M305a vs M1a comparison

KotKotofeich

KotKotofeich

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I picked up a m305a recently, was able to find one without a MIM bolt but I think the receiver is cast... Were there any made with a forged receiver?

I compared it with an AR Sales m14 I have and some things stood out. Some made sense and some I have no explanation for.

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Yes, that bayo lug is ridiculous...

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The receivers are identical for all intents and purposes, so if the receiver gives out it can be replaced with a quality one, no problem there... But what is the hole on the receiver where the barrel is threaded in? Is the barrel pinned on these? Do other m14s have the same?

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I haven't been able to find boltface pictures for these before so you might find this interesting too. The bolt is clearly machined specifically for 7.62x39, not converted from 308 as I thought might be possible... but it still has the hole for the ejector drilled. Is there a reason? Is that hole important for machining out other bolt features. Note the cutout for the special ejector on the left side of the bolt face.

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There's a pinned hole on the underside of the bolts but they are in different locations. My m14 uses a H&R Gi bolt if that's important... Also the orange on the m305a bolt is not rust, just the way my camera interpreted glare...

And some other feature comparison if you are interested:

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The custom ejector for 7.62x39

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Another view of the special ejector.

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Welded in catch for the AK mag. Easy to see how the magwell can be removed and put in a GI wooden stock if needed.

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Trigger group differences. Catch for the AK mag and the extended latch.

Have not shot the rifle yet. It passed the tilt test everywhere except the piston... which turned out to be filthy. Also some rust on the gas plug - suspect previous owner/s ran corrosive through it. The piston passed the tilt test after thorough cleaning but with air audibly sucked in/expelled from the gas block... Is this ok?
 
Cool comparison , I have a Norinco m305 and a Springfield Armory M1A Standard.
Have never shot the Norinco , it has a MIM bolt , bought the SA M1A to replace the 305.
I should take a look myself and see what differences I can find. So far in comparing them they seem very similar mechanically just that the Springfield has an obviously higher level of quality and fit & finish.
 
The screw in the receiver / barrel is done on pretty much every norc I've ever seen but never on GI or US made receivers. I guess norc didnt have complete faith in their product and felt it necessary to add it....still doesnt help with their indexing issues lol
 
I have had nothing but trouble from my 305. It was made in 09, and I’ve put about 250 rounds through it since Sept. At first it wouldn’t accept any mags no matter what brand except for the factory 5 rounder it came with. Ended up having to file out the mag well quite abit to make other mags fit. Even after this, there are still jams and swear words are said when it does this. Now, last two times I took it out, it will not eject the spent shell or cycle the action. On top of that, I can not manually eject the shell. The bolt gets seemingly jammed closed and takes a small screw driver to pry it open to eject the spent round. I have no idea what’s wrong with it. Have any of you experienced this? I was firing Austrian surplus ammo and never had a problem with it before. This will sound stupid but it seems like the round expands in the chamber after being fired resulting in it needing to be pried out.

I bought a loaded Springfield M1A in the summer. Im new to the hobby but I love this rifle. It just seems “right”. Never jams, has a much smoother trigger and shoots like a laser with commercial ammo. If I had to depend on a rifle where more than 8 rounds is needed (M1) I would choose it every time. IMO the fit and finish of a Springfield isn’t comparable. If I had to compare it, it would be the difference between a 1963 Reissued custom shop Fender Stratocaster electric guitar and a cheap no name Chinese replica of a Strat. They both serve a purpose but are no where close in quality. You get what you pay for. I got the 305 to plink with as a truck gun. Hopefully I can get it figured out where it can at least be that.
 
is the gas port open/ closed ?

have you been using corosive ammo or steel cased ammo ?

have you done tilt test?

rubbing on the stock is enough to slow down the op rod so it will not eject brass
 
Gas port is closed. Non corrosive ammo and cleaned after every use.
Excuse my newbness but what is a tilt test?
I also recently changed it over to a Boyd’s wood stock..and it seemed fine until this issue recently popped up.
 
My inexperience is showing..I was thinking of the lug on the front of the cylinder. It is tightened. Everything seems as it should. I’ll take some pictures maybe to better describe what’s happening.
 
The tilt test is when you remove the operating spring so that it no longer drives the bolt forward, and see if the bolt and op rod move freely without dragging or catching anywhere. Ideally, gravity alone should be enough to pull the op rod and bolt forward into lock. If it doesn't, try to figure out what is dragging. As mentioned above, the charging handle / op rod can drag on the stock and create resistance. Some times you need to remove some wood from inside the stock.
 
I have no experience with the 7.62x39 version, but as to your more general questions:

- The Barrel set screw is also on all the 7.62x51 Norcs. It's a bit of a belt-and-suspenders thing that really only becomes an issue if you need to re-index or if you replace the barrel, but it's usually pretty easy to remove.

- If the piston is audibly sucking air and moving slowly enough that it lags behind the rest of the bits during tilt tests that's just a sign you've got a decently-fitting piston/cylinder combo.
 
Thanks! I just never noticed that sucking sound before with a supposedly better fit/finish rifle...

Anyone know why the holes in the bottom of the bolt are in different locations? Or what purpose the hole for the ejector has besides holding the ejector? i.e. could it have been skipped for x39 bolt or is it still there to help machine something else?
 
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