case head separation in .308

[mmb617]

I've only been reloading for a couple years and previously the only bottle neck cases I loaded were .223 for my AR. I have shot several thousand rounds of those without any problems chambering or extracting, and even on cases that were loaded a half dozen times or more I found very few neck splits and I never had any case head separation issues. I load on a single stage Lee press and set up my full length resizing die as directed by Lee, screw it down till it touches the shell holder, then 1/4 to 1/3 turn more. I also anneal my cases after every firing.

A couple months ago I bought a Savage Axis .308 bolt gun and 100 rounds of factory ammo (60 rounds of Aguila 7.62 and 40 rounds of Winchester .308 as that's what was available) since I had no brass. All the factory ammo chambered and extracted without any problems. When I was ready to start reloading I set my FL resizing die up the same way as I did for the .223 and expected similar results.

The first issue I ran into was when some of the reloads would not extract without extreme force on the bolt. I soon realized that it was only the Aguila 7.62 brass that was giving me this problem, the Winchester .308 brass although resized exactly the same way extracted easily. So I set aside the Aguila stuff and bought some once fired Winchester brass. I've since fired several hundred rounds of those reloads without any problems, till yesterday when I got this:





The case didn't completely separate but the crack runs about 3/4 of the way around it. This case had only been fired twice previously so I thought it should have lasted longer than it did. That got me researching the whole case head separation issue and I learned some things about shoulder bump, a subject I'd never even thought about before.

Maybe this case was just a freak as it's the first one I've had with that problem, but it seems like it's something I should be checking. I saw some guys use a bent paper clip to run inside the case to feel if there's a gully forming near the base indicating that case head separation is imminent and I can't feel that in any of the cases I checked, but that's not a real scientific way to check.

One of the videos I watched on the subject showed a couple different methods for measuring shoulder bump and it seemed to me the Whidden case gauge would be the easiest to use so I ordered one. My understanding is that I can take one of my fire formed cases and measure the shoulder bump on it, then set my resizing die so that it bumps the shoulder back from .001 to .003 more than that measurement. Does that sound right?

I also take it that bumping the shoulder back too far causes premature case head separation issues while not bumping it back enough causes chambering issues. Is that also about right?

One more semi-related question. I've always full length resized my cases but I do have a neck sizing die. Since I only have one rifle chambered in .308 and it's a bolt gun, might I be better served to neck size those cases instead of full length sizing them?

I know that some of my question can be answered by trial and error but I don't see why I should try to reinvent the wheel when I'm sure others already know the answers.

If it matters at all I'm loading what are listed as starting loads with 44 grains of BL-C(2) under a 168 grain HPBT Hornady bullet and a CCI #34 primer.

Anyone who wants to give me their thoughts I'm all ears.

 

[The Glockodile]

It is possible that you have a generous chamber, and each firing disproportionately balloons the case and causes this to occur...

... kind of like "excessive headspacing," but the other way round

Neck Sizing does reduce wear on the case heads, but eventually you'll have to FLS...

 

[Kp321]

It seems like 308 dies and shell holders are all over the place on shoulder placement. The best way to avoid oversizing is to purchase a case gauge and use it to set your dies. Would not be a bad idea to have the rifle headspace checked also. If the headspace is not correct, adjusting it is easy on a Savage.

 

[Charlie98]

Case head separations are just a matter of course in the .308 game. You do need to be probing those cases for incipent separation... it's a technique learned with practice. I actually sectioned a few cases when I was learning... cases I thought might be suspect. Some were, and some weren't... but I learned what I was 'feeling' with my paperclip, and now it's not a problem. All brass (any chambering) is not created equal. I stay away from Aguilla brass, generally, because I've found it hard as a rock; just my experience. There are other headstamps I avoid as well... the list is long but distinguished.

