Bolt sticks on extraction - could it be carbon build-up?

[manitou]

I doubt many experiment as much as that "guy in the video" and his cohorts.
Erik Cortina is a national champion long range competitor and makes his living competing and building competition/accuracy products.
His youtube channal addresses accuracy and reloading.
The circles he hangs with are are the "best of the best": World champions, world record holders, custom competition rifle builders, etc.

I suspect he and his cohorts "tinker" more than average.

 

[hawlejr]

Load is 57 grs of Vihtavouri N160 behind various 165 grain bullets. It's middle of the road vs the Vih. loads on their site. There are no overt signs of pressure. The primers are not flattened at all, certainly no extractor marks stamped into the case heads. I just can't believe it's pressure. I'm just trying to use some older brass which has been fired several times in this rifle in a low-work type of reloading. Accuracy really is not my goal. It's practicing different positions, rapid recycling of the bold, shooting off sticks, etc. The loads are well with in 2 moa, so that's fine with me. They just don't extract, and that is a puzzlement. If I do FL size, they do work, but that entails lubing, cleaning, and all that messiness. At least I know how to do it, I have 3-400 30-06 cases in this category that I have relegated to "practice".

 

[Trm82]

Load is 57 grs of Vihtavouri N160 behind various 165 grain bullets. It's middle of the road vs the Vih. loads on their site. There are no overt signs of pressure. The primers are not flattened at all, certainly no extractor marks stamped into the case heads. I just can't believe it's pressure. I'm just trying to use some older brass which has been fired several times in this rifle in a low-work type of reloading. Accuracy really is not my goal. It's practicing different positions, rapid recycling of the bold, shooting off sticks, etc. The loads are well with in 2 moa, so that's fine with me. They just don't extract, and that is a puzzlement. If I do FL size, they do work, but that entails lubing, cleaning, and all that messiness. At least I know how to do it, I have 3-400 30-06 cases in this category that I have relegated to "practice".

Wow !! Really dragging this one out .
You know that FL sizing works now so deal with it.
I hate brass prep with a passion but it's part of the game.

 

[Radman]

I've been using some older 30-06 brass which I've reloaded several times without much cleaning. I use it for practice shooting rather than load development or hunting. The outside of the necks are black with carbon. They may be a little hard on the chambering part of the process, but they are really tough on extraction. After firing, I have to use some force to lift the bolt, but it's not excessive. After the bolt turns, however, pulling it back can be so tough that I sometimes have to hammer on a rod down the muzzle to move the bolt back. There are no signs of over pressure and the groups are running a little over 1 moa, with these practice loads. I'm wondering if it could be that the carbon is burning/melting almost like glue between the neck and the chamber. The carbon on the necks when they first come out is shiny. There is no lube on the cases as I use a collet neck sizer.

I've had this many times in small caliber rifles & in my instances it WAS carbon buildup. If you shoot a lot varying the brand or type (shape) of bullet seems to help some.

 

[JAYgs8163]

More than likely you'll need to trim cases also after full length resize.

 

[Rick Richard]

If it closes without any resistance, but difficult to open after firing, then it is excess pressure.

 

[JAYgs8163]

Wow !! Really dragging this one out .
You know that FL sizing works now so deal with it.
I hate brass prep with a passion but it's part of the game.

X2.

Brass prep is the probably the most important part of the entire preparation reloading process. If it's hated so much then it sounds like factory ammo may be a more suitable way to go.

 

[AkleyFan]

I've been using some older 30-06 brass which I've reloaded several times without much cleaning. I use it for practice shooting rather than load development or hunting. The outside of the necks are black with carbon. They may be a little hard on the chambering part of the process, but they are really tough on extraction. After firing, I have to use some force to lift the bolt, but it's not excessive. After the bolt turns, however, pulling it back can be so tough that I sometimes have to hammer on a rod down the muzzle to move the bolt back. There are no signs of over pressure and the groups are running a little over 1 moa, with these practice loads. I'm wondering if it could be that the carbon is burning/melting almost like glue between the neck and the chamber. The carbon on the necks when they first come out is shiny. There is no lube on the cases as I use a collet neck sizer.

I have a 30-06 that had a similar issue. The chamber was cut with a pull-through reamer typically used for chambering Garands/M1's. The chamber was tight, especially with range pick up brass FL resized with a standard sizing die. Most of my reloads were snug when chambering a loaded round and were difficult to extract after firing. The rounds that went in butter smooth did not act this way. My solution: I polished the chamber with an 800 grit flex-hone - checking the fit with various pieces of fired brass that I measured - I used them as a gauge to check fitment. I also purchased a small base circle FL sizing die and these problems are now behind me. All resized brass chambers without any tension and after firing extract without issue. The rear half of my chamber was honed .0015" larger, the length was within spec. It's a phenomenal shooter now and 100% reliable. I believe that the snug brass/chamber combination did not allow the brass to expand while firing which would have allowed it to rebound/contract to a smaller size - which would allow it to release itself from the chamber walls. Generally, firing the snug brass made extraction after firing even more difficult. Hope this helps.

