6.8 SPC Forums banner
61 - 80 of 83 Posts

·
Registered
Joined
·
247 Posts
"So what are you saying is the issue--that their case diameter exceeds the the chamber spec--or that it's too big to accommodate the variations in chamber cuts? "

....
Yes I've been saying it for 10 years. There is a bulge in the case apx 1/2" from the bottom due to a compressed load. Lay the hornady ammo on a piece of glass or machined straight edge and hold it up to the light, you can see the bulge.
If you chamber a round and remove it, repeat several times the bulge will rub on the chamber wall and scuff the case so it can be seen easily.
The problem is either compounded by a small or worn reamer or eliminated with a large spec reamer. ER Shaw makes Wilson and Bison barrels using PTG reamers. If they are community use reamers owned by Shaw they will use the same reamers for all OEM contracts and the reamers will dull and wear faster. The reamer that cut that chamber should have been replaced long before those chambers were cut. I know the guy that runs the plant and he's a good guy but they produce over 500 barrels a day and he can't inspect every one especially since all stainless barrels are made in one plant and all CM barrels made on the other block. Sometimes things fall through the cracks. If that reamer had been sharp maybe there wouldn't be a problem.
The OP says other ammo falls in and out, only the Hornady ammo gets stuck, there's your sign.
I guess my approach to that would be rather than make the chamber bigger I'd try to reduce the brass--there's no return from advanced wear on the chamber dimensions--if the PPU is already loose it will become more so. I see tight fits fairly frequently with match reamers/chambers. Granted, I guess a commercial utilitarian cartridge should be expected to work across the range of chamber specs. I've seen some cases where it might be only one spot that is slightly larger than min spec, but because of the taper differences between it and the chamber it can cause a "hang-up." It would be helpful to have a real idea of what the dimensions of both the chamber and case are--could be both are culprits.

I still recall all the fun we had with the initial 224 valk roll-out.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #62 · (Edited)
Quick update:

I'm not even going to entertain the replacement barrel. Original barrel is on the gun.

I received some new Hornady brass in the mail as well as the dies. I went ahead and did some load development with the brass as sized from Hornady and they shot fantastic but had the same issue as the Hornady loaded ammo they would not extract a live round from the chamber it was jammed. Shot fine.

When I got back I threw some of this new Hornady brass in the press and set the press up so it just slightly cammed over at the end of the stroke. I sized that piece of brass, and loaded a mock bullet to see if it would extract, it would not....but it was ALOT easier to get out and didn't require a butt stroke.

I kept turning the sizing die 1/16 turn and by the 4th try the loaded round (extracting from the gun) was coming out perfectly! I'm not that well versed but i'd think either my chamber is tight or the Hornady brass weather it be bare brass or loaded ammo isn't sized correctly (for my chamber?). Keep in mind the PPU box ammo worked perfectly in this barrel.

I went on to shoot a 1/2" group with it and all seems to be well, brass is piling up neatly at 3oclock, buffer system feels good (it's got the Maxxim shortened buffer on it) and it's extracting live rounds no problem. Also remember that I had to drill the gas port on it from .072" stock to .086" and i've got an adjustable gas block on it about 3/4 to wide open.

All that being said the chamber still does look rough but it feels fine, fired brass looks OK but you can see the chamber rings in it slightly. When I send the replacement barrel back to Wilson i'm going to see if they can hand select one with a good chamber and if not maybe offer a discount on this one.
 

·
Registered
Joined
·
247 Posts
Quick update:

I'm not even going to entertain the replacement barrel. Original barrel is on the gun.

I received some new Hornady brass in the mail as well as the dies. I went ahead and did some load development with the brass as sized from Hornady and they shot fantastic but had the same issue as the Hornady loaded ammo they would not extract a live round from the chamber it was jammed. Shot fine.

When I got back I threw some of this new Hornady brass in the press and set the press up so it just slightly cammed over at the end of the stroke. I sized that piece of brass, and loaded a mock bullet to see if it would extract, it would not....but it was ALOT easier to get out and didn't require a butt stroke.

