Killshot
X's matter....but 10s win (but damn, Xs feel good)
So I'm loading for F-Class, 6 Dasher. I have used the same load in two different barrels (same reamer, same bore size and twist).
I just experienced a severe overpressure situation at last weekend's match that I'd like to understand.
A little background:
I purchased three of the five pound containers of RL15, all with the same lot identification (CE0519), manufacture date is 2/18/13.
When I used up jug 1 and went to jug 2 there was no change in either accuracy or velocity. I opened and used jug 3 to prepare for this past weekend's Long Range Regional using the same charge of 33.22gr using CCI-450s and Berger Hybrids.
Around the fourth shot the bolt-lift became stiff. Several shots later it wouldn't open without getting out of position and wrenching on it (Blueprinted Rem700 receiver, Kiff bolt). I have no ejector and the cases were stuck in the boltface. It took some rather crude banging the case to remove it from the bolthead.
I managed to finish the match without breaking the extractor but most of the cases were ruined. The odd thing is that it wasn't every case, I would get 3-4 in a row with just a little resistance at the top of the bolt-throw. Of those that stuck, the primers were blown out. (brass on fourth firing, annealed every other)Those that did not blow showed just the slightest flattening at the edges of the primers. The firing pin indentation looks normal, with no cratering or piercing.
The barrel was cleaned in the usual manner before the match and the borescope showed no carbon ring.
All cases were full length sized.
I finished the match and the thing was just as accurate as ever. I noticed the elevation needed at 1K was less than normal. Ballistics calculator indicate these were about 100fps faster (3,150) than I'd chrono'd the load before at 3,050. Barrel is 30" from the bolt-face.
Every case was weighed, every charge weighed to .02gr (scale is not in question) and all bullet bearing surfaces matched.
Powder jugs were only opened long enough to put powder in the thrower, then tightly sealed and stored in a cool, dark space.
Could it really be that this powder (one year old) generated this much overpressure despite it being made on the same lot-run?
I'd understand if I had experienced this last year when I went from jug 1 to lot 2, but that's not the case.
What do you guys think?
And would you just drop down to 32grs and work up a new load with this powder or pickup some new jugs and use this to fertilize the yard?
I just experienced a severe overpressure situation at last weekend's match that I'd like to understand.
A little background:
I purchased three of the five pound containers of RL15, all with the same lot identification (CE0519), manufacture date is 2/18/13.
When I used up jug 1 and went to jug 2 there was no change in either accuracy or velocity. I opened and used jug 3 to prepare for this past weekend's Long Range Regional using the same charge of 33.22gr using CCI-450s and Berger Hybrids.
Around the fourth shot the bolt-lift became stiff. Several shots later it wouldn't open without getting out of position and wrenching on it (Blueprinted Rem700 receiver, Kiff bolt). I have no ejector and the cases were stuck in the boltface. It took some rather crude banging the case to remove it from the bolthead.
I managed to finish the match without breaking the extractor but most of the cases were ruined. The odd thing is that it wasn't every case, I would get 3-4 in a row with just a little resistance at the top of the bolt-throw. Of those that stuck, the primers were blown out. (brass on fourth firing, annealed every other)Those that did not blow showed just the slightest flattening at the edges of the primers. The firing pin indentation looks normal, with no cratering or piercing.
The barrel was cleaned in the usual manner before the match and the borescope showed no carbon ring.
All cases were full length sized.
I finished the match and the thing was just as accurate as ever. I noticed the elevation needed at 1K was less than normal. Ballistics calculator indicate these were about 100fps faster (3,150) than I'd chrono'd the load before at 3,050. Barrel is 30" from the bolt-face.
Every case was weighed, every charge weighed to .02gr (scale is not in question) and all bullet bearing surfaces matched.
Powder jugs were only opened long enough to put powder in the thrower, then tightly sealed and stored in a cool, dark space.
Could it really be that this powder (one year old) generated this much overpressure despite it being made on the same lot-run?
I'd understand if I had experienced this last year when I went from jug 1 to lot 2, but that's not the case.
What do you guys think?
And would you just drop down to 32grs and work up a new load with this powder or pickup some new jugs and use this to fertilize the yard?
