Challenges of loading belted cases?

[XTR]

Anyone who is smart, good looking and reasonably modest, ;D that has read books by Jack O'Conner knows that the .270 Winchester is the absolute best non-belted magnum in the world. [bigedp51]

As for the tirade on head-spacing on the belt, if you're a competent reloader you don't do that with anything other than new brass. [XTR]

Thanks for that comment - it makes the case (no pun intended) against the use of belted cartridges in precision and non-dangerous game roles perfectly. If you use handloading practices to negate the intended role of the belt why have it in the first place? Its existence solely adds cost and potential disbenefits by complicating case and chamber design / manufacture while you're then sizing cases to remove its function! A bit like buying a five-wheel car then putting extra high springs into the suspension to lift the fifth wheel off the road surface!

Laurie, I'm not arguing that the belted case is better, and I'm also not arguing for their usefulness in hunting. I do own a 7mmRM. It hasn't been in the woods since my last mule deer hunt in about '94, and at the time it was the only hunting rifle I had with me in Washington State. My hunting today is done with 7-08, a muzzle loader, and on occasion I use a 45-70 just because I like shooting what I believe is the oldest cartridge still commercially loaded. I think most hunters who shoot magnums are over gunned. Esp. when you consider that 90 odd percent of hunting shots are inside of 200 yards. Bigger and faster is better and kills them "deader", right?

If you are looking for the most velocity, and a lot of people are, that you can get in generally available components and in commercially loaded and available bullets then you look to the 7mmRM and the 300WM. That is because of very successful marketing in the past. I agree that these cases never needed to be belted, but at the time they were developed they were, they used a proven parent case with the most available volume. If I ever rebarrel my 7mmRM it will stay in that caliber, or get switched to 300WM because if I'm in Shotgun Rapids, ID or Dayton, WA and I need to buy ammo I'm pretty darned certain that I can find something in one of those two calibers on the shelf (assuming conditions other than what we are currently experiencing in the US) I am less certain of finding something in a WSM, though that is changing.

 

[Raythemanroe]

"If you are looking for the most velocity, and a lot of people are, that you can get in generally available components and in commercially loaded and available bullets then you look to the 7mmRM and the 300WM. That is because of very successful marketing in the past. I agree that these cases never needed to be belted, but at the time they were developed they were, they used a proven parent case with the most available volume. If I ever rebarrel my 7mmRM it will stay in that caliber, or get switched to 300WM because if I'm in Shotgun Rapids, ID or Dayton, WA and I need to buy ammo I'm pretty darned certain that I can find something in one of those two calibers on the shelf (assuming conditions other than what we are currently experiencing in the US) I am less certain of finding something in a WSM, though that is changing."
[/quote]

+1 what he said

 

[thefitter]

Those are valid points. However I was never planning on needing to use factory ammo.

Thanks

 

[AckleymanII]

I'm thinking about building a .300 wm bolt gun. But I've never loaded belted cases before. What are some of the challenges of loading a belted case? Is it worth it?

Thanks

I currently load for and shoot 3 belted cartridges (264 WM, 300 WM, and 375 H&H).

In spite of all the rumors, I find no challenges.

I love them

I have been loading the 7 mag since 1978, never knew there was an issue with a belt till someone invented it. 7stw's neither.

 

[Savage99]

Make or find a heavy wire or rod with a tiny right angle 'hook' on reach into every case to detect an incipient head separation.

This can happen with other types of cartridges as well.

I set the FL die so that cases with adequate shoulders headspace there.

 

[bigedp51]

Make or find a heavy wire or rod with a tiny right angle 'hook' on reach into every case to detect an incipient head separation.

This can happen with other types of cartridges as well.

I set the FL die so that cases with adequate shoulders headspace there.

The bent paper clip died with the invention of the dial indicator gauge, and a bent paper clip can't measure in thousandths of an inch. :

Below, one of the many uses of the RCBS Case Mastering Gauge, and stop case stretching before it happens.

