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headspace issues

 
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chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Sun Apr 11, 2010 6:22 am    Post subject: headspace issues Reply with quote

will excess headspace hurt accuracy? I had primers back out. I they backed out alot with full length sized brass, not on new norma loads.
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DEFUC



Joined: Aug 17 2004
Posts: 201
Location: UP of michigan

PostPosted: Mon Apr 12, 2010 5:52 am    Post subject: Reply with quote

backed out primers sounds like excess pressure possibly,maybe too light of a load? or way too heavy? ld lean toward too light tho if theres no other pressure signs. As for excess HS effecting accuracy it can.what does your fired brass mic to?
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chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Mon Apr 12, 2010 6:04 am    Post subject: Reply with quote

DEFUC wrote:
backed out primers sounds like excess pressure possibly,maybe too light of a load? or way too heavy? ld lean toward too light tho if theres no other pressure signs. As for excess HS effecting accuracy it can.what does your fired brass mic to?


No... light load. No... heavy load.

As for excess HS effecting accuracy it can. Thank You.
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Smokey



Joined: Sep 07 2006
Posts: 60

PostPosted: Mon Apr 12, 2010 5:31 pm    Post subject: Reply with quote

I almost always back FL sizing dies out for surplus rifles. Normally the headspace is a little generous in the rifle, and the die brings the case right down to minimum. Set the die so the shoulder is not affected and you should be fine. You will have to reconsider the cases you've sized, they're probably candidates for head separations eventually.
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chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Mon Apr 12, 2010 6:12 pm    Post subject: Reply with quote

Smokey wrote:
I almost always back FL sizing dies out for surplus rifles. Normally the headspace is a little generous in the rifle, and the die brings the case right down to minimum. Set the die so the shoulder is not affected and you should be fine. You will have to reconsider the cases you've sized, they're probably candidates for head separations eventually.



I went through this with a 7.65 Argentine. Setting the die to until the brass chambered.

As I stated before, the Norma brass didn't have backed out primers.
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Garandshtr



Joined: Dec 27 2007
Posts: 109
Location: Palm Harbor, FL

PostPosted: Thu Apr 15, 2010 8:50 pm    Post subject: Reply with quote

I'm not familiar with Norma brass (too pricey!). If the primers of those didn't back out, but did on other case types, I would get my calipers out. It does sound like an excess headspace issue, and perhaps the Norma cases don't grip the chamber walls as others do. See how the fired cases compare with each other, and the dimensions specified in a reloading manual.
Does your bolt serial match the rifle? If mismatched, you could easily have a problem. If they don't match, I would suggest you have the rifle inspected by a reputable gunsmith with the proper gauges.
Both of the Arisaka actions are among the toughest actions ever built, so I don't think you are in real danger, but given the stories of how ship board war trophies were made safe for a sea voyage, mismatched bolts are too common!

have fun!
Mark
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Still trying to learn what I can, mainly about the Type 99 and Type 38. I have more curiosity than time, and more time than money.
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chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Fri Apr 16, 2010 4:44 am    Post subject: Reply with quote

Garandshtr wrote:
I'm not familiar with Norma brass (too pricey!). If the primers of those didn't back out, but did on other case types, I would get my calipers out. It does sound like an excess headspace issue, and perhaps the Norma cases don't grip the chamber walls as others do. See how the fired cases compare with each other, and the dimensions specified in a reloading manual.
Does your bolt serial match the rifle? If mismatched, you could easily have a problem. If they don't match, I would suggest you have the rifle inspected by a reputable gunsmith with the proper gauges.
Both of the Arisaka actions are among the toughest actions ever built, so I don't think you are in real danger, but given the stories of how ship board war trophies were made safe for a sea voyage, mismatched bolts are too common!

have fun!
Mark


I excessively FL sized the brass on the R-P and shot factory Norma.
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Garandshtr



Joined: Dec 27 2007
Posts: 109
Location: Palm Harbor, FL

PostPosted: Fri Apr 16, 2010 6:45 am    Post subject: serials Reply with quote

I still suggest you check your bolt and receiver serial numbers.

Mark
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Still trying to learn what I can, mainly about the Type 99 and Type 38. I have more curiosity than time, and more time than money.
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DEFUC



Joined: Aug 17 2004
Posts: 201
Location: UP of michigan

PostPosted: Fri Apr 16, 2010 6:54 am    Post subject: Reply with quote

the norma Ammo is usually undersized to start with, so the case expands to match the chamber,where as home worked up properly FL sized brass is a snugger fit ,I expect the norma is using the pressure to expand the case to meet the chamber dimensions,while the FL stuff is pushing back against the primer.Purely a guess tho on my part,as I dont know exactly what you have going on or what loading your using.Backed out primers is a pressure sign, but why you have pressure can be a lot of things,its not high enough to cause concern,but does need further study to see whats causing it,some mic work and possibly a chamber casting SHOULD solve the matter.How does your brass work once its fireformed to the gun, just neck size and reused? measuring your fired brass versus your new FL brass should tell you quite a bit, other wise, running some cerro-safe in and measuring the exact chamber dimensions would be an idea also.
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chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Fri Apr 16, 2010 10:20 am    Post subject: Re: serials Reply with quote

Garandshtr wrote:
I still suggest you check your bolt and receiver serial numbers.

Mark


you will find that Arisakas don't match. When they were captured they put rifles in one pile and the bolts in another.
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DEFUC



Joined: Aug 17 2004
Posts: 201
Location: UP of michigan

PostPosted: Fri Apr 16, 2010 11:27 am    Post subject: Reply with quote

lots of matching arisaka out there,tho some did get messed up like you say and a lot more have since by careless owners.but theres lots of them that match completely and correctly around
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