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Posted: 4/27/2014 4:23:01 PM EDT
[#1]
if the distance between the screens is off even 1/8 to 1/4 of an inch it will give erroneous readings, also check the battery.
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Posted: 4/27/2014 4:27:17 PM EDT
[#2]
Quote HistoryQuoted:
if the distance between the screens is off even 1/8 to 1/4 of an inch it will give erroneous readings, also check the battery. New battery. Interesting on the screens, I thought they were aligned, but maybe I was off a bit. Hmm. [edit] I did plug in the 2,900 fps avg into my shooting app and at 600 yards my holdover was spot on and I was hitting the target. If I was off 100-200 fps wouldn't they have missed completely? |
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Posted: 4/27/2014 5:18:25 PM EDT
[#3]
Regarding the velocity, I wouldn't put describe what you are seeing as extraordinarily high given the 24" barrel. To be sure, that's above expected data (147 @ 2800 or so is what I would think), but you could have had a chrono issue due to set up or even light conditions. This is why load truing is mandatory to shoot ELR regardless of what chrono you have. Shoot at a half moa target (e.g. a sporting clay) at 800 or so to see where you are really at on velocity.
Velocity aside, regarding your come ups, the difference between 2700 and 2900 fps is only about 3 moa at 600m. If you were shooting an IPSC or something similar, you would have still connected without issue. Even with a 12" plate (i.e. 2 MOA), you still would probably connect about 50%. The difference would be more minimal (and you hit percentage increased) the closer to your chrono speed you actually were. |
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Posted: 4/27/2014 5:20:37 PM EDT
[#4]
Also, for chono verification on a short range, I would suggest a match 22 out of a 16" barrel. I use Lapua SK Match out of a 10/22.
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Posted: 4/27/2014 7:35:59 PM EDT
[#5]
Thanks, I used 3 different .22 brands, all were close.
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Posted: 4/28/2014 3:49:16 AM EDT
[#6]
Quote HistoryQuoted:
New battery. Interesting on the screens, I thought they were aligned, but maybe I was off a bit. Hmm. [edit] I did plug in the 2,900 fps avg into my shooting app and at 600 yards my holdover was spot on and I was hitting the target. If I was off 100-200 fps wouldn't they have missed completely? Quote HistoryQuoted:
Quoted:
if the distance between the screens is off even 1/8 to 1/4 of an inch it will give erroneous readings, also check the battery. New battery. Interesting on the screens, I thought they were aligned, but maybe I was off a bit. Hmm. [edit] I did plug in the 2,900 fps avg into my shooting app and at 600 yards my holdover was spot on and I was hitting the target. If I was off 100-200 fps wouldn't they have missed completely? at 600 yards yes |
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Posted: 4/28/2014 5:02:30 AM EDT
[#7]
I have a savage 10 in .308. I have the exact same problem and really haven't determined a good answer. I was getting pressure problems 2.5 grains below max with varget, lower with other powders. Originally I thought it might be a hot lot of powder or a barrel issue. Problem is magnified with military brass (smaller case capacity is my guess) I now used my chrono and case signs to determine a max load with varget. The positive side is that rifle is Crazy accurate.
I'm tagging this fir any new ideas or outcomes. |
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Posted: 4/28/2014 5:17:47 AM EDT
[#8]
Over the past several years, I've seen a number of posts about the Savage 10 series & high velocities / pressure.
I have a Savage 10 FCP-K, and get 2650 with 42.6 gr of Varget using 175 SMKs with Winchester brass. I was getting pressure signs well before "max" when I worked up. I also worked up loads with Nosler brass - same thing - higher velocity / pressure signs with less powder than the manuals. Without having measured it, I attribute it to a "tight chamber", and am glad I worked up instead of just accepting a book load. |
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Posted: 4/28/2014 5:41:39 AM EDT
[#9]
My Hodgdon manual shows 46 grains Varget max with sie 168 at velocity 2731. I was at 43.8gr getting 2741fps and was getting pressure signs at 44.5grains.
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Posted: 4/28/2014 7:49:16 AM EDT
[#10]
So 147 factory loads are faster than 168s, and you are surprised? Am I missing something?
Posted Via AR15.Com Mobile |
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Posted: 4/28/2014 8:18:54 AM EDT
[#11]
As others have pointed out:
-your results with the Ball ammunition aren't out of line. But the results are determined by weather conditions, barrel length, chamber etc etc etc. So they are off.......... -Sierra with a 150FMJ BT bullet shows a difference of approx. 9-12" between 2700 and 2900 fps at 600yds- so no you shouldn't miss at that distance. If your rifle otherwise shoots well, don't worry about it. |
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Posted: 4/28/2014 8:23:51 AM EDT
[#12]
The Savage 308's have been known to have very short throats. Some are coming off the line so short, Factory ammo will get pig jammed into the lands.
