Discussion Forums

Forum Index > Rifles general discussion > Actions

Actions

22 Jun 2011
@ 04:18 pm (GMT)

Murray McGehan

Nathan, Just wondering if you can answer a question for me.
Having spoken to many Gunsmiths over the years regarding building up and accurising rifles. Nearly always the gunsmiths prefer the Model 700 over the model 70 or the Browning A bolt. I know there are a lot of after market parts available for the 700 but I get the feeling after being told by a well known gunsmith "believe me, you don't want to go down that road" that there is more to it than that.
Are the m70 and A bolt actions that inferior to the model 700?

Replies

23 Jun 2011
@ 10:28 am (GMT)

Quote this

Nathan Foster

Re: Actions

Hi Murray, yes, you are reading that right. However for the smith, its more a case of "I don't want to go down that road".

The M700 is the easiest action for smiths to work with, both for machining and bedding. By easy, I don't mean this as a reflection of time factors or the skill levels of the smith, however skill levels are relative if the shop is employing apprentices. By easy, I mean that the receiver threads are usually cut in such a way that the factory barrels can be removed without the threads galling, litterally ripping and shearing as the parts are undone. The round action is ideal for blue blue printing. The same goes for bedding, the action centers easily and throughout all of this work, the smith can expect the desirable result of good accuracy.

As you have pointed out, after market parts are an important factor. If the smith has apprentices and should the apprentice break something on the M700, such as bumping the new, brittle, X-Pro trigger, an after market trigger can be sourced easily. Its not something people want to talk about but the truth is, humans make mistakes. Making a mistake doesn't have to be the end of the world if parts are available.

The M700 has one weakness, the lack of a good extractor. I have seen three extractor failures this year. The Sako style extractor is the fix, it costs the same to fit an extractor, as it does to flute a barrel. When I think about it now, it is perhaps something that should be put ahead of fluting on custom build priority lists.

One consideration, is that often, the M700 actions are quite close to being as true (as mass produced) and concentric as one could expect from blue printing. The locking lugs are often the same, requiring little to no work.

I do have to admit, Remington have good and bad years. This year is a bad year, I have seen some very poor machining from remington. A general lack of quality control and a lack of work place pride. This does not detract from the action as being an ideal basis for custom work but for factory rifle users, its a punt. Its something people have to weigh up for them selves. If the shooter gets a lemon, he still has the ideal custom action. However, some people don't see it this way, they have just spent their last dollar on a new rifle and can't afford to go straight into a custom build.

The A-Bolt is more difficult to work on. It adds a huge amount of stress to the smith and some smiths will literally lose sleep over these jobs which is just not on in my opinion. During the barrel removal operation, its not uncommon for the threads to gall. The trigger is made of gold painted plastic with a grub screw attached to it as a sear. The housing is made of die cast zinc metal (shit metal is the tech term). If gthe trigger is too heavy and creepy and the smith attempts to drive the pins from the housing, there is a risk that the unit will shatter. If the housing shatters, it can be a mission finding replacement parts outside of the U.S. The bedding platform of the A-Bolt is quite poor and somewhat difficult to work with. The mag box on some of the long action models is only 86mm which is very limiting for magnum shooters with cartridges having COAL's of 90-92mm. The 60 degree bolt lift is not an advantage, I have a feeling that its just the way the design turned out and so, it is pushed as a special feature. I remember having to mallet the bolt open on an A-bolt several years ago, the chamber was cut with a re-sharpened reamer, the throat was so short that factory ammo would engage in the lands, pressures through the roof. Good camming power is far more important than a short bolt lift.

The M70 actions are often slightly out of true but can be jigged and trued. For the smith, this can be a little tough on the nerves if he is worried about the stability of his jig, avoiding chatter, that sort of thing. Once the M70 is trued, its pretty much good to go. The bedding at the tang is a little more fiddly than the M700. The old M70 trigger was a good unit, I have not studied the new unit. The internal mag box length is around 90-92mm for the M70, good for the .300 Win Mag and 2.5" magnums, a bit short for STW length magnums. The major design weakness of the M70 is the two piece floor ware. The middle screw effects accuracy, sometimes dramatically. This adds another unnecessary variable. I wonder if the new M70 has a one piece floor plate? The middle screw can be set to moderate torque with a floating pillar, this is probably the best fix. I have seen quite a few M70's shoot very well after being tricked up. I wouldn't call it a poor design, it has its quirks, found in both the push feed and control feed models.

The Sako AV and Finnbear can be put in the above category. These give best results after blue printing. The Howa actions are the same. The new Sako 85 is a very poor design. There are guys all over the world having troubles with the new bedding plate.

Simplicity really is a key factor for success. I also believe that work place moral is important. Imagine being tuck on a production line all day. I spent two years in a factory on a production line, many people reading will have done or be doing the same. Its not easy maintaining an optimum level of concentration and attention to detail, especially if the work place culture is toxic.

The T3 is a simple design. I get frustrated with the T3 because I sometimes find it problematic to bed. I worry that it is so simplistic as to have neglected fundamental principals in design. That said, it has some desirable features which cannot be overlooked. So again, it is at times more of a case of "I don't want to go there", even though I am suggesting to the client that "he doesn't want to go there" regarding a custom build- unless its for a magnum and we run into definite limitations such as magazine length. As I type this, I have a semi custom custom T3 sitting on my bench. The last one I tricked up a few weeks ago (factory) simply wouldn't put a shot wrong, the worst group was something like .78".

When guys ask me about action designs, I have my favorites like the M700 and those that I feel are very frustrating to work with, creating a great deal of stress and then there are actions that just won't suit the custom build. That said, I don't think its fair of me to then presume that a company has come up with a particular design based on for example, cost cutting, ignorance or at the other extreme, intellectual snobbery. I have inklings, ideas and opinions but no facts to support my opinions regarding the actual design premises of our current rifles. I am very annoyed with the current Sako design but I cannot state whether the design was a deliberate cost cutting excersize or what it was. Perhaps it was a genuine attempt at optimum simplicity for accuracy.