Gunsmithing Why does my Rem 700 bolt handle jump during firing?

[copterdrvr]

I recently put together a .224 Valkyrie using a trued, stainless PTG left hand action with a fluted bolt and an M16 extractor with a Criterion 24 inch light varmint, 1-6.5 barrel. The rifle shoots lights out, the best group was yesterday, shooting FIVE rounds into yes--- .111 using an 80 grain Sierra HPBTM bullet and 27.1 grains of PP 2000 in Starline brass and a BR-4 primer.

I have a Rem 700 left hand 6.5 Creedmoor that I also built but the Creedmoor started life as a "plain old" standard action and the only mod was lapping the lugs and installing a Calvin Elite trigger.

ANYWAY, there is something that the new action does that the old one does not and that is the bolt handle will lift approximately one half inch (measured at the end of the extended bolt knob) when the rifle is fired. The "old" action does not do this.

I pulled the firing pins on both bolts and the "old" bolt uses the factory standard Remington fluted firing pin and the PTG firing pin is a solid, much heavier firing pin. I didn't ask for it in the build but the "solid" PTG firing pin costs 10 dollars more than a "standard" firing pin so I'm assuming they think it's an upgrade.

I swapped out the firing pin assemblies and the "old" firing pin in the new bolt BARELY cause hardly any bolt handle movement at all. The only difference between the two is the weight of the firing pin itself which is fairly substantial.

Why would it do that?

Copterdrvr

 

[Steel head]

As the spring unloads it also creates twist which imparts on the bolt

Tubb made a spring assembly with two springs each with the coils in a different orientation to cancel out the twist imparted on the bolt.

Really I think it’s kinda a nonissue.

 

[Shooter71]

Cocking piece hitting bolt body in ramp. Also if it’s a sloppy action and the root of the handle is resting on its stop, when the sear falls and the rear of the bolt drops, it’ll flick the handle up .

 

[sinister]

Heavy firing pins are going the opposite direction you want to go. A lighter, faster pin with a stronger (not over-powering) spring will cut your lock time.

 

[copterdrvr]

My original thought was possible spring drag on the new, un-fluted firing pin because there's alot of surface area contact between the firing pin spring and the firing pin as compared to the "factory" firing pin which is fluted and has much, much less actual contact with the firing pin spring.

As I said earlier, when I install the fluted factory firing pin in the new bolt it doesn't do it. I don't really have a problem with it, I was just curious as to the physics/mechanics of what could cause a difference. The rifle is a laser and I couldn't be happier with it.

As to the weight of the firing pin, I get that-I have a bunch of Titanium firing pins installed in my rifles. Makes me curious as to why they decided to manufacture and then installed their firing pin over the factory, fluted firing pin. Theirs does cost 10 bucks more, maybe thats the whole reason. Don't get it - their solid pin has WAY less machining on it.

 

[Shooter71]

I want a heavy pin and heavy spring.

 

[LRI]

What a rifle does when dry firing vs what happens when its laying the hate is vastly different.

Go shoot it. It's likely going to be fine.

 

[LRI]

Heavy firing pins are going the opposite direction you want to go. A lighter, faster pin with a stronger (not over-powering) spring will cut your lock time.

K, this is (sorry to say) some disinformation. A primer cup requires both MASS and VELOCITY if it is going to do its job properly when impacted.

These light pins and lock time discussions fail to take that basic necessity into consideration. It's very possible for an alloy striker body fitted with a titanium pin front end to literally bounce off of the primer. Light strikes and stringing vertical in shot groups at distance. These are all tell tail signs of this.

I once watched Sandy Pagel (one of the most accomplished long range iron sight prone shooters in the world) go from solid 98% scores with 75% X counts to barely being able to keep it on the 8 ring. All because she did not care for the heavy bolt lift of an RPA Quadlock action. (A 22.5* bolt throw combined with bellville washers/springs instead of a conventional coil='s HEAVY BOLT LIFT) Alan Warner attempted to solve the issue with a light coil spring design.

The gun absolutely hated it. The moment I changed it back to the OEM setup, she went right back to plot sheets that'd make F class guys jealous.

Doubt it, argue it, whatever. I know this is as fact and if you dig around enough on the internet you'll find the requirements for reliable primer cup ignition. Hatcher's Notebook written during WWI covers a great deal of this. The physics has not changed.

If your shit doesn't meet that need, you will have problems. Count on it.

As for "lock time". It's a great topic to chat over. A horrible one to get super serious about. A HighMaster is a HighMaster. If he/she is shooting Service rifle where the hammer is swung like an axe and he/she produces High Master scores, betting they'll do just a bit better when you throw them behind a raced out match rifle.

If you talked with folks like this, I'd lay a dollar that they'll tell you this: Better trigger, better sights, better cartridges, and better ergonomics. These are going to do more than lock time.

I've built guns for olympic athletes that have won in the olympics. I don't recal Matt Emmonds ever sweating lock time. This is where it might actually really matter. Bullet sucks. Cartridge sucks, and its traveling roughly 1/3'rd the speed of anything cool or fancy.

