Malfunction while firing

lpaalp

This question might belong in the reloading section, but its the malfunction I'm concerned about, so:

Primer separated from the case when a round was fired, remained in the chamber/breach when the next round was fired, generally screwed things up.

In Rem 700 Sendero II, 25-06, Remington Cases, CCI BR2 primers, Reloader 19, 100g Noslers. Per Nosler manual, 54.5g of RL 19 is max, 52.5g is accuracy load.

Load testing, I loaded 4 rounds each with 52.2g, 52.5g, 52.8g, and 53.1g of RL19.

First group, 4 rounds (52.2g RL 19) fired without a hitch.
Second group, 4 rounds (52.5g RL 19) appeared to fire without a hitch
Third group, (52.8g of RL 19) first round fired - very loud and felt particles came back, hit my face. Spent case stuck in the bolt.

Later: Removed the bolt and a spent primer fell out. Can't tell for certain, but I think the primer from the last round fired is still in the pocket, and the body and neck appear normal, albeit stuck in the bolt.. However, the primer is missing from the second to last case (round) fired (4th round of second group). I didn't notice when I ejected this round, but the primer is not in the pocket. The case head is badly smoked, (and, of course, primer is missing) but no other abnormalities.

Dismantled the remaining cartridges - loads are all right on. Always possible I could have screwed up one round... but unlikely. This was the last round of 4, and the first round of the next powder increment. No other cases/cartridges show abnormalities. This is about 90% load density, so no way there was a double charge... anything is possible, but don't really think the load was wrong.

My guess is the primer from the next to last round fired left the pocket (??) remained in the breach (somewhere?) and caused the problem. But I have no clue as to how either of these occured, or why the case from the last round is stuck fast in the bolt (although that is relatively minor).

No camera, so no pictures - sorry.

Any ideas re what happened?

Mobuck

First, there is no place for a popped promer to "remain in the breach". The popped primer could have laid on the magazine follower until the next round was ejected.
Second, something seriously wrong with your reloads. It could be the brass has been overloaded or reloaded too many times previously.
Third, the primer from the case could have fallen out after ejecting.
Fourth, the case is "stuck in the bolt" or stuck in the chamber?
I don't have any reloading manuals with me so can't comment on the load but you need to find the problem before reloading any more of those cases. You may need to have the rifle checked out after such an event. We need more info like cartridge overall length(could the bullet have been jammed into the rifling), did the primers seat too easy,case info like times loaded, condition of the rifle(new,used,or unknown past), all these things might help determine what happened.

airmung

Could that round have had a loose (worn) primer pocket?

lpaalp

OK... I'm the original owner of the rifle, 350 rounds thru it. The brass was remington bought new, loaded/fired, trimmed to spec and reloaded. This was the second time fired. COAL was 2.6" - a little longer than the manual recommendation, but below the rifle's measured acceptable length (2.62" to the lands). Primers seated normally. I chambered each round after it was loaded - bolt closed easily and each round ejected. The case is "stuck" (sorry for the graphic description) on the end of the bolt - assuming the extractor locked on but can't relesase (?). I found the spent primer just behind and below the chamber when I removed bolt and case (together). I realize there is no actual place in the breach/chamber for it to rest during firing - could have laid on the magazine spring/plate...?

Mobuck

Well, that cuts down the possibilities considerably. Is there any chance of some foreign material being in those two cases-like tumbler media or something? Believe this or not. I always do a visual check of powder in the case and found one that didn't match the others. When I dumped the powder and reweighed it, I found it OK. I looked inside the case and found a lump of media had clotted up inside the case and stuck. I'd handled this case 3-4 times after tumbling but still hadn't noticed a problem until I saw the difference in powder height. Another time I found a 224 bullet inside a 243 case that obviously been there for a while but didn't fall out during handling.

edharold

There are manufacturing errors in almost everything. The primer pocket could be oversized but you should have noticed that. That only leaves firing a load that was too hot. When the primer backs out of a new brass I consider that max.

bpost

Please borrow a camera or cell phone and post a picture of the fired cases, this should be moved to the reloading forum.

Primers falling out with known safe loads may indicate the brass is too soft in the head area allowing primer pocket expansion. Are the primers flat in the fired cases that did not blow the primer?

Is there any obstruction in the bore? a jacket blow off or a neck piece from the previous firing????

lpaalp

Foreign material in the case? Anything's possible, but I use an ultrasonic cleaner, so no media, etc. Difficult to imagine what could have gotten into the case. I primed them just before loading, so they were touched/handled minutes earlier.

Comparing primers with others fired with a different load a couple of days earlier, these may be slightly flatter, and possibly larger in diameter... can't measure, so only judging visually. The case with the blown primer is normal, except for a black streak across the base. Calipers show it to be the same dimension as others fired days earlier. Don't have tools to measure the primer pocket, but dimensions look the same. No foreign matter/material evidenced in the bore or chamber, and all of the fired cases are intact.

I realize this smacks of pressure created by a too hot load. I find it difficult to believe... I started with 52.2g of powder, increased .3 after each 4 cartridges. When I came back, the scale is still set to 53.1 ( last charge weight). I took down the remaining 7 cartridges, all checked out perfectly... checked calibration on the (beam) scale, its good. I load and fire single shots, and put empties back into the ammo box in the same sequence as fired (for reference purposes), so I'm sure which case was fired in order... I'm not quite * about this stuff, but very nearly.

I almost put this in the reloading section... but I really can't quite believe it was a reloading problem - I'm looking for other possibilities... but whatever is OK with me.

Mobuck

There has to be a reason however it may not be evident w/o more searching. Fortunately, you were using a tremendously strong rifle and apparently suffered no injuries.

lpaalp

This may end up in the category of the great unknown. I'm certain someone with the proper tools and knowledge could determine cause/effect... but it may not happen this time.

bpost

One last thought before this gets locked, I hope it gets moved.

.......Is there ANY chance you got a large pistol primer mixed into your supply of large rifle primers?

MIKE WISKEY

this 'sounds like' a classic overload, 1- case head expanded so the pimer fell out, 2- next case head expanded so much it 'locked' itself to the bolt head. when you remove the case from the bolt you will probably find the brass 'flowed' into the ejector hole and extractor recess. several things can cause an overload besides powder/bullet/case/primer combo.