Contender™ and Encore™
Question and Answer

This will be a page of information taken from email and other media so as to expand dissemination to all those in the TC fraternity.  If you have questions for Mike, please email him.


Oversize hinge pins and lockup

Issue:
David Hea got two barrels from Virgin Valley that I chambered for him. They fit and functioned fine on my frame and according to the letter back from Virgin Valley, they functioned fine on their shop frame also. But the sizes and locations of the frame hinge pin holes vary, as well as the height of the locking table in the frame, and these two barrels would not function on David's frame at all. They would not lock up enough to allow cocking the Encore's hammer.
Jeff at Virgin Valley found that with some play at the hinge pin using the factory hinge pin, the barrels functioned fine.... on their frame. But when my oversize hinge pin was installed and the "play" at the hinge pin removed, they would not function. The following is my reply to David.



Response:
Hi, David. I am finally getting into the emails and now see what spawned the thread on Accurate Reloading.

Follow this line of logic. If there is play at the hinge pin, when closed the barrel can move upward some. This lets the barrel teeter over its seat in the frame at the rear and lowers the locking bolts a little for a what appears to be a normal lock up. Take the play out of the hinge pin area, and the barrel cannot come up any at the hinge. Thus the locking bolts cannot drop down as far. Naturally, if they cannot engage the frame far enough, they cannot move the interlock back enough to allow cocking the hammer.

Jeff is being somewhat coy about another issue, and that is the vertical location of the barrel hinge pin hole in relationship to the barrel itself. This effects lockup also, I know. But it is quite obvious, or should be, that if it will function with shake and rattle at the hinge using the standard pin and won't function with the oversize pin, it is due to removing the slop at the hinge. Period. The size of the hinge pin is the only variable, right?

Bear in mind also that frame dimensions vary from one to the next. And just because the barrels function on their frame, or frames, does not mean they will function on yours. They should fit the barrels to your frame if they don't function. They have an FFL and you can ship the frame to them, which you should have done in the first place. Hindsight? If they won't fit the barrels, I will be glad to fit them at no charge for my labor if you will pay the dealer's FFL fee on my end, $20, and about $17 for return shipping the barrels and frame separately by ground. Fitting is no big deal.

Encore pin instructions are not as detailed as the instructions with the Contender pins which do mention this fact. I believe it is mentioned on the web pages also.

 


7x57 using 444 brass

Question:
I saw a contender bbl made for a rimmed 7x57 using 444 brass.  The owner says it uses 7x57 load data.  Is this possible? If I understand things correctly, the pressures are too high and the bbl "shouldn't" last.

Response:
Like everything else in the Contender, it all depends on the  pressures, but more specifically the actual thrust or "push" coming out the back end of the barrel.  Not taking into account the strength of the brass itself and the shape of the chamber, but only calculating the actual cross-sectional area of the chamber mouth (at the head of the case) times the nebulous pounds per square inch generated according to published ballistics of the various possible factory cartridges, it appears the frame will withstand up to about 8,000 pounds of actual "push" against it, also referred to as "setback."

Do the numbers and you will see that a  .223 Rem. at 55,000 psi falls under the 8,000 pound mark, and a .308 Win. at 55,000 psi is above 8,000 pounds.  Frames live happily ever after with 55,000 psi .223's and have been know to stretch badly in just a few rounds of .308 Win. when fired by nimrods bound to try it.

The numbers.... Area=3.14 x radius squared.  This fraction of a square inch x the pressure.

This is not presented as the "end all"  scientific determination of what works and what doesn't, but in comparing cartridges, it gives a good benchmark from which to work.   Compare it to highway speed limit signs.  Most states will let you run say 5-7 mph over the posted limit, but a Wyoming highway patrolman that pulled me over doing 82 mph in a 75 mph zone stated emphatically that 75 mph was the maximum speed  in his state.  I got away with it all across Wyoming one way and most of the way coming back, just like Contender shooters do trying to stretch the limits.  Now, I could have set the cruise control on 82 again when he was out of sight and maybe gotten away with it some more,  but I got off with just a warning the first time.  Next time it would cost me.

