Blown Primer

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I am not a "novice" reloader ...although after today's incident...I may need a refresher course! I assume I had a severe spike in pressure...would appreciate some "experianced" comments.

Working up a load for my 260 Rem and decided to try some 120gr Sie MK's using 46.5 gr of H4350. Brass is Nosler custom which had been fired 1 time. CCI BR-2 primers.
First 5 shot group was set 10 thou off the lands and measured 0.6" C to C @ 100M. Temp about 0C. No pressure signs.
When I ejected the second round in the second group which was set on the lands, the primer literally fell out of the case! Needless to say, there was no second group!!!!
At home, I checked all 50 pcs of this nearly new Nosler brass and found that the primer pocket on the "bad" piece was so loose, a new primer would literally fall out. Another 13 pieces took "moderate" pressure to seat primers, and the balance of the 50 were all "tight"

I assume this must be a pressure issue?
 
Issue may relate to pressure or soft brass or both--if the pockets loosened on one firing then it is likely that the load is too hot with that brass in your rifle--did you work up to the load or just pick the load and adjust the seating depth. Were the cases all trimmed to the same length (and not too long) as this may affect the pressure also.

44Bore
 
I double checked the Hogdon Data and the 2009 Manual lists 46.5 gr of H4350for the max on the 260 Rem 120gr SPR SP ...is there that much difference between the SPR and the SIE MK ...or did you look at the starting load data?
The brass is once fired Nosler custom and is the correct length... the only other thing I can think of is the possibility of the neck being too tight as my barrel has a .292 neck. I did measure a couple, but not all, of the loaded rounds and they were .290 at the neck???
Primers were not flat on the brass from the first group, although there were some pressure signs. I don't have a chrony.
Yes, I did shoot some decent groups a while back with 44.0 gr of H4350, but then "jumped" right up to the Max. Guess that is a "lesson learned"!
The other thing I can think of...is that my rifle has a very short throat so I am seating deep with these long bullets. What does that do to pressure?
 
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Usually boat tail bullets are a bit longer than flat base of the same weight and crowd the powder space a bit more. And you say you are seating deeply due to short throat. Those factors have reduced capacity and raised pressures considerably when you might have been near max for your rifle considering the same physical restraints with the previous load. I've never seen or used Nosler brass but there seems to be a bit of unhappiness expressed by some users, sometimes related to softness of the brass. Have no idea if that is a valid criticism of the brass or not.

In the end, a 2.5 grain jump when you are nearing the top is not very prudent and perhaps you are fortunate worse did not occur.
 
Deeper seating depth will raise pressures drastically as you have just reduced the case capacity, it would be like using your max. load for the .308 in say a .300 Sav.!!
 
My Lyman 48th edition list IMR 4350 with 120 Nosler BT at 45.7 Max 2900fps,59,100 psi
There are other powders that give the same velocity with less pressure Like RL19,
Soon as you start kissing lands pressure will go up, try backing off powder a little and kiss lands, might give you best accuracy
good luck
manitou
 
Thanks guys...good advice all around. And yes, I needed to exercise a bit more patience before going to MAX. Given the collective wisdom expressed herein, I suspect the pressure spike was likely most closely related to reducing case capacity because of the short throat, and perhaps the brass was a little soft. Still somewhat puzzled over the fact that the previous 5 shot group (which was very close to the same load) did not show "signs". Oh well, live and learn....the key here is to live.
 
It sometimes doesn't take much to increase the pressure--I was working up loads in a 308 using military brass (all weighed and trimmed, etc) and was increasing the charge weight by .75 grain at a time and went from no pressure signs to primer blown right out while still well below max load.

44Bore
 
Max measn max in theri rifle. Does not mean it is safe in yours. A whole bunch of factors could amke it a over pressure load in your rifle. 6.5 is bad for pressure, as well.

Start at the start load and shoot, say, 3 shots in .5gr increments on teh first session and note where pressure sign develop. Then go home, pull the rest and decide what to test.

In 6.5 the Start load could be too hot for a given rifle.

Read below...
 
