Forcing cone depth

[PacMan]

Received my chamfering kit yesterday and after reading the instructions i set out to recut the forcing cone on a .44 special and one of my .357s. I had also ordered the plug gauges for .357 and .44. Things went well on the .44 sp but when i stuck the gauge into the throat of the .357 it went in way further than the instructions say it should. A little hard to measure but i would say that it went in approx .080 past the top on the gauge.

I worked with the pistol off and on but never got very good accuracy with it so i use it to plink and burn ammo at close range.

I also took a bullet and stuck it into the forcing cone and it rock back and forth like it was resting on two places at 90deg angles.

Could the depth of the cut be the problem or at least part of it?

Dwight

[bhn22]

Your .357s forcing cone is factory cut to a different angle than your reamer, or is cut to the same angle, but is factory cut deeper. You need to determine which forcing cone angle you have, and proceed from there. I couldn't recut my GP100 to match the same angle I cut my S&Ws to, and left it alone.

Here's a link to an old discussion I got into on the Ruger forums that's sort of related to the subject. Some people were ignoring the obvious and assuming that all their revolvers were defective, when all they had were different forcing cone angles

http://www.rugerforum.com/phpBB/viewtopic.php?t=36051&highlight=

I think GP100man got involved in this one as well.

[44man]

Received my chamfering kit yesterday and after reading the instructions i set out to recut the forcing cone on a .44 special and one of my .357s. I had also ordered the plug gauges for .357 and .44. Things went well on the .44 sp but when i stuck the gauge into the throat of the .357 it went in way further than the instructions say it should. A little hard to measure but i would say that it went in approx .080 past the top on the gauge.

I worked with the pistol off and on but never got very good accuracy with it so i use it to plink and burn ammo at close range.

I also took a bullet and stuck it into the forcing cone and it rock back and forth like it was resting on two places at 90deg angles.

Could the depth of the cut be the problem or at least part of it?

Dwight
Never open the forcing cone if the plug gauge goes too deep. You don't want to make the start larger in diameter.
A little does not hurt much but it makes boolit choice more important. That is the time to dump a Keith design and go to the LBT or RNFP.
When you said you had a boolit rock, it means to me you had a Keith style with the nose smaller then the bore. What does your boolit do at the muzzle?

[PacMan]

Actually i was using both a LBT WFN and a Keith bullet. What i did was just stick the bullet into the forcing cone untill it stoped with a little preasure. The bullet would wollow back and forth like a ship in rough seas. I tried the same thing in a GP100 and did not have the same thing,oh maybe slightly,but nothing to the amount on the RBH.

It is like the bullet is resting on two opposing lands and not contacting the others. I would think that when the bullet enters the barrel if it is slightly off center that it would be directed (lack of a better word) even further out of line.

I did try the bullet at the muzzle and it sit as it should.

Dwight

[PacMan]

[QUOTE=44man;1335177]Never open the forcing cone if the plug gauge goes too deep. You don't want to make the start larger in diameter.


That is what bothers me.The plug gauge goes in a good bit further tha what the directions say it should. I am trying to decide if i have a defective barrel or not. I know that there are a lot of thing that contribute to accuracy or lack of.

I wonder somtimes how much powder and lead is wasted trying to find a accurate load when maybe somthing like this problem will never let one find any usable accuracy. Maybe things like this is what makes some revolvers so finiky about the loads they shoot and limit type of bullets and loads that will shoot accuratley.

Just thinking out loud so to speak.

Dwight

[Char-Gar]

Dwight... I am assuming you are talking about the Brownells two step plug gauge. Quite often to remove the old forcing cone, you have to remove enough metal that the gauge goes past the top step.

This used to worry me, but I was told by some folks who should know that these gauges are on the tight side. Every pistol I have recut has done at least as well if not better after the recut than before, even though the gauge went to far in.

As always read my disclaimer below.

[PacMan]

Charger .. yeap it is the 2 step gauge. I am wondering how far is too far.
What are your thoughts about the bullet not fitting square in the barrel/forcing cone? I think that bothers me more than anything. I think that i can ream the forcing cone a little and help or eliminate that but not sure.
Thanks
Dwight

[44man]

Forcing cone angles are different in a lot of revolvers. I just have never proven that it means a whole lot. What counts is how the boolit nose centers in it for a good transition to the bore.
If all is perfect to a millionth on an inch, do you even need a forcing cone?

[subsonic]

Was reading some stuff written by Bob Baker the other day. He mentions using boolits that are too soft for the pressure/speed you are trying to reach will cause "stacking" in the forcing cone, meaning the boolit will obturate too much and grow to reach the larger dimensions present and ultimately "hang up" in there - causing cracked forcing cones and accelerated forcing cone wear. Would be a reason to keep forcing cones to a minimum depth/diameter and shallow angle. Might be a reason that .454s at super high pressure have tight throats? Enough pressure will make anything obturate.

[Char-Gar]

Dwight... I have never tried to hand fit a bullet into the forcing cone. I would guess it would rock around a little as did yours. I doubt if either the cone or bullets would be so perfect there would be no rock. I wouldn't worry about it. Go shoot it and then worry....or not.

[tek4260]

So did the gauge go too deep on the 357 before you cut it, or only after(if you cut it at all)? I have done mine and I noticed that on some, the gauge fell too deep from the factory. I cut just enough on mine to remove the old f/c. I don't really know if too deep matters though. Reeder had maxi-throats and there was a Taylor-throat at one time that was supposed to help. Of course these throats may have simply removed constriction at the threads.... And allowed the boolit to engage the rifling and start to rotate without the rear of the boolit held tight by the throat of the cylinder, distorting the boolit as it started to turn in the rifling.

(poorly worded answer, but hopefully you get the gist of my half asleep rambling)

[leftiye]

Dwight, there is a possibility that your boolits that rock in the forcing cone are cast in molds that are slightly out of round?? Most molds are....

[PacMan]

Leftiye, i know where you are comming from but that is not the problem. I have two other .357s one of which the same bullet sits squarely in the forcing cone. The other it did not sit as well but using the plug gauge i reamed the forcing cone staying within tolorance of the gauge.After doing so the bullet sit nice and evenly without any wobble.

Guys if you sit a bullet into the forcing cone and apply a little finger preasure and it rocks back and forth to the point it looks like it could fall over i think that there is a problem.

I cast up some soft bullets and inserted one into the forcing cone and applied enough preasure that i could tell it was starting to seat.Removed the bullet and as i expected there were two marks on the nose from the lands where the bullet rested.

[Ed K]

Too deep might not be a big issue with a 1* angle but too deep at 11* will also likely be too wide - it is a "cone" after all.

[PacMan]

Yea Ed K being too wide at the mouth cant be good. This one is wider than my other two .357.

So Bill why do you think they will not sit squarely?

[44man]

Somebody turned the cutter back and forth, that will ruin it quick. They must never be turned backwards. There might be a burr rolled over, a stoning MIGHT work.
Long ago I cut my SBH to 11*. Just for kicks I made a WLN boolit mold with the ogive as close to 11* as I could. It really shoots great.