Hello Friends,

I have just finished reading an article in the March/April issue Petersen's "Rifle Shooter" magazine, written by Wayne van Zwoll, wherein he describes the formulas used to determine the interior dimensions of mauser type magazine boxes based on cartridge dimensions. Fascinating!
Now I'm sure this information isn't new to most of you but I have never seen it before, and would like to know in what book or books this, and I hope lots of other useful knowledge, might be found. I'm certain the author read it somewhere and just as sure that some of you know where.

Thanks!

The first two page photo spread of that artical there is a photo of what they describe as a custom Mauser.
Can anyone say 1917 ENDFIELD? duh!

It was a very good article, and a lot of that information came from D'Arcy Echols who I understand knows something about proper magazine box dimensions. Just something I heard.

hmm, Did Wayne copy Jim's data?

it's a voodoo science, involving geometery, welding, and some chickens
'

Of, yeah, an alot of cussing the first couple times
jeffe

You know, now that you mention it, I did notice alot of chicken feathers in D'Arcy's shop. Interesting. At the time I had just assumed that he made feather pillows on the side to support his rifle building habit.

The original geometry was not a mystery, at least after Mauser came up with the design. It is attributed to him but others recently have written articles seeming to have "discovered" the secret to the perfect magazine box.

I have seen it in an old book but the source escapes me.

Paul Mauser's the genius who first pioneered and correctly calculated proper magazine dimensions for bolt action rifles. He went strictly by mathematical formula. I'm amazed at how many of today's riflesmiths are absolutely clueless on this entire concept.



The other day, for example, I was at one of my favorite local gunshops in Hillsboro, OR, and the owner handed me a very lovely custom .340 Weatherby to examine. It was a beautifully stocked (in the finest manner!) Model 70 Classic, which was originally a .338 Win. Mag., but rechambered to .340. I asked the shop owner about accuracy, etc. He said that it shot well, but could not be loaded with 250 gr. bullets, because the magazine wasn't long enough for them (his words). The rifle was rechambered alright, but the short, belted magnum magazine was still in place. How anyone would knock themselves out on a fancy stock, but not take care of important functional details such as a proper magazine box, follower, opened loading port, etc., is simply beyond my comprehension........



Great rifles are built from the inside-out!



Anyhow, D'Arcy developed his own belted-magnum magazine boxes and followers at least ten years ago (I think!), which were based on the original Mauser concept of mathematically calculating magazine box dimenisons in order to arrive at the correct stack angle for a given cartridge. He spent a great deal of time and money on the project, and I believe Tom Burgess (system98) contributed a good deal of his experience and know-how to D'Arcy's efforts as well. No cut & file, trial & error methodology for these guys - no trying to somehow cram a .338 Win. Mag. cartridge into a 7.65 Argentine box, either! Echols has the correct mathematical dimensions for various cartridges written down on paper, and he can probably recite them off the top of his head, I suspect!



All magazine box technology didn't exactly stop progressing before World War II, and these Echols boxes are machined from heat-treated stainless steel, and are a genuine improvement over the original Mauser 98 boxes and followers. If I remember correctly, Finn Aaggard did the first story on D'Arcy's magazine boxes years ago in the "American Rifleman". These boxes in all ways function better than any others that I've worked with, and absolutely resist bullet battering from recoil, even with .375s, .416s, etc.



Wayne Van Zwoll has written a couple of good articles in "Rifle" magazine of Mauser-type magazines, but it's true, much, if not all of his information came from D'Arcy Echols concerning this subject.



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Allen

This is just pure speculation on my part, but I think that Wayne is pretty good friends with David Miller as well, and what he didn't learn from Darcy he may have learned from David, or vice versa.

Blue

Blue, I've owned a couple of Dave's rifles myself, and you can bet that Miller puts correctly-dimensioned custom boxes and followers on any rifle he turns out. He gets most, if not all of them from Ted Blackburn. These are excellent boxes, but they're not as well built as D'Arcy's, in part because they're not milled from thick, heat-treated stainless steel.