Where is this going?  When loads become hot enough that the frame becomes hard to open, you just got a warning ticket.  Reset your powder measure, or next time it may cost you a stretched frame which TC will pay for, but it can also cost you a stretched barrel lug.  If it is not a factory stock TC barrel, it comes out of your pocket, not TC's.

While the above may sound like preaching from the soap box, it is meant to put things into perspective.  Nothing personal.

So how does this apply to the 7mmx57 rimmed, which is what this cartridge technically is, that is also commonly used in European break open guns?  7x57 is normally about a 45,000 psi round, and with this head size, 45,000 psi is ok in the Contender, SO LONG AS the highly tapered case is not setting back too hard against the breech face of the frame as indicated by hard opening, specifically hard unlocking of a barrel that normally unlocks ok.

If it unlocks hard, you may have to back off to loads lower than normally published for 7x57.  This is more likely to occur in the factory 8-groove barrels with the extremely wide, ill-conceived rifling design TC used for years.  Normal narrow rifling in custom barrels are less likely to be a problem. 

I see this all the time test-firing barrels.   Loads that are max in the factory 8-groove barrels can nearly always be bumped up another couple grains (about 5% for the larger cases I am usually working with) when I test fire the same chamber in a custom barrel with narrow rifling.  So DO take into account the rifling design in the barrel.  This applies to all factory barrels from 6mm through .30 cal.  .35's are questionable, but do not throw a red flag in the air, and  I observe no problem with the .375s and up.  But there is nearly always a difference that shows up in the 6mm through .30 cal. range.

Back to your original question, I think I have answered it in regard to whether the barrel will "last" or not.  This depends on the operator, not the cartridge.  However, I nearly ALWAYS try to steer shooters away from tapered cartridges and get them into something straight walled which acts more like a cork holding the pressure in the barrel instead of being more prone to sliding back like a highly tapered case does.

So, would I recommend 7x57 or 7mmx57 rimmed in a Contender?  No, I would not.  Would I chamber for it?  Yes I would, and I have, and btw, I am told it is very accurate, but this is more of a function of the throat than it is the cartridge.  Anything can be accurate if throated right, and the best benchrest cartridge can be purely lousy if not throated right.

The above is more than you bargained for, but I hope you find it helpful in understanding what works and what doesn't in a Contender.

All the best,
Mike Bellm


7.62x39 Imp

Question:
In a link to you that is no longer active I noted a statement that you have over 500 chamber reamers. It is for that reason I am making an inquiry.  I am a member of the CBA and am interested in doing some exploratory work on the development of a small, high efficiency cartridge in .32 caliber similar to the .30 BR for use with cast bullet benchrest shooting. Since I am neither a smith nor a machinist I must approach all my projects by hiring the work done.

The concept of first developing a TC Contender carbine barrel of 24" length gives me the option of using the cartridge for other types of shooting even if it does not show the potential for accuracy necessary for benchrest shooting.  I have been unable so far to find anyone with an improved version of the 7.63x39. Do you have one? My interest in the "improved" chamber is to have sufficient shoulder diameter to provide solid headspace after the neck is opened up to accept a .32 caliber cast bullet. If you do not stock such a reamer can you suggest who might? Thanks for your consideration.

Ken Ewing
Lowell, MI

Response:
Ken, about 10-12 years ago when TC was first producing .32 H& R Mag and .32-20 Contender barrels, I made up a set of 7.62x39 Imp reamers and did quite a bit of work trying to make rechambering these equal land and groove barrels work. The idea was to drop the pressure enough with the increased chamber volume to permit shooting standard 7.62x39 ammo in rechambered Contender barrels.

The bottom line is, it did not work, even with throating for the larger bullets and throating longer. Pressures were still way too high.

