Belted Magnum Collet Resizing Die

[dwm]

I have been pressure testing IMR7977 with 180 grain Berger Hybrids in a 7RM and after 3 firings the Norma cases started to chamber hard, even after sizing in full length Redding bushing dies. Headspace was checked and verified not to be the problem.

I had previously purchased the Innovative Technologies: "Belted Magnum Collet Resizing Die" and decided it was time to give it a try. This die is designed to resize a belted magnum case right above the belt where the case expands due to excessive pressure.

Fired cases measured 0.5145 right above the belt. New Norma 7RM cases measure 0.510 right above the belt.

The Collet Resizing Die is interesting as the die goes in from the underside of the top of the press, not from the top as regular sizing dies do. The collet is removable and needs to be placed on the case, positioned all the way down to the belt before the case and collet are driven into the sizing die with the press.

Cases and the collet need to be lubricated well, Imperial Sizing Wax worked very well for me.

The case and collet exhibited significant resistance when inserted into the die for the the first few cases. The case and collet would only go part way into the die without feeling like they were going to stick in the die. The case and collet were removed from the sizing die and additional lube was added. This was repeated several times until the first case went fully into the die. After about three cases the case and collet would go into the die the first time. It seemed like the collet had to wear into the inside of the resizing die. Cases 4 through 10 resized well on the first try with only nominal pressure required to actuate the press.

Afterwards all 10 cases measured 0.510 immediately above the belt and chambered with ease in the 7RM.

Thoughts?

dwm

As an aside, the Norma cases still hold primers, although it does not take a lot of pressure to install them in the cases. I plan to reduce the load and work with seating depth next.

 

[Buttermilk]

I'm gonna have to check into this die for my 30-338wm.

 

[bigngreen]

I found them useful if your chamber is fat and the area forward of the belt is unsupported. If everything is right between a little spring back and a Redding die you'll never need the Willis die.

 

[dwm]

Thanks Bigngreen, I was pressure testing the 180 Berger loads and didn't want to toss the Norma brass after 3 firings.

Did you find your brass was serviceable after you used the Willis die?

I plan to find a load that shoots well at lower pressures so that the cases don't expand and require the collet die.

 

[Buttermilk]

My 30-338wm has a tight chamber. It won't chamber brass fired in another gun (ie 7RM or 338wm once fired brass) even if I FL resize it in my 30-338 FL die. I can use a small base die and then it will chamber in my gun.

This die might be useful for me.

 

[Deleted member 46119]

What you describe is exactly my experience.

I purchased some "once" fired 257 Weatherby brass. None would chamber and a little blue showed where it was rubbing. So I ordered the Innovative die.

Initially collet into die was sticky, making me worried it would not come out and it wasn't making the size goals.

I switched to Forsters lube which is my main case lube. A little use "buffed" the outside of the collet and now it works perfect.

It's a good tool when you need it which is not that often.

 

[MagnumManiac]

Thanks Bigngreen, I was pressure testing the 180 Berger loads and didn't want to toss the Norma brass after 3 firings.

Did yof 5u find your brass was serviceable after you used the Willis die?

I plan to find a load that shoots well at lower pressures so that the cases don't expand and require the collet die.

Excessive pressure is NOT the cause of the expansion above the belt, it is NORMAL, it's called the expansion line. The measurement above the belt is nominally .513", but factory brass is always smaller than this, hence the expansion.
There are 2 causes of excessive expansion in belted magnum RIFLES, the main cause is the brass case design, Norma cases are not supported adjacent to the belt, their design has the belt finish at the same point as the web, most other case brands finish the web further forward.
Second are rifles that do not support the entire case head properly, their are several rifle systems with recessed bolt faces, this contributes to the problem, as does sloppy chambers and small brass.
Again, it's the make of brass and design of the rifle that cause most of these problems, but, if you only bump the shoulder after the initial firing of new brass, you should minimise this problem, because the brass will not stretch as much if it headspaces off the shoulder.
There are too many misconceptions bandied about for the reasons belted cases pose problems, most are daused gy the reloader, then the brass eesign and finally, rarely, the rifle they're fired in.