 

[Laurie]

A former boss used to say 'We are where we are!', ie we've got to get on and deal with the situation or issue no matter how it might have arisen.

For people with a belted magnum number already, or who want to buy a rifle that uses widely available and effective factory cartridges, especially the 7mm RM, I'd not argue with their views and choices.

For the OP who's looking to have a custom build, and who won't buy factory ammo, the belt is still best avoided. I've got some limited experience here as a friendly precision gunsmith built me a 'bitzer' F-Class rifle out of his parts bin way back in the early days of F-Class. A Winchester P'14 ('Enfield' to you guys on the west side of the Atlantic) action that had been turned down and had a Heath Robinson (our equivalent to Rube Goldstein) match trigger assembly fitted, heavy Bishop 'Match Rifle' stock and a 30-inch ex 'Target Rifle' 1-12" twist .308 Australian Maddco barrel were adapted. The .300 H&H Magnum was chosen as having affordable brass and being so long a case that the reamer would cut out all of the old 308 Win chamber and throat without much set-back needed. I used H4831sc to get around 2,950 fps from 180s, not a particularly heavy load from a cartridge that has near identical capacity and uses the same SAAMI PMax of 65,000 psi as the .300WSM and which gives near identical performance. (It also gives excellent groups and small velocity spreads despite having every cartridge shape 'fault' known to man, or at least to short, sharp shoulders, fat case believers.) There was a final reason. Given my surname (Holland), I had to have an H&H Magnum at some point or other - no relation to those Hollands though unfortunately!

Winchester brass was available at a very good price at the time from a UK dealer and was very consistent once you sorted batches out. This had to be pretty old stuff as it came in 20-round cardboard carton, the old Winchester white ones with Winchestername and prancing horse logo, and 'Super-X' in red lettering.

The whole rig shot very well, but not very competitively against 6.5-284s starting to appear. The one fly in the ointment was that my friendly gunsmith was (still is) a believer in very tight chambers and new cases were a really neat fit in the belt recess - great if I fired them twice only, but being a 308 Win user I expected 12 or more firings from my brass. After firing #2, each subsequent one saw the belt expanded a little more and get tighter in the chamber. On the 4th, at most 5th, loading chambering was hard and cases wouldn't extract. The big Mauser type P'14 extreactor claw simply pulled right through the case extractor rim when the bolt handle was forced up and it became a cleaning rod job (and explaining to the RO that no, it wasn't too heavily loaded ammo and that it was safe to let me continue). I'd read previously about how belt dimensions change and hence the interrelationship with the chamber and thought this theory ahead of fact as there were lots of successful belted case long-range precision shooters around at that time. This was theory being proved in real life in front of my eyes though.

I still didn't regard the project as a bad one, just had to accept four firings from the brass whether cheap Winchester, or as later became the case, very expensive Norma when the dealer ran out of the former and couldn't get any more.

 

[slamfire1]

Apparently I did something with my 375 H&H magnum that no one else does: shot it rapid fire. My push feed M70 jammed with belted magnums fed from the magazine, did so more than once. I shot the thing sitting with a hasty sling. I would not be able to retain control on a 375 H&H shot standing rapid fire, and shooting it prone rapid; the punishment would be intolerable. What happened to me is that the belt on the top cartridge was rim locked by the rim of the next round in the magazine. I was able to clear the jam by sticking my thumb and pushing on the stack, but you know, after having this experience more than once, this is not my idea of a cartridge design to use against dangerous game, no matter how many people say they have done it.

 

[Laurie]

Hmm .... maybe that's why people going to face dangerous beasts buy custom Mausers! Also, more than a few professionals used Ruger 77 Safaris. Believe me, these guys shoot belted magnums quickly and make every shot count - if they and their rifles couldn't, most of them wouldn't be around to tell any tales or guide any more clients.

Get hold of a copy of 'Dangerous Game Rifles 2nd edition' by Terry Wieland. ($26.66 from Amazon.com) It gives the lowdown on what serious African hunters who want to survive the experience use and why they do so.

