Rifle no longer chambers factory ammo

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NitwiT

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As the title implies, I own a rifle, and have owned this rifle for several months. The rifle is a Christensen Arms Mesa, in 6.5 Creedmoor. I have been working up a load for hunting and target shooting, and round count is now sitting at 250 or so.

In the course of this, I had dialed in the rifle to shoot Barnes Factory LRX, and went through a couple boxes playing around with them. I shot handloads in between to continue trying to find a happy medium between accuracy and speed. Having failed that, I settled on a nearly minimum charge varget load, shooting 3/4" or so, at 2500ish fps.

Now, seeing that my rifle likes slower rounds, I decided to try the Hornady ELDX's, (although I love my Barnes). I can't get them to chamber, the bolt will close most of the way, but won't turn down. There appears to be rubbing marks on the brass jacket.

I found this strange, so I went to a 1/4 box of Barnes factory I had left. These won't chamber anymore either. Back to my handloads, and noticing that the bolt closes, however, feels stiff in the final portion of closing.

I've visually (eyeball) inspected the action, bolt, bore, barrel, and all seems well. No noticible discoloring or particles. The ejector and plunger on the bolt appear to be working as they should.

I did try a bit more effort then I should have on one Barnes factory, resulting in the bullet being pulled from the brass upon extraction. This seems to say that the issue is in the throat? (not sure on the term here).

Looking for some ideas on what I can do to solve this

Mark
 
I've never heard of throat contraction before. LRX like a very big jump (compared to jacketed bullets). What distance off the lands were your reloads? Maybe copper buildup in the throat?
I shoot LRX in all my 6.5 (Swede, PRC, X65 RWS) and I've never had this issue. What caliber/rifle are you using?
 
Running your low speed loads can create more carbon fouling, give her a good cleaning and it should be fine.
 
If you were cleaning your chamber/bore after shooting sessions, you pretty much demonstrated that your cleaning regime or the solvent that you were using to be pretty much inadequate for the fouling that you were creating.
 
I'll have to improve my cleaning regimen for sure, I've shot other rifles, factory loads, hand loads, that never had this occur before. Inspection of rounds that I tried to load and pulled, all show a circular ring around the bullets shank, close to the ogive (if I have the right term). I believe the loads I made for this rifle are loaded to 2.71 COAL, and if my memory serves (forgot to write it down) the lands jammed at 2.76. I would understand if my handloads were too long, but the fact that factory loads (same box even), no longer (they did fine before) chamber without sticking, blows me away. I have some sweets on the way, nylon brushes, bronze brushes, and am currently looking for the right technique to deal with the supposed buildup.

Im partially wondering if my brass is getting trimmed to short, allowing for this to occur. I set my full length dies to shoulder bump 2 thou, and then trimmed to size, but have a vague memory of brass not chambering empty, and adjusted the length until they did.
 
NitwiT said:
I'll have to improve my cleaning regimen for sure, I've shot other rifles, factory loads, hand loads, that never had this occur before. Inspection of rounds that I tried to load and pulled, all show a circular ring around the bullets shank, close to the ogive (if I have the right term). I believe the loads I made for this rifle are loaded to 2.71 COAL, and if my memory serves (forgot to write it down) the lands jammed at 2.76. I would understand if my handloads were too long, but the fact that factory loads (same box even), no longer (they did fine before) chamber without sticking, blows me away. I have some sweets on the way, nylon brushes, bronze brushes, and am currently looking for the right technique to deal with the supposed buildup.

Im partially wondering if my brass is getting trimmed to short, allowing for this to occur. I set my full length dies to shoulder bump 2 thou, and then trimmed to size, but have a vague memory of brass not chambering empty, and adjusted the length until they did.
Click to expand...

Several things in your post are confusing. Just trying to narrow down the variable here, so don't take this as criticism, but instead an ask to clarify:

As soon as I see a post citing COAL, and then using that for bullets to describe jammed to lands, I see a problem. COAL has nothing to do with touching the lands or jam. Its cartridge base to ogive (CBTO) length measured with a bullet comparator, or mic, that is measured when referencing length to touching lands or jam, for that specific bullet. And that can change a few thou between bullets in the same box, and between the same bullets of different lots. Jam and touching lands distance are also quite different, several thou different.