Wayne sites and quotes Echols more than any other comtemporary maker in his magazine box articles. As I recall, Dave was mentioned in one photo caption of one article of Wayne's on this subject, but there could be more......

AD

Allen are Echol's boxes available only on his rifles?

I also have a follow up question or two. Why does the box make such a difference at least in terms of quality of it?

I can understand it being too narrow or wide, or short or long, for a particular cartridge but I really am not sure why it needs to be heavy duty etc. For example, Allen why do you think they need to be thick heat-treated stainless steel?

Also with the possible exception of the follower, maybe that is part of the box, what really determines how well a round feeds are the feed rail lips and those are integral to the action on a Mauser and M-70. Also seems that the rails would be the hardest to modify and get right and the potential for screw up very real and difficult to fix.

Allen

I own one of those Blackburn triggerguard/boxes. Sitting here looking at it right now. Gosh, it sure looks well built to me.

Blue

Well, the one thing that I know is that my frickin' 09 in 7mm rem. mag will barely take a standard factory round into the mag, no extra room there.

The mag box on my 03a3 is junk too, just pulled it apart last night to mess with the stock and it's junk. But this may further backup Howard's question, how does the quality of the metal itself affect the function? I mean, the 03a3 has to be at least 40 years old, and the gun has never had a functioning problem (ok. the one, but that was because the gunsmith hadn't worked on the extractor right so it was too tight and not throwing the cases free).

Can somebody post the formula for calculating the mag size? I am just curious about how it is all figured out.

Red

Dago

Are you talking length or width. If you used a standard 09 box, the length of the inside of that box is 3.3 or just a smidgeon more, and the length of a 7 mag in 160 grain is about 3.290 so there should be some room in there, although I grant you it isn't much. The back edge of the box is about .120 and the front edge is about .090. Those could each be carefully filed down to give you a bit more room.

Or, if you have a copy of the book Rifelsmithing by gun digest, there is a chapter in that book that shows how you can cut out the front of the box and weld an extension piece onto the front of the box in order to make it longer to meet your specific needs. Good luck.

Blue

My issue with the whole deal is: If it is such an easy thing why isn't there anyone that makes these things aside from Echols and Blackburn. In addition, to get into it deeper, I have issues with Blackburn stuff. Blackburn quality is great, don't get me wrong, but I have talked to him several times about components for a rifle and have yet to get a straight answer regarding anything I have talked to him about. That is a fact.



I have recently been on the hunt for a box for a model 70 and the 7mm rem mag combo. Hardly an anamoly. My conclusion is that there is absolutely nothing available as an aftermarket box and follower for this combination. So once again, if it is so easy to figure out, why isn't it done. Rediculous, and shame on somebody. It is nice to know that I can have someone engrave my picture on a barrel, but can't find anyone to build a magazine box that is built to the right dimensions.

The formula for optimum magazine width is:

(Cosine(30degrees) X base diameter) + base diameter



For a .30-06

(.866 x .473) + .473 = .882 inches



For a .300 Win Mag

(.866 X .532) + .532 = .993 inches.

D'Arcy's boxes and followers are only available with a D'Arcy Echols and Company rifle. These are also not drop in units but require modification to the action to fit.

As to the question of why the boxes need to be of high quality I'd like to offer a couple ideas. On rifles that have high levels of recoil a box can endure some fairly significant battering by the rounds. A box that has been bashed up may incur some damage and that certainly wouldn't help feeding. Secondly why would one build a high quality rifle only to skimp on some parts? These probably aren't the only reasons.

Bart

Quoting the article, in addition to using the formula quoted by Mauser98 for the head dimension of the cartridge, the same formula is used to compute the box width at shoulder length. So (.866x.436)+.436=.814 for width of the box at 1.948 inches from the rear, for the same 30'06.

Great response, thanks guys. Maybe this isn't in any book after all.