I kept turning the sizing die 1/16 turn and by the 4th try the loaded round (extracting from the gun) was coming out perfectly! I'm not that well versed but i'd think either my chamber is tight or the Hornady brass weather it be bare brass or loaded ammo isn't sized correctly (for my chamber?). Keep in mind the PPU box ammo worked perfectly in this barrel.

I went on to shoot a 1/2" group with it and all seems to be well, brass is piling up neatly at 3oclock, buffer system feels good (it's got the Maxxim shortened buffer on it) and it's extracting live rounds no problem. Also remember that I had to drill the gas port on it from .072" stock to .086" and i've got an adjustable gas block on it about 3/4 to wide open.

All that being said the chamber still does look rough but it feels fine, fired brass looks OK but you can see the chamber rings in it slightly. When I send the replacement barrel back to Wilson i'm going to see if they can hand select one with a good chamber and if not maybe offer a discount on this one.
Just be careful you're not knocking your shoulder back--you could end up over-working the brass.
 

·
Registered
Joined
·
1,712 Posts
I don't have the proper gauges to check but I need some.

It's about as far as I have to cam over my .308 AR10
I'm sure you have a friend who has a 9mm case if not go to a local shooting range and pick one up . That is and a cheap micrometer is all you need to check shoulder bump . Measure fired case and compare to new case . Keep bumping the fired case back to . 003 or . 004 less than fired case . You can go back more but may loose accuracy and will be overworking cases . If you have to go past factory length to get it to function in your chamber you definitely have a problem . Edited it to add . I see in an earlier post you already have the micrometer . Best to take the primers out or push them back in before measuring as a proud primer can effect measurement

Sent from my LM-K920 using Tapatalk
 

·
Premium Member
Joined
·
18,382 Posts
I guess my approach to that would be rather than make the chamber bigger I'd try to reduce the brass--there's no return from advanced wear on the chamber dimensions--if the PPU is already loose it will become more so. I see tight fits fairly frequently with match reamers/chambers. Granted, I guess a commercial utilitarian cartridge should be expected to work across the range of chamber specs. I've seen some cases where it might be only one spot that is slightly larger than min spec, but because of the taper differences between it and the chamber it can cause a "hang-up." It would be helpful to have a real idea of what the dimensions of both the chamber and case are--could be both are culprits.

I still recall all the fun we had with the initial 224 valk roll-out.
And around and round we go. In 2006 the 6.8x43 chamber was the first .422" dia at the base. The only company making brass at that point was SSA .415" dia. when the brass was fired it swelled to .422, a .007" bulge at the .200". mark.
Anyone that loads a lot knows the brass would not last many loadings with that kind of growth. I designed my DMR chamber based on SSA brass to eliminate some of the swelling(.420), as well as correct the 80 degree cone angle and a little shorter freebore to help accuracy. The fact that the brass didn't swell as much also let us run higher pressure before the case would separate. We were running 60-65000 psi during some of the testing with zero brass problems. Every 5000psi over 58k was worth another 100fps. That should explain how we were able push a 80gr bullet to 3400fps. In order for the DMR chamber to work it needed small base dies like RCBS, Redding and Hornady was selling. Most people already knew to use small based dies in autoloaders so no problem.
Around 2008 this guy here on the forum pops up "EWP" from Louisana. We went round and round for 2 years about small based dies and what they actually do. I called every die maker in the country and asked them for design specs. Redding would not provide any info at all, All off the others except Hornady said regular dies are designed to size brass .002" under minimum diameter chamber size, Small base dies are designed to size .004" under minimum diameter chamber size, Hornady said all of their dies are designed to size .004" under minimum making all of them small base dies or the same as every other company's small base dies. .
In the end many wanted to use full size dies (note all Hornady dies, even the ones produced today are small base.) So I had to enlarge my chamber getting rid of the DMR chamber so everyone could use full size dies and we lost the potential of an extra 150fps. Now after you shoot any 6.8 ammo in any chamber you notice there is a pretty good size bulge at the bottom where the thinner case wall swells to the chamber wall. There have been many posts asking why there is such a huge bulge and what is wrong. Many believe they are having case separation.
Hornady brass is designed the largest at .418" dia well below the .422 chamber size but it still sticks...because the swell of the loaded ammo is further from the base.
People buy barrels expecting to shoot any factory ammo, but they don't understand how ammo can be out of spec so they complain about the barrel. Someone has to make it work, the ammo company no, already tried that. The barrel maker? well the ammo wont fit then must be a problem with the barrel right? so the problem gets fixed then they complain about the bulge at the base of the brass.
So SAAMI is supposed to be the institution in charge of making sure all ammo and all guns work together but they publish drawings approved by them clearly showing the maximum brass size can be larger than the minimum chamber size so how does that work? You think SAAMI will change anything? Nope they are all knowing, all seeing just like our government.
 

