Mini 14 issue

M

MSD Mike

New member
So, I have started reloading for my Mini 14 and am having a bit of trouble. Load is 55 gr Hornady FMJ and 25 grains of H335. About once or twice a 20 round magazine the action will not fully cycle (I assume) and the fired round is re-chambered when the bolt moves forward. Have also Tried 3031 with simaler results. Powder charges are being weighed with both powders.
Using small base dies if that makes a difference.
Also, the gun is 100% reliable with several brands of bulk ammo with simaler bullet weight and design.

Any thoughts?

Thanks
Mike
 
It's *Supposed* to be impossible to 'Re-chamber' a fired brass.
The basic design of the rifle is supposed to EXTRACT then EJECT the fired brass.
'Re-chambering' from a mechanical standpoint is virtually impossible.

What more than likely is happening is a failure to extract.

I would check the extractor claw on the bolt.
Weak spring keeping claw from fully gripping the extraction rim on the brass is possible.
Crud getting under the extractor is possible, keeping the extractor from gripping the rim enough.

In each of these cases, you usually see a gouge in the rim of the brass, and brass shows up in the claw of the extractor.

Overpressure or excessively fast powder can produce bolt movement that simply yanks the claw through the rim, either taking a chunk off the rim, or bending the rim.

Oversize cases can wedge in the chamber, Mini 14 bolts being famous for hammering about any round into the chamber, the design has tremendous mechanical leverage compared to other auto loaders, it will hammer an oversize case into the chamber making it hard to extract.

Extractor arm/claw & spring replacement is easy if you find your extractor has seen better days...

There is also the possibility the gas pulse isn't lasting long enough to move piston/rod/bolt.
It will attempt to extract/eject, but simply doesn't cycle far enough backwards to fully extract the brass, but can't make it.
You *Usually* see signs when it's this issue, the brass doesn't get tossed like usual, some brass don't get out of the receiver (stove pipe jams), cases just getting flipped around backwards but not clearing the receiver...

25 grains of H335 and 55 grain bullet is a very hot load.
If memory serves me, the hottest H335 load recommended is 23 grains.
My memory isn't what it used to be, so take that with a grain of salt.
 
Hodgdon's top load of H335 for a 55 grain Speer bullet is 25.3 grains. Hornady's is probably lower. But either way, it is plenty of powder. What's funny is the commercial ammo works OK. You say you are using a small base die. These narrow the brass which squeezes the shoulder forward, so, per JeepHammer's mention, you really want to use a cartridge case gauge to check, or to measure from the head to the shoulder of some new ammo and of your cases as they come out of the sizing die to be sure your's aren't longer. Also, try reducing the charge by 10% and working back up to see what happens along the way. Too much gas could try to operate the bolt too soon.

Finally, call Ruger. They're bound to have heard of this before and may have some further suggestions.
 
Minis have large gas ports (over gassed) so that’s unusual, typically see this when modified gas ports or added rubber recoil buffers. I’m actually working that issue on my own, but I’ve made the gas port too small, and had to try two sizes larger now.

You might want to look into whether there are modifications? Did you buy it used?

My gun rechambers extracted brass right now because of that, I was out shooting yesterday and had factory, reload, and wolf steel cases all doing it. The gas port is too small combined with my other mods. You may also look at dirty or clogged gas. The factory rounds working fine is a standout issue for yours though...

H335 is not a slow powder, similar to TAC, H4895. I use LT-32 for my 223/5.56 reloads which is a little bit faster.


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Andrew - Lancaster, CA
NRA Life Member, SAF / CRPA / FPC member and supporter, USCCA Member
 
Thanks guys, gun was new when I bought it and has about 500 rounds through it at this point. 25 Grains was worked up to thinking low power was not moving the bolt with enough force. I would love to watch it in slow motion to know what it's doing. Nick, for the record I did start at a 10% reduced charge and worked it up to the 25 gr. Did a similar work up with 3031 with the same result.
Factory ammo is 100% and the extractor looks new. Gun, including the gas system are clean and lubricated. I'll invest in a case gauge to verify my ammo is dimensionally correct before I get crazy about the gun. I'm sure its something I'm doing.
You guys are not kidding about being over gassed. Ejection is impressive to say the least.
Thanks for the input so far,

Mike
 
Unclenick, you might want to change 55.3 grains to 25.3 grains.
I don't think a .223 case will hold 55 grains of anything.

