Could someone point me in the right direction for a defination of chopper lump barrels and also monoblock barrels? I take it chopper lump is better?
Any help appreciated.

Stu,

Here you go:

Hallowell

Regards,

Terry

Hallowell is the proper place to go for a description of the defferences between the two systems! Here let me say the "chopper lump", and the "dimiblock" are the same system, and monoblock is the other one! DIMI-BLOCK simply being the Germanic name for Chopper lump!

The two systems are different in the way they are made, fitted, and hardened, but the end result is the same when the firearm is finished, as far as the shooter is concerned, if equal care is taken with each!

At the risk of being lynched, by the purests on the board, I will say the chopper lump, being considered the better of the two systems, by most, double rifle collectors, the Monoblock can be the better of the two, in some cases!

I will explain what I mean by this statement, before I get killed!

The chopperlump barrels are one piece, with half of the lumps being part of each barrel it's self, then soldered together between the barrels, then fitted to the action. This is a labor intensive opperation, to fit, haveing to handle the whole barrel assembly, during this operation. Additionally, the surfaces of the bites must be surface hardened, without damageing the chamber area of the barrels, which must be of a different hardness! With a one piece of steel, needing two different hardnesses, so close together,the transition between these two different hardnesses, sometimes can form microscopic cracks, and it is very hard to stress releave the barrel butts (chamber areas), and the lumps without one or the other being too hard or soft!

On the other hand, the monoblock, can be fitted in it's soft state, and then hardened through, and through, before final fitting. This limits the stress differences between the chamber area, and the lumps, and can readily be stress releaved.
The barrels are then sleeved into the monoblock, and can be left at it's most elastic state, like the rest of the barrel.

IMO, if properly done, there is no parcticle difference in the finished product, other than price, with the chopper lump system being far more expensive, and frankly is not any better than the monoblock. Other than price, and nostalgia, they are the same if both are quality rifles! Most old double rifles will be Chopper Lump, or two barrels, dovetailed, and soldered to a one piece lump, the former being far superior to the latter.

All Mono-block barreled doubles will be comparitively new, made after about the early fifties!

The one problem with the mono block rifles is, there are some very shoddily produced rifles amoung them. Far more than those in the chopperlump rifles. As long as you buy quality, the choice is your's, and depends on what you want to spend the extra money on, that is required for the chopper lump Barrels.

The only flaw I can find in Mac's excellent explanation is that "demi bloc" means "half-block" in... French.

Thanks for the replies. Terry - I knew someone had posted a definitions link sometime in the past but as always I didn't save it to my favorites. Thanks for coming through with that one. Mac - thanks for the extra explanation. I noticed Searcy's specs include monoblock barrels and that raised something from deep within my memory about monoblock being inferior to chopper lump. I was trying to work out why he chose monoblock.

While I've got your attention, I also noticed Searcy makes his double rifle actions from stainless steel, What's the deal with that?

Searcy's prices certainly represent good buying. I might be able to get past the monoblock barrels without second thoughts, but a stainless action? Hmmm. I don't own or even look at stainless bolt rifles. On a double it seems even more sacrilegious

I thought I read somewhere that Searcy made some higher priced Doubles with Chopper Lumps? Something in the $25-30k range?

Interesting enough the only companies that say a monobloc is the equal to a chopper lump are the companies that make monoblocs.

So which of the newer manufactured doubles such as Merkel, Kreighoff, Heym, Chapius, Blaser use chopper lumps and which use monoblock like Searcy.

BigB

Big B, This is from a slightly faulty 66 yr old memory, but all of those you list use the mono block system, in most rifles, as well as offering chopper lump barrels in the top of the line, with the exception of Blazer, which uses only Mono-block. I have both systems, in many double rifles, and if done properly, there is no difference in any of them, except in price! To top this off Krieghoff actions are stainless!

PS:
Searcy use both systems as well, it is up to the buyer!

[ 05-04-2003, 18:06: Message edited by: MacD37 ]

Mickey1, I think you should not use cars to support your argument! I have first hand experience with both Chevolet and Rolls Royce automobiles. The Chevrolet is 10 TIMES more reliable than the Rolls! The Rolls does however, have 100 TIMES the class than the Chevrolet!!

