Primer Seating Depth & Accuracy?
- Thread starter MikeMcCasland
- Start date
Nice to see you fixed the problem. Which powder are you using with the original setup? If you are at the lower end of your node with your loading and the powder does not deal with temperature variance well you could well be dropping enough pressure to bottom out of the node.
Of course a barrel would make all of that that a different ball game.
Ned Ludd
Silver $$ Contributor
Although the issue appears to be intrinsic to the barrel itself, I personally wouldn't say it has been resolved. Although I felt it was highly unlikely that primer seating depth had anything to do with an issue of the magnitude described, I didn't respond with something likely to be viewed as opinion and potentially unhelpful. However, Mike has now indicated that the barrel itself seems to be the problem, although he has not elaborated on what is specifically wrong with it. So I am now very curious as to why a .30 cal barrel from a reputable manufacturer would go south with such a low round count.
For that reason, I'll ask Mike a few questions along those lines. Have you looked at the barrel with a borescope? Have you discussed the possibility of sending it back to be inspected with the manufacturer? Have you done anything to the barrel other than switch it to different rifle to support the notion that the barrel was the problem; i.e. something such as run an abrasive cleaner like KG-2 or JB through it?
Although it certainly can happen, I suspect the frequency at which a .30 cal barrel from a quality manufacturer goes bad at 700 rounds or so is relatively rare. As such, knowing exactly what caused it to go bad might be useful for other members of the forum. Even something as unlikely as a sizable chip out of one of the lands or damage to the crown ought to be identifiable via a borescope, or even possibly with the naked eye. Mike - if you eventually find out why the barrel was bad, would you mind sharing the info? Thanks.
For that reason, I'll ask Mike a few questions along those lines. Have you looked at the barrel with a borescope? Have you discussed the possibility of sending it back to be inspected with the manufacturer? Have you done anything to the barrel other than switch it to different rifle to support the notion that the barrel was the problem; i.e. something such as run an abrasive cleaner like KG-2 or JB through it?
Although it certainly can happen, I suspect the frequency at which a .30 cal barrel from a quality manufacturer goes bad at 700 rounds or so is relatively rare. As such, knowing exactly what caused it to go bad might be useful for other members of the forum. Even something as unlikely as a sizable chip out of one of the lands or damage to the crown ought to be identifiable via a borescope, or even possibly with the naked eye. Mike - if you eventually find out why the barrel was bad, would you mind sharing the info? Thanks.
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MikeMcCasland
Team Texas F-T/R
Greg,
I wish I could tell you what happened here; frankly none of it makes sense to me, which is why I was even considering something as unlikely as primer depth to begin with.
To answer your direct questions, I have looked at this through a borescope; probably spent north of an hour looking for anything in there that would explain the results I'm seeing. I have also used IOSSO/CLR/Eliminator on the barrel and taken it down to bare steel to troubleshoot.
I had previously typed a long dissertation to give some additional background/context to this, but thought better of posting it. I'll type an abbreviated version below.
Background:
Rounds 0-400 the gun hammers; looks like the best tube I've ever had. Mid/High 580s at 1k with low 20 X counts, shot a 500 yard match with it shot a 597-36X. All of the misses so far are 100% on me, this barrel shoots.
I have a few state tourneys coming up and think I'm well positioned going into them.
1,000 yard, 100 round state tourney:
Super high winds (literally hurricane level) throughout the tournament; everyone is hemorrhaging points, but I'm dropping a lot more than the field on day 1. None of the misses I have make any sense, and generally speaking the 'feedback' from the target doesn't feel right. Top TR finisher in day one had dropped 23, I'd dropped 62 (yikes). Worst 60 for score of my life, by a significant margin.
Day two of the tourney winds are worse, I don't clean the gun overnight, and I don't change anything strategy wise; suddenly the gun is shooting how I would expect. I'm dropping points because of the insane winds, but generally hanging with the pace of the rest of the field. Day two I drop 21 more points on day 2.
The results confuse me because of how well the barrel had been shooting. Given the history of the barrel, and my general mediocre level of shooting, I conclude that I must have just grossly miscalculated a condition.
I clean the barrel, and load more rounds for upcoming matches.
The following week: 1,000 yard club match
Gun was hammering for all three matches. I win the match with a 589-22x. This further reiterates my belief that the state match from the previous week was just me being horrible.
The following week: 1,000 yard state tournament #2.
Nothing is changed from the week prior (same range as the club match I just won). I'd cleaned/borescoped the gun and everything looked like I was setup to finish well here.
