Belted cases and accuracy for long range cartridges

[jski]

I've read the pro's & con's about belted cases. Some claim that it's problematic for accuracy for long range cartridges.

Counter example, .30-378 Wby Mag ... from what I've read.

Where does the truth lie?

 

[jski]

From:
Pros & Cons of the .300 Magnums

The Facts

The belted case was a British idea that originated with the .400/375 Belted Nitro Express in 1905, and it was later used in the development of the .375 H&H and .300 H&H Magnums. Since the .400/375 and .375 H&H cases have virtually no shoulder and the shoulder of the .300 H&H is long and mildly tapered, the British figured all needed a belt for positive headspacing, and they were right. Magnum-size cartridges, such as those developed during the early part of the 20th century by Charles Newton, were exceptions, but other magnums that came along after the 1920s had belts on their cases. While the belt was unnecessary on most of those cartridges, it spelled high performance to many hunters, and for that reason it sold lots of rifles and ammunition through the years. Then came a new breed of magnum cartridges without a belt, and suddenly that little band of brass just forward of the extraction groove of a case had more critics than Michael Moore at a soap-makers convention.


While I agree that the belted case outlived its useful life almost a century ago, I am just as quick to add that I have absolutely no objection to a cartridge having one. I have been using rifles chambered for belted cartridges since the 1960s, and not once have I discovered anything to complain about. I am not alone with this opinion. Just ask a few brown bear guides in Alaska what they think of the .338 Winchester Magnum and the .375 H&H Magnum, and their answers will likely be quite positive. You will also get the same response from professional hunters in Africa who have long been, and probably always will be, extremely fond of the .375 H&H Magnum as well as another belted number called the .458 Winchester Magnum. I am saying all this to say that whether or not a cartridge has a belt on its case is of no importance. Like a faithful old hunting dog that has become too old for the chase, it is not actually needed anymore, but keeping it around doesn’t hurt anything either.

 

[taylorce1]

Truth lies somewhere in between. The Army has went to the .300 Win Mag for most sniper applications. There have also been records set in long range competitions by belted magnums.

In 1935, Ben Comfort won the prestigious Wimbledon Cup Match (1000 yards
and scope sights) at the USA National Championships using a custom-built
Super 30 and a Litchert target scope and set a record. That single event
caused most shooters to then consider the .300 H & H Magnum `the' long-range
hunting cartridge and nothing else was considered.

I believe the truth lies in the rifle build, ammunition, and shooter. If you have a quality build on your rifle and ammunition that pretty much leaves the shooter. You can pay for the best rifles and ammunition that money can buy, but if you can't shoot well then your rifle and ammunition won't shoot to its capabilities.

You can have a rifle and ammunition that can only shoot mediocre at best, but if the shooter has exceptional skill they can do amazing things with what they're given. If you read about Carlos Hathcock's M70 rifle he used in Viet Nam, you'll find out it was about a 2 MOA rifle. However it was consistently a 2 MOA rifle, and he could rely on that.

So if you have an exceptional shooter, rifle, and ammunition, I'd say watch out! It doesn't matter what the rifle is chambered in belted or non belted cartridge, you're going to have great results. If you want a belted magnum and are worried about accuracy, I'd say don't. You might not be winning long range competitions with these cartridges anymore with the trend to smaller diameter bullets with higher BC and less recoil, that doesn't make the belted magnum cartridges any less accurate than they've always been.

 

[jmr40]

The belt no longer serves a function and it does indeed impede accuracy. But it isn't something that can't be overcome. Having the belt makes things a trifle more difficult, but belted magnums such as the 300WM and 7mmRM can be very accurate.

The fact that the best big bore dangerous game rounds have belts is simply because they were developed at a time when belts were in vogue, they would be every bit as effective in modern rifles if they had been designed without the belt. And theoretically more reliable. There isn't enough demand, nor advantage to develop similar rounds that are without belts to justify the trouble. The exception is the 375 Ruger. It actually surpasses 375 H&H performance, has no belt, and is designed to work in standard length actions without having to modify them.

While a belted 300 H&H may have have set the standard in 1935, a belt less 300 WSM holds the current 1000 yard record. Or at least it did last time I looked, Google isn't currently working for me so I can't confirm. IIRC 10 shots into just over 3" at 1000 yards.

