6 BRA: heavy carbon(?) on Alpha case neck

[Lynn313]

Shooting my 1st BR family of cartridges & I’m getting heavy carbon deposits on Alpha 6 BRA case necks.
Kreiger 28” 218/243 .272 .104 M24. Impact 737r. New Alpha brass neck turned to .012. Loaded cartridge neck OD = .267 with 105 Scenar-Ls.
I shot my 1st 92 with a light load of 29.5 Varget. I got heavy deposits on all these. I was jumping 20 thou. Never any deposits on shoulder or case body. My thoughts were the Alpha brass is very tough, jumping 20 thou with 2-1/2 thou clearance around the circumference of the neck that it may not be sealing quick enough to prevent some gas entering the void. My thoughts were to increase the pressure to where I would be shooting long term & see if that stops it. I loaded 20 rds in .2 gr increments from 30-31.8 to see if I found pressure. I never saw pressure. There were a couple where with looking real hard there was a “faint” trace of the ejector.
I’m about to load some more at 30.8 Varget to shoot. I‘m posting this to see if someone has an explanation for so much deposit on the neck area.
Note: before cleaning I looked with scope. The chamber, throat, & leade were very clean with minimal copper on rifling. There was a little of this gook in the neck area. I clean when I shoot. The cleaning regimen depends on how much I shot. I’m used to a little carbon, but not this much. I’ve been shooting & reloading for a very long time for hunting & precision. I’ve only been shooting the small cartridges for a short time. I did forget to mention that in addition to the light charge of 29.5 Varget I only had 1 thou neck tension. These last 20 were loaded with 3. Checked with pin gauges. I do realize the rd count is low.
Thanks for any & all help, Lynn

I did have a bolt quit cocking at 31.4 & don’t know why. I pulled a bolt out of another rifle & finished. When home I pulled the bolt apart, just looked at it, & cleaned a little. I didn’t see anything wrong with the bolt & it worked fine when I put it back together. I just measured the fired cases at the .200 line. They were .470-.471. I mention this because I just read thread where Alex & others discussed problems with Alpha brass. I may have a bigger problem than dirty necks.
Fired necks = .271 - .2715

 

[Clancy]

3 things:

1) You got well into dasher territory with some of those loads.

2)Carbon on case necks has never concerned me.

3) #1 might be why your bolt stopped working. Can you elaborate on that a little? Did you blank a primer? There may be/have been a piece of the anvil impeding the bolt.

 

[Lynn313]

3 things:

1) You got well into dasher territory with some of those loads.

2)Carbon on case necks has never concerned me.

3) #1 might be why your bolt stopped working. Can you elaborate on that a little? Did you blank a primer? There may be/have been a piece of the anvil impeding the bolt.

1) thanks. I was loading hoping to find the edge of pressure safely, then to get a load I drop back enough to be safe in bad conditions. What is your recommendion?
2) this was heavy enough I was worried some might be building up in the neck area of chamber. When I scoped it prior to cleaning I did see some in the neck area. It’s late here, but I’ll post a pic of that tomorrow.
3) what surprised me was no markings on case head. The bolt lift heaviness was so little if you weren’t used to that action you would just think it was the action. I also took some pics of the bolt before i tore it apart. If there was something small I could easily have missed it. It’s doing great after putting it back together. I’ll see if I missed something on the primers.

 

[Lynn313]

I didn’t get the pics posted, but ordered quality .4695, .4700, ……through .474 quality pin gauges to remove barrel and check ID of rear of chamber to .200 line. I’ll go back & check but Alpha, Andrew Rixon, & other knowledgeable people have stated if larger than .471 or .4715 it was not usable for Alpha brass due to the Alpha won’t expand enough to seal. At that point it’s either cut off an inch & chamber with Alpha reamer or buy some Lapua BR when available. I almost had decided if SAMMI hasn’t adapted and Lapua didn’t make brass for it, never to build one.

