Rechambering/Gunsmith Reccomendations

[Major]

Here is an article that does a good job of explaining Headspace written by Walt Kuleck for FULTON ARMORY.   He explains all the different types of headspace very well:

http://www.fulton-armory.com/headspace.htm

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Here is an article that does a good job of explaining Headspace written by Christopher B. Ebert for the NRA in their NRA firearms factbook  3rd edition:

http://www.logicsouth.com/~lcoble/dir7/viif1.txt

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Here is another article about headspace written by Patrick Sweeney for PetersonÂ’s RifleShooter Magazine.

http://www.rifleshootermag.com/gunsmithing/headspace_0612/

He even points out that the .303 British has a problem because it headspaces ON THE RIM and the shoulder is too far away for full pressure loading and reloading.   The problem with the .303 British is that they were made with defective headspace to begin with and the three bolts you talk about was just a quick way to try to fix that manufacturing defect.

What you are doing Fred is not changing the headspace but just using the fireforming/resizing case trick a reloader uses to make brass that is not over worked.   It works but is not really headspacing.

[Fred M]

Major.
There is nothing new in these write ups. its old hat to me. Head space is as the word implies the space between the head of the cartridge and the bolt face or standing breech. By what means you establish that, as long as it is right, is of no consequence. Thre are no tricks to fire forming either as long as you know how and do it in a safe manner.

[Major]

We are on the same page here and agree Fred.   Trick was the wrong word to use.   I just meant that with fire forming (usually done with reduced loads) that almost any bad chamber condition can be overcome.   I just want some of these kids here to learn to understand and use the correct terms.

I was originally addressing someone that was saying they used a crush fit of .039-inches and that (if possible) would just be building a bomb.   Being an engineer by trade before I retired, I just have a thing for trying to use the proper terms when describing a condition.   Something I myself failed to do when I used the term trick when talking about fireforming to the shape of one chamber.   I should have said method instead.

It should be noted here, for those that donÂ’t know.   Most times, when a case is fire formed to one rifle chamber it may not work well (or safely) in another chamber of the same caliber.   It is all in how the tolerances stack up.
 

PS: Those links were meant more for others to read and study than for you Fred.   Sorry if I ruffled any feathers.

[Fred M]

Major.
We are on the same wave length. I am too an engineer, retired and old. I have a few years on you. My hobby is BR shooting and my hunting passion
is outfoxing the wily Canada geese using a 20 gauge Win 101 O/U with Kent tungsten matrix shot #3. This shot has steel shot beat all to dickens, it is even better than lead shot.

And of course wildcat cartridges of all sorts are on my mind most of the time.

I am not too sure how I got into this Handi business? :lol: When I got nothing to do I like to do in my reasonable appointed basement shop. Projects seem to be just piling up on me.

[wtxbadger]

Leftoverdj, I got the same advice from a couple of gunsmiths I contacted. They had no major concerns about pressures being to elevated with a .002 difference in diameters. This opens up the possibility of shooting the inexpensive surplus ammo and the factory manufactured hunting ammo. Looks like there are several companies that offer brass for handloading. This is begining to look like a good project to pursue.

I have several mosins and have been impressed with the accuracy of the rifles and this cartridge. Having a handi rifle in this cartridge would be a unique rifle.

Looks like this topic has generated a lot of discussion.

wtxbadger

[jbtazgrabber]

i guess people dont think 2 thousands of a inch is not enough...i do...what is sami specs on a 762.54???is it less oressure than a 3006????now how about a 2 thousands OVERSIZE.....bullet????in all my books i cant find any one shooting a jackedbullrt 2 thousands over???why????lead is softer than a jacked bullet...ok action strength???/you get what you pay for....this is not a ruger frame...ok im not a smith but have built probably more h&rs than most people own..3006 before they could get them out the production door..762.39  x 3 but still only 308 bullets...i wouldnt shoot 311 down a LOOSE 308 bore..please check specs on 762.54 pressure,,,

[Mac11700]

Major...

