Pre 72 was the old designs, 721, 722, 725 and for lack of a better term were strong but not attractive so to speak.
The 700 was the classy looking models and I have one with a 4 digit serial number that I don't think has seen two boxes of ammo.
The 700 was made in a short action and a long action for many calibers. Then there was a 78 which was a Plain Jane without checkered stocks, high polish finish etc. I have at least one and maybe two of them.
The trigger problems were basically because the safety was not so SAFE and you could flip off safety and it fire because it was not adjusted properly. Some folks tried to adjust them to be on the light side and that made things worse yet.
While I have never had a problem I never carry a 700 with a round in the chamber. That being said the M24, M40, M40A1 Sniper Rifles were all based on 700 actions. The M24 was originally built on a long action in 7.62 with the idea of converting them to a belted magnum at a later date. At this time they are being retrofitted for 338 Lapua Magnum caliber in order to increase hit probably out to 1500 meters.
The guy that got the M24 rolling was Herb Wreden on the right in the above picture. I am in the middle and person on the left worked in SAAMI Program at Picatinny Arsenal with Herb. I stopped in Pennsylania to see Herb in 2010 and visited with him a couple days. He died in I think it was 2012 and I went to Pennsylvania for his funeral and myself and the third person in pic were asked to be pallbearers for our friend. I had known both the others since 1978 when I went to the US Army Small Cal Lab at Picatinny Arsenal.
There are some problems you need to be aware of. One is the threads in the actions are not lathe cut and are cut with a tap which most of the time means the threads are not at right angles to the bore line and this is evident in off center striker indents on the primer. Thinking back I have only seen maybe five 700s with a dead center striker indent.
Manson Precision Reamers in the states sells a kit for squaring the action threads in Remington actions and I have seen one demonstrated and it actually causes the striker indent to become more centered on the primer.
Per study conducted at Frankford Arsenal Ammunition Plant if the states offset indents exceeded .020" gets you into the misfire category. The industry recommendation is to not have indents for than half the diameter of the striker tip which are generally .060" range. Thus you can expect to see indents of .030" offset.
I have seen (and have had) several 700s and 40X rifles with crooked bores internally. The outside of the barrel is straight the inside is crooked. A 40X is a short action and identical to a 700 except they are selected for straightness and some actions are banana shaped and the bottoms of the actions are ground in the custom shop. So 40X action may have magazines, some are solid bottom single shot. Some 40X actions have a clip slot cut in receiver for stripper clip reloads for rapid fire. They are called 40XC for Course rifle as highpower competition in the states calls for strings of rapid fire where you load five, shoot five, reload five and shoot 5 in 60 seconds at 200 yards from sitting position and 70 seconds at 300 yards from prone position.
Should you have a extractor failure in the field it is a real bugger to get extractor replaced as they are a ring affair and secured by a rivet on the bottom of the bolt.
Up until 1979 time frame the bolt handles were silver soldered on the bolt body and a number came off thus they started to be laser welded.
During Sandbox 1 I was advised snipers were issued spare bolts to carry as the dust storms there will cause all kinds of havoc.
The 700s came with wood stocks and both ADL and BDL ADL does not have floorplate for unloading the rifles and BDL does. The 40X was also made in 22 long rifle match rifles and I have one of those as well.
A few years ago the original triggers (known as Walker Triggers) were changed due to law suits. The Walker triggers have a grooved front surface and are black in color and properly adjusted will last many years. The new ones are not grooved and are gray. I have not had a new one but I was told they have a short life and break and most everyone buys another trigger if they are going to use it for high volume firing/competition.
Thus I am keeping my older 700s, 78, 40Xs as I know how to keep them going.
Of yes almost forgot when the M24s were first fielded they had 5R barrels on them and last Herb and I heard they were still holding up past 15,000+ rounds at Army Sniper School at Ft. Benning.
The TOP (Test Operation Procedure) for sniper rifles is 10,000 rounds fired one shot per minute for 25 rounds and quickly cleaned and another 25 rounds. Barrel was allowed to be changed after 6000 rounds but original barrel was still shooting acceptance dispersion at 10,000 rounds per Herb who traveled to Remington to monitor the testing.
The best rebuilds I am aware of (commercially) were done by Iron Brigade Armory in North Carolina but they went out of business in the last five years. Their rifles were superb.