Setting dies for a belted mag?

[TOM H]

Got to strongly disagree, that is an old wives tail not backed up by facts for an across the board statement

The majority of the BR (both SR and LR) FL size based on surveys at Br central! They are after accuracy. So that really kills the NS is "the" superior for accuracy theory.

Properly sized dies that are adjusted correctly lead to better accuracy and case life.

NS is touted when people do not know how to adjust the dies, buy oversized dies, then NS and suddenly think it helps them. Yes compared to what they were doing, but not compared to proper dies and correctly setup to FL size.

NS and then body bump die is NOT NS, that is FL size, just done in two steps.

Specific example, world record 5 shot 1.4" group at 1k was shot with shortened 338 Lapua brass that was shot 54 times at time of record setting. Thrown away after 80th reloading. NO NS only brass has remotely every done that.

BH

Bounty Hunter, I don't mean to disagree with you but have you shot SR BR. I got started back in the 80's and we used Wilson Neck dies and custom ones for the 6ppc.

One thing that happens shooting off a rest as you close the bolt depending on how the die is set up you can cant your rifle in the bags. Walt Berger had a good way to set up a die like this take the firing pin assembly out and adjust the die so that the bolt would close on it's own if you released it instead of doing it by hand. You look at the Hood Press or the copy that Harrell makes that set up for a threaded die and arbor die.

I don't shoot Br anymore but I do have a SB FL Type S die from redding for my 6ppc in the early days Neil Jones bushing shoulder bumping die was used and JLC was converting FL sizer over to bushing dies.

I guess you could say a FL sizer was better vs NS but to me just be one less thing to worry about shooting off the bags in truth just saved me from having to readjust the rifle.

I'm sure your experience may be differ.

 

[BountyHunter]

Tom H

Only shot SR group a couple times and some varmint for score. Had a 30 BR SR BR rifle for a couple years. Gun disturbance from hard bolt openings and closing is the same issue in LR BR and FL sizing will assuredly greatly help in that area.

I have a Hood press and use it to load at the matches. I size with the Hood, and I usually seat with Wilson dies at the matches and KM arbor with dial indicator to confirm uniformity of neck tension.

You pretty much laid out the transition in sizing from early BR using NS dies only to now, where the dominant die is a FL (Harrels, custom, JLC, Jones etc) that do a minimal body size to ensure clean bolt closing and less work on the brass.

As to the worry issue, when hunting I absolutely do not want hard bolt closings or openings due to lack of sizing which will happen when you NS only.

BH

 

[7 loader]

So much intrest in the belted mag, a history on it may be in order. in 1904 a patent was introduced by Henry Holland of H&H to the british patent office. It's # is 27,912. the case was the .400/375 nitro express. The 375 H&H came along 7 years later 1912. This info was found in the handloader journal dec. 2009 wrote by Gil Sengel. To set the die for "my gun" I have found to raise the ram to the top, put a regular piece of paper from a notebook on the shell holder, and screw the die down till it touches. This works for me. The comparator helped in this thankyou 375 fan. This is my humble opinion,I don,t have 40 to 50 yrs below my belt but I read for knowledge on this hobby obsesively.

 

[J E Custom]

The belted case is a design that has a purpose . The fact that some(Including my self) decide to
defeat the belt is not the issue.

The belt was designed to prevent a cartridge that was purposely sized smaller that SAMMI
chamber specs In order to chamber under ANY conditions for dangerous game and still not
allow the round to move forward and miss fire.

This is a common problem with shouldered cases that have been sized to small in an already
loose chamber.

A shouldered case with this condition could be disastrous with a large animal intent on causing
you great harm.

The belted case can be sized smaller and with the belt having control of the head space it will chamber in a very dirty chamber and still head space and fire .

The logic and practice is sound, If hunting dangerous game. But for us accuracy buffs oversizing
is detrimental to accuracy and it shortens brass life.

Belted cases can be extremely accurate if chambered and head spaced correctly. but hunting
dangerous game and shooting long distance at targets or non dangerous game requires a
completely different approaches and head space and sizing.

J E CUSTOM

 

[woods]

I was told in order to get the most accuracy out of a belted mag to set your dies to head space off the shoulder and not the belt. How do I do this?