 

[T. O'Heir]

"...problematic for accuracy..." The 'belt' has nothing to do with accuracy. The .300 Win Mag has been used for eons in long range target shooting. However, the issue with magnums, belted or not, is noise and muzzle blast. Both those long range target rifles and sniper's rifles are big heavy things too.
"...it was consistently..." That is what's important.

 

[taylorce1]

The fact that the best big bore dangerous game rounds have belts is simply because they were developed at a time when belts were in vogue, they would be every bit as effective in modern rifles if they had been designed without the belt.......The exception is the 375 Ruger. It actually surpasses 375 H&H performance, has no belt, and is designed to work in standard length actions without having to modify them.

First off the belt wasn't used because it was in vogue, it was used because it was needed to provide headspace. Cartridges like the .375 and .300 H&H with their long tapered necks at the time couldn't create reliable headspace without the belt. This would cause light primer strikes resulting in misfires, the belt reliably solved the problem.

Second the .375 Ruger doesn't surpass the .375 H&H, all it does is equal the H&H performance in rifles of equal length barrels. In rifles with equal length barrels the two cartridges are usually very close in velocity with the same bullet. It doesn't require an action adapted to H&H length cartridges, that part of your statement is true.

While a belted 300 H&H may have have set the standard in 1935, a belt less 300 WSM holds the current 1000 yard record. Or at least it did last time I looked, Google isn't currently working for me so I can't confirm. IIRC 10 shots into just over 3" at 1000 yards.

I didn't imply nor did Bart B. imply that the record hadn't been beat. All I was stating is at that time it was one of the most accurate cartridges available. The point is the .300 H&H still has the same accuracy it always had, maybe even more potential with powder, primer, and bullet improvements made since 1935.

What record, there are a lot of records out there depending on discipline? There used to be a record of a 5 shot group of 1.5" at 1000 yards with a .300 Hulk which is a .338 Lapua necked down, I don't know if it still stands and I don't really care. I don't doubt there is a sub 4" group with a .300 WSM at 1000 yards having been shot, but records are made and broken on a regular basis in the shooting world.

 

[jski]

From a bona fide SEAL sniper:

In the near future, we will be using one of these three cartridges in our primary sniper rifle, which will also be new:

300 Norma
338 Norma
338 Lapua

Two things -

1. I said the 308, as in the cartridge, not the caliber, would become a thing of the past.. in SOCOM.

2. I don’t think people like headspacing off the belt, or the unconventional shoulder on the Wby. People who know about what makes one cartridge more accurate than another make those points...

People rave about the 300 Norma, and the 338 version for that matter. Folks who get into this Precision rifle game, across the whole spectrum of disciplines, are aware of the Wby stuff. No one uses them for that.. they have their reasons; case design is what it’s all about.

 

[jski]

Just been debating whether the .30-378 Wby Mag would make an excellent choice for Marine snipers. From what I've read, the cartridge is ideal for long range accuracy, 1500 yrds or greater.

The next issue would be 'overbore'. Is the 30-378 Wby Mag a barrel burner?

 

[RC20]

And then there are those who head space those same belted cartridges off the shoulder.

If we can do it now then not then?

And there has been a major debate on if a semi auto pistol head spaces off the mouth of the case.

Well I shot 45 GAP in a 45 ACP (not intentionally , fool that I was I did not even know there was a shorter 45 round)

It still fired (didn't eject for diddly which was my clue)

 

[Scorch]

Just been debating whether the .30-378 Wby Mag would make an excellent choice for Marine snipers.

Probably not a great idea. The USMC and AMU did a lot of testing back in the late 1970s-early 1980s (the last time they considered going to the 300 Win Mag as a sniper round) and decided it takes a lot more to teach a shooter to tolerate the 300 Win Mag over the 7.62X51, and shooter accuracy breaks down much quicker in sustained shooting. The 30-378 holds 50% more powder than the 300 Win Mag, and kicks harder commensurate to the extra powder weight.

And then there are those who head space those same belted cartridges off the shoulder.

Pretty much anyone who shoots a belted magnum for accuracy work headspaces off the shoulder. It increases accuracy, and the cases don't separate at the belt after just a few loadings.

 

[RIDE-RED 350r]

As to headspacing from the shoulder with a belted case: Being that the whole reason behind the introduction of the belted case was to give reliable headspacing on cartridges with minimal if not no shoulder, why wouldn't one resize in order to headspace off the shoulder of subsequent belted cases that do have a good shoulder to work with?? IE the Win Mags and others similar?

