The Accurate Reloading Forums
Tight Chamber??

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31 March 2023, 19:28
Prewar70
Tight Chamber??
Picked up a 9.3x62. I have some factory ammo, Hornady, and some Nosler brass. On both, the bolt closes a sticky/scratchy. It's not difficult to close the bolt, just not smooth. I put some magic marker on the case necks and shoulder. What I found is that there is contact at the juncture of the neck and shoulder. Immediately where the neck ends, and the shoulder begins to flair. So what do you think, should I be concerned? Can this be corrected by resizing and bumping the shoulder? Thanks.
31 March 2023, 19:33
dpcd
You will have to full length resize some brass and see. If you think the chamber is too tight, you will need to use gauges, and possibly ream it more, or polish it. What make is the rifle? If it is a custom, then the answers are, no, and maybe. I build a lot of 9.3s, and anything is possible. But if it is just a minimum chamber, that doesn't matter. Why is it not smooth? No one can answer that without inspection.
31 March 2023, 22:16
Prewar70
Agreed. I'm going to bring it to my favorite local gunmaker and have him inspect it. The rifle is a factory ZG47
01 April 2023, 01:56
F. Guffey
quote:
Can this be corrected by resizing and bumping the shoulder? Thanks.


Find a bumper, he should be able to explain it to you.

F. Guffey
02 April 2023, 02:59
eagle27
You maybe able to bump cases to fit but not loaded ammo so you need to resolve the chamber issue. Presumably you have given the chamber a good clean, steel wool on a jag and solvent to polish the chamber. Fine wet and dry paper on a dowel to polish the neck junction in the chamber, should be headspacing on the case wall/shoulder junction not the shoulder/neck junction like it sounds to be doing.
02 April 2023, 03:14
dpcd
Everyone! Stop using the word "bump". It is confusing and meaningless, and causes too many misconceptions.
Of course, you do not want to try to alter loaded ammo. Some idiot will end up killing himself. Obviously you can't alter a case on loaded ammo in a FL die, lest someone want to try that.
Also, do not try to polish the chamber to solve that issue; just don't.
02 April 2023, 18:44
Jim Kobe
We fixed it, short chamber!


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Custom Gunmakers Guild

03 April 2023, 02:23
RogersGunWorks
Thanks to both dpcd, AKA Tom, and the good Mr. Jim Kobe for confirming that some issues are best left to gunsmiths. I know, know, the "I'd rather do it myself" attitude is hard to overcome, especially when there is ample, free, and albeit questionably qualified opinions online. But spending a few dollars with a gunsmith who has invested thousands of dollar in headspace gauges and chamber reamers, not to mention decades of experience, and who can accurately diagnose a problem without equivocation is infinitely better than the well intentioned opinions of those less qualified. For those of you who have suffered at the ham-fisted hands of the back door gun plumber, I commiserate 100%. But please acknowledge that a qualified gunsmith just like a qualified auto mechanic or heart surgeon, is worth his due and may ultimately save you a penny or two while giving the piece of mind that a job or problem has been thoughtfully and correctly addressed.

Cheers,

Roger
03 April 2023, 04:58
eagle27
quote:
Originally posted by RogersGunWorks:
Thanks to both dpcd, AKA Tom, and the good Mr. Jim Kobe for confirming that some issues are best left to gunsmiths. I know, know, the "I'd rather do it myself" attitude is hard to overcome, especially when there is ample, free, and albeit questionably qualified opinions online. But spending a few dollars with a gunsmith who has invested thousands of dollar in headspace gauges and chamber reamers, not to mention decades of experience, and who can accurately diagnose a problem without equivocation is infinitely better than the well intentioned opinions of those less qualified. For those of you who have suffered at the ham-fisted hands of the back door gun plumber, I commiserate 100%. But please acknowledge that a qualified gunsmith just like a qualified auto mechanic or heart surgeon, is worth his due and may ultimately save you a penny or two while giving the piece of mind that a job or problem has been thoughtfully and correctly addressed.