I have found in couple of times the ADI powders get spikey at high pressure.Once it was H-1000 in a 264WM,the other time it was H-4350 in a 30-06. One would think with H-4350 and 180gr Hornady Interlocks and not going over book max,you would be safe. I did three loading range. Luckly I shot over a chrony.The mid weight gave very high velocity and as well as being very erratic. Spikey. I pulled the top loading. This was the 8th 30-06 I had loaded for. I switched to the more lineral IMR-4350 and started well low.
 
killswithkimber said:
I have been hearing lots of stories about that happening with nosler brass it is just way to soft
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For what that #### costs I hope not. When I was in Winnipeg a few weeks ago it was the only .30/06 brass I could find. I do know that this brass has less capacity than other brands, so it needs to be worked up with caution.
 
downwindtracker2 said:
I have found in couple of times the ADI powders get spikey at high pressure.Once it was H-1000 in a 264WM,the other time it was H-4350 in a 30-06. One would think with H-4350 and 180gr Hornady Interlocks and not going over book max,you would be safe. I did three loading range. Luckly I shot over a chrony.The mid weight gave very high velocity and as well as being very erratic. Spikey. I pulled the top loading. This was the 8th 30-06 I had loaded for. I switched to the more lineral IMR-4350 and started well low.
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That is not good news.:(

The load that I settled on for my 30-06 is 56.0g of H4350, 180gr flat base Interlocks, Winchester brass, and WLR primers. There don't seem to be any signs of excessive pressure, it is accurate enough for me, and my chrony says the average velocity is 2740fps. The rifle is a Remington 700 CDL with a 24" barrel. In Hodgdon's 26th Data Manual, the max. for 180 (make not shown) with H4350 is 56.0 for 2733fps, and pressure of 48,800 c.u.p. with a 26" barrel. Hornady shows a max. of 55.3gr of H4350, but I thought it was reasonable to expect around 2700fps give or take a bit out of a 24" barreled '06, which mine wouldn't do until very close to 56 gr.

The last jug of IMR 4198 I bought is "manufactured in Australia, packaged in USA" so I would assume it is made in the ADI plant as well, which I suppose isn't too surprising as I understand Hodgdon owns IMR now.
 
46.5 4350 under a 120? what was the chrony speed?

I load 44.5 grs under a 125 gr Partition, and that is a max load @ 2900 fps (23" brl)
 
Boomer said:
For what that s**t costs I hope not. When I was in Winnipeg a few weeks ago it was the only .30/06 brass I could find. I do know that this brass has less capacity than other brands, so it needs to be worked up with caution.
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I find it soft as well, reminds me of Federal Gold Medal Match. My .308 loads needed to be backed off 2 grains, .300 Win mag needed to go down 2, and the .338 Edge required 4.The 22/250 didn't need any.:confused:
Back your loads off farther than you think, or risk hooping your new brass the first time out. You can lose them to primer pockets before the primers show you much.
 
Todd, I don't have a chrony so don't have any idea of what the velocity might have been. I went 46.5 grs of H4350 as that is the max Hodgdon lists for the 120 SPR SP in both the 2005 Hodgdon Manual and the 2009 Hodgdon Annual Reloaders Manual. In spite of the fact that I have loaded hundreds of 260 Rem rounds, the blown primer was a big surprise. The primer pocket on that case is so stretched that I can literally put a new CCI - BR2 primer in by just dropping it in the hole....and for those of you who use the CCI-BR2's, will know they are pretty hard and generally fit tight. I was testing two loads with 46.5 grs over the 120MK's ....one seated @ 2.730 (which produced a five shot 0.6" group at100M) ...and the next seated on the lands @ 2.740 blew the primer on the second shot. At that OAL, the load was pretty close to being compressed although I did not feel any "crunchyness" when I seated.
The rifle is a TC Icon and has a fat 3 lug bolt...guess it is has demonstrated it's strength.
Based on what has been postulated on this thread, I am of the opinion that the pressure spike was primarily due to the reduced case capacity caused by the deep seat which took up too much internal volume. I am also now a bit suspect of the relative hardness of the Nosler Custom brass...
The bottom line here however, is that features of the strong action and the strong brass that held together, kept me safe!
 
this is a good reason to get a chrony. I would not feel comfortable pushing the limits with pressure, without a chrony as it really helps tell you what ballpark you're in. A chrony costs about $120, a fraction of what a new rifle would cost. It should help you from getting to the point where you're blowing primers and risking damage to your rifle and your eyes
 
todbartell said:
this is a good reason to get a chrony. I would not feel comfortable pushing the limits with pressure, without a chrony as it really helps tell you what ballpark you're in. A chrony costs about $120, a fraction of what a new rifle would cost. It should help you from getting to the point where you're blowing primers and risking damage to your rifle and your eyes
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Ditto to that.
 
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