pacific coned bolt for Rem 700

D

dbergen

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Will this bolt work as a repeater?
What are the gains when going the coned route.
Rifle build will be in 223 Rem.
thanks,
David
 
David,
The cone bolt is primarily for single shot use. This allows for a cone at the barrel that will help guide in a round. A cone bolt won't normally pick up a round out of the mag, it'll ride over it.
 
David, I recently did a barrel for a guy with a Tubb t2k, it had a coned bolt and is required to feed flawlessly through the rapid fire portion of course shooting. I highly doubt Tubb/McMillan would design a rifle with a less than reliable feeding system in place.
That being said, I have several Rem/Ptg cone bolt combination rifles. The rim of the cone is the same diameter as the rim of a factory bolt...and its the face of that rim that strips the round out of the mag box. Mine feed just fine and havent lost or skipped over a single round.
 
It would be nice if a picture or two of a coned bolt and the matching barrel recess were posted... a picture is worth 1000 words...
 
So if I understand correct.
The cone bolt will improve feeding in a repeater. Can you give some info on the barrel cone setup.
The bolt in going to be used in a MAK repeater tubegun kit.
Thanks for the info and reply's.
 
The benefit to feeding has little to do with the bolt, but with the angled surfaces that guide the cartridge to the chamber. The bolt needs a cone to facilitate it fitting in the recess at the end of the barrel. PTG's bolts are set up to fit .010 off the angled surfaces.
 
I understand.
Hopefully somebody posts a picture off the setup
David
 
Why not a partial cone? You only need a small vertical face on the bolt to pick up a round in the chamber.
 
From what I can glean from never have seen a "coned bolt" conversion done to a factory bolt is:

It isn't the bolt that is 'coned'... it is the back of the barrel. Honestly I don't know why you would need to do that other than breaking a few sharp edges... if the bolt is 'coned' it would be a backward step in feeding...

There is only so much coning required... how far off is the cartridge feeding anyway?

For instance on a Weatherby Mark V magnum, where the belt of the cartridge is cut in the chamber, needs to be machined at an angle for best feeding. The whole rear of the barrel does not need coning.
 
Any real improvement would only come with and improvement by getting rid of these phony extractors and figuring out a way for a sliding Winchester extractor to work off of the face of a lug. I just hate the idea of cutting into a bolt body to make room for a SAKO or M-16 extractor.
 
HovisKM said:
The bolt nose has to pick up the round without the assistance of the lug.

Hovis
Click to expand...

What am I missing, are not the lugs in the horizontal position during chambering, and therefore are not involved in either a coned or flat faced bolt?.....................Don
 
I don't know what extractor options you have with the coned bolt from Pacific. I'll send an e-mail to pacific for some info.
David
 
Don said:
What am I missing, are not the lugs in the horizontal position during chambering, and therefore are not involved in either a coned or flat faced bolt?.....................Don
Click to expand...

Absolutely, I don't know what the heck I was thinking. I had been looking at and discussing a horizontal lockup action with a friend who is making a hunting rifle out of it. My bad....headspace off.

Hovis
 
In the instance of altering a factory bolt it sounds like a "coned" bolt is simply a recessed bolt face with a chamferred edge allowing the case head to 'seat' into the bolt head a bit easier. It is not big deal to do that to a 700 bolt for a bit smoother closing of the bolt...

...if the camber is centered in the barrel and the barrel is centered in the action with the bolt race way, any case being pushed into the chamber can only line up with the bolt face and with a little chamfer or polishing of the chamfer that is there, what more would you need? How hard is it to close your bolt?
 
new train of thought

i may be off base but i thought the reason one coned the bolt and barrel was for the bolt to barrel allignment and runout. the exact principle for the "borden bumps on a bolt was to take play out of the bolt and align the bolt centered on the chamber. i believe all of the other issues are like running after rabbit trails. Fred
 
Fred;
Are you saying the bolt actually touches the cone in the back of the barrel??? Intentionally???

Mike Swartz
 
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I'm still trying to understand ANY downside to the coned bolt....... They DO NOT affect how the round is stripped from the chamber as the "coning" affects only the forward lug faces (which as Don said are laying down horizontally in the raceways...)

The only downside I can imagine would be with maybe slim rounds like .223 "could" get a little jacked sideways when they pop up from the mag???? I've not experienced this but could imagine it happening on a repeater.

All this said, they're not really designed for repeaters. They're designed for singleshot conversions which load a round out of a tray which may be set lower than the top of a magazine follower.

They DO NOT "aid in alignment" in any way and they ARE NOT designed to touch the rear of the barrel!

The cone is for FEEDING at high speed.

The only negative aspect is cost.

al
 
The PTG coned bolt is just on the front of the lugs. I have one on order right now for a model Seven I am doing up in 6mmBR. The back of the barrel is going to have the opposite cone in it. Like a classic model 70 but with out the extractor cut. About the only disadvantage I can see is you loose Remingtons three rings of steel. I think Stiller uses PTG bolt in his 700 clones.

Here is the picture of the coned bolt.
 

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denphillips2 said:
About the only disadvantage I can see is you loose Remingtons three rings of steel.
Click to expand...

That's a huge disadvantage in my mind. Not a problem if you never have a big time case failure, but the safety factor has sure changed.

What do you do with your old bolt?
 
You can cone a Remington bolt.

I can't imagine why one would need to "lose the three rings of steel" just from coning. I see this as a separate choice. What am I missing????

al
 
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