Excessive pressure on Speer 25-06 low charge

[lever-hed]

I am quite baffled on something and would welcome any input anyone might have…I got a major warning sign at the range on my first shot of this load:

Speer 120-gr BTSP (.257)
48.5-gr H4831sc
CCI BR2
R-P case, trim 2.488” (1st reload)
Savage 111

I aquired the bullets some time ago and had called Speer to get starting and finishing charges so I could play (start 48.0-gr H4831sc, quit 52.0-gr H4831sc, 2958fps).

Anyway, blown primer and stuck bolt !, took some good muscle to get open to see the extractor had torn off part of the rim due to the case was stuck. Bolt face was lightly marred around the ejector hole . Nevertheless, I wont be using anymore of these bullets in the near future and may replace bolt head.
Very pissed to say the least, and I want to call that guy at Speer and tell him to go pound salt ! does anyone have the Speer book that could verify for me what the actual min/max charges are for this load? Any similar experiences? thanks for any help..

[AJ Peacock]

I don't have access to the speer manual, but according to Quickload, your 48.5 load should be just fine. I'd pull a few of the bullets and Weigh them and measure the diameter. I'd also weight the powder for each one.

AJ

[lever-hed]

Measured 14 of the bullets from the box, diameter at mid-shank was .2575 and with a little thumb pressure I got .257” measured 3 times spinning shank 1/3 turn, on all 14. (Frankford Arsenal digital calipers).

..pulled the remaining 3 bullets for this charge, dia measured same as above. Then set Redding scale back up , rebalanced to exactly zero, and all charges re-weighed 1/10th grain high (48.6-gr, no major issue).
But, noticed at bottom of cases there appeared to be gray marks where powder might have seen condensation from going from warm car to 28 deg.F weather. I don’t think this could be a factor for blown primer..however, I shot from a clean barrel and noticed after removing the stuck case there appeared to be powder in the barrel to what looked like unfired powder residue, maybe from unfired powder flakes due to water from condensation, leaving a low charge (which I’ve heard can be just as dangerous as a hot charge), but this is just me thinking….

All primers seated with Lee hand prime tool and seated with good resistance.
Still baffled.. (wtf).. this is killlllllliiiiiiinnnnnggg me !!

[dirtball]

Are you seating the bullets to, or into the lands? If they are hard into the lands that might be the problem.
If not just back back off 6 grains and try again, then work up SLOWLY.
Remington brass should not be the problem, but you never know, weigh a few and see if they are consistent.
Dave

[AJ Peacock]

I only have 3 ideas for you.

1) Grabbed the wrong powder. ?? A visual comparison and measuring the grains length and diameter with your calipers can help you verify that the correct powder was used.
2) Did you do anything with the primer/flash hole? A too large flash hole can cause blown primer, but not stuck case as far as I know.
3) How hard where the bullets to pull from the case? If the cartridges got wet, maybe the bullet was 'fused' to the case with corrosion.

I know the above are really wild ass ideas, but I'm just throwing them out for you.

Let us know what you figure out.

AJ

[lever-hed]

Ok out of a dozen or so possible explanations, I’ve come to think that there could be 2 possible scenarios (however unlikely) in my mind.. (other than it was just hot load):

a) I have over-deburred the flasholes in the R-P cases; I’ve noticed that R-P cases tend to be ‘stickier’ then other cases when deburring, such as Federal or Winchester cases, they seem to have softer brass and less burrs in them. When deburring flasholes on R-P cases, the brass is harder and more times then not, I come across a large ‘chunk’ that needs extra twists to smooth it out, Its possible I could have over-done this – (primer pockets were uniformed also).

b) My tube is constricted due to copper fouling, although I don’t really feel this could be part of it, as I religiously clean my barrel after every session, 20-40 shots, using Butches, typically 25-30 patches. I have over 500 rounds down this factory barrel and notice no matter how many patches I send down, there will always be some copper fouling.. also I cleaned it real good just prior to going to range with Butches and then sent a couple patches of degreaser down the barrel to finalize. Don’t know if this had anything to do with it..

anyway these may be the answer, maybe not, still figuring itout...bullet seating was .010” off the lands, same as what I use for Sierra and Nosler, in fact I used Nosler 115-gr BT’s a week ago with 48.8-gr of H4831sc and shot fine.
Neck tension was ok, bullets were seated only recently. Maybe I’ll post some pics..
Thanks for your input,. I appreciate it.

[jmason]

Did you weight the bullets just to make sure bullets didn't get in the wrong box?