To the OP, without checking the rim of the brass, both before & after, it's hard to tell exactly what's going on.
With the mechanical leverage the mini 14 action produces, the shoulder *Might* be a little long and the bolt still close enough to fire.

Keep in mind this is a short stroke piston rifle, an air gap between bolt and operating rod will cause bolt movement issues, from wedged bolt (against brass) eating up cycling energy to rod movement stops keeping the OP rod from hitting the bolt carrier hard enough to fully cycle.

I REALLY like the Mini 14 action (probably because I LOVED my Marine Corps M14/M21)
The ONLY issue the gas cycling system has is solid stops on both the gas piston & OP rod, and an occasional broken spring.

With those hard stops, if the bolt doses not fully or freely fall into battery, you will have ejection issues or failure to feed issues.
I used to do nothing more than clean many of these when they wouldn't auto cycle, the part are durable, well made and often just got crud in the wrong place.

You CAN over gas a Mini-14, but it rips the rim off the brass.
The only fault I can find with the Mini 14 is it needs a WIDER extractor.
It probably would have got one on scale with the M14 if it had gone through military testing.

Any rifle can collect brass in the extractor claw, or crud, or carbon...
Check the claw, see that it has a square edge, and it's probably fine if clean & square.
Over gas an AR15 and it will bounce the bolt, jam the bolt/carrier into the SIDE of the next round in the mag, and even leave the brass in the chamber with a damaged extraction groove.

Mini 14 RARELY jams the next round, so even with a failure to extract/eject, it doesn't 'Double Stack' the action. A cycling swipe and you are often up and running again without removing mag, holding bolt back and trying to shake the jammed live round out so you can get the empty brass out.

I'll bet if you check the Datum length you are a little long once in a while,
If that not it, I would bet your charge is a little hot...

All bets are off if you don't check the extractor claw first.
No ripped rims, just a scratch, it's claw or spring under the extractor.

https://www.midwayusa.com/general.mvc/index/Schematics~ruger_mini_14

This is an exploded view of the rifle/action with parts list from Midway USA.
It shows how easy extractor, spring & plunger are to source & replace if you need to.
 
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"Hodgdon's top load of H335 for a 55 grain Speer bullet is 55.3 grains."
"Unclenick, you might want to change 55.3 grains to 25.3 grains.
I don't think a .223 case will hold 55 grains of anything."

Yeah, you can't get 55 grains of powder in a .223 case with a hammer.
 
Just a typo, I make plenty.
Just didn't want someone to stumble across this thread and think they could stuff 55 grains in a .223.
You know how some people are...
 
MSD Mike: "Gun, including the gas system are clean and lubricated. I'll invest in a case gauge to verify my ammo is dimensionally correct before I get crazy about the gun. I'm sure its something I'm doing."

Only if your reloads are the ONLY thing causing the problem.

MSD Mike: "About once or twice a 20 round magazine the action will not fully cycle (I assume) and the fired round is re-chambered when the bolt moves forward."

This suggests the ammo may not be the only problem.

I have seen something similiar. Here is the story. New gun, a few rounds fired to check out the gun, then the gun put away for a few years. When removed from storage, gun fired and began to exhibit the symptoms in your second quote above. Gun then taken down for meticulous cleaning. Return to the range, gun symptoms now WORSE. It starts to re-chamber fired cases very often. When it cycles, it barely throws brass a foot or two. (Mini 14 should try to throw brass into the next county.) At this point it was time for a meticulous inspection of the gun, since I was certain the ammo was not the problem.