My guess is your ammo is up close and personal to the lands and increasing pressure to unacceptable levels. Take the time to measure the distance from your bullet ogive to the lands. I'm bettin you have little to none. |
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Posted: 4/28/2014 8:32:20 AM EDT
[#13]
Those numbers sound fine though. It is a lighter bullet and factory loaded(optimal powder).
A 60kpsi 147gr bullet load is going to be quite a bit faster than a 168gr handload at 60k psi. ETA: I just ran the numbers in QL, just replacing a 168gr bullet with a 150gr bullet while keeping the same PSI gives the exact velocity spread the OP is seeing. 2770 to 2940 Posted Via AR15.Com Mobile |
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Posted: 4/28/2014 9:48:27 AM EDT
[#14]
2600 fps usually provides great accuracy with 168 grain bullets. Lower your powder charge - increase your savings. $. I never load 147 grain bullets, however, I shoot 155's and I don't feel any need to go faster than 2700 fps.
Some rifles hit peak pressures and velocities with substantially lower powder charges. That's why every manual encourages the reloader to start lower, work up. Not everyone follows this advice. 7.62x51mm military brass always causes this phenomena, always. For years reloaders simply guessed their velocities based on the data they used. The wide variation of data in print is the direct result of the variables inherent in all ammo/rifles combinations. Hodgdon's test rifles must have the longest throats in the industry, they publish the highest powder charges that I have seen. I take that into consideration anytime I reference their data. Chronographs are a fantastic addition to any reloaders tool box and I wouldn't consider reloading any quantity of ammo without checking the load for speed. My Oehler 35P has served me well for over 20 years now. |
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Posted: 4/28/2014 12:14:23 PM EDT
[#15]
BTW, I just checked my log book, I fired some Privi 145gr and my 168gr CC load on the same day. The 145s were 2800fps my 168gr load was 2630fps out of my 20" 700.
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Posted: 4/28/2014 7:43:50 PM EDT
[#16]
Quote HistoryQuoted:
The Savage 308's have been known to have very short throats. Some are coming off the line so short, Factory ammo will get pig jammed into the lands. My guess is your ammo is up close and personal to the lands and increasing pressure to unacceptable levels. Take the time to measure the distance from your bullet ogive to the lands. I'm bettin you have little to none. I have not seen any pressure signs other than the velocity. Primers look normal, brass is cool to the touch, not hot at all and I don't see any bulge in the brass from excessive pressure, no primer punctures and no soot around the primer. |
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Posted: 4/28/2014 7:49:24 PM EDT
[#17]
Quote HistoryQuoted:
My Hodgdon manual shows 46 grains Varget max with sie 168 at velocity 2731. I was at 43.8gr getting 2741fps and was getting pressure signs at 44.5grains. Now I don't feel so crazy. It's pretty cool to get that performance out of less powder it it's safe. 
I loaded 44gr for the nosler 168gr bullets but didn't get to shooting them. |
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Posted: 4/28/2014 7:52:23 PM EDT
[#18]
Quote HistoryQuoted:
So 147 factory loads are faster than 168s, and you are surprised? Am I missing something? Posted Via AR15.Com Mobile I know they are faster, it's just the velocities are 100-200 fps faster than what I've seen in reloading manuals and other distance shooting forums. Is it normal for the brass that I've just shot to be cool to the touch? Literally when I'd cycle the casing out that I just fired, there is no heat on the casing, at all. Is this normal? My AR brass while being ejected is hot, so is all my pistol brass etc.... |
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Posted: 4/28/2014 8:26:41 PM EDT
[#19]
Quote HistoryQuoted:
I have not seen any pressure signs other than the velocity. Primers look normal, brass is cool to the touch, not hot at all and I don't see any bulge in the brass from excessive pressure, no primer punctures and no soot around the primer. Quote HistoryQuoted:
Quoted:
The Savage 308's have been known to have very short throats. Some are coming off the line so short, Factory ammo will get pig jammed into the lands. My guess is your ammo is up close and personal to the lands and increasing pressure to unacceptable levels. Take the time to measure the distance from your bullet ogive to the lands. I'm bettin you have little to none. I have not seen any pressure signs other than the velocity. Primers look normal, brass is cool to the touch, not hot at all and I don't see any bulge in the brass from excessive pressure, no primer punctures and no soot around the primer. Velocity and pressure go hand in hand. You may not see true pressure signs at the level you are at. True pressure signs like stiff bolt and extractor marks don't rear their ugly head until the load is past 65-70K. I doubt your load is dangerously hot, but for your own piece of mind I would check the Ogive to lands distance of your loads. If I am correct and your bullets are indeed up close and personal to the lands you can handle it a couple ways. 1) Seat the bullet deeper, this will reduce pressure. 2) do nothing and enjoy your extra velocity. 3) call Savage and Bitch. 4) have the throat reamed by a competent Smith. If it were my rifle and I had no intentions of ever loading a factory round I would choose both 1 and 2. If I was to ever load any factory ammo, I would do both 3 and 4. |