As Glocko mentions, you can get away with neck sizing... or maybe not. It depends on your chamber. Your 44grn load doesn't appear to be suspect, either. If I were you, I would FL size 10 rounds, measure them as a reference, then fire them and measure them again... to see if anything is obvious. Take those 10 cases, neck size them, then load them... and see how they chamber. Maybe 5 of one headstamp, and 5 of your Aguilla, just to see.

If you really want to pull the stops out, you will have to invest in some tools, however, and that's out of my jurisdiction. I reload .308 for my Savage 10 TAC... but I also reload for an M1a... I'm used to brass separating, and retiring it (hopefully) beforehand. I FL size everything because I need it to fit in everything... and I pay the price. I have a fair stash of .308 brass, and factory ammo I use as seed for my brass stash... so I'm not very concerned.

 

[Walkalong]

Give this a good read.

https://www.thehighroad.org/index.php?threads/incipient-case-head-separation.734058/

 

[JFrank]

I've only been reloading for a couple years and previously the only bottle neck cases I loaded were .223 for my AR. I have shot several thousand rounds of those without any problems chambering or extracting, and even on cases that were loaded a half dozen times or more I found very few neck splits and I never had any case head separation issues. I load on a single stage Lee press and set up my full length resizing die as directed by Lee, screw it down till it touches the shell holder, then 1/4 to 1/3 turn more. I also anneal my cases after every firing.

A couple months ago I bought a Savage Axis .308 bolt gun and 100 rounds of factory ammo (60 rounds of Aguila 7.62 and 40 rounds of Winchester .308 as that's what was available) since I had no brass. All the factory ammo chambered and extracted without any problems. When I was ready to start reloading I set my FL resizing die up the same way as I did for the .223 and expected similar results.

The first issue I ran into was when some of the reloads would not extract without extreme force on the bolt. I soon realized that it was only the Aguila 7.62 brass that was giving me this problem, the Winchester .308 brass although resized exactly the same way extracted easily. So I set aside the Aguila stuff and bought some once fired Winchester brass. I've since fired several hundred rounds of those reloads without any problems, till yesterday when I got this:


View attachment 1110268


The case didn't completely separate but the crack runs about 3/4 of the way around it. This case had only been fired twice previously so I thought it should have lasted longer than it did. That got me researching the whole case head separation issue and I learned some things about shoulder bump, a subject I'd never even thought about before.

Maybe this case was just a freak as it's the first one I've had with that problem, but it seems like it's something I should be checking. I saw some guys use a bent paper clip to run inside the case to feel if there's a gully forming near the base indicating that case head separation is imminent and I can't feel that in any of the cases I checked, but that's not a real scientific way to check.

One of the videos I watched on the subject showed a couple different methods for measuring shoulder bump and it seemed to me the Whidden case gauge would be the easiest to use so I ordered one. My understanding is that I can take one of my fire formed cases and measure the shoulder bump on it, then set my resizing die so that it bumps the shoulder back from .001 to .003 more than that measurement. Does that sound right?

I also take it that bumping the shoulder back too far causes premature case head separation issues while not bumping it back enough causes chambering issues. Is that also about right?

One more semi-related question. I've always full length resized my cases but I do have a neck sizing die. Since I only have one rifle chambered in .308 and it's a bolt gun, might I be better served to neck size those cases instead of full length sizing them?

I know that some of my question can be answered by trial and error but I don't see why I should try to reinvent the wheel when I'm sure others already know the answers.

If it matters at all I'm loading what are listed as starting loads with 44 grains of BL-C(2) under a 168 grain HPBT Hornady bullet and a CCI #34 primer.

Anyone who wants to give me their thoughts I'm all ears.

Read the post above this one. One of my biggest gripes is the blanket instructions (or lack of) on die set up, they’re always wrong and will eventually get someone hurt.

 

[Josh759]

This case had only been fired twice previously so I thought it should have lasted longer than it did.

I have had 3 case separation on the same box of 1x fired S&B .303 factory ammo that I full length resized and reloaded with cast bullets the 2nd time. I pulled the rest and tossed the brass. Seems to be common with Enfield rifles due to the generous chamber (still okay when checked with go/no go gauge) and the rimmed cartridge is very hard on the brass. The same gun is okay with IVI brass (3x so far).