 

[gunsandgunsmithing]

I haven't loaded much varget in quite a while and what I have is older. Has Varget gone the route of many powders, to whatever bismuth mix it it that is being marketed to reduce copper fouling? If so, I find pretty much all of those powders to be sooty kinda nasty. Not hard to clean but very dirty. They do seem to do this more to necks as well, IME. It might be that.

I'm not really a fan of the newer blends. Yes, it does seem to reduce copper fouling but I seldom had copper fouling issues before the screwed with the powders. I've been told and my experience agrees, that the makers had to adjust burn rates on these powders due to the affect of the bismuth mix. I've seen some powders that at least for a while, were all over the place, lot to lot speed wise, so it seems logical to me.

Bottom line is I wonder if it's related.

 

[Lynn313]

I haven't loaded much varget in quite a while and what I have is older. Has Varget gone the route of many powders, to whatever bismuth mix it it that is being marketed to reduce copper fouling? If so, I find pretty much all of those powders to be sooty kinda nasty. Not hard to clean but very dirty. They do seem to do this more to necks as well, IME. It might be that.

I'm not really a fan of the newer blends. Yes, it does seem to reduce copper fouling but I seldom had copper fouling issues before the screwed with the powders. I've been told and my experience agrees, that the makers had to adjust burn rates on these powders due to the affect of the bismuth mix. I've seen some powders that at least for a while, were all over the place, lot to lot speed wise, so it seems logical to me.

Bottom line is I wonder if it's related.

I think that’s a good guess that probably happens sometimes. In my case I use the same Varget for 6 GT and I get just a normal trace of carbon, very limited. I’m think it‘s more of a problem of the case not sealing against the chamber. I didn’t do my homework. I let the shop/gunsmith recommend the brass. They probably didn’t know either. After much research it appears the 1st batch of Alpha bra brass would worI with reamers like the jgs wheeler 1. Without telling even the gunsmiths that worked with them on the project they changed the base smaller based on Europe's CIP standards since this is not SAMMI approved. Nobody mentions that now you need their reamer unless you have jgs spec a clone.
A reminder for me of what happens when you get away from Lapua.

 

[Clancy]

Lapua has been available a few places this week.

I’m sure if you post a want ad in the classifieds someone will help you out.

 

[Jet]

How does it shoot?

I wouldn't sweat the carbon on the necks and recommend you keep your velocities between 2900-2980. This weekend I'm testing an older lot of Alpha against Lapua to see which one shoots smaller. Initial tests showed it is capable of shooting small but it doesn't handle the pressure the same way Lapua does.

My thoughts on the bolt not working is the same as Clancy. It is likely you pierced a primer and a piece of the anvil ended up in your firing pin hole.

 

[newbieshooter]

I haven't loaded much varget in quite a while and what I have is older. Has Varget gone the route of many powders, to whatever bismuth mix it it that is being marketed to reduce copper fouling? If so, I find pretty much all of those powders to be sooty kinda nasty. Not hard to clean but very dirty. They do seem to do this more to necks as well, IME. It might be that.

I'm not really a fan of the newer blends. Yes, it does seem to reduce copper fouling but I seldom had copper fouling issues before the screwed with the powders. I've been told and my experience agrees, that the makers had to adjust burn rates on these powders due to the affect of the bismuth mix. I've seen some powders that at least for a while, were all over the place, lot to lot speed wise, so it seems logical to me.

Bottom line is I wonder if it's related.

I haven't seen any differences between Varget I got 6+ years ago vs the Varget I got recently. Label is the same - no references to reduced copper fouling - and shoots the same as my old lots.

 

[gunsandgunsmithing]

I haven't seen any differences between Varget I got 6+ years ago vs the Varget I got recently. Label is the same - no references to reduced copper fouling - and shoots the same as my old lots.

Hopefully that holds true but wasn't it about 6 or so years ago when all this started? Not sure, so asking but that seems about right. Again, the issue may be totally different and this isn't a debate to me...just asking because I saw it with the first and concurrent lots of powders that did not do this before...fwiw.

