Belted Cartridges?

[backwoods83]

Ok, I hear a lot on here about issues with belted cartdges, and how they are not as accurate, efficient,etc... I would personally like to know what the big issue is? For comparison sake take a top notch gunsmith (quite a few lingering around here) have them build a 300 wby mag custom chambering and have him do an identical 300RUM, have a top notch shooter/handloader develope the best load for each, say 208amax 3100fps wby 3250RUM, do you think one will be more accurate than the other, do you think a 160# whitetail at 1700 yards knows the difference in 1050ftlbs of energy vs 900. What's really the big fuss about all these super magnum barrel eaters, everyone wants a 600yrd laser. Why can't you just practice, and worry about shot placement instead of bragging to your buddies, like hey my shot was a few inches off but its ok I turned it for a flip, wonder how many animals including bears have been taken with a 30-30, help me out here I'm still trying to figure this out. Is it compensation for something, bragging rights or what?

 

[pyroducksx3]

I dont necessarily agree that the belted cases are less accurate. Some of the complaints about them are that it is difficult to truely full length resize them, this can be done with special dies though. Also the spacing of the belt can change with different brands or lots of brass. Most people transfer the spacing to the shoulder after firing so thats not really a problem either. As far as saying that the purpose of the new ultra mags is to push the velocity limits for bragging rights, I dont think is really accurate either. The 30-378 weatherby is pretty close to the 300 RUM and the 338-378 weatherby actually has more velocity potential the the 338 RUM. These new cases are just effiecent and a good option for people looking to shoot long range. If 600 yards is your goal you would be better suited with a lesser chambering like 7 rem mag or 300 win mag. When you are pushing limits way out there you want velocity which equals energy these new magnums provide that. Also at extreme distance the benifit of having the extra velocity cuts down your margin for error. if you have a rifle that is shooting 200 fps faster you will have a better ballistic profile. This allows you to have a better margin of error, such as not reading the wind just right

 

[Kevin Thomas]

Backwoods83,

Simple answer here; the smaller capacity, the better the accuracy. Belted, rimless, rebated, doesn't really matter, so long as the case is headspaced properly in the chamber and ideally off the shoulder. Not to say that large cases can't be used for an accurate rifle, but they're more sensitive and a bit more finicky than a smaller, milder cartridge will be. There are trade-offs, however, and for longer ranges, the accuracy loss may be more than offset by the flatter trajectory, better wind resistance. It's a compromise (like any cartridge choice), and you simply have to decide what you're willing to trade, for what you want to get.

As far as the belt goes, it served a purpose at one time, and still does on a very small handful of cases (300 and 375 H&H, 458 Win), but is entirely unneccesary for more sharply shouldered, modern design cartridges.

 

[Hicks]

Backwoods83,

Simple answer here; the smaller capacity, the better the accuracy. Belted, rimless, rebated, doesn't really matter, so long as the case is headspaced properly in the chamber and ideally off the shoulder. Not to say that large cases can't be used for an accurate rifle, but they're more sensitive and a bit more finicky than a smaller, milder cartridge will be. There are trade-offs, however, and for longer ranges, the accuracy loss may be more than offset by the flatter trajectory, better wind resistance. It's a compromise (like any cartridge choice), and you simply have to decide what you're willing to trade, for what you want to get.

As far as the belt goes, it served a purpose at one time, and still does on a very small handful of cases (300 and 375 H&H, 458 Win), but is entirely unneccesary for more sharply shouldered, modern design cartridges.

I have an old bdl in 8mm Rem Mag and while it was always a sub moa gun, once i started to headspace off the shoulder it became even more accurate.

 

[backwoods83]

Guys I appreciate the replies, I have several 300wms 300wbys, a 7mm mag, a 257wby, and I fire form and let the should do the work as you mentioned, what has me unsettled is everyone always downing these, saying they are to small you should build a RUM or an EDGE or an AM. I saw an artical on the 300wby starting that it had been used on prarie dos to an elaphant and everything between, how's that to small, as for compensating for wind, mirage, spin drift, temp ect.... kevin you can correct me if I'm wrong but doesn't the 300wn still hold the overall record for 1000yrd wins? Just trying to figure out everyones need to have a cartridge that has or exceeds there bullet weight in powder capacity, makes no sense, less accurate, cost more to reload, barrels may not last 500 rounds and for a small trade off, I'm just trying to figure out the logic behind this.

 

[Kevin Thomas]

No, not a lot of logic here in all cases, and there's a big dose of plain old personal preference in how many shooters choose a cartridge. No argument at all here that a lot of folks are grossly overgunned, but that's their choice, and not really any of my business . . . unless they ask.