Your reference to factory ammo not chambering, when before it did, lends some credence to perhaps a carbonized throat problem or some other obstruction in the chamber. However I have never heard of the carbon ring actually preventing bolt close or chambering, but rather it is usually referenced as being a factor in accuracy and group size.

I do not understand why you mentioned your brass being trimmed too short, and then not chambering empty after a 2 thou shoulder bump. Brass trimmed "too short" is not going to impede chambering. And a shoulder bump back 2 thou from firing is not going to prevent chambering.

Perhaps some clarification could be provided. For example, what was your base to ogive measure for jam, or touching the lands, prior to the problem, for each bullet that is of issue. You can do the test to determine jam again, by using a sized empty dummy case (NO power, NO primer), barely seating a bullet, lubing the bullet's ogive with sizing wax, and then inserting it in the chamber and closing the bolt. Open the bolt fast and the dummy round should extract, and then you measure base to ogive with your comparator to determine jam length. Compare this to the earlier data you generated before this lack of bolt closure occurred.

(aside: Never load to jam length because it is hazardous for pressure issues. Generally start a good 20 thou shorter than jam length.)
 
NitwiT said:
I'll have to improve my cleaning regimen for sure, I've shot other rifles, factory loads, hand loads, that never had this occur before. Inspection of rounds that I tried to load and pulled, all show a circular ring around the bullets shank, close to the ogive (if I have the right term). I believe the loads I made for this rifle are loaded to 2.71 COAL, and if my memory serves (forgot to write it down) the lands jammed at 2.76. I would understand if my handloads were too long, but the fact that factory loads (same box even), no longer (they did fine before) chamber without sticking, blows me away. I have some sweets on the way, nylon brushes, bronze brushes, and am currently looking for the right technique to deal with the supposed buildup.

Im partially wondering if my brass is getting trimmed to short, allowing for this to occur. I set my full length dies to shoulder bump 2 thou, and then trimmed to size, but have a vague memory of brass not chambering empty, and adjusted the length until they did.
Click to expand...

To me, this implies that your rifle has a chamber cut to median spec or very close to minimum spec.

I've seen this happen with custom rifles and the very odd off the shelf factory rifle.

Your Christianson Arms Mesa could very well be chambered on the tight side and for all intents and purposes, especially for someone that only shoots factory loads, this is a good thing.

When I get a custom reamer cut, I order it with median spec as maximum diameter and stick with suggested minimum spec, unless I'm going to handload from the first shot.

I believe the folks are right about your cleaning not being adequate. Are you cleaning the jacket fouling out of the bore as well???
 
Biologist,

Sure, I understand what you are saying, and I'm terrible at terminology. What I have done in the past, right or wrong, has worked for me in other rifles. When I talk about lands, and COAL, what I have done is taken a dummy round (no primer, or powder), with a seated bullet. I then place it in the rifle and try gently close the bolt, if it gets hung up, and seat the bullet slightly deeper. I keep doing this until the bolt barely closes with minimal effort. When I pull that round out, that is now the COAL I consider to be jammed. I then seat back from that length by 0.01 or something, then do my seating depth test at 0.04 shorter x 3. (Berger recommendation?).

I fired many Barnes LRX factory rounds, and never had an issue. I know my reloads were set quite a ways back from my jam (described above), and once I set a die, I mark it, and keep it for that rifle.

I will try do this test again when I find some time, I recognize mine is not the most accurate, but it works to keep me away from the jam point, with minimal to moderate jump (Barnes tends to prefer more).

Thanks for your insight and efforts, as well as the safety notes.

The trimming leads to a thought about the carbon ring preventing the bolt closing. If the edge of the casing is sitting too far back, there would be room there for buildup of soot/carbon/what have you. This is a question, not a statement. There is no doubt that the chambering hiccup is being caused by bullets sticking, so the question comes up how did it foul that badly that quickly, and what can I do to prevent it. Again, I've shot hundreds of rounds through other rifles with zero indication of this.
 