·
Registered
Joined
·
43 Posts
I just checked a 16" fluted Wilson that has less than 50 rounds through it. The chamber is smooth, no ridges or rough marks that I can see. Did not use a scope just a flashlight.
I dropped a factory Hornady (S&B brass) 120 gr SST in and it dropped in/out without issue.
Wilson seem to be having QC issues?
 

·
Administrator
Joined
·
22,641 Posts
So, that was the source of the rub concerning EWP. Now I know. His downfall was that he couldn't agree to disagree and leave things be, he had to go on the attack on the sly, that's what got him in trouble with the Mods back in the day. When he wasn't 'on a mission', he was a handy reloader to have around.
 

·
Premium Member
Joined
·
18,382 Posts
So, that was the source of the rub concerning EWP. Now I know. His downfall was that he couldn't agree to disagree and leave things be, he had to go on the attack on the sly, that's what got him in trouble with the Mods back in the day. When he wasn't 'on a mission', he was a handy reloader to have around.
That whole thing and the way it ended cost everyone brass life and big velocity when hand loading. Every time someone starts a thread about the bulge at the bottom of the case remember why we have it. Tim and I were pushing 115gr Hornady HPBT(discontinued) to 2800fps out of 16" barrels with plain old H335 back then and had no brass issues. Factory ammo hits what 2400 now, 2470 with 110gr?
Sorry OP I know this is getting way off track, it should be clear what I think the issue is but possibly mixed up in all the other yakking. I believe the reamer was worn or dull and the chamber is smaller than it should be or was designed as. If it was me I'd finish it with 320 grit, stainless is soft and easy to finish out or just wait for a new barrel.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #70 ·
I just checked a 16" fluted Wilson that has less than 50 rounds through it. The chamber is smooth, no ridges or rough marks that I can see. Did not use a scope just a flashlight.
I dropped a factory Hornady (S&B brass) 120 gr SST in and it dropped in/out without issue.
Wilson seem to be having QC issues?
Thanks for letting me know that.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #71 · (Edited)
And around and round we go. In 2006 the 6.8x43 chamber was the first .422" dia at the base. The only company making brass at that point was SSA .415" dia. when the brass was fired it swelled to .422, a .007" bulge at the .200". mark.
Anyone that loads a lot knows the brass would not last many loadings with that kind of growth. I designed my DMR chamber based on SSA brass to eliminate some of the swelling(.420), as well as correct the 80 degree cone angle and a little shorter freebore to help accuracy. The fact that the brass didn't swell as much also let us run higher pressure before the case would separate. We were running 60-65000 psi during some of the testing with zero brass problems. Every 5000psi over 58k was worth another 100fps. That should explain how we were able push a 80gr bullet to 3400fps. In order for the DMR chamber to work it needed small base dies like RCBS, Redding and Hornady was selling. Most people already knew to use small based dies in autoloaders so no problem.
Around 2008 this guy here on the forum pops up "EWP" from Louisana. We went round and round for 2 years about small based dies and what they actually do. I called every die maker in the country and asked them for design specs. Redding would not provide any info at all, All off the others except Hornady said regular dies are designed to size brass .002" under minimum diameter chamber size, Small base dies are designed to size .004" under minimum diameter chamber size, Hornady said all of their dies are designed to size .004" under minimum making all of them small base dies or the same as every other company's small base dies. .
In the end many wanted to use full size dies (note all Hornady dies, even the ones produced today are small base.) So I had to enlarge my chamber getting rid of the DMR chamber so everyone could use full size dies and we lost the potential of an extra 150fps. Now after you shoot any 6.8 ammo in any chamber you notice there is a pretty good size bulge at the bottom where the thinner case wall swells to the chamber wall. There have been many posts asking why there is such a huge bulge and what is wrong. Many believe they are having case separation.
Hornady brass is designed the largest at .418" dia well below the .422 chamber size but it still sticks...because the swell of the loaded ammo is further from the base.
People buy barrels expecting to shoot any factory ammo, but they don't understand how ammo can be out of spec so they complain about the barrel. Someone has to make it work, the ammo company no, already tried that. The barrel maker? well the ammo wont fit then must be a problem with the barrel right? so the problem gets fixed then they complain about the bulge at the base of the brass.
So SAAMI is supposed to be the institution in charge of making sure all ammo and all guns work together but they publish drawings approved by them clearly showing the maximum brass size can be larger than the minimum chamber size so how does that work? You think SAAMI will change anything? Nope they are all knowing, all seeing just like our government.
Just wondering, do you personally use small base or full length now? Also, what brass to you prefer still the SSA?