I had made standard 7.62s in custom .308" barrels with narrow rifling, and while marginal, it was still a viable proposition. But in the equal land and groove TC barrels, it was a definite "NO GO." Even commercial ammo opened primer pockets.

I made a half dozen or so die sets for .308x39 Imp. and marked rechambered barrels like this, indicating that they were set up for .308" bullets, not stock .310" bullets used in military and commercial ammo.

The round is a good one and interesting, but the field of barrels to rechamber and the cost & hassles of custom dies took the fun out of it.

As with all things requiring custom dies, I personally do not want to take the time and responsibility for chasing them down. You come up with the dies and a barrel to chamber, and I will be glad to do the chamber work. I may have to do some digging, but can probably find a fired case or two to use as samples to have dies made if you go that route.

RCBS custom die prices had gone through the ceiling before they sold out, and now that Alliant has taken them over, I am not sure of the status of the custom die department. Redding is pretty amenable to making custom dies, and you might try them. CH has been making some custom dies for me in quantity, but it takes close to a year to get them. By and large, I do not care for Hornady dies. Don't know what Lee and Lyman do for custom die requests.

While I have made a fair number of dies, it is not cost effective for me to do so on a conventional lathe, and I really do not want to take on making any dies at this time. My plate is too full already, and I am trying to work toward making barrels again while continuing to work alone.

Again, if you can come up with the dies, I am glad to cut the chamber.

There is one ray of hope in this regard. A couple years down the road, I may make barrels in quantity chambered for a shortened 7.62x39 Imp. version, and if I do would have dies made in quantity to support these barrels. The dies could be used for the full length version as well, but again, this is a "definite maybe," and it will be quite some time from now.

Hope this helps.

Mike

 


Forming .25-06 Improved Brass

Question:
Mike:

I recently found your site and have learned alot from it.  Thanks for all the info. I hope you can find the time to educate me a little more. Could you please provide me with the best method for forming .25-06 Improved brass from standard .25-06 brass in an Encore?  I have read several comments about doing this, but none were in reference to an Encore. 

Also, I am about to order your CD-ROM for Encore trigger jobs.  I will have three of these to do (myself and friends).  Thank you so much for providing products that are educational as well as economical.

Thanks again,
Kelly Ray
Cape Girardeau, MO

Response:
P.O. Ackley defined an improved cartridge to include the requirement that it fire factory ammo, or factory new brass necked up or down as the case may be, without stretching the case.  IF the person doing the chamber work cuts the chamber to the correct depth, which is by Ackley's definition at least .004" shorter than standard, then all you do is fire the standard ammo in the imp. chamber.  However, two things can occur to effect this.

1) The standard round headspaces on the neck shoulder junction in the imp. chamber.  The shape of this point varies on the brass case and also in the chamber.  Thus sometimes even the .004" shorter headspace is not short enough and will still stretch cases. 

2) Add to this the fact that when the firing pin drives the case forward in the chamber, the headspace point at the neck/shoulder junction sometimes collapses to varying degrees.

In either of the above situations, it is sometimes necessary to take additional steps to insure that no stretching of the case occurs during fire forming.  One method using a highly compressed charge of slow powder with the bullet jammed firmly into the rifling is described on the website.

One point is absolutely necessary to keep in mind.  If on any Improved cartridge, the primer protrudes from a fire formed case, then the case is too short from shoulder to head, and when it is loaded to full pressure, it will stretch.   I.e.. primers should NEVER protrude from fire formed cases.  If they do, you need to take additional measures to make sure your fire formed cases fill the space from the headspace point to breech face or bolt face completely.

Tip:  If you close the barrel in the frame with a standard round in the chamber, it should show a bright ring at the neck/shoulder junction when you remove it..... without firing it.  I.e.., there should be a tight fit at the neck/shoulder junction.