Was this 2x fired from your original factory ammo purchase? Or was it the 1x you purchased later? There is really no way to know if it was truly 1X unless it came from your own factory ammo. It could have been from range pickup where someone left it due to multiple reloads. I have bought premium 30-06 "1X" fired range brass that several of the primer holes were way too loose for the new primers. So not sure if these were actually 1X, multiple times fired or just a factory issue. Most gun community members are helpful and honest but there are always someone trying to recoup a few bucks. It is easier to sell 1x than 5x fired brass.

 

[Nature Boy]

1. Check the headspace on your rifle. A friend has a brand new Savage .338L that had a complete case head separation on the first round he fired using brand new brass. The headspace was not set correctly from the factory.

2. Get a Hornady Case comparator and use it to set your resizing die. Only bump your shoulder back 0.002-0.003 from its as-fired dimension.

 

[AJC1]

A paper clip is definitely low budget but these are cheap.

 

[DukeConnor]

I shoot a 308 M1A , a m1, and a PSA10. I have not experienced a head seperation and have never had a case fail the paperclip test.

I have no idea how many reloadings the mixed brass have experienced. I load at lower charge limits and mostly shoot cheap bulk 150 grain bullets.

I know its a matter of time before I have a blow out and have been thinking about trashing my old brass buying new stuff and tracking the number of loadings.

I load on a rockchucker with Dillon carbide dies using mink oil as a case lube.

Some of these cases gotta be pushing 7 or 8 loadings. Probably ticking time bombs.

 

[AJC1]

Semi is not the same game as bolt, and it's worse for two reasons. Bolt is normally. 001 shoulder set back and semi is in the .002-3 range. The second is extraction. The life of a bolt gun case is high society comparatively.

 

[AJC1]

If you want to be super cheap you can use a range pickup as a hs Guage if you can find a long one. My chamber is short ish so picking up one long enough is easy. Size until it fits. You can feel the transition as you take the case down in size. I recommend removing the expander while doing this.

 

[jmorris]

I load on a single stage Lee press and set up my full length resizing die as directed by Lee, screw it down till it touches the shell holder, then 1/4 to 1/3 turn more.

Try this method.



Less trimming and no separations.

 

[AJC1]

Try this method.

Is this supposed to be a video of the wheeler method? It didn't play and now it does my appoligies.

 

[jmorris]

I don’t know what the wheeler method is, if it’s this,https://en.wikipedia.org/wiki/Wheeler–Kenyon_method it’s not even close to the information I was trying to convey.

It’s just how to set a size die to a given chamber, so when the bolt is closed the case is slightly compressed vs “loose” in the chamber with plenty of room to grow.

Besides not having to trim as much and the splitting problem eliminated, he will also require noticeably less effort to size because he is not moving the brass more than necessary.

 

[AJC1]

I don’t know what the wheeler method is, if it’s this,https://en.wikipedia.org/wiki/Wheeler–Kenyon_method it’s not even close to the information I was trying to convey.

It’s just how to set a size die to a given chamber, so when the bolt is closed the case is slightly compressed vs “loose” in the chamber with plenty of room to grow.

Besides not having to trim as much and the splitting, he will also require noticeably less effort to size because he is not moving the brass more than necessary.

That is the (alex) wheeler striped bolt method. I don't know why he kept going to fit the gage. The lever goes down no crush its done.

 

[Slamfire]

Semi is not the same game as bolt, and it's worse for two reasons. Bolt is normally. 001 shoulder set back and semi is in the .002-3 range. The second is extraction. The life of a bolt gun case is high society comparatively.

I agree! Gas guns are deliberately designed and timed to unlock just when pressures drop below sidewall burst levels, which is about 650 psia, to use the residual gas pressure to push the case out. You can read Chinn's Machin Gun Vol IV, he calls it the residual blow back affect.