Depends on what you mean about the 300 WM holding the records. It may, but I don't recall having ever seen it broken down by cartridge like this. Thing is, you won't see them today. It was a widely used cartridge for 1000 yard matches for 15-20 years, but you almost never see them on the line anymore. Haven't, for at least ten years or more now. Today, the hands-down favortie for this type of shooting is the 6.5x284. With the development of the heavier higher BC bullets in 7mm, they're geting some attention these days. Lot of F-class shooters going that way and getting good results so far. But the 30 cal mags are pretty much a thing of the past for this game. Again, it all comes down to a personal choice. What are you after, vs what you're willing to trade for that performance? There's a good range of high BC bullets available in 30 cal, but with that you get heavier recoil. going to a lighter cartridge (such as the 6mms) to reduce recoil usually means giving up some of that BC. Some cartridges, like the 6.5x284, seem to split the difference quite nicely, and are the current choice. But again, that's always subject to change. It really does come down to what you want.

 

[MagnumManiac]

Guys I appreciate the replies, I have several 300wms 300wbys, a 7mm mag, a 257wby, and I fire form and let the should do the work as you mentioned, what has me unsettled is everyone always downing these, saying they are to small you should build a RUM or an EDGE or an AM. I saw an artical on the 300wby starting that it had been used on prarie dos to an elaphant and everything between, how's that to small, as for compensating for wind, mirage, spin drift, temp ect.... kevin you can correct me if I'm wrong but doesn't the 300wn still hold the overall record for 1000yrd wins? Just trying to figure out everyones need to have a cartridge that has or exceeds there bullet weight in powder capacity, makes no sense, less accurate, cost more to reload, barrels may not last 500 rounds and for a small trade off, I'm just trying to figure out the logic behind this.

All these rumours that a belt is NOT as accurate as a normal bottlenecked case were started by the ammo makers when they brought out their short/fat magnums!
This then made it's way into magazine articles so that more ammo and rifles could be sold, then it went into 'folk lore' as being true!
'Hype' sells rifles, and the magazines are paid to promote these new chamberings as the next best thing better than 'sliced bread', that's how they make their money. The articles are meaningless to them, it's the advertising that they're after!

There is no definitive proof that a belt is less accurate than any other design! Any design can be inaccurate, so too, any individual rifle can be inaccurate. I have seen some VERY accurate 45-70 rifles, but is that the 'norm'?
All the belted mags I've owned have had better than average accuracy, most better than some bottlenecked cases that would just not shoot no matter what technique you used on them!

I still shoot a 300WM on the F-Class line, it's the most accurate rifle I've ever owned, and is still more accurate than some of the newer chamberings I see crop up, even the 6.5's in all their differing configurations!

gun)

 

[backwoods83]

I agree I have 3 bench guns, 2 light, 1 unlitimed the light guns are 6.5x284 and 300wby, the unlimited is a tight neck 300wm. I normally shoot the 6.5x284 because its a little easier to manage but if conditions are horrible the 210 berger at 3070 just flat out gets it done! The wsm's are good cartridges but they should be on long actions, no sense in taking up a 1/3 of the case with the bullet, as for the RUMs I think they are a waste until betram, lapua, or norma start making cases for them. Just my opinion.

 

[Kevin Thomas]

Backwoods83,

What you're getting into here, about the bullet taking up 1/3 of the case, is a run-in between what the cartridges were marketed to do, and what they're being used for in certain circles. The idea for these rounds was to produce a cartridge that delivered magnum performance in an envelope of a short action. Trade-offs had to be made somewhere, and that's part of the deal. for someone using these outside the box, such as a competitive shooter, this opens up a lot of other possibilities. That's where things get interesting. Again, if you're building a rifle for a specific purpose, you're the one who gets to decide what is, or is not a worthwhile trade-off. The F class shooters are gravitating heavily towards the SAUM and/or the WSM's in 7mm. Since the issue of having them work through a mag in a short action isn't a concern for them, like I said, things get interesting. Personally, I do like the idea of getting away form the belts once and for all. They add nothing, and are a potential trouble spot. The newer designs eliminate these potential problems and allow us to concentrate on other things.

Your comments about the 300s are spot on, and exactly what I was getting at here. The 6mm PPC is the most accurate cartridge ever developed, but you don't see it used for 1000 competition. The trade off to a somewhat less accurate cartridge that has the power and BC to hang in at the extended ranges make that the only logical way to go.