You were correct in stating that I forgot a zero on my typing...and that does make a large differnce..from now on I'll type in the  abbreviated word instead of the numbers for you because your intent.

It's very obivious that you haven't ever rechambered a break action rifle before since you don't know the term crush fit...in a Handi...when speaking of crush fit...one tends to think of something very bad...when in fact your doing this to keep something very bad from happening...and it's not unlike making a false shouldr when sizing down in calibers...

Fred has already explained to you the reasons why and I won't reiterate what he's said here...just to say...there are various ways of setting up to rechamber...and it  would be best to have discussed all the possibilities with your gunsmith prior to having it done...and if you wish to allow a 30-30 AI to headspace on the rim...so be it...that's your choice...but you also find that the best accuracy comes from setting it up to headspace off that wonderfull 40 deg. shoulder...



Mac

[wtxbadger]

jbtazgrabber, are the actions that weak? Maybe it is time to look at an alternative to the handi rifle for my family and I to shoot. Based on your concerns, it woud not even seem reasonable to have a 30-06 barrel fitted to my receiver and shoot the handloads I have for my remington bolt action. I am not being facetious nor belittling you with this post. If the guns are that weak then it is time to reconsider shooting the ones I own and my wife and son's rifles.

wtxbadger

[quickdtoo]

wtxbadger, I wouldn't worry about handi strength with any sane load that shoots well, too many people here have great shooting hot loads that are extremely accurate in calibers that are at the high end of non magnum and some magnum standard SAAMI pressures like the .25-06, .270 and .280.

http://www.leverguns.com/articles/saami_pressures.htm

[Mac11700]

jbtazgrabber:

If the bore is .308.....I wouldn't shoot any .311 jacketed bullets down it...it doesn't make sense to...and would be down right dangerous as well...if your loading hot for it...and from the 10th edition of Cartridges of the World...

With the 150 grain bullet,the 7.62mm Russian is in the same class as the 30-06.However,since the rifle has a shorter magazine it will not do as well as the 30-06 when loaded with heavier bullets( In a Handi...this wouldn't be a problem if it's throated correctly)..Although military bullets measure 0.309-0.311-inch in diameter,rifles with tighter bores will shoot 0.308 bullets just fine....Standard working pressure is about 45,000 PSI

So if your rechambering to this round...just get the appropiate sized expander/decap assembly for your sizing die...and you should be ok.

Mac

[wtxbadger]

Thanks for all of the feedback on this potential project. The rifle will not be rechambered to 7.62x54r. Anyone want to buy a bunch of weak actioned handis?  :wink:

[lik2hunt]

Anyone want to buy a bunch of weak actioned handis?

My good friend MSP Ret would be happy to take that 30-30 off your hands I'm sure. As for the rest of 'em post 'em with your prices.....they'll go like "hotcakes" :wink:   .

[MSP Ret]

:shock: , A 30-30 ? I must have missed it, I'll go back and check this thread right now!!! Put me in line as #1 for the 30-30!!!....<><.... :grin:

OK wtxbadger, just waiting for the list of those weak-actioned Handi's (and in particular a 30-30 barrel) at a good used price!!!....<><.... :grin:

[Leftoverdj]

now how about a 2 thousands OVERSIZE.....bullet????in all my books i cant find any one shooting a jackedbullrt 2 thousands over???why????lead is softer than a jacked bullet

I got lots of examples for you. Already gave  one.  Finnish Moison-Nagants have a .308 groove diameter and shoot 7.62x54R, which runs .310-311. Ruger used a .308 groove and a long throat on the early 7.62x39 Ranch Rifles.  European .22 Hornets usta run .221-.222 (may still do) and people shoot .223-.224 bullets through them. .44-40 barrels are .427 and people use .429 bullets in them. Norma usta sell .309 match bullets for use in .308 bores and some of those barrels would have run tight.

Most folks just don't appreciate how loose specs were pre-WWII. Barrels varied and bullets varied. Plus or minus .002 ain't nothing surprising.

