PTG bolt slow to start cocking firing pin on rem 700

[Gil P.]

I'm wondering what might be causing this and how to fix it.

My PTG bolt takes noticeably more movement before it starts cocking the firing pin when lifting the bolt handle vs the stock Remington bolt. This results in a heavier bolt throw.

The PTG bolt has Gre Tan internals installed by Greg.

Could it be the cocking piece? I noticed the PTG cocking piece looks shorter, but I haven't measured the two yet.

My Remington bolt starts cocking the firing pin almost as soon as I start to lift the bolt handle.

ETA using a CG Xtreme mod 22 trigger.

 

[Alex Wheeler]

PTG cocking cams are different than a rem 700. The standard firing pin assemblies do not make use of it. Shorten your firing pin, but not enough to bottom the cocking piece nose out in the ramp. This not causing heavier lift however. The ramp is steeper, plus any other issues you have have are whats causing heavier lift.

 

[Gil P.]

PTG cocking cams are different than a rem 700. The standard firing pin assemblies do not make use of it. Shorten your firing pin, but not enough to bottom the cocking piece nose out in the ramp. This not causing heavier lift however. The ramp is steeper, plus any other issues you have have are whats causing heavier lift.

It looks like I'll have to send it off again to be fixed.

The original gunsmith got everything working with the PTG bolt and Gre Tan parts. The bolt lift was still quite heavy and I could hear a squealing noise when cocking the bolt.

I sent the bolt (no action or trigger) to Greg Tannel to see what he could do. He improved the bolt lift and I don't hear the squealing as much anymore.

Whatever else is going in is beyond my competence level.

Who should I sent it off to?

Heres a link to what my bolt looks like when cocking.

 

[AlNyhus]

These issues can be subtle, hard to describe and very difficult to diagnose w/o having the action in hand. But from the video, it doesn't look all that bad. The first thing I'd check is the firing pin spring tension...make sure it's not some 28-30 lb. spring in there.

The PTG does the 'work' over a shorter amount of bolt rotation than an original Remington....which is why it has more movement before it starts doing the 'work'. And because the 'work' is being done over a shorter amount of movement, the effort is going to be more.

I would suggest taking a very close look at the cam angle on the receiver relative to the cam angle on the bolt as they meet and the mechanical primary extraction (camming) takes place.

Some close shots or a video of that area would help, too.

Educate yourself completely on this before you send the action and bolt off to have it 'fixed'....there aren't many that truly understand this subject. Do your homework!

Good shootin'. -Al

 

[Gil P.]

These issues can be subtle, hard to describe and very difficult to diagnose w/o having the action in hand. But from the video, it doesn't look all that bad. The first thing I'd check is the firing pin spring tension...make sure it's not some 28-30 lb. spring in there.

The PTG does the 'work' over a shorter amount of bolt rotation than an original Remington....which is why it has more movement before it starts doing the 'work'. And because the 'work' is being done over a shorter amount of movement, the effort is going to be more.

I would suggest taking a very close look at the cam angle on the receiver relative to the cam angle on the bolt as they meet and the mechanical primary extraction (camming) takes place.

Some close shots or a video of that area would help, too.

Educate yourself completely on this before you send the action and bolt off to have it 'fixed'....there aren't many that truly understand this subject. Do your homework!

Good shootin'. -Al

I didn't know that about the PTG bolts. I'll take some pictures and maybe be a video of the camming surfaces tonight.

 

[Ggmac]

It looks like I'll have to send it off again to be fixed.

The original gunsmith got everything working with the PTG bolt and Gre Tan parts. The bolt lift was still quite heavy and I could hear a squealing noise when cocking the bolt.

I sent the bolt (no action or trigger) to Greg Tannel to see what he could do. He improved the bolt lift and I don't hear the squealing as much anymore.

Whatever else is going in is beyond my competence level.

Who should I sent it off to?

Heres a link to what my bolt looks like when cocking.

