fully extract. I think it was the one that went way low. The next four all went into the 10 ring. On the next five rounds (again, using the Lee die ammo on the right target), the first one did the same thing (it failed to extract and it went low).  I fired one more magazine of Lee crimped ammo and all five worked okay.

Somewhere in those first two magazines of the Lee crimped ammo, I had two light primer strikes that did not fire. I extracted and chambered them again and they fired on the second attempt.  I didn’t know why those two rounds had light primer strikes.  Maybe the round had not fully chambered? Maybe because the Lee factory crimp die distorted the case mouth or something and it didn’t fully chamber?  Or maybe something was interfering with the firing pin’s travel?  I didn’t know and I wouldn’t find out until I disassembled rifle.

Then I fired 10 more uncrimped rounds at the target on the left and I had one failure to eject. My Mini 14 sometimes acts funny like that with the neck sized brass. It’s not a duty gun, so I thought I could live with an occasional failure to eject.  But I don’t like it.

So back to those misfires.  In the past, I’ve had to clean debris from around the firing pin, and it looked to me like it might be time to do that again. That could account for the two light firing pin strikes I had.

One other thing…I had painted the front sight with red nail polish, and that actually made the front sight’s top edge harder to see.  I want to go back to the plain blued front sight.

I also want to adjust the Lee factory crimp for less of a crimp. These first rounds used a max crimp. I didn’t trim the brass for this test because it was only fired once, but I don’t know how even (in length) it was. I used bulk Remington loaded ammo to get the brass (having fired it previously in the Mini 14) because a couple of years ago that stuff actually cost less than unprimed brass.  But inexpensive bulk ammo is not precision made and I suspect the case length had some variation (my suspicions were later confirmed, as you’ll read below).

When I reloaded the rounds fired in this test, I checked a few case lengths after neck sizing. The “trim to” length (per the Hornady manual) is supposed to be 1.750 inches, with a max case length of 1.760 inches. These cases (after two firings and neck sizing) were all over the map.  They ranged from 1.752 to 1.780. That alone could account for some of the anomalies described above.  I ran them all through the trimmer and reloaded a hundred for the next range visit. I backed off a bit on the Lee factory crimp die, too, as my good buddy Robby suggested.

I gave the Mini 14 a good cleaning and I was surprised at how filthy it was. This is not a rifle that I clean religiously…I’ll shoot it on several outings before cleaning (heresy, I know, but hey…it is what it is).  I wanted to grab a few photos of what a funky Mini 14 can look like, but my hands were so dirty and greasy I didn’t want to handle my Nikon camera.  After the most recent range visit, I Hoppes No 9’ed the Mini 14 bore for a couple days to get all the copper out (you know, until the patches came out with no green).

There were bits of what appeared to be very thin sheet brass in the bolt around the firing pin as well as a whole bunch of greasy carbon residue in the bolt. That could account for the couple of misfires. Removing the firing pin is not an easy job (it takes a special tool I don’t have or want); the drill here was to shpritz the hell out of the bolt with carb cleaner and work the firing pin back and forth to push the nasty stuff out. The thin brass bits might have been primer cup material.  Or they might have been chips from the extraction operation that found their way into the bolt and were peened flat. There’s no way of telling, as some of that ejected brass ends up in the next county (a trait Mini 14s are famous for).  By the way, when you’re working with that carb cleaner, you need to do it outdoors where there’s plenty of fresh air.  It’s highly flammable and if I use that stuff indoors, I get lightheaded and nauseated pretty quickly.

There was a lot of carbon gunk in the stock channel clear back into the action.  There was also a lot of carbon in and on the guide rod, as well as around the extractor. This could account for the occasional failures to eject. I blew it all out with WD 40 (in the stock) and carb cleaner (for the metal pieces).  There was so much carbon residue in the stock’s barrel channel that I thought I might have a leak around the gas port, but I didn’t see any carbon residue around the gas port and I’ve got the Allen bolts around that part tightened as tight as I dare go. I tried the smaller diameter aftermarket gas ports last year, but every one of them gave me unreliable function, so I went back to the stock port.

I’ve got a little more than a pound of ARComp, and that has been my “go to” Mini 14 powder for several years. When things started to get tight last year, my reloading outlet had an 8-pound bottle of XBR 8208 (it was the last bottle of anything he had). I had never heard of that powder before but I figured it would work in something, and in poking around on the Internet I found that 8208 gets the nod as a great powder for the .223 cartridge. The hundred rounds I just loaded are with ARComp, but I think I will do another 100 or so with different 8208 charges to see how they do. I’ve still got several hundred 62-grain Hornady full metal jacket bullets and I have another 500 55-grain bullets that just arrived from Midway. And I have small rifle primers and a potful of .223 brass. Unlike a lot of folks, I’m in good shape for .223 for a while (and no, I don’t want to sell or trade any components).

What’s the bottom line to all this?  Did the Lee factory crimp die improve accuracy?  The short answer is: I don’t know yet. I think it does, but I had too many other things going on with the rifle and the brass to be sure. If you ignore the first two rounds that went low, I think the accuracy edge goes to the Lee crimped ammo. Bear in mind that I was shooting with iron sights at 100 yards, so the differences may be more due to me than anything else. There were only four rounds outside the 10 ring with the Lee ammo; the uncrimped ammo had six rounds outside the 10-ring. But again, it’s iron sights at 100 yards, so who knows?

I’m going to share this post on Facebook, and you can bet some yahoo will tell me that he shoots 1/2-inch groups at 200 yards with open sights on his Mini 14 all day long.  Hey, it’s the Internet.  You have to ignore those buttheads.  As far as the Lee factory crimp die’s accuracy edge goes, I think it’s real.  I’ll find out for sure (maybe) the next time I go to the range.  Everything in the Mini is clean, lightly oiled, and ready for action. We’ll see what happens on the next outing, and you’ll read about here on the ExNotes blog.

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Those other Mini 14 blogs I mentioned above?  You can find them here!

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