[wtxbadger]

I would not dream of endangering anyone by selling them one of these rifles :roll:  Guess I will have to bear the burden of keeping them from injuring anyone :wink:
Now I just need to find the key to my underground vault and get them in there quick. You never know, one of them might let go without any warning. Would not do to have such a weak actioned rifle out where it could do harm to someone. :roll:
On the serious side of this issue it amazes me how on one hand the handi is supposed to be the next best thing since sliced bread, but then it seems there are some who consider it to be lacking in internal strength and quality but still buy them. Seriously, I shoot WWII made rusian made Mosins whose quality of construction would give you pause to use them, but here we have a modern manufactured rifle and the impression I got from several posters on this thread that they are one of the weakest gun actions made.
I enjoyed shooting my 30-30 handi, have been impressed with how accurate my wifes handi .223 is, and with a little more work my son's .243 will be a close second to the .223 in accuracy. The gist of my original posting was that I was hoping to have a handi rifle in a unique cartridge that performs close to 30-06 or .308 specs without having to spend as much as having a new barrel fitted by H&R.


wtxbadger

[Mac11700]

The gist of my original posting was that I was hoping to have a handi rifle in a unique cartridge that performs close to 30-06 or .308 specs without having to spend as much as having a new barrel fitted by H&R.

You can if you find a gunsmith that is willing to take on the project for that price...and loading and shooting the cartridge with .0308 diameter bullets in the Russian.. isn't a problem out of a 30 caliber converted Handi...there is some loading data available....and since the working pressures is well below what the Handi is capeable of taking with the current cartridge choice...that aspect isn't a problem either...

While the Handi...may be considered a realatively weak action..it still works great for me...it won't ever be loaded for the true Magnum class...but that's ok...if I want one of those...I'll buy a bolt action...or if I want a different single shot...then a Ruger...or a Dakota...

Mac

[Donaldo]

If we are talking about the SB2 action, why are some thinking this is a weak action.  The 243, '06, 270 and 308 are all loaded to about 52,000 psi if I remember correctly.  I would not consider this to be "weak" operating pressures.  Has anyone had a SB2 action fail.  Has anyone loaded anything really hot?  I think the new WSSM's are loaded to 65,000 psi.  In my opinion that is the main reason they out velocity some of the old standards.  Load up a 243 to 65,000 psi and it will probably have the same velocity as the 243 WSSM, or more.

[Major]

Donaldo,

It isnÂ’t just chamber pressure that has to be considered here.   It is the amount of back pressure (rearward movement) that is put on the case head that presses rearward on the standing breach action (break open action) like HandiÂ’s and even the T/C Contenders and Encores.   To put it as simply as possible it is the actual loading onto that standing breech which is a function of total case pressure times the diameter of the case head.   A small diameter shell will push backward less than a large diameter shell even though both have the same total chamber pressure.   It is this back pressure that is the reason T/C came out with the Encore to cover the rearward loading the Contender canÂ’t handle even though several of the Contender chamberingÂ’s are for high pressure rounds.   If you do a study you will find that some Contender frames were actually stretched because of case head pressures that were to high for the frame to handle.

To put it another way 65,000 PSI (Pounds per Square Inch) will not push as hard on a1/2-inch area as it will on a 3/4-inch area or a 1-inch area.

That is also the reason the SB-1 action canÂ’t handle the same rounds as the SB-2 can.   ItÂ’s action is of a different material that isnÂ’t as strong so canÂ’t take the same amount of rearward movement.

[wtxbadger]

Major,

While I would I agree with you on metallurgy in actions, your statements on distributed load force is the reverse of basic physics.

wtxbadger

[Fred M]

wtxbadger

your statements on distributed load force is the reverse of basic physics.

Perhaps you can enlighten us on the basic physics as to how case head pressure works on a standing breech or a bolt face?

[Major]

Contained pressure pushes equally in all directions at the same time and each direction must be contained or you have movement.  