You can see on this gas pressure curve of a 308 Win M1 Garand gas system. Dwell is more or less the movement of the operating rod as it unlocks the bolt. There is a slight shape difference to the timing and pressure curve with the M14 gas expansion system.




this is a picture from Chinn, you can see there is a drop off period in gas pressure







this is something Chinn put together to show the timing on a blow back action




This unlock period for a gas gun will stretch case sidewalls. In a clean chamber, with an unlubricated case, the front of the case sticks to the chamber mouth, but the sidewalls have to stretch to allow the case head to stay in contact with the bolt face during unlock.

I stopped case head separations in my Garands and M1a's by lubricating the cases. I tried all sorts of lubes, greases, oils, hair gel!. The actual best for match competition was Johnson paste wax spread all over the case body. Paste wax turns to a liquid under the pressures and heat of combustion, and that allows the case to slide to the bolt face without any body stretch. It also drys hard, so when fumble fingers dropped them on the ground, my cases did not collect a bunch of dirt. By the way, there are teflon sintered coated cases out there. The teflon is on the case for the same purpose as my wax, but is an even better lubricant. Phillip Sharpe reported the WW2 Germans created a burnt on wax coating on their steel cases, to reduce friction between case and chamber.

Pedersen used his own special mix of wax for his Pedersen cartridges.



I took these cases 22 firings before I decided the pockets were getting too loose for comfort







The FAL cases were unlubricated.

something I did find, with the lubricated cases, was that the shoulders moved forward as the case was extracted.







I believe the gas pressure was still high enough to move the shoulder as the case extracted. The case was too slick to adhere to the sidewalls, so as the case was extracted, the shoulder folded out to fit the space available.

So, for gas guns, you cannot measure the base to shoulder of a fired case, and use that to set up your sizing dies.

For the original OP, I bump my shoulders back 0.003" for all cartridges, if possible. (the 35 Whelen is an exception) For bolt guns, I used these chamber gauges



The Wilson gauge is cut large between base and shoulder so a fired case can be dropped in. From there, I measure the before and after sizing.

the steps cut in these gauges assume the rifle chamber is cut to SAAMI dimensions, and sometimes, chambers are not. In which case, bump the shoulders back 0.003" from a fired case.



The fact the OP had hard extraction makes me believe has some hard brass in the mix. Brass hardeness varies by the maker. American brass tends to be softer and easier to size. Foreign brass is often harder, for technical reasons. I think this chart came from a 1960's AMCP pamphlet


If the OP has hard brass, then his sizing die won't reduce the cases by much. And the stuff won't contract worth a flip after firing. Which means, after firing, those cases are under compression from the chamber walls, leading to difficult extraction.

This came from some Government report





This is another reason I like small base dies, I want my cases to be smaller than the chamber. At some level of case expansion, even small base dies won't work, and Roll Sizers are the ticket. A very expensive ticket.

 

[AJC1]

I agree! Gas guns are deliberately designed and timed to unlock just when pressures drop below sidewall burst levels, which is about 650 psia, to use the residual gas pressure to push the case out. You can read Chinn's Machin Gun Vol IV, he calls it the residual blow back affect.

You can see on this gas pressure curve of a 308 Win M1 Garand gas system. Dwell is more or less the movement of the operating rod as it unlocks the bolt. There is a slight shape difference to the timing and pressure curve with the M14 gas expansion system.

View attachment 1110386


this is a picture from Chinn, you can see there is a drop off period in gas pressure

View attachment 1110387

View attachment 1110388



this is something Chinn put together to show the timing on a blow back action

View attachment 1110389


This unlock period for a gas gun will stretch case sidewalls. In a clean chamber, with an unlubricated case, the front of the case sticks to the chamber mouth, but the sidewalls have to stretch to allow the case head to stay in contact with the bolt face during unlock.