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bearhunter;

I have a vague memory of comparing my above described self attained jam length, and finding it shorter then the SAAMI specs for the cartridge. Even the book values I had from Barnes and Nosler indicated a longer COAL then what I was able to attain.

I must not be cleaning the jacket fouling out of the bore, all I typically do is run a rod through the barrel with some Hoppes and put it away. I'm not watching Eric Cortina's video of "Speedy" doing his benchrest cleaning, and will adopt some of that.

I still can't help but think something in my reloading practice caused this, as it seems rather unheard of. I think I've only found one other post on the interweb dealing with something similar.

Trying to avoid buying a borescope... but hmmm..
 
NitwiT said:
Biologist,

Sure, I understand what you are saying, and I'm terrible at terminology. What I have done in the past, right or wrong, has worked for me in other rifles. When I talk about lands, and COAL, what I have done is taken a dummy round (no primer, or powder), with a seated bullet. I then place it in the rifle and try gently close the bolt, if it gets hung up, and seat the bullet slightly deeper. I keep doing this until the bolt barely closes with minimal effort. When I pull that round out, that is now the COAL I consider to be jammed. I then seat back from that length by 0.01 or something, then do my seating depth test at 0.04 shorter x 3. (Berger recommendation?).

I fired many Barnes LRX factory rounds, and never had an issue. I know my reloads were set quite a ways back from my jam (described above), and once I set a die, I mark it, and keep it for that rifle.

I will try do this test again when I find some time, I recognize mine is not the most accurate, but it works to keep me away from the jam point, with minimal to moderate jump (Barnes tends to prefer more).

Thanks for your insight and efforts, as well as the safety notes.

The trimming leads to a thought about the carbon ring preventing the bolt closing. If the edge of the casing is sitting too far back, there would be room there for buildup of soot/carbon/what have you. This is a question, not a statement. There is no doubt that the chambering hiccup is being caused by bullets sticking, so the question comes up how did it foul that badly that quickly, and what can I do to prevent it. Again, I've shot hundreds of rounds through other rifles with zero indication of this.
Click to expand...

OK thanks, that clarifies my questions. Sounds like you are on the right track.

Re cases trimmed to short and carbon: I just recalled that I saw a YT video recently on this subject, where the person used a bore scope and showed that there was indeed a carbon build up in the neck of the chamber where his brass was on the short side. That extra area provided a recess for the carbon to build up. It was not a barrier to bolt closure in this video, but it was a concern.

With the proper tools, a good carbon solvent, and regular cleaning, I think you should be able to eliminate the carbon ring in the throat and in the neck area. I have had good success with KRG Carbon remover and one piece of an aluminum take-apart cleaning rod and a slotted end that I use a big wad of patches, and I just twist and twist it in the chamber and throat, and it seems to clean out alot of carbon. I use that same aluminum rod piece and scrub the throat with a bronze and nylon brush.
 
Thanks Biologist,

Thats what I'm going to do, keep cleaning and scrubbing until I can load factory again. In regards to the cases trimmed to short, in retrospect I doubt that is what caused this issue. The cases even if trimmed back 2 thou or whatever it took, wouldn't cause the buildup that is sitting where the shank meets the ogive. My thought is that the rifle wasn't getting cleaned properly, and had a small build up, that is now acting on the bullets to build up faster. Or something like that.

Thanks for your time.

Mark
 
Carbon build-up - within past year I received a "previously owned" Savage rifle - had a recessed muzzle crown, and a "flash hider" threaded on the front of barrel. I decided I wanted to remove that flash hider - do not have any others on other rifles - the "look" was not to my taste. When I finally got that thing to unscrew off the barrel - that recessed muzzle was solid full of carbon - appeared as if the chamber from that recessed muzzle to the first baffle in the flash hider had packed full of carbon from previous firing. I used a steel dental pick to "pop" most of it from the muzzle - came off in chunks. When I got most of it off, I hosed a rag with CRC "Clean-R-Carb" stuff from NAPA store - seemed to dissolve what was left and it rubbed out. But, lesson learned for me - carbon residue for sure a "real thing" - gets VERY hard packed - and likely needs regular cleaning with a solvent that will deal with that stuff. Which is no doubt different solvent than what takes out copper jacket from a rifle bore.
 
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