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Post by bigbrowndog on Nov 12, 2016 18:53:49 GMT -5
ive had issues with cases sticking in my chamber after firing since I had this rifle built. Some will stick others with the same load will extract and eject without issue. On Loaddata, they show a cartridge drawing with specs, some drawings show a 34degree 21 minute shoulder and others show a 17 degree shoulder. The shoulder diameter is .441, however the standard 30-06 shoulder diameter is .436 and the shoulder is 17 degree 28 minute. I am wondering what the reamer dimensions were on my chamber, and if I'm causing the issue by having my loading dies alter the fired cases to a dimension that is not quite what the chamber is.
does anyone know of an easy way to measure shoulder angles on fired cases?? The fried case should give me an exact copy of my chamber specs, then I guess I'll have to cerrosafe my dies.
anyone else have suggestions???
Trapr
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Post by Encore64 on Nov 12, 2016 19:11:31 GMT -5
First off, many times drawings show shoulder angle against shoulder angle. Basically 17° on both sides equates to 34°.
I'd check for case length. A tad of neck jammed into the throat can spike pressures on the longer rounds.
Sure there are others that can provide more and better solutions.
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Post by bushog on Nov 12, 2016 19:46:43 GMT -5
Have you tried just neck sizing your brass?
At least that way you would know the dies were'nt the problem but I really don't see how they could be.
Strange some stick and others don't.
I'm still thinking about the case length thing but that's easy enough to remedy...
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Post by bigbrowndog on Nov 12, 2016 20:04:02 GMT -5
Oal is below max, and cases that do not stick fall above and below length of those that do stick,.....so I know thats not he issue. Also, the stuck rounds do not exhibit pressure signs, classic pressure signs, flat primers, shiny spots on case head, etc. Interestingly, the extractor of my Springfield 03A3, is slipping off of the rim, albeit with some force.
I can predict which rounds will stick by using chambering force as a gauge, some rounds require more bolt closing effort than others, nothing extradinarily stiff, just more effort. This is not my first or only nonstandard caliber, but it is the one that has given me the most grief........35/8mm mag, 25x45 Sharps, 300BO, 6.5 Grendel from 7.62x39 cases, 358 Norma mag from 338 win mag, etc.
The neck sizing sounds like a good idea, I might give it a try, but I would still like to figure out the issue.
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Post by bushog on Nov 12, 2016 20:44:58 GMT -5
Sounds like pressure....
Do you have a tight neck chamber? Shouldn't be since you're stretching the brass from .30 to .338....
Check the wall thickness on your necks if you have the right kind of micrometer...
Aaaah, load some rounds and measure the outside diameter of the cartridge necks with a mic.
See if the ones that don't chamber easily are bigger thn the ones that slide in.
What kind of brass? All the same?
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Paden
.375 Atomic
Lower Goldstream Creek
Posts: 1,132
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Post by Paden on Nov 12, 2016 21:55:46 GMT -5
Oal is below max, and cases that do not stick fall above and below length of those that do stick,.....so I know thats not he issue. Also, the stuck rounds do not exhibit pressure signs, classic pressure signs, flat primers, shiny spots on case head, etc. Interestingly, the extractor of my Springfield 03A3, is slipping off of the rim, albeit with some force. I can predict which rounds will stick by using chambering force as a gauge, some rounds require more bolt closing effort than others, nothing extradinarily stiff, just more effort. This is not my first or only nonstandard caliber, but it is the one that has given me the most grief........35/8mm mag, 25x45 Sharps, 300BO, 6.5 Grendel from 7.62x39 cases, 358 Norma mag from 338 win mag, etc. The neck sizing sounds like a good idea, I might give it a try, but I would still like to figure out the issue. The two emboldened statements are interesting clues. What is causing the the extra force required to close the bolt on the ones that subsequently stick? Answering that question is where I would focus effort. Have you measured your throat length using the bullet in question? Doing so is the only true way to know the OAL for this chamber, with this bullet. OAL below max as published for a different gun/bullet is pretty meaningless; doesn't necessarily mean you're not forcing a bullet into the lands. Lots of potential variables are potentially at play there. If stiff bolt closure is due to a bullet hard against the lands, you could easily be causing excessive pressure, and thus sticky extraction, in spite of an apparent lack of other "pressure signs".
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Post by bigbrowndog on Nov 12, 2016 22:18:59 GMT -5
I've loaded various bullets, all produce the same sparodic issue, Nosler accubond, Hornady GMX, Hornady SP, Nosler partition
All the brass is R/P 30-06,.....but I have factory 338-06 that I'm going to try and see if the issue persists.
I will measure necks,
As to oal length, and forcing a bullet into the lands,....I've measured loaded rounds to bullet ogive and compared to round loaded to touch rifling, I'm not touching rifling. Something I forgot to add, the bolt closing effort is not reliant on a bullet being in the case.
Things I will look further into are, polishing the chamber, measure neck diameter before and after firing, trying factory 338-06 brass, I will also segregate the brass that does not produce the issue and see if it does so consistently. Thanks for the help, I'd like to get this figured out because I really like the rifle and it shoots very well.