I'm shooting team matches (hurricane winds for team day too lol, lucky me) before the two day individuals kick off, and by sighter 4-5 I can tell the gun is back to not shooting well. I've got a guy who is probably top 5 in the country for calling wind for a TR gun with the 20X, and the gun is dropping 10 points plus a match. We win despite my gun being a boat anchor for the team.
I do a light cleaning in the parking lot after the team match. A little C4 and eliminator, with a bronze brush.
Day one of individuals and the winds are back down to normal levels (4-7 mph). Someone in TR shoots a national record, and I drop 11 points match 1. Match 2 is the same story, I drop 12. Match 3 (hottest, and highest winds of the day) the gun suddenly starts shooting. I drop 5, and finish 3rd for that string.
I don't clean or do anything overnight.
Day 2 match 1 (calmest winds, lowest temp), the gun is hammering again. Winds are calm, and I drop two and had the top score for that relay by X-count.
Day 2 Match 2, winds are still calm. By sighter 15 I can't find the 10 ring for two shots in a row. Same everything for match 1 in terms of ammo/equipment, and I shoot a 180-1X. There were no cross-fires. Yikes.
So there you have it, that would be the prologue to this thread and my troubleshooting (a good portion of that troubleshooting hasn't been listed, but lets just say I'm thorough).
Nothing makes much sense, especially how it's seemingly going in/out of shooting. I would generally have concluded that I have a scope problem, except for the fact that the problem follows the barrel, and I can screw on a new tube with the same ammo and groups shrink in half. I would have also thought maybe it's the load being on the edge of a node, except it's shot well in the hottest and coolest matches of the day; pulled down rounds all weigh the same/all measure the same.
If I get time today I'll take it down to bare steel and post a video of the borescope results so yall can inspect it.
I haven't contacted the mfg. I honestly don't know what went wrong here, but I don't believe them to be at fault etc.
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WyleWD
Silver $$ Contributor
Mike, do you uniform your primer pockets as part of your brass prep on new cases? I began uniforming them several years ago and found it to be beneficial to consistent seating depth and a consistent "feel" when using a primer seater such as the Century 21.
It appears that you've tracked it down to the barrel and that's great.
Also relative to the topic, I had a conversation with a tech at CCI that emphaticly recommended that that their primers be seated 5-7 thousandths below flush with a slight crush to set the anvil feet on the bottom of the pocket. Assuming that all new brass have exactly the same primer pocket depth is flawed. It varies and it shows on the target. JME. YMMV.WD
intermittent failures are difficult if not impossible to diagnose in every complex system. If I were the manufacturer of that barrel I would really want it returned so I could do a full inspection. Could be a minute difference in bore diameter that fouling intermittently "plugged" that could only be detected by air gauging,
I uniformed all my 308 cases when new , tested with stock and uniformed pockets , as long as they bottomed and below flush I found no difference in group size . Never competed , shoot every Sunday with friends , some have competed , we share information , great group of guys . In my area the ranges are max. 200 yards , I only shoot 200 in good condition and never below 50° getting soft in my later years . When reading wind , that's for the big boys. Would just add another excuse for screwing up a good group.
WyleWD
Silver $$ Contributor
Yes sir. WD
MikeMcCasland
Team Texas F-T/R
Wouldn't show up on two different actions either.
Ned Ludd
Silver $$ Contributor
Thanks for the write-up, Mike. I'm interested for a couple reasons. First, I've recently heard about several instances where F-TR shooters had barrels apparently "going bad" well before you'd ever expect them to in terms of round count. Second, I recently experienced a situation not unlike yours, although not nearly as severe from what it sounds like. One of my F-TR rifles started shooting much less well than it had. The scores with it were still "ok", but the X-counts were noticeably lower. When I bore-scoped it, I found a lot of hard, almost crystalline, carbon down in the grooves starting about an inch or two in front of the throat, extending 6 to 8 inches further down the barrel.
In the past, I would check a barrel with the borescope after cleaning maybe every third of fourth time I would clean it, perhaps every 300-400 rounds or so. I never saw anything that would have led me to think my cleaning procedure wasn't working. In the last couple weeks or so, I have been working on getting that carbon out of the grooves, and believe me, it hasn't come out easily. It's that super hard, almost volcanic glass-looking carbon and it really didn't want to leave its home in the bottom of the grooves. Nonetheless, I have managed to remove most of it with a combination of repeated soakings in Kroil and several strokes with a bronze brush, as well as a treatment with KG-2 bore polish, which is similar to JB Bore paste. I have not yet had the opportunity to see how the barrel shoots after removing the carbon, but I'm betting [hoping] it will return to shooting the way it did when new. I have no idea how this carbon built up like that, when I've never seen it in a barrel previously, even barrels with twice the round count that this one has on it. I'm using the same powder and primers (Varget/Fed 205s), so unless they've changed the formulations on those, I wouldn't they'd be the source since I've pretty much always used Varget and Fed 205s.