Cheers.
gun)

 

[Deleted member 46119]

Excessive pressure is NOT the cause of the expansion above the belt, it is NORMAL, it's called the expansion line. The measurement above the belt is nominally .513", but factory brass is always smaller than this, hence the expansion.
There are 2 causes of excessive expansion in belted magnum RIFLES, the main cause is the brass case design, Norma cases are not supported adjacent to the belt, their design has the belt finish at the same point as the web, most other case brands finish the web further forward.
Second are rifles that do not support the entire case head properly, their are several rifle systems with recessed bolt faces, this contributes to the problem, as does sloppy chambers and small brass.
Again, it's the make of brass and design of the rifle that cause most of these problems, but, if you only bump the shoulder after the initial firing of new brass, you should minimise this problem, because the brass will not stretch as much if it headspaces off the shoulder.
There are too many misconceptions bandied about for the reasons belted cases pose problems, most are daused gy the reloader, then the brass eesign and finally, rarely, the rifle they're fired in.

Cheers.
gun)

Dude, I love ya but I respectfully disagree.

You add 2 more possible sources of brass excessive brass expansion but do not eliminate previous ones.

Re-read the OP. Clearly states over pressure loads preceded excessive case diameter at the belt body junction. Clearly states belt body junction diameter in excess of .513

My own experience is with brass from a different rifle that would not resize at the belt body junction. "Once fired" factory brass. Problem solved by one time collet sizing the belt body junction.

There are many factors that precede belt body excessive diameters. You add 2 that are clearly in the "not my fault" realm. If those were always true then the subject rifle would never function properly with resized brass which is clearly not true. The rifle would never be able to rechamber a fired round before collet resizing which is clearly not true.

 

[dwm]

So to add to the overall subject matter, has anyone used a 7RM small base die?

I use them on the 7WSM and 6.5/300WSM, but didn't think they were available for belted magnums.

Would a 7RM small base die also resize the area right above the belt to 0.510?

Thanks,

Doug

 

[Deleted member 46119]

So to add to the overall subject matter, has anyone used a 7RM small base die?

I use them on the 7WSM and 6.5/300WSM, but didn't think they were available for belted magnums.

Would a 7RM small base die also resize the area right above the belt to 0.510?

Thanks,

Doug

I would never have thought it but yes indeed there is a small base die set for 7RM. Not sure it would fix the problem. If it does it much cheaper ~$40 at RCBS Small Base 2-Die Set 7mm Remington Mag

The difference if course is that Innovatives will do "all" belted magnums and a small base die is chamber/caliber specific.

Even though I say I don't like belted case designs, I have 6 rifles in 4 chamberings. All Weatherby. Used to have more until I rechambered some as xxx/26-Nosler

 

[thethirdpig]

Can you explain the web design a little more? Is Norma a better or worse design. I have used nosler in the past but just had my 30-378 re-barreled. i bought some norma brass but have not used it yet. My old noslers do not fit my new chamber/barrel.

 

[blacknzr1]

I have that die.
I think it's the top where you can drop a case in to see if it needs sizing or not. My hornady brass sized with hornady full length die drop in no worries. So don't need doing. The magnum die squashes the brass down further than my hornady die. So iv never used it.
Maybe I don't understand the die but I don't really see the point with it. It does nothing my hornady die doesnt.

 

[Deleted member 46119]

If all your brass is fired in only one rifle and you never push your brass so hard it won't rechamber, you probably will never need the collet die.

 

[Innovative]

The rest of the story . . . .

I designed the Belted Magnum Collet Resizing Die. So, let me know if you have questions. I have been (and still am) continuously available to handloaders by phone and email since this unique die hit the market, back in 2001. At this time, there are well over 6,000 shooters using it. Unlike conventional resizing dies, this patented collet design squeezes the case inward only, and it can't plow brass rearward.

Belted magnum case bulge almost always occurs at (or soon after) the 3rd firing. This is caused from cumulative case stretching. The first firing is especially bad, because a NEW belted case has over than 3 times more shoulder clearance than a non-belted case. So, the first firing is a REAL case stretch. Most of the excessive case bulge happens during the reloading process. After a few years, I re-wrote the instructions because I found that too many shooters were using this die to over-resize their cases.

You only need to reduce case diameter .001" smaller than one of your FIRED cases. That makes the die much easier to use. (Most shooters figured that out.) The drop gauge on top of this collet die just shows how your cases fit in the average SAAMI spec chamber - which may or may not be the same size as your chamber.

Measuring case diameter above the belt should be done with the WIDE part of your calipers. This clearly shows the difference between a new case, a once fired case, and a case that won't chamber. Once a handloader sees this, it doesn't usually take long to understand what is needed to make reliable fitting handloads.