/VH
Hillary ain't in jail, so leave me to hell alone!
This past weekend while shooting my rifle, I had an unexpected experience and I am hoping some of the more experienced shooters can give me some insight on what happened.
BACKGROUND INFO:
RIFLE: Atlas Factory 6.5x47 Lapua hunting rifle with a .293 (tapered) nk (basically a tight/no turn). It has a 26†Krieger #4 sporter contour, a 2.5-25x March scope in Kelbly rings on Kelbly bases. It has shot very well for having such a light bbl. with a variety of bullets (123 Scenars, 130 & 140 Berger VLDs, 120 A-MAXs, 130 Scirocco IIs and 129 Accubond Long Ranges) at distances out to 360 yds., using R-15 and H4350. The rifle, hampered by me, has fired some 100 yd/3 shot groups less than .200â€, most under .400†with a little development and a few 200 yd./5 shot groups less than .500â€.
CRONOGRAPH: Shooting Crony (I know not the best but it’s what I have) set 7’8†from the muzzle.
ME: I have been shooting since the early 60s and handloading for rifles, shotguns and handguns since the early 70s. I have competed in a few NBRSA short range group matches with a 6ppc in a Panda action where I have done all my own brass prep from fire forming through neck turning and feel that I have more experience and therefore knowledge than most average hunter guys in regard to what is required to develop accurate loads, though I have virtually no experience with ranges beyond 400 yds. I also not only own but have read the loading manuals from all of the major domestic bullet and powder brands, along with Lapua and Vita Vouri. Until I shot benchrest, I always “stayed within†a printed manual with power charges. However, I expect most of us know that “within†one manual may be exceeding another by 2 grains or more. In the PPC world, with the guidance of several helpful shooters, I came to learn of the strength of custom actions and that there were no manuals that included data with loads as hot as most group shooters were using. Over time and through my experience, I developed within my own mind a perception (this may be the problem) that with fairly typical rifle loads when one has worked up to a powder charge with a heavier bullet, a lighter bullet (neglecting a substantial increase in bearing surface, change in jacket hardness, increase in diameter, change in seating relative to the lands, etc.) could pretty likely be safely substituted with the same powder charge.
Now to what happened; I had never before loaded any R-17 and wanted to try it. I had worked my way to 37.5 gr with Berger Hunting 140s and 129 Accubond LRs both seated at the lands, shooting 200yds and not being overly impressed. I then continued on with the 129 ABLRs to 38.4 gr. and managed about a ¾†group at just over 2800 fps. I wanted to try some 120 A-MAXs, so I just loaded the same three shells substituting only the bullets with the A-MAXs, seated at the lands. Expecting a slight increase in velocity, upon my first shot, the chrony read 3429! No hard bolt lift, no visible pressure signs on the brass or primer, no excessive recoil and the bullet hit the top edge of the 1†10 ring. I decided it may have been a fluke reading that possibly the muzzle blast may have caused. (I had previously gotten 9 legitimate looking readings from the crony with the other bullets, with no error messages). So, I decided to fire one more……3407 flashed for a couple seconds on the crony screen and the ERR2. No detectable pressure signs again and cut the bottom right edge of the 10 ring. Well, I only had one more loaded like that so………….3417! The third one cut the bottom left edge of the 10 ring.
Finally the durn question: (Hope no one passed away in the course of reading this but I think details matter in this game) Do you suppose those bullets really went that fast or did I probably blast the crony by having it too close?
Seems like awful consistent readings for a blasted crony or a gross overcharge.
I loaded those same 3 cases again, same load but went back to the 129 ABLRs. No loose primer pockets and the crony went back to the middle 2700s.
I also know that Berger lists R-17 with 130 & 140gr. bullets but not the 120s. Is there something peculiar about this powder that may have caused a 600fps increase with a 9gr decrease in bullet weight.
I’d appreciate the reasonable opinion of anyone that might care to offer one.
Thank you.
If I haven’t exceeded your patience, there is another phenomenon (a good one) with this rifle, custom sizing die, and the great Lapua brass that I’d like to throw out there sometime and see if anyone else has experienced the same.