Cheers,

Roger


Really, then maybe you should ask Saeed to close down the Gunsmithing section of this forum. Members should not be asking for advice here, they should be going straight to a gunsmith with any firearm issue. Perhaps we could just have a list of your favorite gunsmiths posted here with a direction to members to consult one of the qualified professionals on the list instead of asking forum questions.
03 April 2023, 18:59
Jim Kobe
I think what Roger is suggesting is that there are too many garage mechanics working at way over their head, Knowledge capacity over the limit and not knowing when to throw in the towel and look for legitimate help


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Custom Gunmakers Guild

03 April 2023, 20:36
F. Guffey
quote:
I think what Roger is suggesting is that there are too many garage mechanics working at way over their head, Knowledge capacity over the limit and not knowing when to throw in the towel and look for legitimate help


"We fixed it, short chamber!" The OP started with Hornady factory ammo and Nosler cases; I believe someone missed a teaching moment. If the chamber is short and the ammo has no clearance, scuff the case when the bolt closes


And then there learning how to measure the length of the case from the datum/shoulder to the case head, and then there are are case gages and chamber gages.

F. Guffey
03 April 2023, 20:59
Duane Wiebe (CG&R)
quote:
Originally posted by eagle27:
quote:
Originally posted by RogersGunWorks:
Thanks to both dpcd, AKA Tom, and the good Mr. Jim Kobe for confirming that some issues are best left to gunsmiths. I know, know, the "I'd rather do it myself" attitude is hard to overcome, especially when there is ample, free, and albeit questionably qualified opinions online. But spending a few dollars with a gunsmith who has invested thousands of dollar in headspace gauges and chamber reamers, not to mention decades of experience, and who can accurately diagnose a problem without equivocation is infinitely better than the well intentioned opinions of those less qualified. For those of you who have suffered at the ham-fisted hands of the back door gun plumber, I commiserate 100%. But please acknowledge that a qualified gunsmith just like a qualified auto mechanic or heart surgeon, is worth his due and may ultimately save you a penny or two while giving the piece of mind that a job or problem has been thoughtfully and correctly addressed.

Cheers,

Roger


Really, then maybe you should ask Saeed to close down the Gunsmithing section of this forum. Members should not be asking for advice here, they should be going straight to a gunsmith with any firearm issue. Perhaps we could just have a list of your favorite gunsmiths posted here with a direction to members to consult one of the qualified professionals on the list instead of asking forum questions.



Might be a whole lot safer!
03 April 2023, 21:05
Saeed
Funny this.

I have never had any gunsmithing instructions.

Last time I checked my reamers I have over 400 different types.

Many are wildcats of my own design.

My friend Dwight Scott used to go “oh Jeez! WHAT? You are just crazy!” Whenever I asked him for a reamer! clap

I don’t sell rifles.

For me, and my friends, it is just a hobby we enjoy.

I always chamber barrels to minimum dimensions.

Never had any rifles chambered for factory cartridges refuse to chamber with factory ammo.

Last barrel I chambered was a Lilja match 22 rim fire.

It is was done for a specific test.

Anyone interested should look at the rim fire forum.

Very I indeed!


www.accuratereloading.com
Instagram : ganyana2000
03 April 2023, 22:29
custombolt
Prewar70. Now that the short chamber was fixed how about more information on the action? Custom XXX match chambered barrel?


Life itself is a gift. Live it up if you can.
04 April 2023, 01:02
Prewar70
I had no idea this would get so many passionate responses. When I blackened the case, and saw the spot of contact, I suspected short chamber. I knew it wasn't ideal, might be fixed with reloading and resizing brass, but I wanted it checked out for sure and to see if there were other issues I wasn't seeing. Not having any go no/go gauges for a 9.3, and with Jim Kobe living 5 miles from me, I figured that was my best and easiest and safest course of action. I think it's fine for anyone to tinker as much as they want to, free country. But I was at the limit of what I could do. Jim touched up the chamber, bolt closes pefectly now, and I suspect it's a minimum spec'dimensions seeing how little had to be done. Plans are to keep this ZG47 completely factory. I'm working on completing it, sourcing a stock, bottom metal, and trigger. I'm trying to find factory ZG screws, which I think are non existent. Probably go back to Jim and have him make me some.
04 April 2023, 09:26
eagle27
quote:
Originally posted by Prewar70:
I had no idea this would get so many passionate responses. When I blackened the case, and saw the spot of contact, I suspected short chamber. I knew it wasn't ideal, might be fixed with reloading and resizing brass, but I wanted it checked out for sure and to see if there were other issues I wasn't seeing. Not having any go no/go gauges for a 9.3, and with Jim Kobe living 5 miles from me, I figured that was my best and easiest and safest course of action. I think it's fine for anyone to tinker as much as they want to, free country. But I was at the limit of what I could do. Jim touched up the chamber, bolt closes pefectly now, and I suspect it's a minimum spec'dimensions seeing how little had to be done. Plans are to keep this ZG47 completely factory. I'm working on completing it, sourcing a stock, bottom metal, and trigger. I'm trying to find factory ZG screws, which I think are non existent. Probably go back to Jim and have him make me some.


