M305S fails to feed first round.

Silverado

Silverado

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The one I was shooting today is a bone-stock Norc shorty. I have 2 Norc mags, and 5 CMI mags, and was shooting Norc copper-washed ammo.

This gun absolutely will not feed the first round out of the magazine. That round gets caught part way into the chamber, basically with the bullet on the feed ramp. It will chamber and fire if I push on the op rod handle when it gets stuck.

The gun then runs fine through all 5 rounds in the mag, and has never failed to fire, extract or eject.

Help?
 
Is the mag catch pin busted?
Does oprod pass tilt test?
Does it have a scope mount and if so is side bolt too long and catching left bolt lug?
Is stripper clip guide pin protruding into receiver?
Is she well greased?
Is oprod "arm" at the front where it ends at the stock, rubbing? (common in chinese wood stocks)

These are things I'd check anyways.
 
Confirm you're pulling the charging handle all the way to the rear and letting it fly, rather than easing it forward?
 
45ACPKING said:
Is the mag catch pin busted? Nope.
Does oprod pass tilt test? (Furiously searches for this test LOL... I'll check.)
Does it have a scope mount and if so is side bolt too long and catching left bolt lug? No scope mount. Horrible Chinese irons only.
Is stripper clip guide pin protruding into receiver? Nope
Is she well greased? Very greasy!
Is oprod "arm" at the front where it ends at the stock, rubbing? (common in chinese wood stocks) Not that I can tell? It's a plastic stock if that matters.

These are things I'd check anyways.
Click to expand...

Thanks!
 
Tilt test: Fail.

Is the concave portion of the op rod supposed to actually ride along the underside of the barrel where the chamber is? Mine does, quite agressively. This occurs at a point in the action's travel where the op rod handle is in line with the front of the rear sight, basically the last inch of action travel.
 
The oprod "saddle" should not rub on underside of barrel.
This might be a different issue though and could cause it to fail to load a second round, but...
If yer rackin her hard on the first round , and it's failing to chamber, the saddle has long cleared the barrel.... But then again....

So first, ensure barrel index is not way off. Then ensure oprod guide (attached to barrel and supports oprod tube) is in alignment with gas system. If she still fails tilt test after the above , and still drags the saddle under barrel, this can be remedied with lapping compound applied between saddle and barrel until binding is gone. Or, try an oprod from a different rifle and see if the problem persists.
 
Silverado is this happening with every magazine? Will it chamber properly with only 4 rounds in the offending mag/mags?

If the magazines are the newer import black ones as opposed to the older greenish parkerized, they may need alot of massaging to bring into shape with proper functioning mags.



These newer mags are riveted, not just the follower extended, and were causing excessive round entrapment inside the mag because the rivets were placed too high, and the 5th round has to be forced in. They should almost allow a 6th round for perfect functioning with 5 in my mind.
If you have this coupled with the op rod dragging hard on barrel, I can see your problem. Thomas has covered all the rifle mechanicals to check and tweek, I'm just curious on the magazine generation if its a new shorty.

On a side note, I had a P-H 1200c in .308 that would not feed the first round into the chamber from one mag. It was exactly like the others except for the last round was tight going in. Omit the last round on this mag and it functioned flawlessly like the other two with a full ammo load out, so magazines are the most important part of any action types reliable feeding.
 
It happens with all mags. The 2 Norc mags I have are grey, and are blocked internally with welded floor plates. The 5 USGI Checkmate mags are revited, and they are a little tight on the 5th round. They're grey too.
 
Silverado said:
Tilt test: Fail.

Is the concave portion of the op rod supposed to actually ride along the underside of the barrel where the chamber is? Mine does, quite agressively. This occurs at a point in the action's travel where the op rod handle is in line with the front of the rear sight, basically the last inch of action travel.
Click to expand...

Please note: this was the situation and solution for me only and may not be yours.

I had the EXACT same issue: would 'hang up' on top round and the 'tilt test' was always poor.

Situation: the top round puts the most, what I will call, 'angled' stress on the bolt and op rod due to heavy spring pressure in the magazine. When my 'tilt test' was bad/failed then this issue was sure to occur.

Problem: the op rod guide pin that aligns and hold in place the op rod guide (see exploded diagram) was broken in the middle allowing the op rod guide to move under heavy pressure, but not when I tried to move it myself.

