Chambering

[ChrisT]

I been pondering this question and been reluctant to ask but,what chambering a barrel ,supposing the counterbore for the bolt nose was done away with and the tenon cut accordingly to suit what would be the outcome?.
In effect the chamber would not be recessed and it bolt nose was say held 5 thou clearance from rear of the chamber,would this be a problem?

 

[Dusty Stevens]

If its a remington youll need a rod to knock the fired brass out since you wont have an extractor anymore

 

[jkohler]

On a Remington I imagine your talking about. Your basically doing away with one of the built in safety's. There three rings of steel. Doing away with it would have no advantages or disadvantages unless you had a case failure.

 

[Dusty Stevens]

Oh sorry i thought you were talking about modifying the bolt til i re-read your post. It may also affect your feeding just having a flat wall instead of steps

 

[ChrisT]

I was thinking Rem,Stiller etc,only disadvantage I can see is as has been mentioned if there is a failure of the case,but if loading within known boundaries and using good brass would it be a problem,I suppose I am being lazy but its one less step when chambering.

 

[Preacher]

Buy one of PT&G's 705 counter bore reamers and you'll do the job in a matter of minutes..
It takes longer to find the correct bushing than it does to do it...

 

[Erik Cortina]

You are correct, you are being lazy.

Is this barrel for yourself or a customer?

 

[ChrisT]

Erik its for myself,I am just starting out and thought i would ask,if there wasn't a problem and no danger or harm in not doing a counterbore then i don't see a problem.

 

[Keith Glasscock]

These pictures were taken at our last month's 600 yard match.

The shooter is a seasoned shooter using a known safe load that he has used in that barrel for 2000 rounds. The brass was brand-new, first firing. The cases of the 5 shots immediately prior, and the string before that showed absolutely no pressure signs. Due to case volume limitations, it is not possible to double charge.

I was about 6 feet to his right when it went. Sounded like a grenade. He got a face full of burning gas.

He was fortunate in two ways: First, he was wearing safety glasses. Second, and most importantly, he had a properly fitted barrel in a super-strong custom 3 lug action and it held. The immediately visible damage was the extractor.

The shooter, being conservative, is going to have the action evaluated to see if it is still usable.

Why this long story? Because the three rings of steel in the Remington design is the difference between getting a little gas in the face and getting chunks of metal. I realize that Savage does have a flat face, but I think that going with the original design is the safest and best idea.

Keith

 

[ChrisT]

Ok I can see your point,I asked cause I really don't know and if I compare say this to a Coned bat I couldn't see any difference between the two......that is unless I am missing something,educate me please.
Busdriver in that picture is that the three rings of steel that you refer to?

 

[Tzed250]

Three rings of steel=

Bolt face counterbore
Barrel tenon counterbore
Receiver

 

[ChrisT]

Do Coned bolt faces come under the bolt nose counter bore ,three rings of steel classification?.

 

[Erik Cortina]

ChrisT, cutting corners is a really bad way to get started in Gunsmithing. Do it right or don't do it at all. My $.02

 

[ChrisT]

Ok I could leave this thread at that but why is it considered cutting a corner or not doing it right?,obviously it is an accepted practice to counter bore on Remingtons etc but why?,is it something that is "just done".
I am looking at tenon prints and see quite a few that have coned bolts and they dont have the "three rings of steel" does that make them any less safe,any less usable?
Yes I am a newbie to smithing but I like to know the why's and where fores,I am a heavy diesel fitter of 26 years so I know how to measure and such but I dont see why say a counter bore for the nose of a Viper,Dback,etc is needed and just because thats the way its done ,or "just because" dont make it right,its ok to say its the lazy mans way or its cutting corners but tell me why it is.
I am not trying to be argumentive but I have seen and used rifles,barrels done this way and I dont see any negatives but dont see many discuss this subject either.


Regards Chris.

 

[Erik Cortina]

Ok I could leave this thread at that but why is it considered cutting a corner or not doing it right?,obviously it is an accepted practice to counter bore on Remingtons etc but why?,is it something that is "just done".
I am looking at tenon prints and see quite a few that have coned bolts and they dont have the "three rings of steel" does that make them any less safe,any less usable?
Yes I am a newbie to smithing but I like to know the why's and where fores,I am a heavy diesel fitter of 26 years so I know how to measure and such but I dont see why say a counter bore for the nose of a Viper,Dback,etc is needed and just because thats the way its done ,or "just because" dont make it right,its ok to say its the lazy mans way or its cutting corners but tell me why it is.
I am not trying to be argumentive but I have seen and used rifles,barrels done this way and I dont see any negatives but dont see many discuss this subject either.


Regards Chris.

Ok, the reason it is done that way is for safety. If you every over-pressure a case the bolt nose will expand into the counterbore and seal most of the gases, it is a great design.

Here is the bottom line, if you are not doing it like the original design, you are cutting corners. Lets take a coned bolt for example, you could technically do it without the cone, but you will sacrifice feeding and also gasses will flow easier if case rupture happens which would not be good.

 

[ChrisT]

AhhhHaaa so its to save us from ourselves,I have been shooting and reloading for a little while now and never had a case head separtation,case rupture or a locked bolt,so given that then I would be safe to assume that there is no real reason to carry out that extra step.
Having said that like yourself and others have pointed out its not an overly labourious task to do ,like cleaning primer pockets some think it dont matter others couldnt sleep at night knowing they didnt do it.

 

[Erik Cortina]

Yeah, it's not hard to do. I single point cut it and I can do it in less than 5 minutes.

If you do away with counterbore, you will also have less thread engagement between tenon and action and a huge gap between barrel tenon and lugs.

 

[ChrisT]

Ok Erik you have convinced me to do it,now do I single point or purchase the tool, from PT&G.

 

[Erik Cortina]

Ok Erik you have convinced me to do it,now do I single point or purchase the tool, from PT&G.

Just single point it. Buy yourself a good small boring bar and you can do it with that or grind yourself a HSS tool for it. It's easy.

 

[tclaunch]

I use a Circle titainium coated micro boring bar for the calibers I don`t have the .705" counter bore, works like a charm, but the counter bore is much easier. The circle boring bars are over on E-Bay for prices in the $20.00 range