Furthermore, Rolls Royce and BMW use Chevrolet automatic transmissions. Well they are General Motors transmissions.

Again, I would suggest, that you NOT use automobiles as "CASE IN POINT" examples to support your arguments.

Axel

[ 05-04-2003, 18:59: Message edited by: Axel ]

Mickey 1, I would like to ask you one thing! How is glueing two flat surfaces together, between the barrel butts,as in the chopper any stronger, or better than glueing two cylinders into two holes in a solid one piece mono block? The two halves of the chopper lump are not machaniclly joined, in most cases, other than with the silver brazeing them together!

I, too, like the old Britt rifles,I collect Westley Richards doubles, and the skill needed to fit them is a must, but it takes no less skill to fit a mono block barrels set to the action. It is also true there will always be a market for quality,or what some seem to think is quality, and there will always be those things that can be done, in easier ways, that will work just as well, or better, but do not have the required SNOB APPEAL some require, and are willing to pay for. The price difference has only to do with buying the chopper barrel blanks from only a few people who still make them, at very inflated prices,and the fitting is the same with both types. The skill that matters has nothing to do with the method joining of the two barrels, but is in the fitting the barrel assembly to the action, and the regulating of the barrels for composite group.

It would be silly to suggest a top of the line ROUND" barrel blank, like a Hart, is somehow less quality than another barrel simply because of it haveing a chopper attached! The top names are just that NAMES, and no guarantee what you are getting is better, or even made by them. I went into the H&H store in London, and saw a neck tie that could be made for two dollars, in Tiwan, that sported a price tag of $300 US, because it had H&H in the pattern. In fact, it was most likely made in Tiwan.

I don't think you can demonstrate how the use of chopper lump is superior to mono block, in any practical way. As I said, the chopper barrels available from Searcy, are not only on his top rifles, but an option on any rifle he makes, the difference is in the cost, and time of obtaining the chopper blanks. Blanks, I might add, that are no better than a quality round blank, made in the USA, if as good!

As far as your analogy of automobiles ("sort of chevrolet") means nothing since, as with anything, that depends on the purpose it will be used for, and your pocket book will not turn a $100,000 Ferrari into a Chevrolet 4x4 for use in the out back, their respective value is subjective. Because they are cheaper, or more costly, to make, has little to do with durability,or dependability, for the purpose, other than to impress your neighbors! Personally, I wouldn't give two hoots in hell for either of the two mentioned, when I can buy a better, and more dependable automobile,or 4x4, than either, from Japan!

It is simply my opinion, the "QUALITY" lable is a very nebulous thing, and, in most cases, is strictly superficial, and has more to do with one's desire to impress, than real value! The market will always reflect the supposed quality, rather than real quality, as in the phrase "A Cadillac Of it's kind" assumeing the Caddy is the finest one can have! Yeh right! It's just a Chevy with some doll ups on it, and a big price tag, and both will be in the shop more than they will be on the road. BYE!

MacD37, correct me if I am wrong, but with the chopper lump the seam is along the long axis of the barrel while the monoblock is radially around each barrel. Therefore, with the chopper lump each barrel's bites and hook are integral to the individual barrel. So the thrust forces are carried by each barrel's locking bites and hook!

This is simply not true with the monoblock where the monoblock houses both the bites and the hook., while the barrels are soldered into the monblock. The thrust forces are carried then by the solder joint between the barrel and the monoblock. This is fine, as long as, the solder joint is strong enough, which it should be if the design is CORRECT.

I of CONFIDENT if you were to conduct an ULTIMATE STRENGTH test between the chopper lump and the monoblock it would take SIGNIFICANTLY MORE Force to break the chopper lump than the monoblock.

In all reality it most likely means NOTHING, but academically the strength advantage is there.