 

[ThunderDownUnder]

Hey Fitter, in answer to your question about challenges with belted mag cases, I would like to say in my experience in developing a long range F-Open rifle using a 300WM case there has not been any challenge to it. The case is extremely easy to use and to develop accurate loads for the heavy high BC 30 cal bullets. In my case I have loads for both the Berger 230gr and 200gr hybrids.

I'm launching the 230gr bullets at 2850 fps and the 200gr bullets at 2930 fps. I went for this case based solely on my need for a large capacity case to use slow burning powders, (retumbo, etc) that would give me velocities up to 3000 fps from 32" barrels. Accuracy nodes are very wide and with the 230gr bullets the node extends from 2850 fps upto 2910 fps. Accuracy can be a subjective thing but I can shoot single hole 3 shot groups at 100 metres with the 200 grainers and stay well inside 0.25" moa with the 230 grainers shooting 5 shot groups for the entire range of the accuracy node.

Your question relates to f-class and my comment would be that the 300WM with the new heavy projectiles is a back to the future move as the case is readily available and has the capacity that is required.

In club competitions at ranges of 600 metres and above I have shot high X count scores and in a recent open long range comp at 900 and 1000 yards I was lucky enough to win the F-Open section up against some members of our national F-Class team (the team that had success at Raton).

Its taken me a little time to come to terms with recoil management but if you are looking for a challenge then its not the belted case, its the belted shoulder from shooting 230 grain bullets. I have had a lot of success shooting the 7mm with 180gr bullets but the 300WM with 230gr high BC bullets is looking good to me for the moment. When (if) Berger release the 7mm, 195gr hybrids then the 230 grain bullets will lose the big advantage they now enjoy at long range.

My advice is forget the case has a belt and head space it off the shoulder and you have the perfect solution for the new heavy bullets. The 300 WSM case does not have the capacity to run with the 300WM out to 3000 fps with the heavy bullets.

Ian

 

[Raythemanroe]

Berger said all new bullets have been put on hold while they try to keep up with demand.

 

[slamfire1]

Hmm .... maybe that's why people going to face dangerous beasts buy custom Mausers! Also, more than a few professionals used Ruger 77 Safaris. Believe me, these guys shoot belted magnums quickly and make every shot count - if they and their rifles couldn't, most of them wouldn't be around to tell any tales or guide any more clients.

Get hold of a copy of 'Dangerous Game Rifles 2nd edition' by Terry Wieland. ($26.66 from Amazon.com) It gives the lowdown on what serious African hunters who want to survive the experience use and why they do so.

Thanks for the reference but I am going to stick to my experience rather than relying on authority. If my rifle jammed with belted magnums, then it happened. And it happened more than once.

Controlled feed Mausers would not fix what is an magazine issue. That claw extractor does not come into effect until after cartridge release and what I experienced was something that happened in the magazine before cartridge release.

There are good reasons why rimmed rifle rounds became obsolete immediately after the introduction of the rimless cartridge: rims will cause jams due to rim lockup. Belts just create new and novel failure mechanisms. The Mosin Nagant rifle had an “interruptor”, something that mechanically held the second from the top round from rising in the magazine. This was to prevent rim lock, and even though it is supposed to work, and it does work say 99% of the time, with Chinese ball ammunition I have had rim lock in a Mosin Nagant. Something was off, probably the Chinese rims were just a little too wide. Whenever a rimmed service round was replaced due to obsolescence , I am unaware of one being replaced with another rimmed round. (Lets say for everything after 1930).

Surprisingly I never experienced rim lock in the 303 Brit. References warn to stack the cartridges a particular way on the stripper clips though.

Big rims, wide belts, and fins may look great on vintage automobiles, but on cartridges, they catch on things. The belted magnum design is poor from a number of perspectives, some of which have already been discussed. I had to buy a Sinclair special case gauge for my belted magnums, and each one can only be used with one only particular rifle as the base to shoulder distance is not controlled by any industry standard for belted magnums.