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Posted: 4/28/2014 9:37:42 PM EDT
[#20]
Quote HistoryQuoted:
Velocity and pressure go hand in hand. You may not see true pressure signs at the level you are at. True pressure signs like stiff bolt and extractor marks don't rear their ugly head until the load is past 65-70K. I doubt your load is dangerously hot, but for your own piece of mind I would check the Ogive to lands distance of your loads. If I am correct and your bullets are indeed up close and personal to the lands you can handle it a couple ways. 1) Seat the bullet deeper, this will reduce pressure. 2) do nothing and enjoy your extra velocity. 3) call Savage and Bitch. 4) have the throat reamed by a competent Smith. If it were my rifle and I had no intentions of ever loading a factory round I would choose both 1 and 2. If I was to ever load any factory ammo, I would do both 3 and 4. Quote HistoryQuoted:
Quoted:
Quoted:
The Savage 308's have been known to have very short throats. Some are coming off the line so short, Factory ammo will get pig jammed into the lands. My guess is your ammo is up close and personal to the lands and increasing pressure to unacceptable levels. Take the time to measure the distance from your bullet ogive to the lands. I'm bettin you have little to none. I have not seen any pressure signs other than the velocity. Primers look normal, brass is cool to the touch, not hot at all and I don't see any bulge in the brass from excessive pressure, no primer punctures and no soot around the primer. Velocity and pressure go hand in hand. You may not see true pressure signs at the level you are at. True pressure signs like stiff bolt and extractor marks don't rear their ugly head until the load is past 65-70K. I doubt your load is dangerously hot, but for your own piece of mind I would check the Ogive to lands distance of your loads. If I am correct and your bullets are indeed up close and personal to the lands you can handle it a couple ways. 1) Seat the bullet deeper, this will reduce pressure. 2) do nothing and enjoy your extra velocity. 3) call Savage and Bitch. 4) have the throat reamed by a competent Smith. If it were my rifle and I had no intentions of ever loading a factory round I would choose both 1 and 2. If I was to ever load any factory ammo, I would do both 3 and 4. What if my chronograph was not perfectly level? Could my chrony be off a 100 fps by one window being slightly higher/lower than the 2nd on an uneven surface? I need to test some federal gold medal match I have. Also interesting are my hand loads have not shot very well 1-2 MOA but I shot some short Sierra 110gr that shot 1/2 MOA and they are much shorter than the 150+ gr bullets. You may be onto something. |
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Posted: 4/29/2014 4:15:30 AM EDT
[#21]
Jump to the lands and its affect on accuracy is a complex relationship, and has a lot to do with the bullet ogive design. Keep in mind a lot of long range competition guys "soft seat" their bullets, meaning they are actually pushing the bullet into the lands upon chambering. So, short jump is not necessarily a bad thing, but it may affect accuracy and will affect the pressure curve (the longer the jump, the more of a "running start" the bullet gets before obturation, and the less maximum pressure exhibited). Now, keep in mind that if you "soft seated" a bullet that had been factory crimped, you *might* actually get LOWER pressure as the crimp and neck tension have been lowered, even if the "running start" is eliminated. As I said, it is a complex relationship.
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Posted: 4/29/2014 4:33:50 AM EDT
[#22]
Also interesting are my hand loads have not shot very well 1-2 MOA but I shot some short Sierra 110gr that shot 1/2 MOA and they are much shorter than the 150+ gr bullets. You may be onto something. It appears that you have tested one load 43.2gr of Varget with 168gr Nosler CC? That is almost at the Start Load. Both Hodgdon and Nosler have a Max of 46gr Varget. When testing for accuracy it's best to start low and work your way up towards max looking for that accuracy node. With your rifle, I would work up slow, prolly .3-.5gr increments. Here is what Nolser recommends for OAL. 
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Posted: 4/29/2014 5:02:04 AM EDT
[#23]
Quote HistoryQuoted:
if the distance between the screens is off even 1/8 to 1/4 of an inch it will give erroneous readings, also check the battery. Doesn't need to be that far. If the chassis of a Chrony isn't completely open it will measure speeds that are too high. A chronograph that is not level will also yield incorrect measurements. Lot to lot variation of gunpowder can cause the same problem, although in my experience it is most common in Alliant Reloder 19 and 22, I have some Reloder 15 left that is 100 fps faster than every other lot I've bought. |
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