I recently "upgraded" my Rem 700 bolt to a heavy firing pin spring. After several cycles of cocking, opening of the bolt became very difficult. Finally it wouldn't move and I had to use a soft hammer to get the bolt to cycle open. I finally figured out that the surface of the bolt that the cocking lever (that silver thing in the bolt shroud) rides on was heavily galled and this was preventing the bolt from getting the firing pin to go into the cocked position. I was able to smooth it down and then oiled it, and I put in the original spring and it seems ok. Needless to say, I don't ever want this to happen again. Is anyone familiar with resurfacing/contouring the bolt surface that the cocking mechanism rides on? Any advice on how to increase the ease or smoothness of cycling/cocking the bolt? Thanks.
Gunsmithing bolt firing pin cocking tuning?
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Re: bolt firing pin cocking tuning?
The correct term for the part you reference is the cocking piece. The angled face of this rides on the corresponding surface on the bolt body. These two surfaces can be polished with rouge to mirror bright and will smooth up the action as long as you don't alter the surface angle. I generally use a very light smear of grease on this surface. What bothers me is that replacing the spring should not in and of itself cause the problem unless the spring is over sized. Did you check the spring against the original. It will probably be longer due to the set in the original but count the turns to see if they match.
The correct term for the part you reference is the cocking piece. The angled face of this rides on the corresponding surface on the bolt body. These two surfaces can be polished with rouge to mirror bright and will smooth up the action as long as you don't alter the surface angle. I generally use a very light smear of grease on this surface. What bothers me is that replacing the spring should not in and of itself cause the problem unless the spring is over sized. Did you check the spring against the original. It will probably be longer due to the set in the original but count the turns to see if they match.
Re: bolt firing pin cocking tuning?
I give up, why would an aftermarket spring have the same turns as the factory one? BTW, smoothing the sides of the cocking piece and shroud and a bit of moly grease also helps.
I give up, why would an aftermarket spring have the same turns as the factory one? BTW, smoothing the sides of the cocking piece and shroud and a bit of moly grease also helps.
Re: bolt firing pin cocking tuning?
Best answer is to take you bolt to a smith and have it tuned up. I ran into galling last year, when I took my bolt apart to "clean" it. I only used oil and that is not enough. Bolt started to get harder and harder to lift enough that the rifle was rotating when I cycled the bolt. I went ahead and stoned the surfaces ever so slightly (not sand, not file, stone) and then buffed the surfaces on a wheel with #5. Too aggresive and you can jack up your bolt and it will be gritty and gall over and over again. Dab of grease and it is now good to go. Note: do not go too crazy with the grease, as it can melt and drip down in the trigger assy. You can get various stones from brownell's. This was my experience, stone at your own risk.
As for the spring size in above post. The spring constant( the measure of potential energy) is derived from the radius of the wire and the type of material (the bonds at the molecular level). Sure length has to do with compression, but in a rifle bolt you want the size to be the same.
Just imagine making a spring out of solder, and one out of bailing wire. Both the same size. The spring made of wire will be stronger.
In short, grease the cam, lightly oil the pin and spring.
Best answer is to take you bolt to a smith and have it tuned up. I ran into galling last year, when I took my bolt apart to "clean" it. I only used oil and that is not enough. Bolt started to get harder and harder to lift enough that the rifle was rotating when I cycled the bolt. I went ahead and stoned the surfaces ever so slightly (not sand, not file, stone) and then buffed the surfaces on a wheel with #5. Too aggresive and you can jack up your bolt and it will be gritty and gall over and over again. Dab of grease and it is now good to go. Note: do not go too crazy with the grease, as it can melt and drip down in the trigger assy. You can get various stones from brownell's. This was my experience, stone at your own risk.
As for the spring size in above post. The spring constant( the measure of potential energy) is derived from the radius of the wire and the type of material (the bonds at the molecular level). Sure length has to do with compression, but in a rifle bolt you want the size to be the same.
Just imagine making a spring out of solder, and one out of bailing wire. Both the same size. The spring made of wire will be stronger.
In short, grease the cam, lightly oil the pin and spring.
Re: bolt firing pin cocking tuning?
Grease is a better lubrication on the cocking ramp than oil.
Oil generally won't be able to handle the pressure that exists at that sliding junction.
Grease is a better lubrication on the cocking ramp than oil.
Oil generally won't be able to handle the pressure that exists at that sliding junction.
Re: bolt firing pin cocking tuning?
Thanks for the advice everyone. I'm not 100 percent certain it was the spring, but that was my guess. I will definitely try the grease instead of oil, after I figure out where I can get some polishing compound and a buffing wheel of some sort. I assume I would polish both surfaces and I can do this with a Dremel type tool.
Thanks for the advice everyone. I'm not 100 percent certain it was the spring, but that was my guess. I will definitely try the grease instead of oil, after I figure out where I can get some polishing compound and a buffing wheel of some sort. I assume I would polish both surfaces and I can do this with a Dremel type tool.
Re: bolt firing pin cocking tuning?
I don'think ist's the spring:I have mounted a quicker lock-time spring on my sa 700,but never happened a progressive stiiffening of the cycling_ felt wheel + Iosso paste on dremel will works great for your purpose
I don'think ist's the spring:I have mounted a quicker lock-time spring on my sa 700,but never happened a progressive stiiffening of the cycling_ felt wheel + Iosso paste on dremel will works great for your purpose
Re: bolt firing pin cocking tuning?