I stopped case head separations in my Garands and M1a's by lubricating the cases. I tried all sorts of lubes, greases, oils, hair gel!. The actual best for match competition was Johnson paste wax spread all over the case body. Paste wax turns to a liquid under the pressures and heat of combustion, and that allows the case to slide to the bolt face without any body stretch. It also drys hard, so when fumble fingers dropped them on the ground, my cases did not collect a bunch of dirt. By the way, there are teflon sintered coated cases out there. The teflon is on the case for the same purpose as my wax, but is an even better lubricant. Phillip Sharpe reported the WW2 Germans created a burnt on wax coating on their steel cases, to reduce friction between case and chamber.

Pedersen used his own special mix of wax for his Pedersen cartridges.

View attachment 1110390

I took these cases 22 firings before I decided the pockets were getting too loose for comfort

View attachment 1110391

View attachment 1110392

View attachment 1110393

The FAL cases were unlubricated.

something I did find, with the lubricated cases, was that the shoulders moved forward as the case was extracted.

View attachment 1110394


View attachment 1110395


I believe the gas pressure was still high enough to move the shoulder as the case extracted. The case was too slick to adhere to the sidewalls, so as the case was extracted, the shoulder folded out to fit the space available.

So, for gas guns, you cannot measure the base to shoulder of a fired case, and use that to set up your sizing dies.

For the original OP, I bump my shoulders back 0.003" for all cartridges, if possible. (the 35 Whelen is an exception) For bolt guns, I used these chamber gauges

View attachment 1110396

The Wilson gauge is cut large between base and shoulder so a fired case can be dropped in. From there, I measure the before and after sizing.

the steps cut in these gauges assume the rifle chamber is cut to SAAMI dimensions, and sometimes, chambers are not. In which case, bump the shoulders back 0.003" from a fired case.

View attachment 1110397

The fact the OP had hard extraction makes me believe has some hard brass in the mix. Brass hardeness varies by the maker. American brass tends to be softer and easier to size. Foreign brass is often harder, for technical reasons. I think this chart came from a 1960's AMCP pamphlet

View attachment 1110398
If the OP has hard brass, then his sizing die won't reduce the cases by much. And the stuff won't contract worth a flip after firing. Which means, after firing, those cases are under compression from the chamber walls, leading to difficult extraction.

This came from some Government report

View attachment 1110399

View attachment 1110400

This is another reason I like small base dies, I want my cases to be smaller than the chamber. At some level of case expansion, even small base dies won't work, and Roll Sizers are the ticket. A very expensive ticket.

Very interesting... I know squat about gas guns so that was a pile of new to me stuff.

 

[Slamfire]

Very interesting... I know squat about gas guns so that was a pile of new to me stuff.

Earn your Distinguished Rifleman Badge, as I did, with an M1a, and you learn all sorts of things about making reliable gas gun ammunition. No one was as interested as I was in how the things actually worked, the majority of shooters just wanted their rifles to go bang and put the bullet in the middle.

 

[AJC1]

Earn your Distinguished Rifleman Badge, as I did, with an M1a, and you learn all sorts of things about making reliable gas gun ammunition. No one was as interested as I was in how the things actually worked, the majority of shooters just wanted their rifles to go bang and put the bullet in the middle.

As a matter of curiosity, I know the mini is not an m14 but is the function for these purposes the same. Only semiautomatic I own, besides pistols.

 

[Slamfire]

As a matter of curiosity, I know the mini is not an m14 but is the function for these purposes the same. Only semiautomatic I own, besides pistols.

The gas system is of a cheaper quality on a Mini 14, the cartridge has a different pressure curve, but the operating principles are the same. And both mechanisms have been known to slamfire in and out of battery due to firing pin inertia and sensitive primers!