During the inspection, it was noticed that the extractor could not be moved with thumb pressure. Dis assembly of the ejector and ejector spring revealed a lot of gunk to be cleaned but operation was acceptable. Dis assembly of the extractor, extractor plunger and extractor spring revealed why the extractor could not be moved by thumb pressure. Both the plunger and spring were essentially glued in place by "petrified gunk" which may once have been gun grease. Rather than clean them, it was simpler and economical to replace them. The mini 14 has functioned normally ever since, never another problem.
 
Another thing to note since cleaning and lubrication was brought up. Mini 14 like all other gas piston op rod and rotating bolt guns (Minis, M14, M1A, M1 Garand, etc) should be greased with high temp lithium grease. They run much better with that and ample amount of it, but not so much that you’re building up piles of grease with dirt and carbon caking up. Unlike AR15s, the right answer is enough not more.


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Andrew - Lancaster, CA
NRA Life Member, SAF / CRPA / FPC member and supporter, USCCA Member
 
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True. Bolt roller grease does help.
True. Lubricants do harden over time & cause issues.
That was the point I was trying to make.

You can also include those crappy aftermarket mags.
They cause a LOT of issues, usually fail to feed, not fail to extract/eject.
 
Thanks for the charge catch. I changed it. I probably typed 55 grains for the bullet weight, then my fingers went on autopilot. :o Fortunately, as Mobuck said, from a safety standpoint, you couldn't fit it in the case. But typos are easy to come by, so it is always important to check other sources when considering loads posted on a forum.

Highrolls,

The case gauge is a good idea. You can also improvise by slipping spacer over the neck that has a hole through it that stops somewhere around the middle of the shoulder, then apply your caliper to the case and spacer together. A 30 Carbine case would make a good "spacer" for this, mouth-down against the neck. This won't make accurate absolute measurements, but it will let you compare.
 
Do you REALLY want 50 posts from some guy complaining he couldn't get 55 grains in a .223 case?
You know it's possible...

Anyway, I posted the exploded view so MSD knows what/where to clean & inspect.
It's even easy to aquire an extra extractor, small parts are always a good thing if you intend to keep the rifle long term.
Springs in particular are super handy to have around.
 
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Thanks for all the helpful information. The fact that the gun runs perfectly with factory bulk ammo makes me believe I'm missing something in my loading process. However, I will disassemble the gun to verify cleanliness and that all components related to extraction/ejection are in good condition and working order. I'll report back when I sort it out.

Thanks
Mike
 
I had a mini 14 that would eat and spit out anything commercial that I fed it....even Russian steel rounds. Did not have any loading problems, but then I only loaded 55 grain Sierras at starting loads too. Gave the rifle to my youngest son.....his choice of all I had at Christmas time when I gave my boys an "extra" surprise.....I think it's trouble-free nature had something to do with his choice.

I'm wondering if it might be your brass, your choice of powder/primers, or a hot load it didn't like.

I know the Mini spits cases enthusiastically, but could thowing them to the next county be a symptom of too hot that could also cause feed problems? Just a thought.
 
Hi GWS,

Just now saw your comment:"I know the Mini spits cases enthusiastically, but could throwing them to the next county be a symptom of too hot that could also cause feed problems? Just a thought. "

Lets see if I can clarify, minus my "next county" humor. I estimate that the mini-14's I have had experience with would chuck cases about 12 to fifteen feet perpendicular to the fire angle with a few going slightly more forward or slightly back. I would compare that to my most recent experience with a Ruger 556 AR and S&W M&P 15 Sport, both of which would leave a neet pile of cases about six feet out and three feet back of the fire position.

To make such a comparison, there is a missing factoid. I tend to check out 223/5.56 using a diagnostic load that was developed some time ago for the M-16. I have found it to be equally useful for semi-auto as well. That is what I meant when I said I was sure the ammo was not the problem.

(for 55 gr V-Max seated to channelure, 25.3 gr IMR 4895, CCI #41 primer, all charges hand weighed to +/- tenth grain, and case type not critical since powder/bullet/primer combo is under SAAMI 223 pressure spec.)
 
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