I LOVE my 6 and a half!
BACKGROUND INFO:
RIFLE: Atlas Factory 6.5x47 Lapua hunting rifle with a .293 (tapered) nk (basically a tight/no turn). It has a 26†Krieger #4 sporter contour, a 2.5-25x March scope in Kelbly rings on Kelbly bases. It has shot very well for having such a light bbl. with a variety of bullets (123 Scenars, 130 & 140 Berger VLDs, 120 A-MAXs, 130 Scirocco IIs and 129 Accubond Long Ranges) at distances out to 360 yds., using R-15 and H4350. The rifle, hampered by me, has fired some 100 yd/3 shot groups less than .200â€, most under .400†with a little development and a few 200 yd./5 shot groups less than .500â€.
CRONOGRAPH: Shooting Crony (I know not the best but it’s what I have) set 7’8†from the muzzle.
ME: I have been shooting since the early 60s and handloading for rifles, shotguns and handguns since the early 70s. I have competed in a few NBRSA short range group matches with a 6ppc in a Panda action where I have done all my own brass prep from fire forming through neck turning and feel that I have more experience and therefore knowledge than most average hunter guys in regard to what is required to develop accurate loads, though I have virtually no experience with ranges beyond 400 yds. I also not only own but have read the loading manuals from all of the major domestic bullet and powder brands, along with Lapua and Vita Vouri. Until I shot benchrest, I always “stayed within†a printed manual with power charges. However, I expect most of us know that “within†one manual may be exceeding another by 2 grains or more. In the PPC world, with the guidance of several helpful shooters, I came to learn of the strength of custom actions and that there were no manuals that included data with loads as hot as most group shooters were using. Over time and through my experience, I developed within my own mind a perception (this may be the problem) that with fairly typical rifle loads when one has worked up to a powder charge with a heavier bullet, a lighter bullet (neglecting a substantial increase in bearing surface, change in jacket hardness, increase in diameter, change in seating relative to the lands, etc.) could pretty likely be safely substituted with the same powder charge.
Now to what happened; I had never before loaded any R-17 and wanted to try it. I had worked my way to 37.5 gr with Berger Hunting 140s and 129 Accubond LRs both seated at the lands, shooting 200yds and not being overly impressed. I then continued on with the 129 ABLRs to 38.4 gr. and managed about a ¾†group at just over 2800 fps. I wanted to try some 120 A-MAXs, so I just loaded the same three shells substituting only the bullets with the A-MAXs, seated at the lands. Expecting a slight increase in velocity, upon my first shot, the chrony read 3429! No hard bolt lift, no visible pressure signs on the brass or primer, no excessive recoil and the bullet hit the top edge of the 1†10 ring. I decided it may have been a fluke reading that possibly the muzzle blast may have caused. (I had previously gotten 9 legitimate looking readings from the crony with the other bullets, with no error messages). So, I decided to fire one more……3407 flashed for a couple seconds on the crony screen and the ERR2. No detectable pressure signs again and cut the bottom right edge of the 10 ring. Well, I only had one more loaded like that so………….3417! The third one cut the bottom left edge of the 10 ring.
Finally the durn question: (Hope no one passed away in the course of reading this but I think details matter in this game) Do you suppose those bullets really went that fast or did I probably blast the crony by having it too close?
Seems like awful consistent readings for a blasted crony or a gross overcharge.
I loaded those same 3 cases again, same load but went back to the 129 ABLRs. No loose primer pockets and the crony went back to the middle 2700s.
I also know that Berger lists R-17 with 130 & 140gr. bullets but not the 120s. Is there something peculiar about this powder that may have caused a 600fps increase with a 9gr decrease in bullet weight.
I’d appreciate the reasonable opinion of anyone that might care to offer one.
Thank you.
If I haven’t exceeded your patience, there is another phenomenon (a good one) with this rifle, custom sizing die, and the great Lapua brass that I’d like to throw out there sometime and see if anyone else has experienced the same.
I LOVE my 6 and a half!