I never bothered with lubricating 223 cases. I picked up coffee cans worth of once fired Federal Gold medal match from the Service Rifle teams at Camp Perry, and to make the round move fast, we all loaded the round hot: the primer pockets would enlarge in about three reloadings. Use of the AR15 really picked up once the AMU started winning the Service Rifle National Matches in 1995, and the firing line quickly dumped the M1a. I came after the Garand transition, I understood once good M1a's came out of Geneseo Illinois, the transititon from Garand to M1a was almost as fast. Even though I had at least one five gallon bucket of once fired military match 308, 308 brass was getting hard to find by the mid 1990's, and I sure wanted to keep mine in good shape. Since I learned from a gunsmith, Distinguished HM about taking a set of lubricated cases a whole shooting season, I kept on doing it. Waste not, want not.

You know, I was not born with this knowledge about mechanisms. I had to learn it from those who passed it on, in print. And the best non mathematical source is Vol IV of Chinn's Machine Gun series. Read it free, and down load the whole series at Hyper books:

http://www.ibiblio.org/hyperwar/USN/ref/MG/

Before there was an internet, I had to pay $100 for my hardcopy of Vol IV at the Great Western Show in Pomona. That $100 would be worth about $300 today, but I was glad to get the book. The seller told me, Vol IV was not a big seller, buyers wanted Vol 1 which had all the pretty pictures of antique machine guns. Vol 1 was interesting when I did buy one of them later, but Vol IV is the principles. And they are universal.

Something interesting to me, Chinn knows all about the greased, oiled, waxed cases of pre WW2 machine guns, but his volumes do not discuss chamber flutes. If any technology put greased and oiled cases on the ash heap of history, it had to be chamber flutes.











Chamber flutes are a very successful case lubrication technology, been used in rifles, pistols, and machine cannons. From what I read, the Germans captured a Russian aircraft machine cannon that used chamber flutes, saw a good idea, and copied it. Originality is overstated, if you see a good idea, use it, that's what humans did for hundreds of thousands of years. From there the Germans used the fluted chambers on their roller bolts, and it worked fine. I think it strange that Chinn could be unaware of fluted chambers, post WW2, but his team must have been.

I typically lubricate new cases, particularly for belted magnums.





The base to shoulder distance is not standardized on a belted magnum. That shoulder can be way up there, and many reloaders have reported very short case lives with belted magnums because they full length resize, push the shoulder way the heck back, and fire the case again. By lubricating the case, I make sure there is no sidewall stretch on first firing. The case slides to the bolt face, the shoulder folds out, and I end up with a perfectly fireformed, stress free case. Belted magnums are such a horrible case design though, and I had to buy expensive, adjustable case gauges. Once I bump the shoulder back 0.003 inches, those cases are only useable in the one rifle they came out of.

Greased cartridges shoot well







I really hate belted magnums, I have had rim lock in my 375 H&H, The case on top of the magazine, its rim got behind the case beneath it, and the belt locked on the rim below, causing a jam. This happened several times in that rifle, and I would hate to have a charging rhino, elephant, water buffalo coming at me, and little old soft shelled me having to figure out how to clear the jam. The way to do it, is push down on the cartridge stack with my thumb, let the cartridges shuffle themselves back into some order, and then rack the bolt again. That's too slow for some situations.

 

[AJC1]

The gas system is of a cheaper quality on a Mini 14, the cartridge has a different pressure curve, but the operating principles are the same. And both mechanisms have been known to slamfire in and out of battery due to firing pin inertia and sensitive primers!

I never bothered with lubricating 223 cases. I picked up coffee cans worth of once fired Federal Gold medal match from the Service Rifle teams at Camp Perry, and to make the round move fast, we all loaded the round hot: the primer pockets would enlarge in about three reloadings. Use of the AR15 really picked up once the AMU started winning the Service Rifle National Matches in 1995, and the firing line quickly dumped the M1a. I came after the Garand transition, I understood once good M1a's came out of Geneseo Illinois, the transititon from Garand to M1a was almost as fast. Even though I had at least one five gallon bucket of once fired military match 308, 308 brass was getting hard to find by the mid 1990's, and I sure wanted to keep mine in good shape. Since I learned from a gunsmith, Distinguished HM about taking a set of lubricated cases a whole shooting season, I kept on doing it. Waste not, want not.