It looks as if your bolt handle base ( the part that 90 deg

 

[DaveTooley]

A random neutron bumped into something in my head. I'm curious what the HS number is for that action. Also the amount of firing pin fall.

 

[Gil P.]

A random neutron bumped into something in my head. I'm curious what the HS number is for that action. Also the amount of firing pin fall.

What's an HS number?

 

[AlNyhus]

Be aware that later 700's are notorious for having little to no mechanical extraction camming....there is very little cam angle on the rear of the receiver. And what is there generally makes little or no contact with the bolt handles cam angle. It's the interface between this and the root of the bolt handle (which has a corresponding angle) that physically starts the bolts extraction action by mechanically 'camming' the bolt back. This is what initially pulls the case back out of the chamber.

If this is a later receiver or one of the bare receivers that flooded the market as Remington was circling the drain, the trouble may lie in the receiver itself. Take some close up pics or video of the bolt handle angle/receiver angle as they come together and post them.

The lug abuttments in the receiver can also be part of the issue. Specifically, the relationship of the angle on the back of the bolt lugs to the lug abuttments as the bolt opens.

Not to wander too far off track, but this is a custom BR action I owned that had all of these issues. The original bolt had only a sharp edge on the handle as the cam contact point. It also started camming back before the bolt lug angles were clear of the abuttments....major issues with hard bolt operation. Stan Ware's fix was extensive...a new handle profiled to exactly match the receiver cam angle along with a recut of the angles on the back of the bolt, among other tweaks. With the new camming angles, the result was a bolt that I could lift with my index finger on a stout 30BR load.

Hopefully these pics will give you some idea of what goes on and some food for thought.

Good shootin'. -Al

 

[Gil P.]

I can try and get some more pictures out tonight. My cam angles don't match up as nicely as yours.

Im sending mine out to get worked on tomorrow, I'll update this post when I get it back.

 

[AlNyhus]

I can try and get some more pictures out tonight. My cam angles don't match up as nicely as yours.

Im sending mine out to get worked on tomorrow, I'll update this post when I get it back.

Well, they don't have look perfect to work well, either.

Couple pretty obvious things there.
Hopefully the 'smith is well versed in this and you're sending the action, trigger and bolt.

Looking forward to your results and the fix (es). -Al

 

[DaveTooley]

What's an HS number?

head space. The distance from the shoulder of the barrel to the end of the chamber gage.

 

[DaveTooley]

Never mind that random neutron was indeed a ricochet. The cocking cam surface is too deep into the bolt body and/or the bolt cocking piece is too short. It may be possible to replace the cocking piece and improve/shorten up the engagement point.

 

[Gil P.]

I forgot to mention, we bought the rifle new in 2010. I'm not sure what their quality was like back then. My barrels are always off to one side in every chassis or stock I've ever put it in.

 

[Gil P.]

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Messed up the name of the video.

 

[DaveTooley]

You might not like it but if it functions properly the only negative would be harder bolt lift.

 

[Will Henry]

If it was mine (and I'm thankful it is not), I would extend the nose of the cocking piece so it comes within about .020 of the bottom of the cocking cam notch. Then I would re-cut the cam so it moved the striker back just far enough to allow the trigger to set. I would then harden and polish the camming surface. It would cock so easily you would think the spring was missing. If it was a customer's, I would emphasize the cost and difficulty and hope he chose to just live with it! WH

 

[Gil P.]

You might not like it but if it functions properly the only negative would be harder bolt lift.

Boyd Allen was having me make some measurements.

The gap here is 44 thou, which I've learned is not good.

 

[DaveTooley]

I understand. The only easy solution is a new longer cocking piece. Maybe
Something seems odd. I would want to know what surface is limiting the firing pin travel. The cocking piece or the internal shoulder on the firing pin. That might give you options. Can you disassemble the firing pin assembly? If you can measure the firing pin protrusion before and then after by inserting the naked firing pin into the bolt. Also how much firing pin fall do you have.

 

[AlNyhus]

Can you substitute a standard 700 cocking piece?