belted cartridges

[nicholasjohn]

Conceptually it does have A problem. Practically it doesn't seem to matter enough to cripple it, maybe only wound it in the extreme outer fringes.


Holds hand up; have had case head separations in a belted case. From first fired Norma brass at that. Split right where Lowedown describes, thinned and then separated just above the belt. Was an 03-A3 action in .308 Norma Mag that was gradually increasing it's head-space, owned by a nuuB who didn't understand what was happening but knew enough to know it was bad.

The original reason for the belt was to head-space in double rifles. It wasn't marketing that said "Hey, let's put a thicker part here on the case and we'll claim some dubious advantage."

The magazine writers were the ones who claimed the advantage. The standard-length cartridges that were based on the old H & H case had the belt, because there was no reason to remove it - it wasn't hurting anything. The ammunition manufacturers were already tooled up to make these cases, so they shortened the design to fit into 30-06 length actions, and necked them to accept bullets of the popular diameters at the time. ( What they were looking for was the increased case capacity over the 30-06 case, not the belt.) In those days, reloading wasn't as popular as it is today, so not too many people cared if the brass was only good for one firing.

Once more people started to reload these cartridges, guys figured out that they should size them in a manner that didn't push the shoulders back every time, and everybody who was "in the know" did just fine. Again, no real problem stemming from the belt that couldn't be dealt with. Guys who didn't know learned pretty quickly from the guys who did.

The problem, I think, came from magazine writers associating the belt on the case with the word "magnum," and they ginned up these perceived problems to have something to write about. Now they would look smarter to everybody who reads their work. This cooked up the need for more new stuff - like the "beltless magnum," which cured a problem that didn't exist. More rifle cartridges is not a bad thing for shooters,though, so I think this is just fine.

Another "problem" they have been working on is the short necks on the belted magnum cases. It gets a lot of ink, but the 300 WM's short neck doesn't seem to be negatively affecting its performance like some would have us believe. It seems to be long enough for even the fussiest accuracy nuts, but if somebody wants a longer neck, there are cartridges out there that have one. Suit yourself - it's a good excuse for a new rifle.

If I was going to start from scratch and buy ( or build ) a new rifle, I'd probably go belt-less - because it doesn't add any benefits that I can see. I've always been perfectly happy with the 30-06-based family of cartridges, but if I wanted more case capacity I'd go to a bigger cartridge that looks more like that design. Again, I see no advantage to either design concept.

 

[coop2564]

I bump the shoulder back every load about 2 thousands, been reloading for 7RM for many years, I do nothing different on it than I do all other cartridges.

 

[crkckr]

I have (and love) my Ruger 77 .338 WM. That said, the bottom line on belts is that they are antiques and simply not necessary in todays world. And the cases will stretch (a lot!) on the first firing but that can be compensated for with proper sizing technique, just like with any cartridge. The belt shouldn't cause any problems with accuracy or case life, it just isn't necessary. But hey, if you like belts go for it. If I'd of had a choice when I bought my .338, I would have gotten the RUM but since it didn't exist back then I got the best thing available at the time and have no regrets now. However, if just starting out now, why get an antique belted round when you can get a "normal" cartridge such as the RUM?
Cheers,
crkckr

 

[gator378]

Please explain to me what people are talking about when they talk about potential problems with belted cartridges.

I have 7RM and have a 6.5 RM that's shot out....I'd like to be better informed before I build another 6.5 RM,

Just headspace on the shoulder. I eliminated all case separations from my 300 Weatherby by headspacing on the shoulder. easy to do. Just set the dies up to just kiss the shoulder. I have been ignoring the belt for years. On Weatherby.dk website based out of Denmark. A lot of big Weatherby fans in that area. They have pictures where owners machined the belt off the 300 Weatherby cases and never have problems. Belted cases are no problem, just make sure the dies are set up correctly.

 

[jlvandersnick]

When you say your 6.5 RM; I assuming it's a 6.5 Remington Magnum that is shot out, in what way, throat, lands & grove or headspace?? There's nothing unnatural about a belt on a cartridge other than in many cases, actually always all cases they aren't needed. Other cartridges like the .458 Win Mag they are, they are needed do to the .458's straight wall case. Could you bring this boat a little closer to the dock?

Yes 6.5 Rem Mag. The barrel is shot.....deep excessive fire cracking in the throat and a deep wide parallel crack in the riffling at the muzzle.
I bought the rifle used and believe the previous owner got it HOT. The rifle was also dropped muzzle down. There is a dent in the barrel at the muzzle. The rifling with the crack in it runs right up the the dent.
Pics attached....not the best resolution....but kind of tells the story

 

[Pappabear]

300WM is my favorite cartridge. I have 6.5's and 308's and all have their place, but 300 rules the roost. We have RWS brass on 10 plus loadings. This belted nonsense is just that.

PB

 

[jarnold37]

They don't know what they're talking about, or don't know how to properly resize belted cases, or they have cheap junky dies. They're regurgitating some mindless drivel that someone once spewed onto the interwebz, and now it's gone mainstream stupid-matrix.

