upper receiver action block: I need to take some pics of what one of these looks like, and how to use it.
live bullet stuck in cz 52: This is an interesting problem indeed. I'll have to make up an inert round and try to see how this could happen.
7.62x45mm pictures: I should take some pics of 7.62x45mm next to 7.62x39mm.
romanian side folder: I need to do a writeup on the Romanian steel side folding stocks.
remove upper from lower of ar15: I should take some pics of this. Just push the pins out.
ak rear tang install: I need to take pictures of this the next time I do it.
Brief Answers
do dremel bits work in a rotozip?: Yep. Not all attachments work, but the bits themselves do.
what size primers for 270 caliber bullet: Completely depends on the brass. In the case of 6.8SPC, there are both small and large rifle primers available. However, other than 6.8SPC, most applications for .270 caliber bullets use large rifle primers.
ar15 single shot upper: Other than things like the Bohica Arms single-shot upper, AR's are usually rendered single shot by the use of single-shot lowers. These lowers typically have no magazine well. DPMS is known to make one. Other than the lack of magazine-related parts (i.e. release button), single-shot lowers accept all standard AR-15 parts.
how to install permanent flash hiders on barrel: ATF usually recommends blind pinning, silver soldering, or both.
removing bolt carrier ak-47 century: How to remove the bolt carrier varies slightly with different countries. In the vast majority of cases, you simply hold the rifle by the rear buttstock and use your right thumb to press in on the exposed part of the recoil spring (which is a nub sticking straight out the back of the bolt carrier). If you're dealing with a Yugoslavian AK, there's also a push pin located right underneath the rear of the dust cover, on the rifle itself. Press that button, and then the recoil spring is released. Once the recoil spring is pushed back, use your left hand to lift the dust cover off of the rifle from the rear. Once the dust cover has been removed, push the recoil spring forward until it's free from the rear trunion. Lift it up a bit so that it clears the rear trunion, then lift it out of the way. You can now pull back on the bolt carrier until it slides back all the way, and you can lift it out of the rifle.
ak operating rod: The AK-47 does not have an operating rod. It has a gas piston, but no operating rod. SKSes, on the other hand, do have operating rods.
922r what is trigger housing ak: The AK-47 does not have a trigger housing. It has a trigger guard, which is a angled piece of sheet metal which keeps the trigger from being pressed accidentally. However, the trigger and the rest of the fire control group are inside of the receiver.
keltec su-16 conversion kits to fully automatic: Besides the obvious fact that this is very illegal, has anyone thought about what happens when you heat up a mostly-plastic gun with sustained full-auto fire? Even if this were legal, I wouldn't want to mess with it.
ar 15 buffer spring too long?: There are two commonly encountered lengths of buffer spring on the AR-15: rifle length (used with A2 stocks, Magpul PRSes, etc) and carbine length (used on collapsible stocks).
saiga rifles are not imported anymore in the us: As of when I checked on June 7th, it'd been around 8 months since the last shipment of Saigas had been sent to the US. Any guess as to why, would be speculation. But it is definitely driving the price of Saiga rifles way up from where they were.
ak 47 helical magazine: I am unaware of any helical magazines ever having been produced for the AK-47. There are, however, several Russian-made submachine guns which use helical magazines. [[http://world.guns.ru/][World.guns.ru] is the best site for researching these.
installing a scope on a romanian par 1: Any standard AK scope will mount onto the side rail. SVD scopes, however, will not.
shorten the a2 stock: To get just a little shorter, you might want to look at a Vietnam-issue A1 stock. But if you want it a lot shorter, look for what's called an "entry stock".
ar-15 buttstock too short: If you're dealing with an A2 stock, you might want to look at a Magpul PRS stock, or consider getting a recoil pad to replace the rear plate of the buttstock.