Maybe the guy is just looking for a simple explanation, if so:

1. Set your gun up on the bench and close the bolt paying attention to the amount of force needed on the bolt handle to close it
2. Take a fired case and chamber it and see if it takes more force to close the bolt, it will be only a slight difference most times but you can feel the case being tight in the chamber, called a "crush fit"
3. If you do not have a crush fit then you need to size without pushing the shoulder back. You can size the case body but need to let the case shoulder continue to move forward with subsequent firings until you get the crush fit. Depending upon exactly where your case shoulder is, sizing the case body will squeeze the case like a balloon and push the shoulder forward so you need to try the case again after sizing. To set your die to size the case body and the neck without touching the shoulder, thread it in until it hits the raised shell holder and then BACK IT UP about 1/4 turn. That will size ~90% of the neck and almost all the case body. Again check the case in your chamber to see if it has ballooned forward to a crush fit.
4. If you do have a crush fit then you need to size to push the shoulder back the least amount possible to get rid of or greatly alleviate the crush fit. To do this with a normal FL die, thread the die in until it hits the raised shell holder and size a case. Try it in your chamber. The crush fit may still be there or may have gotten worse (that ballooning thing again). THREAD THE DIE IN a very small amount and try the case in your chamber again. Keep doing this until you feel the crush fit go away or decrease, IOW when the bolt closes easier. This usually happens when you have threaded the die IN OR DOWN an additional 1/8 turn from where it hit the shell holder. It helps if you put witness marks on the die and press

It helps if you have a headspace gauge. I use the Hornady headspace gauge and it attaches to your caliper and takes a measurement on the shoulder

That way you can track exactly how much your case is expanding and use the gauge to keep from pushing the shoulder back too far (.001" to .002" good .003"+ too far).

Here is an example of the belted magnum problem being discussed and how it can be a hidden problem that will not show up with the gunsmith go-no-go headspace gauges. 264 win mag Model 70

that is an expansion of close to .040" on new cases even though the actual headspace as measured on the belt was only .007". That excessive expansion is what leads to case head separations.

Hopefully this helps but if you already knew all this then I have just bored us all to tears and disregard as necessary.

 

[CatShooter]

I was told in order to get the most accuracy out of a belted mag to set your dies to head space off the shoulder and not the belt. How do I do this?

As others have said, you can get a neck sizer die (not expensive) of just back off your FL die.

Buying a set of Comp shell holders is silly for this application (at $48 a set).

The H&H cases were (as JE Custom aptly stated), designed to be more loose in the chamber than "normal" cartridges, because the case MUST feed and chamber, and MUST extract withOUT problems, or you are dinner for some fuzzy critter in the 800 (and "+") pound category.

What was said by bounty hunter is not true... the fact that benchrest shooters often FL their cases is NOT because it makes for better accuracy.

Bench shooters do compromises in loading (just like all of us) to get the best possible end use. In bench shooting, disturbing the rifle at rest is more costing of time than the tiny lack of accuracy justifies. If the rifle/case is tight, between waiting for minimum wind and mirage, and resetting the rifle after it was torqued off the bags, you may loose your time and be forced to shoot at the end of the time limit, even if the wind/mirage is at it's worst.

So staying in battery position is more important than the possible advantage of better groups vs bolt torquing the rifle out of alignment on the bags.

Back in the days of "real" benchrest with moving backers cuz the groups were so small that you couldn't count the shots, no one in their right mind would ever consider FL sizing a match case...

... and these days, in long range shooting, the same applies.

I no longer shoot formal bench, cuz the atmosphere in the sport has radically changed... now my bench rifles are all converted to long range varmint rifles, and I would NEVER full size a case. When my 6mmBR gets very tight, I use a bump die on it to "BUMP" the shoulder back until it is just a bit snug to close the bolt... that equals about -.002 headspace (that is minus headspace).

So... bench shooters DO FL their cases, but not because it is more accurate, but because they are easier to chamber under stressful conditions....

... NO ONE has demonstrated that FL sizing is more accurate, in fact it has been repeatedly demonstrated that neck sizing is more accurate (in high quality riffles).

---

So in summary, the easiest way to neck size is to back your FL die off one turn and lock the ring... it's "free" and will neck size your fired cases.

You might have some problems with this, if the FL die is tight in the body - my 264WM FL die has a tight body and so I chose to buy a Neck size die (kinda cheap @ $20 to 25 dollars)

If the cases ever get hard to close the bolt on, then use the full size die, but turn it down in 1/16th increments and run the case in after each increment, until the case chambers like you like, and then lock the ring and enjoy your rifle.

There is no reason that belted cases should fail any sooner than standard cases, IF you use proper procedures when loading - I shoot a .375 H&H, a 300WM, and a 264WM, and I have NEVER lost a case.

Meow...

 

[boomtube]

"Boomtubes Lee Collet and a body die still equals FL sizing also, just two steps. That point is often not stated by someone touting NS, "

That's so obviously true I didn't think it was necessary to spell it out. ??

 

[Steve O]

Thanks for everyones input. I just got some dies for my 338 win mag, and will be trying some reloads in it this coming weekend. I have reloaded for a couple of years, a 30-06, 280, and a 223, but have never loaded for a belted mag.

 

[CatShooter]

"Boomtubes Lee Collet and a body die still equals FL sizing also, just two steps. That point is often not stated by someone touting NS, "

That's so obviously true I didn't think it was necessary to spell it out. ??

Not quite. If you use a Lee collet and then a body die - and then check neck run out on a dial indicator, you will find that there is more run-out than if you FL size in one step... it does not equal FL sizing.