For me, belted magnums are a triumph of advertizing over function.

 

[Hopkins]

I don't think it's possible to rim lock a belted magnum cartridge in a properly functioning Mauser actioned rifle.

 

[Steve Blair]

The 300 WSM case does not have the capacity to run with the 300WM out to 3000 fps with the heavy bullets.

Ian

[br]
Ian, [br]
This statement is demonstrably incorrect. .300 WM has a velocity edge over .300 WSM but it is not large in long barrels. My 34" WSM can easily achieve 2950 with 230 Hybrids, comfortably below max pressure. My teammate, Erik Cortina, was running 215 Hybrids at 3050 from 32". If you have an appropriate freebore for long bullets, .300 WSM has adequate powder capacity. I shot .300 WM in prone back in the eighties and always found best accuracy well below top velocity. It never tuned well near max pressure.

 

[ThunderDownUnder]

The 300 WSM case does not have the capacity to run with the 300WM out to 3000 fps with the heavy bullets.

Ian

[br]
Ian, [br]
This statement is demonstrably incorrect. .300 WM has a velocity edge over .300 WSM but it is not large in long barrels. My 34" WSM can easily achieve 2950 with 230 Hybrids, comfortably below max pressure. My teammate, Erik Cortina, was running 215 Hybrids at 3050 from 32". If you have an appropriate freebore for long bullets, .300 WSM has adequate powder capacity. I shot .300 WM in prone back in the eighties and always found best accuracy well below top velocity. It never tuned well near max pressure.

Steve, I read your article on your 300WSM and found your comments agree pretty much with what I found shooting the 300WM. It took me a while to develop the recoil management to do justice to the accuracy the 230gr Bergers are capable of achieving. I started my 300WM project specifically to shoot the 230gr hybrids for all the obvious BC gain reasons that go with it, but the biggest surprise for me was the wide accuracy nodes and extreme accuracy!

I am using a 32" Krieger 5R in 1.25" straight taper barrel and can see that you can get a bit more out of the 300WSM with a longer barrel which in your case is 34" What I found in using the 230s is that I have an accuracy node that starts at 2850 fps and extends all the way out to 2910 fps. This node achieves better than 0.25 moa, (at 100 metre) across its width. I also run within this lower velocity accuracy node. If the 300WSM can run at 2850 fps without pressure signs and destroying brass then thats good enough and I agree with your comment. The accuracy at 100 metres at the 2850 fps, bottom of the node is single hole 5 shot groups well under 0.25 moa.

My reason for using the 300WM case was to ensure I had enough capacity to experiment with my load development across a larger range of velocities than the 300WSM offered. I have found the Norma/Nosler brass to be excellent and completely without any case expansion problems associated with load development extremes. I head space off the shoulder and have a chamber cut with my custom reamer, throated for the 230gr hybrids. Anyone interested in trying the 230gr hybrids I recommend the 300WM case as being a strong contender and having the capacity and robustness to last for many reloads without any problems. The accuracy I have using this case and bullet combo has really surprised me and like Steve my preferred cartridge was the 284 Shehane.

Dont be put off by the comments on this forum that somehow try to relegate this case to history because it has a belted design. Ignore the fact that it has a belt and look at the case capacity it offers for load development and its strength of manufacture. If you want to shoot the 230s in F-Open competition then both Steve and I have found solutions that deliver on the promise the big bad Bergers offer!!!!!!

Ian

 

[jnyfeler]

I used to shoot the .300 WM in sling competition with great accuracy. However, I did encounter chambering issues with it on reloaded brass and as a result switched to the .300 WSM. I continue to have great accuracy but no more chambering issues.

Here was my scenario: I was shooting .300 WM brass from the mid 80s era. We know that the brass Winchester sells is the stuff that didn't make the cut for factory ammo, so it's not the most dimensionally consistent. In particular, the placement -- fore and aft -- of the belt on the case.