The information that you provided indicated the bolt was not closing smoothly on loaded rounds and cases, and Tom was first up suggesting the chamber maybe a little short and may possibly need a ream or polish. I then noted that I thought it was a chamber issue too and suggested making sure the chamber was clean and perhaps a polish of the shoulder neck junction area in the chamber.
You asked the question whether it could be cured by resizing and bumping the shoulders to which both myself and Tom indicated this maybe possible with cases but is not possible with loaded ammo. Got to fix the chamber which obviously now Jim has done for you, the problem that was exactly identified by Tom and myself.

I took issue with RGW's condescending and unnecessary post basically saying that everyone else other than qualified gunsmiths are cowboys and and shouldn't be giving opinions or suggestions.
How does RGW know who is qualified on these forums and what does qualified mean, here is Saeed who is not formally qualified but has probably done more quality and varied gunsmithing than many others collectively.

Anyway all is well that ends well and you have a good rifle in excellent cartridge to play with.
04 April 2023, 09:42
Wstrnhuntr
The real question is, was the 9,3x62 "short chamber" done by a backyard bumpkin like me or by a gunsmith with a worn out reamer? popcorn



AK-47
The only Communist Idea that Liberals don't like.
04 April 2023, 18:09
Jim Kobe
quote:
Originally posted by Wstrnhuntr:
The real question is, was the 9,3x62 "short chamber" done by a backyard bumpkin like me or by a gunsmith with a worn out reamer? popcorn


it appeared to be factory installed


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Custom Gunmakers Guild

04 April 2023, 20:39
z1r
quote:
Originally posted by Jim Kobe:
quote:
Originally posted by Wstrnhuntr:
The real question is, was the 9,3x62 "short chamber" done by a backyard bumpkin like me or by a gunsmith with a worn out reamer? popcorn


it appeared to be factory installed


I had a Husqvarna 46AN that was too short as well from the factory.




Aut vincere aut mori
04 April 2023, 21:00
dpcd
Given the facts that this thing was developed in 1905 and has chambers, reamers, gauges, ammo, dies, and brass, made over all these years, on multiple continents, it is no surprise that this slight interference fit between what was likely a chamber and ammo, made within the spec.
When I chamber one, I make the user send me the exact brass or ammo he will use.
05 April 2023, 00:51
z1r
quote:
Originally posted by dpcd:
Given the facts that this thing was developed in 1905 and has chambers, reamers, gauges, ammo, dies, and brass, made over all these years, on multiple continents, it is no surprise that this slight interference fit between what was likely a chamber and ammo, made within the spec.
When I chamber one, I make the user send me the exact brass or ammo he will use.


you see this quite a lot with the 9,3x57. In this 9,3x62's case, a crush was obtainable but only with the assistance of a mallet! Big Grin




Aut vincere aut mori
10 April 2023, 14:02
eagle27
quote:
Originally posted by dpcd:
Given the facts that this thing was developed in 1905 and has chambers, reamers, gauges, ammo, dies, and brass, made over all these years, on multiple continents, it is no surprise that this slight interference fit between what was likely a chamber and ammo, made within the spec.
When I chamber one, I make the user send me the exact brass or ammo he will use.


With all due respect dpcd couldn't you be perpetrating the problem if you chamber to suit the exact brass and ammo a customer supplies. What if the supplied components happen to be on the small side and at some stage the customer, or a subsequent owner changes ammo/cases. We end up with the problem the OP has now with ammo and cases that are a bit too snug of a fit (for him).

I agree with what you have said re chambers, reamers, gauges etc., etc., mismatching over the years.

I suppose we can see the advantages of the belted case where most manufacturers produce brass and ammo on the slack side. Headspace fine on the belt and don't give a shit about a little fireforming, at least the ammo fits all chambers.