An important point to be made is that you cannot rechamber an existing .25/06 (or any standard chamber) to its improved counterpart without setting the barrel back.  And with the lug welded on the barrel, this is not practical to do.  On a fixed barrel receiver where the barrel is threaded into the receiver, it is a simple matter to face off appropriate surfaces on the barrel and simply screw the barrel in further, thus moving the existing neck/shoulder junction back..... then rechamber.  Again, this cannot be done on these break open TC firearms.  You have to start with a shorter chamber such as .... .256  Win Mag, .25-35, .257 Roberts, etc. in order to rechamber to .25/06 Imp.

A final point.  You can rechamber the .25-06 chamber to the improved configuration, cutting the chamber deeper than normal, and take measures to fire form the shoulder forward correctly.  But since it will not fire the factory ammo without stretching cases, technically, it is not an improved, but something else.

Tip:  Neck down .30/06 brass leaving the neck and new shoulder junction on the case far enough up the .30/06 neck to get tight head-spacing on it.  It will be simply a step on the neck where you stopped necking it down to .25 cal.    This can be done with a standard .25/06 die backed off the appropriate amount.

Another tip:  Starting with the .25/06 chamber, you can cut a .25x.280 Rem. Imp. chamber, which is about .050" longer from head to neck/shoulder junction, and have a true improved chamber.

RE: the CD - You're welcome.  But also, you get the satisfaction of doing it yourself, and I get to spend more time doing machine work instead of bench work.  So we both win.

All the best,
Mike Bellm


7mm Bellm #2 Encore

Question:
Interested In Your 7mm Bellm #2 Encore! When will this info be available on your website??? I will be ordering
a second Encore barrel soon and would like to know more about your #2 7mm Bellm as it compares to the 7-08...
Is there any advantage to a rimmed case vs. 08 cases with the Encore?
Are the pressures the same?
Velocities with the heavier bullets for hunting?
How does it compare to the Contender 7mm Bellm?
Same 444 Marlin case?
What would be the best stock barrel for you to rechamber a #2?

Thanks for any "nuggets" Mike.

Sincerely,
David M. Cleveland
Olympia,WA. 

 

Response:

Q.)When will this info be available on your website?
Should have been done a long time ago, but Contenders are still getting the most of my attention.  Thanks for the nudge though.

Q.) The 7mm Bellm #2 as it compares to the 7-08?
In a handgun it closes the gap some between 7mm-08 and .280 Rem.  Capacity is just below that of .30/06. But main purpose has been to get rid of the factory throat and cut a new one aligned with the bore.

Q.) Is there any advantage to a rimmed case vs. 08 cases with the Encore?
Certainly.  The rim is always an asset, if for handling purposes only, it is still better than rimless.

Q.) Are the pressures the same?
Yes.  Same as 7mm-08.

Q.) Velocities with the heavier bullets for hunting?
No data on hand, but with the added capacity for slower powders, yes it is quite safe to assume it will handle heavier bullets better.

Q.) How does it compare to the Contender 7mm Bellm?
In terms of velocity, no comparison since pressures must be kept lower in the Contender. Neck is longer on the Contender version, thus body is longer on the Encore version.

Q.) Same 444 Marlin case?
Yes.

Q.) What would be the best stock barrel for you to rechamber a #2?
7mm-08.

The Encore  "No.2" versions of both 7mm Bellm and .308 Bellm have not received a lot of attention, and I have only done a few here and there.  But as time goes on, I will be putting up more info on them.  They are excellent rounds, but demand for Contender work far outweighs the demand for Encore work here, and thus I have not done much with the No.2s.

Note that I did not suggest a .358 Bellm No. 2.  Wonder why?  It already exists as .358 JDJ, or .35x.444 Marlin.

All the best.
Mike Bellm

 


Seating Depth Short Course

Question:
How dose one find setting depth of a bullet. I know one should be 0.005 back off the lands. But how dose one find that depth???

Mike M.