 

[Lynn313]

I shoot the same Varget in a 6 GT & I don’t think that is the issue. I bought several 8# jugs all from the same lot.
I won’t know for certain until my larger gauge pins arrive & I measure the rear of the chamber. I bought this barrel during a Black Friday event at one of my fav stores. The 1st barrel arrived with wrong size & buggered muzzle threads. I had to send this back & they sent me this in return extremely fast. The chamber may be fine with Lapua brass. Alpha was recommended so I bought 300 Alpha.
My current plan is to send this to my gunsmith and let him cut an inch off. He will then chamber with an Alpha 6 BRA reamer.
*Please read attached comments from Andrew Rixon, part owner/engineer at Alpha. Also, in this same forum find the thread “Alpha BRA brass question” and just read what Alpha team told Alex Wheeler. I don’t know Mr. Wheeler, but I think he’s done enough to earn respect from all.
I started off just concerned over the “volume” of carbon on my necks. My concern since posting has expanded to include the entire chamber/case compatibility. I post to learn & get help. I Welcome not only advice, but constructive criticism. Thanks to all trying to help.

 

[gunsandgunsmithing]

Shooting my 1st BR family of cartridges & I’m getting heavy carbon deposits on Alpha 6 BRA case necks.
Kreiger 28” 218/243 .272 .104 M24. Impact 737r. New Alpha brass neck turned to .012. Loaded cartridge neck OD = .267 with 105 Scenar-Ls.
I shot my 1st 92 with a light load of 29.5 Varget. I got heavy deposits on all these. I was jumping 20 thou. Never any deposits on shoulder or case body. My thoughts were the Alpha brass is very tough, jumping 20 thou with 2-1/2 thou clearance around the circumference of the neck that it may not be sealing quick enough to prevent some gas entering the void. My thoughts were to increase the pressure to where I would be shooting long term & see if that stops it. I loaded 20 rds in .2 gr increments from 30-31.8 to see if I found pressure. I never saw pressure. There were a couple where with looking real hard there was a “faint” trace of the ejector.
I’m about to load some more at 30.8 Varget to shoot. I‘m posting this to see if someone has an explanation for so much deposit on the neck area.
Note: before cleaning I looked with scope. The chamber, throat, & leade were very clean with minimal copper on rifling. There was a little of this gook in the neck area. I clean when I shoot. The cleaning regimen depends on how much I shot. I’m used to a little carbon, but not this much. I’ve been shooting & reloading for a very long time for hunting & precision. I’ve only been shooting the small cartridges for a short time. I did forget to mention that in addition to the light charge of 29.5 Varget I only had 1 thou neck tension. These last 20 were loaded with 3. Checked with pin gauges. I do realize the rd count is low.
Thanks for any & all help, Lynn

I did have a bolt quit cocking at 31.4 & don’t know why. I pulled a bolt out of another rifle & finished. When home I pulled the bolt apart, just looked at it, & cleaned a little. I didn’t see anything wrong with the bolt & it worked fine when I put it back together. I just measured the fired cases at the .200 line. They were .470-.471. I mention this because I just read thread where Alex & others discussed problems with Alpha brass. I may have a bigger problem than dirty necks.
Fired necks = .271 - .2715

If you're saying the new Alpha brass is smaller at the base, I doubt that's the issue with sealing at the neck and I don't see carbon down the shoulder, like I'd expect from lack of seal at the neck. Just my thoughts though.

 

[Lynn313]

This is the pics of the bolt before I tore it apart. There was a pierced primer at 31.4. I have no idea as to how I missed it as I was singularly checking each case for pressure signs.

 

[Lynn313]

If you're saying the new Alpha brass is smaller at the base, I doubt that's the issue with sealing at the neck and I don't see carbon down the shoulder, like I'd expect from lack of seal at the neck. Just my thoughts though.

