Gunsmithing Reducing bolt lift/cocking on R700?
- Thread starter wes1
- Start date
Firing pin spring, though you may have light primer strikes. Also polishing the cocking ramp helps
1. Do not touch the spring. That is the worst thing you can do.
A little background:
It helps to have this in mind as it'll help point you into the direction you need to go.
You have a coil spring. Off the top of my head I don't know the rate, but it matters little. You look at basically two things; The amount of preload the spring has while assembled, but in the "uncocked" position. Next, look at the cocked position. How far is this? Its easily measured. Drop the bolt, pull the trigger. Now measure from the shroud to the cocking piece button in the center of the shroud. Now, cock the gun and measure again.
Its somewhere south of a quarter inch. Now, think about that. If you are only compressing the spring somewhere around .250" then its not like that spring goes from nothing to absurd. They just don't work that way. Even when preloaded.
I write all this for you to absorb so that you get a better comprehension of what is going on and what itsn't.
Here's where you start looking.
First, pull stuff apart and look down the hole of the bolt body. M700's are soldered in three pieces. Head, body, handle. It's not uncommon at all for the bore that the fire control rides in to be contaminated with residual solder/flux. That has to be cleaned out first. Easy way is to buy a reamer. Just a simple $15.00 chucking reamer will do. What size? Well, the threads for the shroud are 1/2-13. Tap drill size for that is between 27/64 and 7/16 depending on the thread engagement percentage your after. I would personally opt for the 7/16 as it ensures you scrub the crap out of the hole.
So, that's the first part. What you did here is ensure you have zero resistance while cocking the spring, as well as, ensuring it has zero interference when driving home to hit the primer.
Next:
Now, take a marker or some layout die and stain the cocking ramp on the bolt body in the back. Assemble and run the bolt a few times. Is the smear even or is it on one edge? Either inboard or outboard? If its even, your solid. If it's bias to one side, you have work to do. It's more or less kinda, sorta like setting up ring/pinion gears on a car's differential. You need lots of contact without binding. That spreads the load out. Kinda like a broad shoe sliding on ice vs golf shoes. -I guess.
Altering this may or may not be in your wheel house. It's something I take for granted as I have a lot of dedicated tools. Lapping is one way, but if you do this, you MUST polish it again afterward. Surface finish matters here and shiny slick is what your after.
Believe it or not, these two surfaces are bearings. Plain bearings to be technical. Only problem is they are not receiving any hydraulically delivered lubrication like the crankshaft of your engine is. The principle is the same however. Having them polished goes a long way to reducing friction.
Next:
Bolt shroud to bolt body fit. If its crunchy, the threads need to be chased. It should be nice and fluid. Don't overly concern yourself with the thread fit. Its important, but not a deal breaker. You can lap here too, but be darn careful. Very easy to get them stuck. I generally just chase the threads with a roll tap. -One that does not really remove material. It's a "pusher" that forms the thread rather than cutting. Since the thread is already there, I just want to burnish the finish a bit.
Last:
Look at your cocking ramp again, but here pay attention to where it ends and transitions to the very back of the bolt. Notice the detent feature next to it? This is important. It prevents the shroud from rotating and dropping the striker assembly home accidently while the bolt is out of battery. Occassionally, Remington cuts this detent a touch deep and it becomes very noticable when rolling into battery. You'll feel as though the thing is climbing a mountain. All you have to do is knock down the peak between the detent and the start of the ramp a little. You do need to pay attention here. Small moves make big changes. Take it down too far and the gun will still work, however it won't take much to roll that shroud and drop the assembly into the "fired" position.
Why this is a big deal: People have literally been killed by this. Not at the range, but places like Africa. Its one reason why guides and PH's make an effort to steer away from using actions like the M700 when pursing dangerous game. Your ultra high dollar, "custom space modulator rifle" just became a very expensive canoe paddle the moment this happens. The likelyhood of you fixing it on the fly under the stress of a charging Cape Buffalo or pissed off kitty cat is about like being struck by lightening as your being eaten by a shark while winning the lottery.
In reality you just paid north of $50k to be a critters punching bag or scratching post.
These four basic things are what makes the rifle smooth or crunchy when throttling the bolt.
Hope this helps.
not to derail the thread, but after a answer like that from LRI there should not really be anymore replies.
if a 700 is not a primary choice for DG in africa etc, what action would you steer toward.
might have a safari in a few years if i can get my shit together (wife, kids, etc)
if a 700 is not a primary choice for DG in africa etc, what action would you steer toward.
might have a safari in a few years if i can get my shit together (wife, kids, etc)
Not to state the obvious here, but do you have an upgraded bolt handle/knob? Longer lever and all...
It all depends. If your going after plains game or just want to blast baboons (personal favorite) then bring whatever. Its the stuff that'll make you a snack or a smashed asshole that you have to be more careful with.
Double rifles and control round feed bolt guns are the go to solution for Africa when pursuing dangerous game. Just listen to the folks who do those trips routinely. They are still breathing because they listened to someone much smarter than me.
We pay more for custom receivers with the expectation that we are buying more for our money.
This is a Remington and there is nothing wrong with that. Its no different than buying a cast iron 5.3L truck block for a drag motor or buying the aftermarket block at 10+ times the price.
Making it all work is a function of experience and letting it guide the effort to enjoy the desired outcome.
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