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300-221 problems with extraction
300-221 problems with ejection
-------------------------------------------------------------------------------- Wondered if some of you might be able to help. I have a 16" .300-221 upper, pistol length gas tube, 3-way gas block (High, Low, and Off). My handload 125 grain supersonic ammo, which works fine in my 8" .300-221 (same specs other than barrel length) is doing the following: 1 - It loads fine into battery, and I can hand-clear it - so the chamber/barrel isn't too tight 2 - It fires just fine. 3 - 90% of the time, though, it will not eject the spent case. It is stuck and I have to tap it out with a rod. The rim is slightly mangled from where the extractor tried to grab it and obviously yanked off some brass when it wouldn't budge. 4 - It doesn't try to strip and load a new cartridge, though. So, I assume this is a gas problem? Perhaps over-gassed - i.e. too much gas is getting into the system and before the bolt has a chance to work and pull out the spent case it causes the brass to expand and gets stuck in the chamber? I've tried it with all three settings - the High setting (which slightly restricts gas) does what is described above, the Low setting (which opens it up totally) really tears off a bit of rim, and of course doesn't eject, and the Off setting doesn't work the bolt at all, doesn't hurt the brass, but is very tough to tap out the brass. I'm thinking that maybe a JP adjustable (screw) gas block might do the trick since I can adjust it a lot more than the 3 settings I have right now. Could it be the pistol length gas tube is too short? Could it be gas block alignment, though that wouldn't make much sense if I'm overgassed. Or could it be something else? Buffer, buffer spring, etc.? |
Please post the load details that you're currently using.
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It doesn't sound like a gas problem to me. The fact that when completely shut off you still have a tough time tapping out the spent shell means you probably have a brass/chamber size problem or you're pushing chamber pressure over the limit. Are there any other marks on the brass? Any primer flattening or other signs of overpressure?
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18.5 grains H110 powder CCI primer Brass is new/reformed bought from member here who advertises all the time for brass - made from .223, I believe. 2.04 OAL .333 at neck .360 at shoulder .373 at end The subsonics are the same except: 220 SMK BTHP 9.6 gr. H110 2.20 OAL |
No marks on the brass, but here's something new I just noticed.
I decided to try and dry chamber and eject both the subsonic and supersonic rounds in the 16". While the chambered fine, they would NOT eject manually - I had to use a mallet on the charging handle to unstick the rounds from the chamber. So, I gave the dimensions of the cartridges I've loaded. If those are not out of spec, it appears my chamber is not right in the 16". What can be done about this? Any gunsmiths out there that can fix this problem? |
Are you shooting the subs in newly loaded brass or were they shot first as supers?
I would recommend first fire forming by super then loading sub. I also had a hard time with H110 and eventually moved to AA1680. From your most recent post it's looking like an issue with thick necks. |
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I'm not having ANY problems with the subs in my 8". It is the supers I'm having problems with in my 16". What I need to do is try supers in my 8" and subs in my 16" But as noted above, tonight when I tried loading and ejecting by hand the subs and supers in the 16", I couldn't extract them and had to use a mallet to pop the charging handle back. No such problems on my 8". |
Looks like the chamber specs on the 16" are a bit snug.
You can either get someone to touch them up with a reamer, or get a neck trimmer and work them down a few .001's at a time until the issue is resolved. |
BTW - I just looked at the spent cases - the primers are very flattened. What does this mean?
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It would lead me to believe that your loads are running at higher than recommended pressures. However, after you having tested a loaded round and without firing it having problems extracting it... leads me to believe that the neck tension may be causing the excessive pressure.
I would consider getting something like: http://www.midwayusa.com/viewproduct...tnumber=462291 |
If you don't know what flat primers mean, that's not good. It is fixable through education, however, and that's a good thing. Glad to see you're OK. One question that hasn't been asked, and may be your problem, is what are you trimming your brass to? Are you trimming to JD Jones' length of 1.4"? If you have a 1.355" chamber (nominal) you are going to have the problems you are describing. Also, what is the jam length of your rounds? Perhaps you are jamming your rounds into the lands. Take a look at the loaded rounds upon extraction. Do you see rifling marks at the ogive?
Respectfully, Kevin |
I agree with N310toN170's logic--neck tension causing the sticking of unfired rounds and causing higher than normal pressure upon firing causing the flattened primers and stuck cases. But definitely check your case length at 1.355" or less.