I don't have a way right now of measuring my cases other than for length so i'm not sure if i'm bumping the shoulder back slightly or getting more into the base. I'm using RCBS full length.

One thing's for sure is that whatever spec Hornady sizes their brass to doesn't fit my chamber well.
 

·
Premium Member
Joined
·
18,382 Posts
Just wondering, do you personally use small base or full length now? Also, what brass to you prefer still the SSA? If I use my DMR chamber in a custom barrel I use small base. If I'm running a production 12.5 then I use full length RCBS.

I don't have a way right now of measuring my cases other than for length so i'm not sure if i'm bumping the shoulder back slightly or getting more into the base. I'm using RCBS full length.

One thing's for sure is that whatever spec Hornady sizes their brass to doesn't fit my chamber well. The problem isn't what it was sized to, the problem is what it swelled to when they compressed the powder.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #73 ·
The problem isn't what it was sized to, the problem is what it swelled to when they compressed the powder.
Understood, however even the new unloaded Hornady brass that I bought had the same characteristics as their loaded ammunition which made me scratch my head. I loaded those from the box and they stuck just like the box ammo.

When I made dummy rounds to check fit when setting up the sizer die I had no powder in them and they still stuck just like the loaded rounds up until I had the die where it needed to be.

I'm no expect so I appreciate everything i'm learning here, and hopefully this thread might help some people down the road.
 

·
Registered
Joined
·
425 Posts
Just my experience with Hornady. I have a box of factory Custom 223 that if you chamber a round you have to mortar the firearm to get it out. I also have a box of 68 custom that will not fire in all 4 of my ARP barreled rifles. This 223 was bought several years ago. The 68 last year.
 

·
Premium Member
Joined
·
18,382 Posts
Maybe it's worn out forming dies. I've never had any problems with new Hornady brass only loaded ammo. You'll have to figure that one out. try painting the whole case and bullet black with a sharpie marker. Chamber it several times then look at the case to see what part is sticking.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #76 ·
Maybe it's worn out forming dies. I've never had any problems with new Hornady brass only loaded ammo. You'll have to figure that one out. try painting the whole case and bullet black with a sharpie marker. Chamber it several times then look at the case to see what part is sticking.
I did just a line previous and the only part rubbing off was toward the base.
 

·
Registered
Joined
·
1,712 Posts
Just wondering, do you personally use small base or full length now? Also, what brass to you prefer still the SSA?

I don't have a way right now of measuring my cases other than for length so i'm not sure if i'm bumping the shoulder back slightly or getting more into the base. I'm using RCBS full length.