 

[Culpeper]

Load is 57 grs of Vihtavouri N160 behind various 165 grain bullets. It's middle of the road vs the Vih. loads on their site. There are no overt signs of pressure. The primers are not flattened at all, certainly no extractor marks stamped into the case heads. I just can't believe it's pressure. I'm just trying to use some older brass which has been fired several times in this rifle in a low-work type of reloading. Accuracy really is not my goal. It's practicing different positions, rapid recycling of the bold, shooting off sticks, etc. The loads are well with in 2 moa, so that's fine with me. They just don't extract, and that is a puzzlement. If I do FL size, they do work, but that entails lubing, cleaning, and all that messiness. At least I know how to do it, I have 3-400 30-06 cases in this category that I have relegated to "practice".

As mentioned already and worth noting FULL LENGTH SIZE THE BRASS ETC. Do the work before you end up with a stuck case or worse. Be safe not lazy. I don't have a problem with neck sizing until the bolt tells you it is time to FL size again. But you are looking for an easier softer way and there isn't one. How long have you been reloading?

 

[tony d willIiams]

Cleaning the brass is a minor inconvenience, at least to me. I use a sonic cleaner, hit the power and clean buttons, de-prime, clean again. No rush, I clean, rinse, then dry and when ready to reload, the brass is ready.

I weigh, measure each piece of brass when new, and after 3~5 reloads. I also write a number on each brass with an acid pen. All logged into a data base on laptop in the reloading folders.

If something changes, I want to know before damage is done. I, and hopefully you have seen rifles where the loads were too hot, and the chambers came apart.

I keep the ammunition I am shooting against my body, so the temperature is close to 96℉, always.
I was practicing in the desert, and being careless I left my ammo on the table, 122℉ ambient temperature.
The last round went into my chamber easily, as usual. The kaboom was louder, the recoil was much greater. I had to force the bolt up, but could not get the brass out.
Day was over except for pistol practice.
I went home and used a .300" brass rod and tapped it out.

 

[Taylorbok]

FL sizing only adds cleaning which is easy. buy a media tumbler ($50 ish) and toss them in for like 15-20 mins.
FL sizing every time will help keep the brass dimensions in check, if you let the base grow to much a regular die may not bring it back and may need to get a small base die to bring it back.
IMO you are making more hassle by not FL sizing every time.

EDIT: To answer your original question I have never heard of carbon making brass stick in a chamber.

 

[slikmrc]

I think it's great you are practicing different shooting positions. I do the same including using a sling. Didn't read the whole thread but a couple things come to mind. Cases not extracting after complete bolt lift may be due to bad primary extraction with your action. You absolutely need to assume an over pressure problem. But if you can chamber a fired round and extract it before neck sizing it, I would look at the bolt bolt function. Having to use a cleaning rod to extract a case and not see extractor marks like galling extractor groove or popping off the case is suspect to me. At a minimum I would be using some 0000 steel wool to clean the neck and shoulder when neck sizing. Think a FL sizing and trimming is in order for your brass.

 

[emp1953]

Cases are trimmed. I don't have a good case cleaner, and I'm trying not to put in too much work on these as they are practice rounds. I think I'll try reducing the loads (although in new bright shiny cases there is no problem), and see if that eliminates the problem. If it doesn't, it's definitely got something to do with the carbon build up. I have been using a rotary brush with carbon cleaner on the chamber throat, but, perhaps after a few rounds it has built up enough carbon in the chamber to form a bond with the carbon on the case neck. I'm using 57 grs. of Vihtavouri N160 in 30-06 165 gr bullets either Hornady spitzer flat base, or deep curl projectiles ( all 165 gr.) The max listed for these/similar 165 gr. bullets is 61 grs. I've also used the 165 gr. GMX bullet with 55 gr of N160. All of the loads can show very tough extraction once in a while to the point of needing to use a rod down the muzzle to break the case free.

Any rounds that I put into a good rifle, I do all the work on the brass. Unless it is a crap rifle and all I want to do is make noise on 4th of July.
Chamber a new round or a good one that chambers easily.
With a dial caliper measure the distance from the bottom of the case to the start of the shoulder on both cases. They should be very close to the same .001 or so difference is ok.
If you trim the cases do you remove the burr that always occurs on the inside and outside of the case neck.
Using dirty cases with dirty necks will cause the following. The case expands upon firing. The neck expands and seals the chamber so no gases migrate between the case and chamber. If the case is dirty enough it will not seal and excessive carbon buildup will occur in the chamber. The brass will expand against that carbon build up and will stick. Use a good bore cleaner on the chamber or have someone with a borescope look at the chamber for you. There is probably carbon there. After it is removed cases should not stick anymore. But..... because of using dirty cases the carbon buildup will return, with a vengence and it will be a merry go round. I advise cleaning the cases, put the extra work into it. Do everything you can to insure the best round that you can create every time. That way when something goofy starts happening you have fewer possible causes to look at.

 

[Rich Coyle]

I doubt many experiment as much as that "guy in the video" and his cohorts.
Erik Cortina is a national champion long range competitor and makes his living competing and building competition/accuracy products.
His youtube channal addresses accuracy and reloading.
The circles he hangs with are are the "best of the best": World champions, world record holders, custom competition rifle builders, etc.

Just the other day Ki read benchrest guys jump on anything the winner does. They are just like most folks. They follow someone's else's success.

I test.