In a rifle with a "perfect chamber" the belt is somewhat insignificant due to the fact that the chamber isn't fat at the back. Many lathes people are using today have a tailstock center that is at least 2 thousanths high. Most lathes come that way as everyday wear lets the tailstock wear into true center. Take the chamber that is reamed with a center that is 2" high and the result is a chamber that is 4 thousands big at the back of the chamber. Yes, right where the belt is. I had my tailstock ground to 7 tenths high and it will still ream a little fat at the back. The belt will swell if you have a fat chamber and resizing dies will crack trying to size that belt even neck sizing. Even with a "trued" tailstock I had problems cutting belted magnum chambers with them being big allowing the belt to swell and be big also. And it does seem to add difficulty to sizing down at web area as it is somewhat protected from that good for nothing belt. I switched and now use a floating reamer holder which counter acts the misalignment of the tailstock to some degree.

 

[J E Custom]

To understand the belted case you first have to know the reason it was developed. Many people lost their lives because of a dirty or fouled chamber and in many cases the case it's self had not been sized. (A common practice on big dangerous game cartridges). Many of them were simply loaded as fired and the bullet was crimped in the neck with a hand tool. It was recommended by experienced guides that all loaded rounds were checked to make sure that would still chamber before going hunting.

This practice paid off most of the time until the chamber got dust or other fouling in it and that's when things got dicey. Inter the belted case. It was designed to chamber under any circumstance and was head spaced using a belt and a grossly under sized case that would chamber under the worst conditions. These cases were considered disposable instead of the clients.

With cases sized 15 to 20 thousandths smaller that the chamber it allowed cartridges to be chambered in any chamber and withstand this first fire forming in a much larger chamber. the only danger to a first fired case of any kind is head space. A non belted case will almost without a doubt separate just in front of the case web if head space is more than .007 or .008 (This is the reason that no go or field gauges are set to reject any chamber that exceeds these gauges.

Most belted case have a thicker area in front of the belt and web to compensate for this greater amount of expansion in the first firing.
From then on, it is up to the loader to properly size the belted case.
for longevity. With proper sizing there is no reason that a belted case cant do everything wanted, You can size the case so it becomes a shouldered case and head space of the shoulder or still head spaces of the belt with no, or minimum shoulder set back.

Just a side note: Many wild cat cartridges based on belted cases actually fire form with great accuracy and can be hunted with much like the Ackley cartridges because there is no need to form a Donut or seat the bullet long to hold head space to a minimum.

Case capacity is sometimes an issue for belted cases but there are also very large belted case that can hold 125 grains of powder before they are modified like the 378 Weatherby that with Wild catted designs can hold 145+ grains of powder. so capacity is not an issue in most cases.

Just saying

J E CUSTOM

 

[sable tireur]

Many lathes people are using today have a tailstock center that is at least 2 thousanths high. Most lathes come that way as everyday wear lets the tailstock wear into true center.

Respectfully, if my lathes had showed up with a center which was intentionally high to allow for "wear in", it (they) would have been sent back to the manufacturer for me to get a full refund. No one that I know who does high quality precision lathe work would ever consider working this way under any circumstances. This included gunsmiths who routinely cut chambers. I'm not sure where this idea came from but I've never seen seen it or even heard of this happening.

 

[MudRunner2005]

In a rifle with a "perfect chamber" the belt is somewhat insignificant due to the fact that the chamber isn't fat at the back. Many lathes people are using today have a tailstock center that is at least 2 thousanths high. Most lathes come that way as everyday wear lets the tailstock wear into true center. Take the chamber that is reamed with a center that is 2" high and the result is a chamber that is 4 thousands big at the back of the chamber. Yes, right where the belt is. I had my tailstock ground to 7 tenths high and it will still ream a little fat at the back. The belt will swell if you have a fat chamber and resizing dies will crack trying to size that belt even neck sizing. Even with a "trued" tailstock I had problems cutting belted magnum chambers with them being big allowing the belt to swell and be big also. And it does seem to add difficulty to sizing down at web area as it is somewhat protected from that good for nothing belt. I switched and now use a floating reamer holder which counter acts the misalignment of the tailstock to some degree.

Floating reamer holders are pretty standard practice for finish-reaming a chamber.

 

[sable tireur]

Maybe floating reamer holders but not a tailstock.

 

[MudRunner2005]

Maybe floating reamer holders but not a tailstock.

Yes. That's what I meant. Sorry, concentrating on work stuff while trying to respond is not a good idea. Haha

 

[jarnold37]

Respectfully, if my lathes had showed up with a center which was intentionally high to allow for "wear in", it (they) would have been sent back to the manufacturer for me to get a full refund. No one that I know who does high quality precision lathe work would ever consider working this way under any circumstances. This included gunsmiths who routinely cut chambers. I'm not sure where this idea came from but I've never seen seen it or even heard of this happening.

My first new chinese lathe measured almost 3 thousanths high and purchased a new 14-40 Nardini and it was 2 and 7tenths thousanths high. A gunsmith I knew said you have to true even the most expensive lathes. Your tailstock is your adversary.

 

[Gregg C]

The belts are ugly.... ¯\_(ツ)_/¯
sorry that's all I got

See, now, that's all about perception...I like the belt. They look more,...I dunno, masculine. Robust. MANLY !!! Yeah , that's it- MANLY !!!