Yet not a word said...

On that note. Wanna make an M700 wake up if it has lethargic ignition? All you need is a 27/64 reamer and a cordless drill. Pull the fire control, squirt some oil down the hole, and ream it to the bottom. M700 bolt heads are soldered. Often a little fungus will be left as a byproduct of that process. It drags on the spring and makes shit lazy. Reaming it to the minor ID of the thread (1/2-13) all the way to the bottom of the hole fixes it 99.99999% of the time.


Hope this helps.

"Without fact, you have an opinion."
-Paul Yaw

 

[fdkay]

K, this is (sorry to say) some disinformation. A primer cup requires both MASS and VELOCITY if it is going to do its job properly when impacted.

These light pins and lock time discussions fail to take that basic necessity into consideration. It's very possible for an alloy striker body fitted with a titanium pin front end to literally bounce off of the primer. Light strikes and stringing vertical in shot groups at distance. These are all tell tail signs of this.

I once watched Sandy Pagel (one of the most accomplished long range iron sight prone shooters in the world) go from solid 98% scores with 75% X counts to barely being able to keep it on the 8 ring. All because she did not care for the heavy bolt lift of an RPA Quadlock action. (A 22.5* bolt throw combined with bellville washers/springs instead of a conventional coil='s HEAVY BOLT LIFT) Alan Warner attempted to solve the issue with a light coil spring design.

The gun absolutely hated it. The moment I changed it back to the OEM setup, she went right back to plot sheets that'd make F class guys jealous.

Doubt it, argue it, whatever. I know this is as fact and if you dig around enough on the internet you'll find the requirements for reliable primer cup ignition. Hatcher's Notebook written during WWI covers a great deal of this. The physics has not changed.

If your shit doesn't meet that need, you will have problems. Count on it.

As for "lock time". It's a great topic to chat over. A horrible one to get super serious about. A HighMaster is a HighMaster. If he/she is shooting Service rifle where the hammer is swung like an axe and he/she produces High Master scores, betting they'll do just a bit better when you throw them behind a raced out match rifle.

If you talked with folks like this, I'd lay a dollar that they'll tell you this: Better trigger, better sights, better cartridges, and better ergonomics. These are going to do more than lock time.

I've built guns for olympic athletes that have won in the olympics. I don't recal Matt Emmonds ever sweating lock time. This is where it might actually really matter. Bullet sucks. Cartridge sucks, and its traveling roughly 1/3'rd the speed of anything cool or fancy.

Yet not a word said...

On that note. Wanna make an M700 wake up if it has lethargic ignition? All you need is a 27/64 reamer and a cordless drill. Pull the fire control, squirt some oil down the hole, and ream it to the bottom. M700 bolt heads are soldered. Often a little fungus will be left as a byproduct of that process. It drags on the spring and makes shit lazy. Reaming it to the minor ID of the thread (1/2-13) all the way to the bottom of the hole fixes it 99.99999% of the time.


Hope this helps.

"Without fact, you have an opinion."
-Paul Yaw

Chad,
It is really awesome that you take time out of your day, not only to answer questions, but explain things.
I have learned much just reading your responses and explanations.
Thank you.

 

[MarinePMI]

K, this is (sorry to say) some disinformation. A primer cup requires both MASS and VELOCITY if it is going to do its job properly when impacted.

These light pins and lock time discussions fail to take that basic necessity into consideration. It's very possible for an alloy striker body fitted with a titanium pin front end to literally bounce off of the primer. Light strikes and stringing vertical in shot groups at distance. These are all tell tail signs of this.

I once watched Sandy Pagel (one of the most accomplished long range iron sight prone shooters in the world) go from solid 98% scores with 75% X counts to barely being able to keep it on the 8 ring. All because she did not care for the heavy bolt lift of an RPA Quadlock action. (A 22.5* bolt throw combined with bellville washers/springs instead of a conventional coil='s HEAVY BOLT LIFT) Alan Warner attempted to solve the issue with a light coil spring design.

The gun absolutely hated it. The moment I changed it back to the OEM setup, she went right back to plot sheets that'd make F class guys jealous.

Doubt it, argue it, whatever. I know this is as fact and if you dig around enough on the internet you'll find the requirements for reliable primer cup ignition. Hatcher's Notebook written during WWI covers a great deal of this. The physics has not changed.

If your shit doesn't meet that need, you will have problems. Count on it.

As for "lock time". It's a great topic to chat over. A horrible one to get super serious about. A HighMaster is a HighMaster. If he/she is shooting Service rifle where the hammer is swung like an axe and he/she produces High Master scores, betting they'll do just a bit better when you throw them behind a raced out match rifle.

If you talked with folks like this, I'd lay a dollar that they'll tell you this: Better trigger, better sights, better cartridges, and better ergonomics. These are going to do more than lock time.

