Slowest STW known to man
01-02-2007, 10:07 AM
#13
Guest
Posts: n/a
RE: Slowest STW known to man
ORIGINAL: jeepkid
I loaded up some 160's for my 7mm Rem Mag with H-870 and the book says they should be right at 3200 fps. But I haven't chronographed them yet. They were Accubonds.
I loaded up some 160's for my 7mm Rem Mag with H-870 and the book says they should be right at 3200 fps. But I haven't chronographed them yet. They were Accubonds.
01-02-2007, 11:11 AM
#14
Dominant Buck
Join Date: Feb 2005
Location: WC FL
Posts: 26,323
01-02-2007, 11:15 AM
#15
Join Date: Mar 2005
Location: Colorado
Posts: 4,127
RE: Slowest STW known to man
Mark - I hate to break this to you, man; but you might have just gotten a really slow barrel here. I've seen this before - had a .300 Weatherby 26" Shilen barrel back in 1996 that couldn't safely make 3,000 fps with any 180 gr. bullet. On the other extreme, I have also had a couple of Shilen SS barrels in 7 STW that could safely make 3600 with a 140 gr. bullet. It is what it is . . . . and I doubt if playing around with a bunch of powders is going to improve things very much.
Having said that, have you checked the amount of freeboreahead of that chamber? It is also possible that this gun has a really long throat, and the loads you are shooting are not developing the kind of pressure that we normally associate with "full throttle" - even though they are close to what the book lists as a maximum charge? Just a passing thought . . . .
Having said that, have you checked the amount of freeboreahead of that chamber? It is also possible that this gun has a really long throat, and the loads you are shooting are not developing the kind of pressure that we normally associate with "full throttle" - even though they are close to what the book lists as a maximum charge? Just a passing thought . . . .
01-02-2007, 11:26 AM
#16
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Posts: n/a
RE: Slowest STW known to man
You might be right Roskoe. I am going to give RL25 and Retumbo a try. Its just a shame to burn 80gr of powder for 7mmremmag velocities.
And yes, it does have alot of freebore. I load to 3.63", to fit my mag, and it doesn't touch the rifleing until 3.75". But it shot factories fine. I should have chrono'd.
I do have a spare barrel. I got it off a guy who bought a Sako75 and never shot the first round off, but had it rebarreled immediately. So maybe I could get my gunsmith to back up the freebore some. I still got some options.
And yes, it does have alot of freebore. I load to 3.63", to fit my mag, and it doesn't touch the rifleing until 3.75". But it shot factories fine. I should have chrono'd.
I do have a spare barrel. I got it off a guy who bought a Sako75 and never shot the first round off, but had it rebarreled immediately. So maybe I could get my gunsmith to back up the freebore some. I still got some options.
01-02-2007, 01:26 PM
#17
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Posts: n/a
RE: Slowest STW known to man
Just got off the phone from the Shooting Chrony folks. They said they bet anything that I am shooting too close to the chrony in why my velocities were so low.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
01-02-2007, 05:18 PM
#19
Nontypical Buck
Join Date: Oct 2005
Location: Berkeley Springs, WV
Posts: 1,293
RE: Slowest STW known to man
ORIGINAL: bigcountry
Just got off the phone from the Shooting Chrony folks. They said they bet anything that I am shooting too close to the chrony in why my velocities were so low.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
Just got off the phone from the Shooting Chrony folks. They said they bet anything that I am shooting too close to the chrony in why my velocities were so low.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
01-02-2007, 05:54 PM
#20
Guest
Posts: n/a
RE: Slowest STW known to man
ORIGINAL: Duckbutter48
Dumb question, should all Chronys be that far away? Ive never heard that and when me and bud occasionally shoot thru it, wellthe results areusually disappointing to say the least.
ORIGINAL: bigcountry
Just got off the phone from the Shooting Chrony folks. They said they bet anything that I am shooting too close to the chrony in why my velocities were so low.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
Just got off the phone from the Shooting Chrony folks. They said they bet anything that I am shooting too close to the chrony in why my velocities were so low.
Ok, yesterday was the first time I have shot so close thru my chrony. Usually at my normal range, I have to put out like 17ft to get sunlight causethe range iscovered. Yesterday I didn't think about it, and was shooting with mossy. I had the chrono like maybe 8ft away from my muzzle. The guys at shooting chrony told me the more powerful gun I shoot, the worst it should be off. Sounds right, my 45-70 was decently on, what I would expect, my 308win was about 50-60fps slower than expected from previous shooting, mossy's rem mag was 100-130fps slower than expected, and my STW was 150fps slower than expected. I have never shot that close, so he may be on something there.
So this may explain my crazy slowness. He told me minimum of 15ft from the muzzle. I have always read that, but didn't expect it to make a difference.
I ain't no expert on the Chrono, as I use it 3 maybe 4 times a year as it takes away from my concentration when load development.
I also used to use scotch tape over the sensors on bright days, and it seemed to make results very repeatable. I can see how that might help minimize the blast effects also.
Well, mossy, I will load up another 40 rounds and lets give it another try on Sunday?