Having gone through this process, it makes me wonder whether some of the other instances I have recently heard of where people's barrels suddenly started shooting poorly, and at a round count well below where you'd expect a quality barrel to behave that way, might have also been due to such carbon build-up. It sounds as though it's unlikely in your case; from your description, the cause seems likely to be something else wrong with the barrel. Nonetheless, it makes me wonder whether some of the barrels I've recently heard about "going bad" merely needed a good cleaning and a treatment with KG-2 or JB to get the carbon out of the grooves. I believe the real key in my particular case is to modify my cleaning process such that the carbon is never allowed to build up like that. If nothing else, I've also learned that I need to bore-scope after every single cleaning, which in my case is every time I fire the rifle, just to make sure that in fact, the barrel really IS clean.
In any event, thanks for posting the detailed description and I hope you are able to determine why the barrel stopped performing.
In the past, I would check a barrel with the borescope after cleaning maybe every third of fourth time I would clean it, perhaps every 300-400 rounds or so. I never saw anything that would have led me to think my cleaning procedure wasn't working. In the last couple weeks or so, I have been working on getting that carbon out of the grooves, and believe me, it hasn't come out easily. It's that super hard, almost volcanic glass-looking carbon and it really didn't want to leave its home in the bottom of the grooves. Nonetheless, I have managed to remove most of it with a combination of repeated soakings in Kroil and several strokes with a bronze brush, as well as a treatment with KG-2 bore polish, which is similar to JB Bore paste. I have not yet had the opportunity to see how the barrel shoots after removing the carbon, but I'm betting [hoping] it will return to shooting the way it did when new. I have no idea how this carbon built up like that, when I've never seen it in a barrel previously, even barrels with twice the round count that this one has on it. I'm using the same powder and primers (Varget/Fed 205s), so unless they've changed the formulations on those, I wouldn't they'd be the source since I've pretty much always used Varget and Fed 205s.
Having gone through this process, it makes me wonder whether some of the other instances I have recently heard of where people's barrels suddenly started shooting poorly, and at a round count well below where you'd expect a quality barrel to behave that way, might have also been due to such carbon build-up. It sounds as though it's unlikely in your case; from your description, the cause seems likely to be something else wrong with the barrel. Nonetheless, it makes me wonder whether some of the barrels I've recently heard about "going bad" merely needed a good cleaning and a treatment with KG-2 or JB to get the carbon out of the grooves. I believe the real key in my particular case is to modify my cleaning process such that the carbon is never allowed to build up like that. If nothing else, I've also learned that I need to bore-scope after every single cleaning, which in my case is every time I fire the rifle, just to make sure that in fact, the barrel really IS clean.
In any event, thanks for posting the detailed description and I hope you are able to determine why the barrel stopped performing.
MikeMcCasland
Team Texas F-T/R
That's actually been my habit to borescope every cleaning, but admittedly I'd been slacking on it with this barrel. That said, since my troubles began I'd been scoping every time I cleaned it.
Cleaning the snot out of the barrel was my first step after the TX state match. I hit it with CLR, bronze brush, then Eleminator, bronze brush (repeat multiple times over). After I had it as clean as I could get it with those products, I hit it with two patches of IOSSO (focusing on the throat, then taking longer strokes). The thing was looking brand new aside from the mild fire-cracking you'd expect.
If anything, I was worried I'd cleaned the barrel too much.
That was before this past Saturday's testing, which included re-running an OCW of N150 (the powder it had been running), and Varget to see if I could get them to shoot.
I just finished doing a mild cleaning and don't really see any areas of concern. There's no carbon ring, and no hard-carbon in the first ~6-8 inches of the barrel. The steel has a darker tint in that area of the barrel, but I am 100% confident if I ran some JB or IOSSO in there it'd shine up like the muzzle end. I pulled slightly more copper out than I ever have before, but I may have over IOSSOed the damn thing Friday night as part of the 'troubleshooting'.
I'm probably done messing with it. I still have 2,200 of the same lot 200.20X bullets for this barrel, and I really don't want to waste more of them trying to diagnose the barrel when I could just re-allocate them towards the Bart or Brux.
Sometimes the best way to troubleshoot a barrel is to stick it in the closet for a while, and pull it out a few years later.
MikeMcCasland
Team Texas F-T/R
Wonder if the CLR has anything to with it?
LOL.
Doubtful, otherwise about 7-8 other barrels would be having issues.
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