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Antlers
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Ok, this is a new one for me. I've loaded some 300gr HDY FPs in my Heym 450/400 and they shoot to the same POI as my 400gr DGX loads.

Now the mystery - after shooting alot of these I noticed on picking up the brass that there were small squarish black spots embedded into the brass. The spots scrape off with a fingernail and they're very thin, but leave indentations. What is this stuff? My first thoughts were cellulose from the powder, but if that's it, why is this happening and how do I fix it? Never seen this before, but I bet some of y'all have.


Antlers
Double Rifle Shooters Society
Heym 450/400 3"
 
Posts: 1990 | Location: AL | Registered: 13 February 2002Reply With Quote
MacD37
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quote:
Originally posted by Antlers:
Ok, this is a new one for me. I've loaded some 300gr HDY FPs in my Heym 450/400 and they shoot to the same POI as my 400gr DGX loads.

Now the mystery - after shooting alot of these I noticed on picking up the brass that there were small squarish black spots embedded into the brass. The spots scrape off with a fingernail and they're very thin, but leave indentations. What is this stuff? My first thoughts were cellulose from the powder, but if that's it, why is this happening and how do I fix it? Never seen this before, but I bet some of y'all have.


Antlers, this sounds like the chamber pressure is not enough with the 300 gr bullets to expand the case fast enough to avoid unburned powder blowing back between the case walls, and the chamber walls. Just a guess on my part, however!


....Mac >>>===(x)===> MacD37, ...and DUGABOY1
DRSS Charter member
"If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982

Hands of Old Elmer Keith

 
Posts: 14634 | Location: TEXAS | Registered: 08 June 2000Reply With Quote
degoins
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I've had unburned powder stuck on my cases like that.


DRSS
 
Posts: 1176 | Location: Pamplico, SC USA | Registered: 24 August 2005Reply With Quote
DM
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posted Hide Post
quote:
Originally posted by MacD37:
quote:
Originally posted by Antlers:
Ok, this is a new one for me. I've loaded some 300gr HDY FPs in my Heym 450/400 and they shoot to the same POI as my 400gr DGX loads.

Now the mystery - after shooting alot of these I noticed on picking up the brass that there were small squarish black spots embedded into the brass. The spots scrape off with a fingernail and they're very thin, but leave indentations. What is this stuff? My first thoughts were cellulose from the powder, but if that's it, why is this happening and how do I fix it? Never seen this before, but I bet some of y'all have.


Antlers, this sounds like the chamber pressure is not enough with the 300 gr bullets to expand the case fast enough to avoid unburned powder blowing back between the case walls, and the chamber walls. Just a guess on my part, however!


I agree... I've seen it before with low pressure loads too.

DM
 
Posts: 696 | Location: Upper Midwest, USA | Registered: 07 February 2007Reply With Quote
nitro450exp
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Hello,

Try a faster burning powder or crimp harder or even use a magnum primer if you aren't already.

Nitro


"Man is a predator or at least those of us that kill and eat our own meat are. The rest are scavengers, eating what others kill for them." Hugh Randall
DRSS, BASA
470 Krieghoff, 45-70 inserts, 12 ga paradox, 20 ga DR Simson/Schimmel, 12 ga DR O/U Famars, 12 ga DR SXS Greener
 
Posts: 813 | Location: USA / RSA | Registered: 14 January 2008Reply With Quote
500N
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If you go with a Magnum Primer, start your load development again
as a Magnum primer can be the equivalent of 2 - 3 gs of powder.

I would try a couple of cartridges and crimp them quite hard
to see if that at least stops the blow back of unburnt powder.'

Then go from there.
 
Posts: 3191 | Location: Victoria, Australia | Registered: 01 March 2007Reply With Quote
Bob Nisbet
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I'm no expert in this area, but was thinking that if you take cases that were fired with full weight bullet and loads, then only do neck sizing, you may eliminate the problem.
The cases will have been blown out to match your chamber and only doing neck sizing will probably mean the brass will not leave a void for unburned powder.


Bob Nisbet
DRSS & 348 Lever Winchester Lover
Temporarily Displaced Texan
If there's no food on your plate when dinner is done, you didn't get enough to eat.
 
Posts: 830 | Location: Texas and Alabama | Registered: 07 January 2009Reply With Quote
Antlers
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quote:
Originally posted by MacD37:
quote:
Originally posted by Antlers:
Ok, this is a new one for me. I've loaded some 300gr HDY FPs in my Heym 450/400 and they shoot to the same POI as my 400gr DGX loads.

Now the mystery - after shooting alot of these I noticed on picking up the brass that there were small squarish black spots embedded into the brass. The spots scrape off with a fingernail and they're very thin, but leave indentations. What is this stuff? My first thoughts were cellulose from the powder, but if that's it, why is this happening and how do I fix it? Never seen this before, but I bet some of y'all have.


Antlers, this sounds like the chamber pressure is not enough with the 300 gr bullets to expand the case fast enough to avoid unburned powder blowing back between the case walls, and the chamber walls. Just a guess on my part, however!


Hey Mac, this sounds likely. I am using magnum primers, but wasn't crimping - I'll give that a try.

Thanks to all who replied!


Antlers
Double Rifle Shooters Society
Heym 450/400 3"
 
Posts: 1990 | Location: AL | Registered: 13 February 2002Reply With Quote
herrdoktor
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I also think a stronger crimping may help. And if cases are formed just enough to chamber, much the better.
 
Posts: 40 | Registered: 02 November 2007Reply With Quote
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