I have a 338 Win Mag and based on some advice and documentation given to me by a member, I began adjusting my resizing. Lo and behold, I have fired some cases 5 times and they still seem to be holding up fine. I just incrementally work my sizing die down till I get just a small amount of drag as the bolt cams fully closed.

Seems like a good method to me provided you are working with a belted case that has an adequate shoulder to it.

 

[OzeanJaeger]

My GAP .300WM has about half the recoil of a 700 in .308 with the Badger Ordinance Brake, or the can on it. I shoot PRS with it when it's permissible, and have cleaned plenty of stages with it.

While .338L has higher BC, more energy, and stays supersonic longer, it does have a great deal more recoil. If you're not regularly shooting beyond 1,200 yds .300WM is hella accurate and perfect to the task IMHO.

 

[oldscot3]

The 'belt' has nothing to do with accuracy.

I don't know if I agree with that, at least in my experience which is limited to just one belted magnum, a 338WM. As other posters noted, I did the neck up, then back down procedure to change the headspace from the belt to the shoulder on my 338 ammunition. Accuracy has improved with my Ruger using those loads.

Perhaps, if I were to buy another belted magnum rifle, I might not get the same result but I would hesitate to make a blanket statement regarding the effect of the belt on accuracy.

 

[Mobuck]

I had a wonderfully accurate 300 Win mag long range rifle that performed best with handloads that headspaced off the shoulder rather than the belt.

 

[jski]

Reloading Belted Magnums (Questions & Answers)

Looks like Larry offers a resizing die specifically for belted cases.

 

[hooligan1]

I own the Willis die, only used it on one case.
At the same time I purchased a set of Forster Bonanza Benchrest dies for my 7mm rem mag and I use it to full length resize my cases, and I noted that the Forster die corrects that bulge each and every time.
So the Willis die is just there to stare down from a shelf only to be used on range brass to see if the host rifles chamber was sloppy.
I have cases that have 7 and 8 reloads on them, and yes I always check every batch of 7mag brass.
If Im not mistaken the Willis die was a Hair over 100.00 with shippin........that would by more powder if I was to send it packing...

 

[Art Eatman]

Back around 1970, give or take a few years, the 7mm RemMag held the world record for group size at 1,000 yards. (No idea as to who dunnit or what rifle was used.)

 

[RIDE-RED 350r]

Just fired my 338 Win Mag today to make sure things are still good to go for the upcoming season. This thread got me thinking... I can EASILY chamber a fired case, tried it with a couple of today's empties. The bolt locks down as easy as it does on an empty chamber. I think I am going to get a neck sizer and only run it into the full length sizer when and only as much as needed.

Rifle is a 2014 Winchester 70 Super Grade.

Am I on the right track for accurizing and extending brass life? Seems to me that as long as a fired case still chambers without difficulty, I should only NEED to resize the neck to restore neck tension on the next bullet.

 

[Paul B.]

The following is something I wrote up for a post on another site. I decided to save it as the question keeps coming up. Works with either belted or non-belted cases.

It's also interesting to measure the belts on magnum brass. There is enough variance on belt width to affect headspacing. Anyway, the following takes care of the problem with my .300 Win. Mag. ammo and accuracy ranges from .375" to .75" depending on which rifle I'm shooting.

This is how I set up my sizing die for bottleneck cartridges.

1. Take a once fired factory round and blacken the neck and shoulders with a Magic Marker or Sharpee pen. Some people like to smoke the neck and shoulder, but I find the Magic Marker/Sharpee pen a bit better.

2. Carefully lubricate the case.

3. Loosen the lock ring on the sizing die and back off about two turns from when the die is set to touch the shell holder.

4. Size the case. Note where the marks are on the case and turn the die down about a half a turn and size again. Turn down some more, and resize again. What you are looking for is the marks on the blackening just touching the shoulder.

5. Clean the lube from the case and try it in the rifle. It may chamber just a bit on the snug side. If so, turn the die down ever so slightly, lube and size again. Wipe off the lube and try in the rifle. If it slides in as easily as a factory round, you should be good to go. If not, usually one more very slight adjustment should fix the problem.

6. Tighten the locking ring for the die and you're done. You have just set your sizing die up for a custom fit to your specific rifle, rather than a generic one size fits all guns.

Paul B.

 

[RIDE-RED 350r]

Thanks for that Paul.

But what about my situation where a fired case still easily chambers in my rifle?? Is what I said above ok to do? Neck size only till the need to resize the whole case presents itself?