PSI means Pounds per Square Inch.     That word “PER” is very important so donÂ’t overlook it.     If you have 65,000 PSI then you feel 65,000 pounds on each one square inch of area that you have.     Two square inches feel 65,000 pounds in each square inch or a total of 2 times the 65,000 PSI.     Three square inches will feel 3 times the 65,000.     So you have 65,000 on each square inch times the 3 square inches.     Ten square inches will get 65,000 pounds on each and every one of those 10 square inches.

Now if you have half of a square inch how much do you think you feel?.     How about a quarter of one square inch?     Does that help you understand how it works wtxbadger?

[Donaldo]

I fully understand psi, (pounds per square inch).  If you will notice all the rounds I mentioned have the same case head dia.  Except for the WSSM. I was not suggesting the handi be chambered for the WSSM, which does not do anything a good 243 or 6mm Rem can do.  I just said that the standing breach frame takes the loadings of '06 and 270, that does not sound like a "weak" frame to me.  I have since read, I think in the new "Rifleman" that the 270 is loaded to 65,000 psi MAP.  That is maximum average pressure.  The area of a standard 0.473" dia case is 0.1757 square inches.  At an operating pressure of 65,000 psi, doesn't this give a theoretical backward thrust of about 11,421.5 lbs., (thats pounds not psi) assuming no friction between the case and chamber.  If the handi SB2 can take this kind of loading, it sounds like it is pretty strong to me.  I know it is not as strong as a good bolt rifle, but it is not necessarily a "weak" frame.  Now tell me if my calculations are correct.  :wink:

[Mac11700]

Donaldo:

While some of the folks thinks the Handi's a weak...they really aren't as some of the older variations on the market...and they do a good job with the class of cartridges available...and you are right about the 243...it's a fine cartridge...but as I understand it...it seems NEF put the wrong twist in a-lot of them...and the folks can't stabilize the heavier bullets...I don't know...I haven't had a Handi in that caliber...but I do know a few guys at work that have a couple of the older ones...and they do shoot great.....my good friends 9 year old son took a dandy 10 point buck on this years youth hunt with his...


Mac

[Fred M]

Donaldo.
The back or thrust pressure can only act on the base aria inside the case which is considerale swaller than the cartridge head. At the pressure ring the case O.D. measures .468". The case walles at that point are about .040" or more. So the effective area the pressure can work on is only .388"in diameter. The area is .118 sq/in" x 65kpsi= 7681 lbs. That is close to 1/3 less than you quoted.

The 3/8 hinge pin if the steel yields 125kpsi will be more than enough to retain 7670 lbs. Of course allowable design shear strength of the pin will be less. Forget about the reduction of back thrust because of case kling to the chamber.

That idea is in totall error. How can low tensile strength metal like brass retain a pressure of 65kpsi. At that pressure brass starts to become plastic. The rear part of a cartridge case is solid brass and does not expand so it got only one way to go and that is against the breach or bolt face.

The cartrice walls do indeed stick to the chamber walls but not the solid part. That is why you get case head separation with too much head space,or repeatedly shorten the case by too much sizing. The separation always occurs at the pressure ring, about .200" above the base.

[Major]

You are so right here Fred.   In my example above I was trying to keep things simple but in fact the pressure does only react upon the inside of the case head which, as you point out, is smaller than the case head (or bolt face) so that reduces the back thrust loading even more than I had mentioned before.   Good catch there.

[wtxbadger]

Well gentlemen, wtxbadger bows out of this one not so gracefully and leaves this discussion to those more educated on the matter.

wtxbadger

[Donaldo]

I think, more or less, that is what I said.  Maybe less than more.  But you get the idea.  I still say, the SB2 is not a weak action, maybe not a really STRONG action but not weak, and that was my only point.  The SB1 is a weak action.  For what ever reason, I don't know.  Maybe it is the pin through the action, maybe it is the steel the action in made of, maybe it is the heat treatment.  Whatever, it is apparently a weaker action than the SB2.  Why doesn't NEF just simplify the  problem and make all actions of the SB2 strength.  Couldn't cost that much extra could it?  What 2- 3- 4 or 5 bucks.  Come on NEF.  Get on the ball.