On the brass with the more forward-occurring belts, the case bodies were being sized sufficiently during reloading and posed no problem. However, the cases whose belts resided slightly more to the rear on the case, left a void area in the chamber just forward of the belt where brass would flow to during firing. The brass in this area went untouched during sizing and by the second or third firing began impeding the chambering of the rounds. So, it's only a problem for the more rearward occurring belts and would only present if your brass exhibited this kind of variance in the placement of the belt. If you were using a more consistently manufactured brass, you may not experience this problem.

They both shot well for me, but since I did experience the chambering problem with the WM, I made the switch to the WSM.

Jeff

 

[hogan]

Some years back, I helped a friend with a .300 Weatherby project. He wanted a tight neck short thoat chamber that would allow seating 180 grain bullets into the rifling at a length that would fit in the magazine of his custom stocked Weatherby. (He is a meticulous loader and very bright, or I would have never agreed.) Looking at new and fired brass from his factory chamber, I could see (with proper tools) that the shoulders of new cases were being blown forward about .021. Putting aside the neck (which required a clean up turn for proper loaded round fit) and the freebore shortening , addressing the reamer body design, I used the stock Weatherby diameters up through the shoulder, but I located the shoulder such that a new cases shoulder would only be blown forward .006 when fired. After the barrel was fitted, we took the whole reloading and chronograph setup to the range and started our testing well down from the maximum book load, not being sure of what effect the short throat and loading into the lands would have on pressure. I used a single case, for our pressure investigation, and although we had a FL die, the neck die worked perfectly all the way through. We did one shot per load, a half grain apart, and went up past where we were getting a bright circle from ejector hole, to the point where the belt diameter showed an increase for the second time, the first being on the initial firing. After the pressure test, I could easily chamber the case. I attribute this to not having too tight of chamber body dimensions. Shooters tend to think that tighter is better, and in some dimensions it can be, to a point, but I have seen more than one instance where a chamber was too close to fired brass's size, where tight extraction came at a pressure level that was lower than it would have been in a looser bodied chamber. The rifle shot well, and on its first hunt after rebarreling, dumped and large bull elk at about 600 yards with a high withers shot.

I was with you, Boyd, right up to where you said you left the reamer so that brass would move forward .006.

That is way long. I ream my belted magnum chambers to be short oal by .0005 maybe up to .001.

 

[BoydAllen]

I think that with the security of the belt, blowing the shoulder forward .006, is not a functional problem at all. Have you compared where shoulders are on new rimless cases of that size, compared to chambers of correct headspace? The reason that I did it was to have a little insurance for avoiding a doughnut, since this was a tight neck chamber. There were absolutely no negative effects from letting it blow forward that amount. Sometimes I think that there is an unwarranted fascination with close clearances, in places where they may not be the best choice, and gain nothing. After testing a single case well above reloading manual maximum, loads that were given for the stock Weatherby freebore, with all of the sizing being neck only, the case went back in the chamber without any tightness. (The whole test was done with 180 grain bullets slightly into the rifling.) Try that with a chamber that is a tight fit, in the body, of unfired cases. I am pretty sure that the bolt would have gotten tight much earlier in the progression.

 

[Savage99]

Make or find a heavy wire or rod with a tiny right angle 'hook' on reach into every case to detect an incipient head separation.

This can happen with other types of cartridges as well.

I set the FL die so that cases with adequate shoulders headspace there.

The bent paper clip died with the invention of the dial indicator gauge, and a bent paper clip can't measure in thousandths of an inch. :

Below, one of the many uses of the RCBS Case Mastering Gauge, and stop case stretching before it happens.

BigEd,

I have that RCBS gage and while it's useful for other purposes it will not detect a weak web in a case that might fail!

The "Bent paper clip." is indeed well and active in detecting bad brass.

For instance a belted magnum will stretch it's web on the first shot with new brass!. It's a design problem built into the prints!