You know, I was not born with this knowledge about mechanisms. I had to learn it from those who passed it on, in print. And the best non mathematical source is Vol IV of Chinn's Machine Gun series. Read it free, and down load the whole series at Hyper books:

http://www.ibiblio.org/hyperwar/USN/ref/MG/

Before there was an internet, I had to pay $100 for my hardcopy of Vol IV at the Great Western Show in Pomona. That $100 would be worth about $300 today, but I was glad to get the book. The seller told me, Vol IV was not a big seller, buyers wanted Vol 1 which had all the pretty pictures of antique machine guns. Vol 1 was interesting when I did buy one of them later, but Vol IV is the principles. And they are universal.

Something interesting to me, Chinn knows all about the greased, oiled, waxed cases of pre WW2 machine guns, but his volumes do not discuss chamber flutes. If any technology put greased and oiled cases on the ash heap of history, it had to be chamber flutes.


View attachment 1110452

View attachment 1110453

View attachment 1110454


View attachment 1110455

Chamber flutes are a very successful case lubrication technology, been used in rifles, pistols, and machine cannons. From what I read, the Germans captured a Russian aircraft machine cannon that used chamber flutes, saw a good idea, and copied it. Originality is overstated, if you see a good idea, use it, that's what humans did for hundreds of thousands of years. From there the Germans used the fluted chambers on their roller bolts, and it worked fine. I think it strange that Chinn could be unaware of fluted chambers, post WW2, but his team must have been.

I typically lubricate new cases, particularly for belted magnums.

View attachment 1110456

View attachment 1110457

The base to shoulder distance is not standardized on a belted magnum. That shoulder can be way up there, and many reloaders have reported very short case lives with belted magnums because they full length resize, push the shoulder way the heck back, and fire the case again. By lubricating the case, I make sure there is no sidewall stretch on first firing. The case slides to the bolt face, the shoulder folds out, and I end up with a perfectly fireformed, stress free case. Belted magnums are such a horrible case design though, and I had to buy expensive, adjustable case gauges. Once I bump the shoulder back 0.003 inches, those cases are only useable in the one rifle they came out of.

Greased cartridges shoot well

View attachment 1110458



View attachment 1110459

I really hate belted magnums, I have had rim lock in my 375 H&H, The case on top of the magazine, its rim got behind the case beneath it, and the belt locked on the rim below, causing a jam. This happened several times in that rifle, and I would hate to have a charging rhino, elephant, water buffalo coming at me, and little old soft shelled me having to figure out how to clear the jam. The way to do it, is push down on the cartridge stack with my thumb, let the cartridges shuffle themselves back into some order, and then rack the bolt again. That's too slow for some situations.

Never owned a belted case gun but in piles with rim's. I fully intend to avoid the particular piece of "technology".

 

[Slamfire]

Never owned a belted case gun but in piles with rim's. I fully intend to avoid the particular piece of "technology".

In my opinion, fins and rims are best left on classic cars:

Studebaker!



my, what big bombshells!

 

[AJC1]

In my opinion, fins and rims are best left on classic cars:

Studebaker!

View attachment 1110475

my, what big bombshells!

View attachment 1110476

I'll have the car and the rimmed cartridges. Better times...

 

[jmorris]

That is the (alex) wheeler striped bolt method. I don't know why he kept going to fit the gage. The lever goes down no crush its done.

If this is the wheeler method you are referring to,
https://precisionrifleblog.com/how-to-measure-the-distance-to-the-lands-on-your-rifle-barrel/, that’s also not what the video is showing. That is dealing with how to find where the bullet touches the lands. I have other tools for that task but that’s a different thread.

If the case were not under some amount of compression, the bolt would fall all the way down, the OP could even test this with his current “touch + fraction of turn” dies settings. Using one of his sized cases at current settings the bolt will fall just like it was on an empty chamber.

The gauges were thrown in to illustrate the differences in case gauges as well as how if you load using them, you can still be moving the brass more than necessary.