Solution: I got a punch, a cheap Princess Auto pin and replaced it. It was a pure b!tch to remove because the two halves impacted on each other, but it completely solved the issue. I was also able to drill it slightly larger, put in a larger pin, and thus correct an alignment issue too.

The way I found out was to dissassemble it from the stock, got someone to hold on to it hard, and tried loading a snap cap (NOT live ammo) into it. I could then see the pressure move the op rod guide, op rod and such.

Good Luck.
 
Aniest said:
Please note: this was the situation and solution for me only and may not be yours.

I had the EXACT same issue: would 'hang up' on top round and the 'tilt test' was always poor.

Situation: the top round puts the most, what I will call, 'angled' stress on the bolt and op rod due to heavy spring pressure in the magazine. When my 'tilt test' was bad/failed then this issue was sure to occur.

Problem: the op rod guide pin that aligns and hold in place the op rod guide (see exploded diagram) was broken in the middle allowing the op rod guide to move under heavy pressure, but not when I tried to move it myself.

Solution: I got a punch, a cheap Princess Auto pin and replaced it. It was a pure b!tch to remove because the two halves impacted on each other, but it completely solved the issue. I was also able to drill it slightly larger, put in a larger pin, and thus correct an alignment issue too.

The way I found out was to dissassemble it from the stock, got someone to hold on to it hard, and tried loading a snap cap (NOT live ammo) into it. I could then see the pressure move the op rod guide, op rod and such.

Good Luck.
Click to expand...

Now here's something that I would never have considered.

This is why if you can't get it figured out on the Main Battle rifle forum, you may need a gunsmith.

Great post Aniest and something for everyone to remember for future binding issues.
 
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RememberTheSomme said:
Now here's something that I would never have considered.

This is why if you can't get it figured out on the Main Battle rifle forum, you may need a gunsmith.

Great post Ardent and something for everyone to remember for future binding issues.
Click to expand...

That's not ardent man!
He would have said that rifle is going to kaboom in your face and he has a 305 in pieces on his workbench to prove it! :p
 
I had a look at this just now... that pin isn't broken, but the op rod guide is very loose; I can move it about 1/8" back and forth around the axis of the barrel.

I think this gun is heading off to someone qualified for tuning/fixing/upgrading. I would rather have fun at the range than mess with this, lacking parts and tools. Can't make a Hungry clinic this year either.

I have another 2007 Norc that I bought from another CGN which has some upgraded parts, and doesn't have any issues (other than a worn rear sight cover.)

The problem gun is a 2012 shorty that I bought new over the winter.
 
That's not a lot of movement on the op rod guide. I have one rifle that moves that much and it runs perfectly.

If you want to fix it, it's not hard at all. Drive the old roll pin out and slide the op rod guide forward. Use a center punch to raise dimples on the barrel where the op rod guide sits. Hungry recommends two or three dimples at each "hour" position around the collar.

Tap the op rod guide back onto the collar, lining it up with the notch in the barrel and the gas cylinder. Re-intstall the roll pin. IIRC, it's 1/8 x 3/4". Easy peasy. It will probably take you half an hour the first time, after that it's a 10 minute job on the next rifle.
 
Silverado said:
I had a look at this just now... that pin isn't broken, but the op rod guide is very loose; I can move it about 1/8" back and forth around the axis of the barrel.

I think this gun is heading off to someone qualified for tuning/fixing/upgrading. I would rather have fun at the range than mess with this, lacking parts and tools. Can't make a Hungry clinic this year either.

I have another 2007 Norc that I bought from another CGN which has some upgraded parts, and doesn't have any issues (other than a worn rear sight cover.)

The problem gun is a 2012 shorty that I bought new over the winter.
Click to expand...

Funny, there are some Fort MakeMoney M14 graduates of my clinic nearby.... see if one of them can sort out this op rod guide pin problem... It's really an easy fix. :D You should not have to seek the assistance of a gunsmith for this one. You see, this is one of the op rod fixes we do early in my M14 clinic with you m14 lovers. :)

Cheers,
Barney
 
I'm actually not sure it's the guide pin that's the problem. The op rod saddle rides the underside of the barrel pretty hard. Overall, there is a lot of gritty feel in that last inch of action travel at the rear...
 
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