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Dykem up one of your rounds and carefully place it into the chamber. Release the bolt so it slams shut. Remove the round and see were the Dykem has been rubbed off. This will tell you were your brass is sticking. You can also use a black marker to color the round if you don't have Dykem.
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There are a number of long scratches that go around the diameter of the shell case (say from 12 o'clock to 6 o'clock, starting just past the shoulder and ending about .12" before the rim - about 6 of them evenly spaced apart. No rifling marks at the ogive. Any suggestions on how to measure jam length? |
What does your case neck measure on a loaded round?
What does the neck measure on a spent case fired in the 8"? What does the neck measure on a spent case fired in the 16"? What is the origin of both barrels? |
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Origin of both barrels was from a member here who makes custom gas blocks and barrels for the .300 - can't recall his name/handle off the top of my head but I think he does a lot of them. |
Knowing the fired case neck OD will allow us to know how tight your chamber is in that area. Typically, that measurement will be .001" larger than the fired case neck OD. As far as the scratches go; run a cotton patch into the chamber area and check for burrs. It couldn't hurt to polish out that chamber area either; stuck cases or not. A little JB non-embedding bore paste on a spinning case will do the job nicely. Hornady (formerly Stoney Point) makes a tool for checking the jam length of a barrel with a given bullet. Here's a link:
http://www.hornady.com/store/Lock-N-...Straight-1Each There is a lot of knowledge here; feel free to tap into it as much as you like. Kevin |
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You are loading to too high a pressure. 18.5 grains of H110 with a Nosler 125 to that OAL is not reasonable.
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Neck measures OD on a spent case fired in 8" = .333 Neck measures OD on a spent case fired in 16" = .336-.339 Case length on loaded round (both super and sub) = 1.363-1.366 Case length on fired round from both = from 1.355-1.385 |
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http://quarterbore.com/300whisper/supersonic.html It recommended 22 grains of H110, so I loaded down more than 10% thinking it was safe - should I try something like 17 grains? |
Here is what Sierra shows in the book
http://i155.photobucket.com/albums/s...sper125grn.jpg |
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Speaking of that, in your first post you said that unfired rounds weren't sticking and later you said they were. Could you clarify? As for the load, 22.0 grains of H110 sounds awful hot. In the link it also shows an MV of over 2400fps with the 125gr Nosler, which is about 200fps more than I would expect from a 16" 300 Whisper. It was from a bolt action so perhaps JD was just pushing it really hard, but I wouldn't be comfortable with 22.0 grains. With the 18.5gr load your problem may be your loaded length. The 125gr Nosler is longer than most 125gr .308 bullets and if you load it too deep it is eating up case capacity and can lead to higher pressures. |
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If you bring it out to 2.100 OAL then you will likely be fine with 18.5. You can see Sierra lists 19.0 as a max load for a flat base bullet. The Nosler is a boat-tail and so uses up more case capacity for any given OAL. So I still say 18.5 if you extend your OAL. |
As H110 is a relatively slow powder for the Whisper seems likely to have a long pressure curve and you described your primers as "flat," I would first suspect your loads are too hot.
Is wise to remember that even cannister grade (commercial) powders vary enough that max loads should be worked up for a new lot of powder. Ever check the velocity of your load? |
Thanks for the data, guys - I really do appreciate it. I'd like to get this resolved as I've had thoughts of chucking the barrel and getting a 7.62x39 to replace it, or some other flavor and I'd rather not spend the $$ :)
I'll pull the bullets, resize, go with 17 gr. of H110, and extend the OAL and see what happens. Oh, and I'll also clean the hell out of the chamber and make sure there are no burrs. |
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I'd say your neck in the chamber is carbon fouled, and making extraction difficult. Are you using a can with this rifle? Are the necks of your ejected brass sooted up? I have ran into this problem before in a bolt gun where the loads were not building sufficient pressure to seal the chamber, and the gas was getting into the neck area. Had to beat the bolt open to extract the brass. Took a bronze brush to the neck of the chamber, got the carbon out, and the problem went away. Have you brushed out your chamber? A rotating 9mm or 35 CAL bore brush will work with your .335"-ish neck OD. If you have a short pistol cleaning rod and a cordless drill, that will work the easiest. Try that and get back to us.
Kevin |
I feel rather weird asking this, but as my Dad once said - there are no stupid questions, only stupid people.