The unaltered M700 fire control mechanism is properly designed, and any modification that increases the forces involved may be unwise. It adds to wear and operating effort; while exceeding any degree of force actually necessary to initiate primer ignition.
Efforts to reduce locktime are of only a limited value, with such value decreasing as supported shooting positions become more stable.
A more effective and benign approach to locktime improvement involves mass reduction; where lightweight firing pin and striker components are substituted.
Logically, the physics involved would suggest that a shorter locktime should decrease POI deviation between the times of sear release and primer ignition.
In practical terms, such gains are an illusion; being so small as to be insignificant except in instances where firearm motions during the firing cycle are unusually vast, as in wingshooting.
In less energetic shooting situations, good adherence to the correct marksmanship basics will negate any true need for locktime improvement, and less locktime will not improve any situation where bad habits impair proper marksmanship.
Greg
The unaltered M700 fire control mechanism is properly designed, and any modification that increases the forces involved may be unwise. It adds to wear and operating effort; while exceeding any degree of force actually necessary to initiate primer ignition.
Efforts to reduce locktime are of only a limited value, with such value decreasing as supported shooting positions become more stable.
A more effective and benign approach to locktime improvement involves mass reduction; where lightweight firing pin and striker components are substituted.
Logically, the physics involved would suggest that a shorter locktime should decrease POI deviation between the times of sear release and primer ignition.
In practical terms, such gains are an illusion; being so small as to be insignificant except in instances where firearm motions during the firing cycle are unusually vast, as in wingshooting.
In less energetic shooting situations, good adherence to the correct marksmanship basics will negate any true need for locktime improvement, and less locktime will not improve any situation where bad habits impair proper marksmanship.
Greg
Re: bolt firing pin cocking tuning?
Hatchers notebook. . .
You can reduce mass to shorten the locktime. It works. However you have to be observant of the kinetic impact energy delivered too. Lighter components lack the inertia that heavier ones do. This means ignition can become erratic.
The factory arrangment is sufficient. What does help is a better fitting spring that doesn't look like a snake that ate a half dozen eggs when compressed. The drag along the inside of the bolt can fuss with things.
Lack of energy means bouncing pins on primers. That means elevation at long distance.
Hope this helps.
C.
-last:
Keep in mind that lock time is a marketing effort to get you to buy shit for your gun. The 03 spring field prolly has the worst of any semi modern bolt action. Its like a flint lock compared to the modern hot rod custom receivers. Look at scores from 100 years ago to now. Yes they are better. So are bullets, powders, barrels, optics, etc. Locktime isn't what got us there.
Need more proof? Look at an AR or M1A. Swinging hammers. . . Yet look at the scores shot at Perry during highpower week.
Leave lock time for what it is: novel high minded conversation with your buddies.
Hatchers notebook. . .
You can reduce mass to shorten the locktime. It works. However you have to be observant of the kinetic impact energy delivered too. Lighter components lack the inertia that heavier ones do. This means ignition can become erratic.
The factory arrangment is sufficient. What does help is a better fitting spring that doesn't look like a snake that ate a half dozen eggs when compressed. The drag along the inside of the bolt can fuss with things.
Lack of energy means bouncing pins on primers. That means elevation at long distance.
Hope this helps.
C.
-last:
Keep in mind that lock time is a marketing effort to get you to buy shit for your gun. The 03 spring field prolly has the worst of any semi modern bolt action. Its like a flint lock compared to the modern hot rod custom receivers. Look at scores from 100 years ago to now. Yes they are better. So are bullets, powders, barrels, optics, etc. Locktime isn't what got us there.
Need more proof? Look at an AR or M1A. Swinging hammers. . . Yet look at the scores shot at Perry during highpower week.
Leave lock time for what it is: novel high minded conversation with your buddies.
Re: bolt firing pin cocking tuning?
+ a million...
Messing with the striker assembly is not going to do anything significantly good for your scores.
+ a million...
Messing with the striker assembly is not going to do anything significantly good for your scores.
Re: bolt firing pin cocking tuning?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: xs hedspace</div><div class="ubbcode-body">I give up, why would an aftermarket spring have the same turns as the factory one? BTW, smoothing the sides of the cocking piece and shroud and a bit of moly grease also helps. </div></div>
Whenever I replace any gun part I compare them. Packaging errors do occur. As far as the turn count goes, changing the turn count will change the spring rate and the pre-load in inverse proportion. When a new spring is binding, as an above poster mentioned, the spring could be forced during compression into an S shape and bind on the interior surface. This is where length is important. Many spring manufacturers vary there springs by changing the wire diameter rather than the turn count. When comparing an old to new spring the old spring, having taken a set, will generally appear to be three or less turns shorter.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: xs hedspace</div><div class="ubbcode-body">I give up, why would an aftermarket spring have the same turns as the factory one? BTW, smoothing the sides of the cocking piece and shroud and a bit of moly grease also helps. </div></div>
Whenever I replace any gun part I compare them. Packaging errors do occur. As far as the turn count goes, changing the turn count will change the spring rate and the pre-load in inverse proportion. When a new spring is binding, as an above poster mentioned, the spring could be forced during compression into an S shape and bind on the interior surface. This is where length is important. Many spring manufacturers vary there springs by changing the wire diameter rather than the turn count. When comparing an old to new spring the old spring, having taken a set, will generally appear to be three or less turns shorter.