Gents, Turn over time for articles in magazines is supposed to be 3 1/2 to 4 years. That is about correct for Wayne's article. Not much over a year here. Wayne didn't wish to use my formula directly so he went to the cosine, and made it slightly more complicated. Trying to make sense out of the figures you arrive at doesn't make sense if you start measuring Mausers. The Werke did not try the Winch. one size fits all approach but did take what was pretty close and go from there depending on inventory of actions.
The Stoeger numbering system up to 20 or whatever was not particularly followed and this can throw you off. This formula is based strictly on common sense and does not accomodate the looser tolerances for ctgs. in thankfully bygone years. It will I assure you not cause headaches to reason the why of it. It will do so if you try to cut corners.
The AR link http://www.accuratereloading.com/ubbthreads/showflat.php?Cat=&Board=UBB5&Number=213650

About 20 Jan 2003.

Blue,

that would seem to be about what I have left in the mag. I don't know that it is a problem or not, haven't shot the gun enough yet to know if it will need to be changed.

Red

Thanks, Systeme98, for the link to your previous post. It and the ACGG info associated with it are exactly what I was looking for when I started this. Getting it from the horses mouth is even better.
Just sorry I wasn't here to see it the first time.

Bart, you're correct on all points, and Howard, I doubt that D'Arcy will ever sell his magazine box and follower seperately. As a client and user, feeding is just as critical an issue for me as fundamental accuracy is, and it's the one aspect of rifle function that can keep you alive at high-noon in the thick bush. More so than one-hole groups, that's for darned sure.

And there are no acceptable compromises. A rifle either feeds right or it doesn't, and a magazine system is either calculated, built, installed, and adjusted properly or it isn't. I've lived enough grief, seen enough grief, and heard about enough grief caused by disfunctional feeding systems to know that a gunmaker is either an established master of this subject, or he simply isn't going to get my business. Varmint rifles are easy and .270/.30-06 rifles are easy, but belted-magnums and dangerous game rifles simply MUST have the right box on board, or I'm headed in another direction.

I was reading Jeff Cooper's book, "Fireworks" the other day, and I took special interest in the story about his .460 G&A - a cartridge which was developed by Tom Siatos. Cooper's .460 G&A rifle was custom built on a Brno ZKK 602 action by the great Georg Hoenig of Boise, ID. According to Cooper, he had considerable trouble with the custom five-shot magazine becoming battered over time due to bullet impact caused by recoil. This is a considerable problem with heavy-caliber rifles, and it's especially not uncommon for sheetmetal factory boxes to split open (the stock as well) from recoil battering. It's not uncommon for custom boxes to get beat up either, especially if they're built from soft, conventional steel.

This is one of the reasons that D'Arcy machines his boxes from thick, heat-treated stainless steel. Not only are these beautifully finished, smooth, and feed perfectly, they're super-tough and resist cartridge battering better than anyone else's product. So by building them to the right mathematical dimensions to begin with and crafting them from the best materials possible (heat-treated), he achieves increased case capacity (no drop magazine required), superior feeding, superior weather resistance, and superior durability to withstand the battering of even a magazine full of .458 Lott cartridges loaded with 500 gr. solids. A great many benefits are achieved from just one well thought-out and executed magazine and follower assembly!

Of course, the whole works has to be properly fitted, which is another story in and of itself. All I can say is, if anyone thinks the magazine assembly is not a critical component for proper rifle function, they couldn't be more wrong, and as a purchaser, user, and student of custom rifles, I've seen just about every shortcut and amaturish hack-job imaginable when it comes to feeding systems. I had one riflesmith ruin a custom .416 Remington for me some ten years ago, simply because he had no grasp of the concept whatsoever, and it proved to be a problem that he was incapable of resolving at all. Not a happy outcome for either of us, I'm afraid.....

Chuck you're right, there really aren't very many options out there in the way of proper boxes, and fitting them and adjusting them is no simple, drop-in proceedure. Not by any stretch of the imagination.

AD

I have zero experience with rounds above the 30-06/7mag level. If the recoil beats up the mag boxes not sure I want experience either.



Thanks Allen.

Chuck

I am curious. I think that I am correct that on most model 70s (I have only owned the later featherweight models myself) the box is a separate item from the triggerguard unit.