Answer:
There are about as many theories about seating depth as there are people seating bullets.  So .005" off the lands may be a good spot or not.  You have to experiment to find where your barrel wants to shoot.

In short:

1) Use feeler gauges to measure the distance from the end of the barrel to the breech face by closing the barrel on successively thicker gauges until one is snug

2)  Take the barrel OFF of the frame.

3) Size your cases so they will protrude from the end of the barrel .001" less than the above barrel to frame dimension you obtained.  You can compare the case head protrusion to your feeler gauges, or you can buy a machinist's depth mike.  Careful measurements with a caliper are ok, too.

4)  Start a bullet into a properly sized case.  Drop the case into the chamber, gently press the case head into the chamber, and note how far it sticks out the barrel.  The amount it sticks out is the amount the bullet must be seated deeper in the case until the head is back to the original position you obtained in 3) above.

5) Turn the seat stem down a bit at a time and try the case in the chamber until the case head is back to its original position.  Try it several times to verify you are at "zero."  Once you find zero make a note of the overall cartridge length with that bullet.   You can seat bullets more or less deeply from this point until you find where your barrel shoots best.

For fine tuning the seating depth, use the threads on the seating stem like a micrometer.   Find what the number of threads per inch is on your seating stem.  RCBS for example uses a 1/4x28 thread, or 28 threads per inch.  Divide 1 inch by 28 to get the span between threads.  In this case, it is .0357, which means that one full turn of the seat stem is about .036" up or down.    Half a turn is .018," and 1/4 turn is .009," etc.  1/8 turn, half of a quarter turn, is .0045" and is under the .005" order of magnitude you need to work with.  Half a quarter turn is easy enough to see.

This is not a perfect world we live in, so you will often see that the bullet is not contacting the rifling perfectly straight on.  Thus you will have some difficulty establishing exactly at what point the bullet is in contact with the rifling.  Eliminating as much bullet run out in the case as possible makes this easier and also improves accuracy of course.  All you can do is the best you can.  I do everything I can to keep the chamber, throat, and bore all lined up, but seat dies often do not get bullets seated perfectly straight.

Hope this helps.  Anything else, just let me know.

Mike Bellm


Choice of elk cartridge in an Encore for this fall

Question:
....after a long day of hunting last Nov. around the fire, one of the guys created a new theme for this elk season; we would all acquire single shot rifles....Kenny wanted the Ruger(280), Jose' wanted the 1885(45-70) and I would choose the Encore....All our own personal
fav's....Well, I now have mine with the .223 tube (for fun) and your #1/#2 pins.  I was about to order a 7mmRem. or 300 Win. until I stumbled across your website recently....After reading Mikes' stuff and still reading more "stuff" I want you thoughts on cal. selection for Elk on the east side for Nov....never hunted there before....The only thing I do know is that I want a Bellm-cut chamber/throat no  matter what the cal.  Also I guess that a rim & the Encore go hand in hand....The more I read about the .308 Bellm (compared to Mikes' 7mm), it might be more suited to the task at hand?.....Accordingly, I buy into the heavier (Strong) bullet/slower speed camp (180's-200's)!....Do you agree?....

Answer:
Depends on what the conditions are. I got quite a "come uppance" from a gent named Larry Young in Utah. For years I held that until you moved a 180 gr. bullet 3000 fps plus, you made little or no gain over the standard .270 Win, .280 Win, .30/06 type cartridges. So if these are not elk rounds to one's way of thinking, then elk rounds must be 180 gr. bullet at 3,000 fps. plus.

Then I met Larry, tried to insinuate he was irresponsible for shooting elk with a standard .22-250, and was promptly shot down for my efforts. Trying to negotiate his front room for all the huge elk racks taken with a standard .22-250 should have been sufficient evidence to support his position. However, it took awhile for me to see the light. Now, I am not so sure about my original position regarding what makes an elk cartridge.

What I might consider ideal, according to Larry is totally absurd, useless stupidity. Know what? He might just be right!