I have a Redding die set, 2 dies. One is a seating die, the other I assume is the full-length sizing/depriming die. Could someone give me a down and dirty step-by-step on how to create a round? It has been a while and maybe I'm missing something - like I've got the dies not set up right, etc. The way I recall was take clean brass, lube (not too much), set up resizing die so that it touches the shellholder and then back out enough so that it engages when the lever is pulled down but not where it requires a herculean effort. Then prime, put powder in, seat bullet. |
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Screw the resize die to where it touches the shellholder, lower the arm the arm and screw the die in 1/8-1/4 of a turn to make sure the press cams over. However, not being able to get factory ammo to chamber says something else is going on. |
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OK, this just in - new information!
I decided to take some of the advice give. I cleaned the hell out of the chamber, used a drill/brass brush combo, cleaned, used a bunch of CLP on the carrier and bolt, cleaned everything very well, then did the drill/brass brush combo again. I loaded up a safe round (no primer) and full-length resized it, shell was 1.355 case length. Wiped off all case lube. Seated the bullet so that OAL was 2.10 Chambered it in my 8" first - NO PROBLEM. Well, it was a little (just a wee bit) "sticky" on extraction (I'm talking a slight resistance) but still it came out just fine, no scratched, no problems. Then I chambered it in my 16" (remember, I just totally cleaned it, etc.) Well, the round stuck. When I worked the charging handle no dice - so I did the POGO method and it pulled back but didn't grab and pull out the round. I had to really pound it out with a rod, and when the round popped out the bullet had found it's way into the brass shell - I assume this happened as I was pounding the round out with the rod. I tried a brand new, never fired shell - loaded it up the same way after full-length resizing, same measurements. This one wouldn't come out either, but when I did the pogo method of popping it out it came out and the bullet had not been pushed into the casing. I noticed numerous scratches, like lines, that ran the entire circumferunce of the neck from the opening of the neck to the shoulder - quite a few (over a dozen) all around the neck, evenly spaced. Pretty faint, but I could see them. Not really any marks on the bullet (the one that stayed in). There were a couple of faint, long scracthes on the body of the brass down to the rim. I tried the same thing with one of my 220 grain subsonics - worked fine in the 8", got stuck REALLY bad in the 16" - I had to really POGO that thing - still nothing - finally had to resort to a method I hate but have used in the past - a flathead screwdriver through the magwell to engage the underside of the bolt carrier and pop it loose with a hammer - yeah, I know, bad juju, but it was the only way to get it loose. That round also had the above markings, including a few more long scratches on the body and a few on the bullet. |
it sure sounds like your chamber came out flaky, I would say send it back to be checked/rechambered
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I have a barrel made by the same person you did ... it is TP555. I haven't had any really stuck cases like yours, but I have had issues with the markings around the case neck. I have also had to really do a lot of load developing because not all flavors like to eject like a lot of load data would say was good. I haven't thought about making any changes until reading your post, but I might take my honing rod and polish the neck area of the chamber now and see if that helps things. I wonder if these barrels were cut with an old reamer that was worn and caused the deminsions to be out of spec ... a tad on the small side.
Sarg |
The 1.4 reamer is tight compared to the 1.35" and I can open it up with the 1.35 PTG reamer.I will do that for my customers N/C.However I am waiting on a 30 AAC blackout reamer to arrive so I can spec it out.Supposed to arrive in a week.Want to see what the differences are.I'll let you know when it does.
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Pics of new brass case that I resized, marked with a magic marker, then chambered - had just as much trouble getting it out as I did with the loaded dummy and real rounds, so I don't think it is the bullet getting stuck or having an issue with being the problem -
http://img829.imageshack.us/img829/9702/imga0293.jpg http://img838.imageshack.us/img838/1936/imga0294.jpg http://img801.imageshack.us/img801/8287/imga0295l.jpg http://img801.imageshack.us/img801/3133/imga0296.jpg http://img828.imageshack.us/img828/7715/imga0297.jpg |
I'm gonna go with scored chamber on this one.
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TP555 is going to check it out for me.
Now, a question - if I get this reamed out to 300 AAC blackout, I assume I can still use and load my 300-221 super and subs, right? Meaning I can make ammo that will work in both the 300-221 8" and the 300 AAC blackout re-reamed 16", but then I can use factory 300 AAC Blackout in the 16". Given that (if true) would I gain anything by getting 300 AAC Blackout dies? Would I need different brass then to take advantage of anything that the 300 AAC Blackout would give me? |
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