Does the box have to be machined???

could one not take 4 pieces of heavy stainless steel of the correct dimensions and have those 4 pieces of steel solidly welded together. then clean up the welds with a good file, or a mill if you have one, and away you go.

I don't know, I am not a machinest (wish I were sometimes) but I would think it would work, and now that we have been provided the formula maybe it might be worth your while to give it a try.

blue

I have no doubt that a box could be made. In fact a machinest could make one from a solid billet of steel. However, it starts to become cost prohibitive unless the maker, and more importantly his clients, are committed to multipe rifles with the some basic design. IE D'Arcy Echols and his Legends. That is why someone who makes components and aftermarket parts would be better suited to the task.

Now in fairness the problem lies with customers. They don't care and would sooner have the newest short and fat than put some thought and money into something that is designed and functions correctly. We wonder why assembly line one size fits all parts adorn factory offerings and quality is cuntinually going south. Its simple. The consumer would choak if he had to pay $1500 for a rifle. Large firearms manufacturers do what they can to attract buyers. Keep costs low and offer new redundency.

As to those that offer, or don't offer, certain aftermarket "improved" parts. People are cheap parts are expensive and if the consumer can't "do it themselves" instead of hiring an expert to properly install said part they aren't interested.

That, succinctly put, is exactly what the problem is with contemporary factory rifles and even some "custom" ones. I managed a retail gun store for a brief period and the continual whining about "price" and "lousy quality" nearly drove me bonkers. It usually emanated from the high wage union workers with minimal education/training who were always ready to drink the free coffee and tell me what crap my "old" Mod. 70s were compared to their bargain Savage 110s which...shot a 1" group...!!!

Most of these experts also laughed at my little Toyota 4x4, Rolex watch and Zeiss binocular as they prefered their 3/4 ton domestic iron, Timexs and Tascos as well as their ATVs, snowmobiles and dirt bikes. Backpack hunting was "too much like work" and their usual yearly bag was a yearling Black Bear shot while groggy at emergence.....

Real quality costs, but, most of those who complain about this wouldn't recognize it, in any case.

Those interested in a technical discussion on magazine geometry are refered to:

AMC Pamphlet AMCP 706-260
Engineering Design Handbook
Gun Series
US Army Materiel Command
February 1970

I don't know where you can get a copy ..... Stan

Unfortunatey, quality costs more than it should. The primary reason for this is a lack of real "thinkers" in the gun industry who would try to come up with more efficient methods for manufacturing quality parts, rather than figuring out how to make the overall product just cheaper.
Substituting casted parts for ones with machined parts isn't that expensive, and sometimes cheaper in many cases.

The problem is that the gun industry as a whole is far behind the technological curve in regards to machining and manufacturing processes in general. They still seem to be trying to overcome processes for manufacturing that were developed before WW2.

The manufacturing of firearms was state-of-the-art when Paul Mauser, John Browning, and the like were involved, but we haven't evolved much sense then compared to the automobile industry, or for that matter, the aerospace industry, which didn't exist. I think the biggest reason for this is the fact that those who understand what it takes to manufacture these rifles are not interested in them. They'd rather design automobiles and airplanes.
Pitty too, because it's an industry that needs some help in a big way.

If you're going to manufacture something right, you must first have some solid experience in it. Not only in it's use, but the techiques of manufacturing it as well. Unfortunately, the making of the product begins in the marketing department, who's experience in the world of firearms in the field is limited to none, the latter being the norm.

The fact is, if you don't know how to use it, you sure as hell won't know how to build it.

How very true.

You mention pre-64 Model 70s. Those rifles really were quality-built firearms, and yes, even the magazine boxes were properly made up until the short, belted magnums were introduced.

If you work with a pre-64 M70 in .300 H&H or .375 H&H, you notice that those magazines are no deeper than that of a Model 70 in .30-06, yet they hold four-down and feed superbly. Winchester engineered those boxes from the beginning for those H&H cartridges, and the results speak for themselves. Likewise, boxes for the .30-06 and .270 are engineered perfectly, and feed perfectly.