Trapr
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Paden
.375 Atomic
Lower Goldstream Creek
Posts: 1,132
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Post by Paden on Nov 12, 2016 23:53:57 GMT -5
Hmmm, well, I sure wouldn't go doing anything to the chamber until I figured out what the inconsistency was with the brass... In this equation the chamber is a relative constant. Inconsistency in bolt closure and extraction indicates something inconsistent with the cartridge and/or load. Neck length, headspace, or a bulge near the case web are only other things coming to mind which could cause difficulty closing the bolt. If difficulty closing bolt is a consistent predictor of sticky extraction, the case web dimension or neck are suspects. Case web area being too fat will cause difficult bolt closure and sticky extraction without even being fired, because you're wedging the case into the chamber under the spring pressure of the brass. I think after sizing I'd chamber each piece of brass before loading to rule out that issue, and go from there. Or maybe you've got a crappy batch of RP brass that's too soft and/or your load is hot... I've only ever run Winchester brass for mine (in a Mod-70 action). I only neck size, never FL size. Only issue I've ever had with sticky extraction was due to a load that was way too hot. (That was a published starting load by the way!)
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Post by sixshot on Nov 13, 2016 2:00:39 GMT -5
Are you loading single shot when you are test firing? Might be that the extractor is behind the case head on some & in the extractor groove on others. Also you might need to do a chamber cast, could be a lot of things. Mine was build by my son on a Mauser action & he polished the extractor so it would slide past the case head without jamming the case into the chamber. I've been out of rifles for many years but if I remember correctly a 30/06 is 2.494" long & a .473" bolt face, if you do fire form it's most likely to shorten just a tick on the first firing, so I don't think case length is going to be your problem, Interesting anyway, hope you tell us what you find. I always used powdered graphite to lube my case necks to avoid stretching.
Dick
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Post by bradshaw on Nov 13, 2016 9:36:18 GMT -5
Trapr.... .338/06 cases sticking, with the Mauser extractor on your Springfield 03-A3 jumping off some rims? What is the origin of your brass, and was any of it fired in another rifle before fire forming in your .338/06?
* Brass fired in another chamber may not size down enough for your chamber, in which case it will stick both going in and coming out. * You say there are no signs of excess pressure on the cases; I agree from info provided pressure is not the issue. It takes a lot of pressure to stick a case the way you describe, enough to blow a primer pocket. * Formed cases should be worked through the action before loading. * If some cases stick on extraction, while others do not, the sticky ones may be soft in the head. * Make a DUMMY ROUND, using a case which freely chambers. Mark the neck with a felt-tip pen. Chamber dummy round to check for binding. If the chamber is tight in the neck you will both feel and see it. This kind of interference is extremely dangerous. (I doubt this is the problem). * A round which chambers freely, yet the fired case extracts hard, may indicate a flaw in the chamber. * Mark a fired case----one that doesn’t stick----and rechamber it with the mark at, respectively, 12, 3, 6, and 9 o’clock. Position of case should not affect chambering; if it does, chamber may be out-of-round. David Bradshaw
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Post by bushog on Nov 13, 2016 9:40:57 GMT -5
The black marker is my friend some days....good thought!
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Post by bigbrowndog on Nov 13, 2016 10:13:40 GMT -5
Thanks guys some very good ideas here, The polishing of the chamber idea came from seeing circular tool marks on fired cases?? I'm curious if a finish reamer was not used??? If memory serves me, all cases were new unfired, but I'll use new ones now to verify. With the Mauser extractor I always place the single round in the magazine and close bolt from that position. I will darken/mark a case and look for binding in a consistent location Also will mic cases that chamber effortlessly and compare t o those that do not. I have reset the dies to bump the shoulder on a fired case .002, it was originally set according to manufacturer directions and was resetting shoulder .005
Thanks again, Trapr
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Post by bigbrowndog on Nov 13, 2016 18:03:54 GMT -5
Ok got home from work, and went to work with your guys ideas. First- chambered resized rounds with no bullets, reloaded rounds and fired but unsized rounds. All chambered, but some of the loaded rounds did require a bit of effort. Second- I measured all the rounds I just tried chambering, base diam., shoulder diam., and neck diam........These are all R/P 30-06 cases that have been formed to 338-06 in my dies and have all been fired at least once in my gun. Case head size for resized cases-.465 to .467 Case head size for fired cases- .464 to .466 Case head was measured approx. 3/16 from rim groove Next, neck diam. Fired- .369 Neck diam. Reloaded with bullet seated .361 Third, shoulder diam. Loaded with bullet in place- .438 to .441 Fired and unresized shoulder diam.- .441 Last I reversed a bullet and started setting it into the case until it would chamber with the same effort as an empty case, Now these measurements are from case bottom to top of reversed bullet. 2.823--stiff but easy effort 2.819--slight resistance 2.814-- same as above 2.807--easier but some resistance 2.785-- same as above 2.790-- same resistance as an empty formed R/P case Interestingly enough, I found my 338-06 brass and it appears to be A-Square brass as that is all the marking on the base states, 338-06 A-Sq. / A-Square This brass. Glides effortlessly into the chamber and the bolt closes as if the chamber was empty? I think Im going just stop using the converted 30-06 brass and go strictly with the made for the caliber A-Square brass, at least for now I'll load 10 or so rounds with the A-square stuff and try them to see if the same issues crop up. Trapr
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Paden
.375 Atomic
Lower Goldstream Creek
Posts: 1,132
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Post by Paden on Nov 13, 2016 18:14:31 GMT -5
Ok got home from work, and went to work with your guys ideas. First- chambered resized rounds with no bullets, reloaded rounds and fired but unsized rounds. All chambered, but some of the loaded rounds did require a bit of effort. If sized unloaded brass chambers easily before loading, but requires effort after loading...
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Post by bigbrowndog on Nov 13, 2016 21:48:01 GMT -5
I believe your point Paden, is that it points to Bullets being the culprit.........however, utilizing the ogive measurements it shows that no bullet contact with rifling is being made. I will take that same sized but unloaded brass, and load a bullet with no powder into it to check, and I'll report my findings.
Trapr
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