I've built guns for olympic athletes that have won in the olympics. I don't recal Matt Emmonds ever sweating lock time. This is where it might actually really matter. Bullet sucks. Cartridge sucks, and its traveling roughly 1/3'rd the speed of anything cool or fancy.

Yet not a word said...

On that note. Wanna make an M700 wake up if it has lethargic ignition? All you need is a 27/64 reamer and a cordless drill. Pull the fire control, squirt some oil down the hole, and ream it to the bottom. M700 bolt heads are soldered. Often a little fungus will be left as a byproduct of that process. It drags on the spring and makes shit lazy. Reaming it to the minor ID of the thread (1/2-13) all the way to the bottom of the hole fixes it 99.99999% of the time.


Hope this helps.

"Without fact, you have an opinion."
-Paul Yaw

I believe Pope and Narramore had some interesting points on the need for consistent ignition as well. As you said, this is not something new, but I think many have forgotten to pick up some of these older books (like Hatcher's Notebook) and spend some time reading. There are a lot of nuggets in these old texts, if they can be had.

Besides, as a close friend (retired gunsmith) of mine said "You can tell a true gunsmith, not by his investment in tooling, but rather, his investment in his library". You sir, I believe, have done both. A rare thing these days...

 

[Hundo]

Chad,
It is really awesome that you take time out of your day, not only to answer questions, but explain things.
I have learned much just reading your responses and explanations.
Thank you.

Chad knows his shit. That is why he builds great rifles and I buy them :>)

 

[sinister]

Chad, going with both a light firing spring and a light pin will get you inconsistent ignition -- no doubt of that. But a lighter firing pin with a heavier spring bouncing off a primer cup?

Step away from the crack pipe.

Stuart Otteson, The Bolt Rifle, Winchester Press 1976.

Science: US Patent 3056226 to Olin Corporation https://patents.google.com/patent/US3056226

Was Matt Emmons shooting a Remington 700 at the Olympics?! Your Sandy Pagel citation is an apples-oranges comparison. The Quadlock was designed for the Bellevilles, which ensured the pin's velocity. Of course a lighter coil spring was going to slow down the whole works and make it inconsistent.

And yes, I've had Olympic Gold Medalists and US Olympic Team gunsmith-armorers working for me as well.

Yes, a better barrel, trigger, sights, ammo, and ergonomics. The whole rifle system as well as better performance are needed to win. USAMU gunsmiths have hung Anschutz triggers on 40s and 700s to win.

 

[LRI]

Chad, going with both a light firing spring and a light pin will get you inconsistent ignition -- no doubt of that. But a lighter firing pin with a heavier spring bouncing off a primer cup?

Step away from the crack pipe.

Then explain why I see no less than 30-40 "speed locks" come through here annually with the same exact problem: Light strikes and depreciation of group size. Going back to an OEM fire control solves it.

Crack? Really?

Stuart Otteson, The Bolt Rifle, Winchester Press 1976.

Science: US Patent 3056226 to Olin Corporation https://patents.google.com/patent/US3056226

A patent means what exactly? I can't duplicate your shit for a certain amount of time. It states nothing about the item being patented as a good idea or a bad one. Case in point:

Patent: Mechanized dildo

Was Matt Emmons shooting a Remington 700 at the Olympics?!

No, he wasn't. My point has nothing to do with what action he used. 03 Springfields have LT's measured with a sun dial compared to most modern high performance bolt actions. -Yet, I know of several people who've kicked major ass with them. The point still stands.

Your Sandy Pagel citation is an apples-oranges comparison. The Quadlock was designed for the Bellevilles, which ensured the pin's velocity. Of course a lighter coil spring was going to slow down the whole works and make it inconsistent.

Thank you for doing nothing more than reinforcing my point: The fact that a certain amount of energy and mass is required to deliver consistent, reliable ignition to the primer and anvil.

And yes, I've had Olympic Gold Medalists and US Olympic Team gunsmith-armorers working for me as well.

Your dick is still bigger, relax....

Yes, a better barrel, trigger, sights, ammo, and ergonomics. The whole rifle system as well as better performance are needed to win. USAMU gunsmiths have hung Anschutz triggers on 40s and 700s to win.

Yeah, I designed half of those trigger carriers almsot 20 years ago. Mine don't butcher the receiver or the trigger. Again, the point. You missed it. I'll try again:

IF a high caliber shooter can perform well with current, "raced out" equipment and also do extemely well with systems that pale by comparision. IE: A conventional coil/striker assembly verses a swinging hammer, then it stands to reason that "lock time" is not the doomsday issue so often made out to be.



Last:

I managed to offer a constructive argument without making insults. Try it sometime dickhead.

 

[Shooter71]

I know you guys are fighting and everything, but the sun dial comment had me rolling! I have an 03a3 I’m going to do some surgery on and build a sort of vintage sleeper.

Carry on..

 

[stangfish]

 

[LANCER]

My Tikka and SOTIC (Sako) do the same thing. Not really an issue.