That's why, amoung other reasons, when I order a custom .270 or '06 I always specify a pre-64 Model 70 action. The box and follower are right to begin with, and don't need to be replaced.

AD

Makes the 300 & 375 H&H an appealing choice.

Localhand

The math that Mauser98 shows is the start of the magazine box geometry.



It is the limting factors that dictate what the magazine will become for that certain cartidge. If you don't know what all the limting factors are then that is when you see all the chicken feathers come out, along with lots of hair from your head.

You also need to know the following.



Width of reciever.

Length of reciever, or how long you can open it up to safely.

Depth of magazine box walls.

Depth of rear guard screw, this affects the grip diameter.

Location of trigger vs the bow location.

Angle of lower magazine box wall, this sets up the forearm angle.

Type of floorplate, standard or pocket.

Dims of the follower to fit that cartidge.

Dims of the magazine spring.

FEED RAILS, must fit the magazine and work for the cartidge.



If you are going to do a trigger guard (one piece) or just a magazine box insert with a rail system. The first time it needs to be drawn to scale to work all this out. I have been making trigger guards now for 20 years. All the first one were drawn out, now I can lean on those measurements to make new guards in different calibers. Also having a computer with CAD helps a lot.



I machine trigger guards for the following families of cartidges.



223

250-3000

7x57

308

30-06

280 Ackley

9.3x64

338 Win Mag

330 Dakota

375 H&H

404 Jeffery

416 Rem

500 Jeffery

416 Rigby

460 Weatherby

505 Gibbs



The interior of these magazines are different widths, length, tapers, and depths depending on the action it fits.



Jim Wisner

Custom Metalsmith

Jim, Killjoy. They get near the water, and just about the time they're fixin to wet a toe, you gotta tell about the circling sharks and like that.

Don't worry, Thom, I ain't scared yet, just more cautious than I was before.

That is correct, I have owned and used 5 Pre-64s in .338 and 1 in .264, they only hold 3 rounds down, while the 3 rifles in .300 H&H and 3 in .375H&H I have had will hold and feed 4 down and 1 up, flawlessly. I might add that I spent many years working alone in the most remote parts of B.C. and Alberta as well as supervising large crews of forestry workers in Grizzly country; I have used a wide variety of rifles for dealing with bears and I came to prefer a Pre-64 Mod. 70 in .375 over anything, period.

I agree with Allen's opinion on these rifles, I have now owned and used 32 of them and they kick ass. I have had some standard weight .270s that shot honest .25" groups with Norma factory ammo and a simple Leupie 3x or 4x scope. These were used rifles, un-tuned and not pampered; they also work properly when covered with mud, in the -40 F temps. of winter and hold their zero in the wettest conditions of the B.C. coast. I will not keep a rifle that doesn't work every time and old 70s do just that.

I consider these to be the single greatest contribution to human civilization from the United States and their demise coincided with the start of the decadence that grips all Western nations now.

Now a specific question. I own an Argentine actioned rifle in 7 mm Rem mag. It won�t feed. What needs to be done to make it feed properly?

Blackburn has changed their name to CNC Machine Specialites.
However, their website remains www.blackburnmachine.com.

Howard, I am no smith, but have had some of your troubles in the past. How far out are you seating your bullets. if they are way out, then the angle of the feeding ramp may have to be reduced and polished.

Blue

I can't say without seeing it and I have also experienced this problem with re-barreled Mauser 98 rifles. I would take it to a top 'smith such as Mr. Burgess, Jim Wisner or the gentleman in Olympia, whose name escapes me at the moment. I have seen or owned work by all of these men and they do it right.

I have also seen a couple of quite decent custom 98s ruined by amateurs with Dremel tools, Mauser mag-ramp geometry is for expert gunsmiths to work on, IMHO.

Howard, if your 1909 Argentine action retains the original 7.65 Argentine magazine box, it will not feed properly, and case capacity will be limited. You'll need a replacement box and follower from Ted Blackburn.

The problems that I've seen with Mausers converted to belted magnums is when the bolt face is opened up, the feed rails opened up, and the extractor altered, but the original box still in place or improperly altered.

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