One thing's for sure is that whatever spec Hornady sizes their brass to doesn't fit my chamber well.
What do you mean you have no way of measuring shoulder bump ? Did you skip over #65? Or did you loose your micometer or were you unable to find an empty 9mm case ? Either way it seems you have it figured out as far as the sticking goes . Just polish it good or don't put one in the chamber until you are ready to shoot it . After it is shot measure from base to shoulder as outlined and start bumping it back until it's . 004 less than fired .

Sent from my LM-K920 using Tapatalk
 

·
Registered
Joined
·
247 Posts
And around and round we go. In 2006 the 6.8x43 chamber was the first .422" dia at the base. The only company making brass at that point was SSA .415" dia. when the brass was fired it swelled to .422, a .007" bulge at the .200". mark.
Anyone that loads a lot knows the brass would not last many loadings with that kind of growth. I designed my DMR chamber based on SSA brass to eliminate some of the swelling(.420), as well as correct the 80 degree cone angle and a little shorter freebore to help accuracy. The fact that the brass didn't swell as much also let us run higher pressure before the case would separate. We were running 60-65000 psi during some of the testing with zero brass problems. Every 5000psi over 58k was worth another 100fps. That should explain how we were able push a 80gr bullet to 3400fps. In order for the DMR chamber to work it needed small base dies like RCBS, Redding and Hornady was selling. Most people already knew to use small based dies in autoloaders so no problem.
Around 2008 this guy here on the forum pops up "EWP" from Louisana. We went round and round for 2 years about small based dies and what they actually do. I called every die maker in the country and asked them for design specs. Redding would not provide any info at all, All off the others except Hornady said regular dies are designed to size brass .002" under minimum diameter chamber size, Small base dies are designed to size .004" under minimum diameter chamber size, Hornady said all of their dies are designed to size .004" under minimum making all of them small base dies or the same as every other company's small base dies. .
In the end many wanted to use full size dies (note all Hornady dies, even the ones produced today are small base.) So I had to enlarge my chamber getting rid of the DMR chamber so everyone could use full size dies and we lost the potential of an extra 150fps. Now after you shoot any 6.8 ammo in any chamber you notice there is a pretty good size bulge at the bottom where the thinner case wall swells to the chamber wall. There have been many posts asking why there is such a huge bulge and what is wrong. Many believe they are having case separation.
Hornady brass is designed the largest at .418" dia well below the .422 chamber size but it still sticks...because the swell of the loaded ammo is further from the base.
People buy barrels expecting to shoot any factory ammo, but they don't understand how ammo can be out of spec so they complain about the barrel. Someone has to make it work, the ammo company no, already tried that. The barrel maker? well the ammo wont fit then must be a problem with the barrel right? so the problem gets fixed then they complain about the bulge at the base of the brass.
So SAAMI is supposed to be the institution in charge of making sure all ammo and all guns work together but they publish drawings approved by them clearly showing the maximum brass size can be larger than the minimum chamber size so how does that work? You think SAAMI will change anything? Nope they are all knowing, all seeing just like our government.
I will say this about hornady brass; in my experience it tends to be the "stretchiest" of almost all the different makes I use especially in the web/head area it's usually the first of the brands I use to start dropping primers.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #79 ·
What do you mean you have no way of measuring shoulder bump ? Did you skip over #65? Or did you loose your micometer or were you unable to find an empty 9mm case ? Either way it seems you have it figured out as far as the sticking goes . Just polish it good or don't put one in the chamber until you are ready to shoot it . After it is shot measure from base to shoulder as outlined and start bumping it back until it's . 004 less than fired .

Sent from my LM-K920 using Tapatalk
got it!
 

·
Registered
Joined
·
1,712 Posts
I will say this about hornady brass; in my experience it tends to be the "stretchiest" of almost all the different makes I use especially in the web/head area it's usually the first of the brands I use to start dropping primers.
Are you referring to the Hornady produced or S&B produced brass? Do you weigh and seperate them ? S&B has more volume and is better brass . If you work up a stiff load in S&B made brass and load it in Hornady made brass you will probably get overpressure signs .

Sent from my LM-K920 using Tapatalk
 
61 - 80 of 83 Posts
Top