I'll hold this a bit short of all the details, but he shoots low behind the shoulder, ie., heart shot, never loses an animal, and never has to track them any distance. They get stung instead of taking a walloping that kicks the adrenalin into high gear, bleed out quickly inside, and die.... simple as that. A .22 LR would do well also probably, but it just would not do it as far away.

Bottom line, chapter and verse of Larry Young, is put the bullet where it counts. Quoting a veterinarian friend from Illinois who found out the hard way, "A gut shot is a gut shot, even with a .458 Win. Mag." For what it's worth.

A larger caliber in the timber is ok so long as you can shoot it well. That is the key. And since most people don't shoot big guns well, most are far better off to use something they CAN shoot well, well enough to poke the heart at whatever the distance, though I will make allowances for bigger calibers on angling/front/rear shots where penetration is crucial to reach vitals. I personally have only shot one elk in the heart since getting pulled up short by Larry, and it was with a hot .30 cal. of mine similar to the old .30 Gibbs & approaching ballistics of a .300 Win. Mag. Other shots have been less than ideal.

So, I'll let it rest at that.

If you cannot buy into the small caliber school of thought.... and, btw, I have seen first hand 85 gr. Sierra boat tail hollow points from a standard .243 Win. go through both shoulders on a cow elk & drop it quickly....... I would suggest either 7mm Bellm No. 2 or .308 Bellm No. 2 if you don't go to a magnum.

First off, the 7mm Bellm, .308 Bellm, and .358 Bellm I reserve solely for Contenders. The little known as yet No. 2 versions follow exactly the same line of reasoning and handling as the Contender versions, but the shoulder is farther forward, thus the neck is shorter, and a .444 Marlin size die is mandatory to reach and size the case webs. Ie., you use standard off the shelf dies in the appropriate caliber to size the necks, locate the shoulder, and seat bullets.

Case capacity is just below that of a .30/06, about 54 gr. depending on what the powder is. As a 7mm it will have the rim, of course, and not be too far behind the .280 Rem. .30 cal. version will be close to .30/06. You could also do the same thing with rechambering a .260 Rem. barrel to the same configuration. Of these, the .260 version would probably be the most efficient of all, easiest to shoot, and flattest shooting.

These three choices are what is available that you would be able to get done in the span of time available with fall coming up. Anything custom would not likely make it in time.

Mike Bellm


Lug Welding

Question:
How much does the heat from the lug welding process effect an **already cut** chamber area on a given barrel destined for Contender/Encore use, in terms of warpage and other stress related effects?

Sean HHI #7364

Answer:
Sorry I can't give a more highly technical response than 1) heat does move metal, and 2) in principle, I don't the idea of welding on a chambered barrel at all.  How much does it effect a barrel that has more metal in this area because it has not had the chamber cut prior to the welding process?

The greater the mass of metal the less distortion I would expect to see.

What I DO see is a significant amount of warpage up and down in most barrels.... except Virgin Valley's barrels which show very little such warpage in the form of run out in the bore. They claim to put as little heat into the barrel as they can by doing the welding very quickly. This may be true. However, I always feared a brittle weld and had the shop I farmed welding out to do a preheat to the barrel and lug to a specified temperature, plenty of heat applied to the weld area using a moderate tensile strength fill rod, then packing the barrels in silicon bat for a very, very slow cool down. Barrels welded one day would still be too hot to handle the next. This was done for stress relieving the weld, and I never lost a lug, nor was there as much run out due to warpage as I commonly see in TC factory barrels, for example.

My opinion is that the welding should be done first, the bore dialed in "true" for chambering, and thus there will be no change in straightness or roundness of the chamber to even consider.

Virgin Valley may be quite on track in regard to a quick weld, and so long as they do not lose lugs due to a brittle weld, the end results so far as I can see have been quite good. Will I do it this way? Call me chicken for now. Scares me, and I'm fearless. 

Mike Bellm


 

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