Axel

AXEL, if you will determine the area bonded by the solder on each barrel butt, compaired to the area covered by the solder between the choppers, you will find the combined area of the mono to be a much larger area.This combined with the fact that a Mono block may be heat treated better,without interfereing with the temper of the barrel butts, the steel is far stronger. The fact is, as you say, it makes little difference, because they are both very strong, and with proper loads neither will give a problem. The damage done by pressure , in a double, is more the side pressure in the chamber area, and is dependant on wall thickness, and proper elasticity of the steel. As long as proper cartridges are used in a double rifle, "Off Face" is caused more by the bending of the action bar, and poor care of the bite, and hook area, than reverse thrust!

My post, above, about the brands useing mono block was misleading. All makers use mono block in their O/U double rifles, but they all do not use both in their S/S rifles. The brands above, Merkel, Krieghoff, Chapuis, PV, Heym all use chopper lump in their S/S rifles, and only use the mono block in their O/Us. The Merkels, for instance have rifles that sell from $5000, to $25,000 in the S/Ss. Yet people seem to think their rifles are somhow inferior. This is not true, I own a Merkel,( which is Chopperlump) and it will out shoot my $20,000 Westley Richards!

In my 45 years of owning, and shooting all makes of S/S double rifles, chambered for everything from 22 hornet, to 577NE 3", I have never seen a monoblock barrel come loose. It is just like many other miths surrounding fire arms, and balistics, people simply hear someone say something, and for some reason want to repete it, eventhough they have absolutely no knowledge of the subject, from a first hand point of view! It just seems some people don't feel good unless they are running down one thing or another, usually based, solely, on hearsay! I have nothing to gain by telling the truth, because I have both types, and they are both well made. No matter the system, a shoddily made rifle is junk, and one put together properly is worth haveing!

[ 05-05-2003, 01:00: Message edited by: MacD37 ]

I wonder if we would ever have seen choppper lump guns if monoblock technology was available 100 years earlier.

Butch Searcy confirmed to me that his barrels are threaded into the mono block, not soldered. Just thought I'd throw that one out there.

StuC, threading may or may not be stronger than the solder joint. It depends on the pitch of the threads used in the one case, and the quality of and solder used in the other.

MacD37, in the chopper lump configuration the solder joint between the lumps is NOT loaded in any appreciable degree of shear! As a matter of fact the solder joint in the chopper lump is practically not loaded at all! In the monoblock system the solder joint IS loaded primarily in shear. Again, the entire discussion is academic since the gun manufacture MUST design the joint to withstand the loads applied by firing of the gun. This said I stand by my earlier post that in an ULTIMATE STRENGTH test the chopper lump WILL be stronger!

HOWEVER, DURING THE ULTIMATE STRENGTH TEST, IT IS ALMOST CERTAIN, THAT THE LUMPS WILL NOT FAIL NOR WILL THE BARRELS PULL OUT OF THE MONOBLOCK. I would predict that the water table breaks off/severely bends!!!

Axel

MacD37, what exactly are we in disagreement about? Both systems will provide a completely satisfactory shooting rifle if PROPERLY executed! If IMPROPERLY executed either system will be a fiasco! To me this is rather like the cast receiver versus the forged receiver. Is one "better" than the other? Perhaps, but we the users should NEVER NEVER know it!

Axel

MacD: Now that the dust has settled...
I am very curious about something you mentioned in your earlier posts:
"The two systems are different in the way they are made, fitted, and hardened", "the surfaces of the bites must be surface hardened", "fitted in it's soft state, and then hardened through and through", and "the fact that a Mono block may be heat treated better, without interfereing with the temper of the barrel butts".
This highlights a huge gap in my knowledge of double rifles. I had no idea that barrels were 'heat-treated', 'hardened', or 'tempered' during the making of doubles, British at least, and I have never heard of 'surface-hardening' the bites. Could you give me a good reference to this part of the process, as I would very much like to bring myself up to speed with this. I have welded and re-cut bites and hooks on doubles which I am still shooting, and can't conceive of the need to harden or temper anything.

...and Stu, are you sure about this? "Butch Searcy confirmed to me that his barrels are threaded into the mono block, not soldered."
I had always suspected they would be threaded AND soldered".

Thanks for any enlightenment, guys!

Stu, you have a PM

Regards

Richard

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