Agree with you completely. I posted only worried about the above normal volume of carbon on the neck, but the heavier bolt lift without ejector marks, etc on brass concerns me. My concerns have expanded since I posted.
If I had rear bolt thrust due to case not being able to expand completely per what Alpha, Andrew Rixon, stated would that cause a heavier bolt lift? Could it factor into piercing a primer?
Though if it wasn’t sealing it seems like I should get some carbon fouling on the body & shoulder? There was no carbon at all on the shoulder or body.

 

[gunsandgunsmithing]

This is the pics of the bolt before I tore it apart. There was a pierced primer at 31.4. I have no idea as to how I missed it as I was singularly checking each case for pressure signs.

I'd be a little bit concerned about the fp hole. It might be ok but it appears to be kinda hex shaped and possibly bushed already but that parts hard to say for sure, but it looks that way and that whoever did the work likely did the fp hole at the same time. It may be why you had a pierced primer and a pierced primer might be why it looks out of round too, as the escaping gasses might have burned the fp hole out of round and oversize, which compounds the pierced primer issue. The same escaping gasses can etch the fp tip, again compounding the problem. I think I'd have it looked at by a competent smith but don't continue shooting if it pierces primers as it'll only get worse. Put a fresh spring in it and address the fp hole issue for starters. They'll fix the pin tip at the same time, or should.

A temporary fix might be a harder/thicker primer like cci 450's. It may well stop the piercing for the time being. You may or may not need to re-tune but starting over and working back up is the default answer there.

 

[Lynn313]

I'd be a little bit concerned about the fp hole. It might be ok but it appears to be kinda hex shaped and possibly bushed already but that parts hard to say for sure, but it looks that way and that whoever did the work likely did the fp hole at the same time. It may be why you had a pierced primer and a pierced primer might be why it looks out of round too, as the escaping gasses might have burned the fp hole out of round and oversize, which compounds the pierced primer issue. The same escaping gasses can etch the fp tip, again compounding the problem. I think I'd have it looked at by a competent smith but don't continue shooting if it pierces primers as it'll only get worse. Put a fresh spring in it and address the fp hole issue for starters. They'll fix the pin tip at the same time, or should.

A temporary fix might be a harder/thicker primer like cci 450's. It may well stop the piercing for the time being. You may or may not need to re-tune but starting over and working back up is the default answer there.

I’ll take some better pics of the bolt, including firing pin assembly & post if you’ll look at them. If there’s something wrong with the bolt I’m sure it would be a result of the pierced primer. I had this action on another rifle previously & it’s always performed great.
The primers are already 450s. I have an “old” box of 450s that I use on the 1st 100 rounds I fire out of a new barrel. If I have lower quality bullets I usually use them on the 1st 100 rds also. On this one I started with the bullets I hope to use through the life of the barrel.

 

[gunsandgunsmithing]

I’ll take some better pics of the bolt, including firing pin assembly & post if you’ll look at them. If there’s something wrong with the bolt I’m sure it would be a result of the pierced primer. I had this action on another rifle previously & it’s always performed great.
The primers are already 450s. I have an “old” box of 450s that I use on the 1st 100 rounds I fire out of a new barrel. If I have lower quality bullets I usually use them on the 1st 100 rds also. On this one I started with the bullets I hope to use through the life of the barrel.

I and likely others will be happy to look at other pics. This is the pic that concerns me. You can see, that hole doesn't look nice and round any more.

 

[SKWERLZ]

I and likely other will be happy to look at other pics. This is the pic that concerens me. You can see, that hole doesn't look nice and round any more.
View attachment 1449342

No it doesn’t.
If your blanking #450’s something is definitely happening because I find them quite tough.

 

[Lynn313]

Here’s some more pics. If there’s something else you would like to see I can get it….thanks

The .072- pin wouldn’t go in. This is the .071- pin that is in it.

 

[Lynn313]

3 more pics