Just found this thread again. To the OP: Now you know why I typically drop in GI hammer and trigger when asked to upgrade people's 305's for them. I'm betting your safety proved to be OK also.
Ususally the 305's will shoot too high and require a taller front sight. This is especially true of the 18.5" and 16" barrelled norincos.
If the gun is shooting too low, you don't "need" a new set of sights, you need to lern how to adjust your rear sight aperture height at the "1" setting to shoot to POA. Lots of youtube videos on how to do this. On most guns it's between 2 and 12 clicks up from the bottom-most setting.
That said, GI sights are tighter, crisper, and more reliable. A M14 or M1 rear sight (USGI) is a solid upgrade if you plan to shoot with irons. If you just use a scope, it's a waste of money to upgrade.
Honestly, when I used to go help at the various M14 clinics, I would bring a bag of GI hammers and triggers to sell to people at my cost (I don't have extras to sell any more, but several vendors in Canada do). It's amazing how many Norinco guns had hammer follow and sear engagement issues that were completely fixed with a simple parts swap.
Primary things I'd advise people to do, in no particular order:
1) hammer/trigger replacement
2) re-index barrel, don't use the flat on whatever FS you are using to hold your parallel. The Chinese cast FS's are usually not square, but you want your sights to move in the same plane as the rear sight when adjusting windage. It's more important that the top dovetail on the FS is parallel to the rear sight ledge than for the barrel to appear straight to the eye.
3) Tighten op rod guide. I prefer knurling.
4) install a decent after-market round profile (or fluted) op rod connector (i.e. an op rod spring guide)
5) install a GI connector lock pin after machining it to fit. I used to make them on the lathe for people, not a difficult job. The Norinco pins are a few thou smaller in diameter than GI pins. the popsicle mod is for people who don't have the right machine tools available to them and is an inferior method, more prone to failure.
6) Check bolt lug contact with Prussian blue, lap until both lugs make at least 30% contact on the left lug, or 70%+ contact if you also plan to use a match barrel and do some NM mods.
7) peening gas cylinder and FS splines.
8) shimming gas systems. Barney used to bring punches to make cheap shims, in my case, I had bought a large volume from Brownells. Whatever works, they are just spacers. Most people don't need a unitized gas system. I would always tell ppl not to expend any money or effort on unitizing unless you were doing a full NM spec bedding job. One won't improve anything without the other in my experience. - IMPORTANT! - use a feeler gauge (like a #48, .076" drill bit or drill rod) through the port in the bottom of the gas cylinder to ensure the barrel gas port is centered in the opening for the gas cylinder after install. If not, add or subtract shims until the cylinder lock indexes and the holes are aligned.
9) Put USGI internals in your Norinco bolt. Almost as important as using GI hammers and triggers. Moreso if you plan to use a scope mount like a Sadlak, ARMS, SEI or Brookfield. The norinco bolt springs are garbage, and too long. The ejector bevels are all wrong and will cause stovepipes against a scope mount.
10) If you have a black plastic chinese stock, you need to remove and set back the ferrule. These stocks are ALL molded too long (or at least I've never worked on one that was not too long) and put forward pressure on the gas system & ferule. This is a recipe for vertical stringing. They aren't a bad stock once you set back the ferule and bed it, they are at least the equal of the current SAI crappy plastic M1A stocks once fixed. I never see this referred to on the forums, but it's a real issue.
11) remove that stupid set screw in the receiver ring and either throw it as far as you can.... or shorten it and re-install it so it plugs the hole but doesn't contact barrel threads.
12) Take apart the gas spindle assembly, clean out the blasting media and other junk, then re-assemble. I've never seen one that did not need serious cleaning out of the box.
13) I like USGI recoil springs. I don't like chinese, wolf or brownells springs. I hate + springs, which most Chinese, wolf or brownells springs are - unless you only shoot 168gn loads, they cause short-stroking with normal ball ammo in the 150gn range.
14) If you own one of these rifles, I consider it essential to own castle nut pliers and tools for cleaning the interior of the gas piston and gas plug.
15) Chinese receivers have a different rear right receiver profile than US commercial or USGI stocks. An M305 receiver is NOT a drop-in to a USGI stock. You either have to mill the receiver or inlet the stock to get the proper receiver seat in a USA-made stock. They will fit without modification and will lock up, but they won't shoot optimally unless you fix the geometry on either the stock or the receiver. Builders like Vulcan or M14Medic know this and offer receiver milling as an option. It's cheaper to mod the stock, but receiver milling is more elegant.
16) Don't over-tighten a FS castle nut. The nut is not meant to hold the FS tight on the barrel, it's to prevent the FS from shooting off the front. Spline fit is what keeps a FS from moving around, the nut is just a shoulder to prevent the FS from moving forward. Tighten the castle nut by hand until it's snug, then back it up to the first place the set screw will enter a castellation. Do NOT crank the castle nut tight with pliers until the set screw will just engage a castellation. You will risk warping the flash suppressor, and this is the reason why brownells now sells a FS alignment gauge. Warped flash suppressors that were over-torqued. If the splines are fitted correctly and the castle nut is hand-tight, that's all you need for accurate shooting.
Those are the big things off the top of my head
Cheers.
