300 SST Boat tails at 300 yards again
Feb 25, 2015 11:52:54 GMT -5
Post by Richard on Feb 25, 2015 11:52:54 GMT -5
300 SST Boat tails at 300 yards again
Nursing a head cold I showed up at the range yesterday morning with the temp’s at 29* and snowing.
Again, for those first time readers, I am shooting a 25 ½” Pac-Nor .45 on a Rem. ML action; .028” bushing plug. And, starting out with a squeaky clean barrel.
Group #1 was strictly shot as a fouler. On past occasions I have shot the 200 gr. XTP with no wad and one of my duplex loads and have gotten misfires. This is mainly due to cleaning residue left in the barrel and the fact that the last few inches before the bullet hits the powder is somewhat looser than the main part of the bore. So this week I thought I would try to fool it. I went with and “upped” charge of 13 gr. Clays with 62 gr. of H-4198. Then I increased resistance by putting a slight knurl on the bullet (these bullets will normally slip right down the bore with little resistance and fall the last few inches) and adding a wad and a CCI magnum primer……………………Pow!………………….3065 fps! Shot #2 did not give a chronograph reading and I had to remove snow from the photo cell.. Shots 3 and 4 went off with no problem but their velocity dropped (which seems to be a usual occurrence for me with multiple shots and the barrel just “slightly” warming). For the fifth shot I did no knurling and did not use a wad. Velocity did drop the most but still hit right in same hole (measures .482”) as shot number three. Not a good 100 yard group if your target shooting but would certainly work on a deer. (NO sticky primers!)
OK, out to 300 yards with the snow still coming down. I was able to some what put the second mil-dot approximately in the center of the bull. This is the 300 gr. SST that I cut a boattail on the base in the lathe. The bullet was then undersized with a .4495” die (thanks Al), then knurled up to .452” and resized with a .451 die (from Al). They were just a little too tight last week so I ran them thru the Swinglock die on the 7th mark. They do go down with some resistance but nothing close to “hammer downs”. My thought on the charge was to hit them harder than usual with 12 gr. of Clays but drop the main charge back to 58 gr………….again, just to see what would happen? I did get some variation in the velocities…….mainly with shot #1 and #4 for a 55 fps ES…However if you look at shots 2,3 & 5 there is only 6 fps ES. Group wise, shots 2, 3 & 4 (in a row) were a respectable 1.7” while the remaining five made it 4.6” but no drastic change in POI. Definitely “dead deer”. In this group of five shots I had 4 that there were no sticky primers and one slightly sticky…But, one of the NS primers show signs of leakage between the primer and cup---on the outside that contacts the BP. So, feeling that maybe there was too much pressure with the 12 gr. of clays, I dropped back to my normal 10/60 load for the last group.
Same bullet combo and 10/60 Clays/H-4198……….Shots 1, 2 &3? 2 fps ES; Shots 1, 2, 3 & 4? 7 fps ES! It was only the last shot with opened the ES up to 14 fps. Here again, shots 3, 4 & 5 = .919”. Add in shot #4 and we get 2.8” and with Shot 5 it brings it up to 3.3”. Now, when it comes to the primers? 4 did not stick, one did stick and one of the non-sticky ones leaked again around the primer inside the cup? And it was the lowest velocity of the five?
We only go about an inch of snow but it will play heck with the chronograph if too much gets on them.
Richard
Nursing a head cold I showed up at the range yesterday morning with the temp’s at 29* and snowing.
Again, for those first time readers, I am shooting a 25 ½” Pac-Nor .45 on a Rem. ML action; .028” bushing plug. And, starting out with a squeaky clean barrel.
Group #1 was strictly shot as a fouler. On past occasions I have shot the 200 gr. XTP with no wad and one of my duplex loads and have gotten misfires. This is mainly due to cleaning residue left in the barrel and the fact that the last few inches before the bullet hits the powder is somewhat looser than the main part of the bore. So this week I thought I would try to fool it. I went with and “upped” charge of 13 gr. Clays with 62 gr. of H-4198. Then I increased resistance by putting a slight knurl on the bullet (these bullets will normally slip right down the bore with little resistance and fall the last few inches) and adding a wad and a CCI magnum primer……………………Pow!………………….3065 fps! Shot #2 did not give a chronograph reading and I had to remove snow from the photo cell.. Shots 3 and 4 went off with no problem but their velocity dropped (which seems to be a usual occurrence for me with multiple shots and the barrel just “slightly” warming). For the fifth shot I did no knurling and did not use a wad. Velocity did drop the most but still hit right in same hole (measures .482”) as shot number three. Not a good 100 yard group if your target shooting but would certainly work on a deer. (NO sticky primers!)
OK, out to 300 yards with the snow still coming down. I was able to some what put the second mil-dot approximately in the center of the bull. This is the 300 gr. SST that I cut a boattail on the base in the lathe. The bullet was then undersized with a .4495” die (thanks Al), then knurled up to .452” and resized with a .451 die (from Al). They were just a little too tight last week so I ran them thru the Swinglock die on the 7th mark. They do go down with some resistance but nothing close to “hammer downs”. My thought on the charge was to hit them harder than usual with 12 gr. of Clays but drop the main charge back to 58 gr………….again, just to see what would happen? I did get some variation in the velocities…….mainly with shot #1 and #4 for a 55 fps ES…However if you look at shots 2,3 & 5 there is only 6 fps ES. Group wise, shots 2, 3 & 4 (in a row) were a respectable 1.7” while the remaining five made it 4.6” but no drastic change in POI. Definitely “dead deer”. In this group of five shots I had 4 that there were no sticky primers and one slightly sticky…But, one of the NS primers show signs of leakage between the primer and cup---on the outside that contacts the BP. So, feeling that maybe there was too much pressure with the 12 gr. of clays, I dropped back to my normal 10/60 load for the last group.
Same bullet combo and 10/60 Clays/H-4198……….Shots 1, 2 &3? 2 fps ES; Shots 1, 2, 3 & 4? 7 fps ES! It was only the last shot with opened the ES up to 14 fps. Here again, shots 3, 4 & 5 = .919”. Add in shot #4 and we get 2.8” and with Shot 5 it brings it up to 3.3”. Now, when it comes to the primers? 4 did not stick, one did stick and one of the non-sticky ones leaked again around the primer inside the cup? And it was the lowest velocity of the five?
We only go about an inch of snow but it will play heck with the chronograph if too much gets on them.
Richard
I just wish I knew why one in five primers would leak with both loads? Even the velocity on one was lower than the rest and yet it still leaked? You could just see the black ring surrounding the primer against the cup. When that happens is when you start getting that erosion around the firing pin hole on the bolt face.