Reasonable velocity spread
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- .17 HMR
- Posts: 164
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- Location: SA
Reasonable velocity spread
G'day All,
Just spent a little time putting a few of the rifles and handloads through their paces over a F1-Chrony this weekend. There were some suprising (and disappointing) results there that's for sure.
I would just like to know - what do you deem as acceptable velocity spread on handloaded rounds? I was getting up to 55fps variance over a number of shots.
Thanks,
CZ550
Just spent a little time putting a few of the rifles and handloads through their paces over a F1-Chrony this weekend. There were some suprising (and disappointing) results there that's for sure.
I would just like to know - what do you deem as acceptable velocity spread on handloaded rounds? I was getting up to 55fps variance over a number of shots.
Thanks,
CZ550
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- 50 BMG
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Re: Reasonable velocity spread
I would be happy with 55fps difference. when it gets over 100 (and it doesent anymore now i weigh each charge) I get a bit pissy.
- Camel
- Ultimate AusVarminter
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Re: Reasonable velocity spread
Dunno, Ive only ever put 2 shots through a crono, both within 10fps, so I guess that's my standard, until next time.
- mick_762
- 50 BMG
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Re: Reasonable velocity spread
For my Target Rifle, i hate getting over 15fps varience, but thats just my anal retentiveness.
For my Hunting rifles 50fps is my allowable spread.
For my Hunting rifles 50fps is my allowable spread.
Re: Reasonable velocity spread
under 20 seem to be about the mark for my long range guns under 10 is real nice and a few loads n calibres shoot it
General hunting ones don't really care as long as they shoot around moa
All the best
John

General hunting ones don't really care as long as they shoot around moa

All the best
John
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- .308 Winchester
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Re: Reasonable velocity spread
Did some load development for the Nesika /shilen 6br on Saturday ,up to 40 fps differance sometimes but even with that much differance was still able to put down a couple of 5 shot groups around the 1/4 moa or slightly larger at 200 yds , for varminting out to 400 yds 40 or 50 fps isn't going to matter ,but if your shooting long range comp I'd be aiming for 10 to 15 any more than that would worry me as other blokes in the know have said 

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- .338 Lapua Magnum
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Re: Reasonable velocity spread
There are some people on here dunno if they will jump in about it, but their work on tuning rifles is nothing short of sensational.
Now firstly I dont mean to sound rude but that F1 readings your getting probably arent worth the cardboard box the unit comes in. I have one and know of others that just couldnt get any reliable accuracy from.
Yesterday we set up on the 900m mound at the range and used a magnetospeed MS2 on a couple of rifles to tune loads for the queens prize. We shot strings of 10 shots and 2 sighters and recorded everything. Basically at the end of it, my rifle shot 58.8X at 900m in some horrible mirage. The two lost points were boils and change in mirage direction. A mate watched it closely and shot a 60.6 with his 243AI which was an outstanding effort. Best of all the elevation was probably 5 bullet holes high. He will be tough to beat in the queens we have coming up in a fortnight. My rifle that shot really well had a SD of 18. Im not happy with that, but I am happy with the way it shot. Quite often I have found a really flat shooting load at long range has poor SD and ES and have dismissed the figures a bit until recently. X ring elevation at 900m is very very good but we need repeatable velocities to maximise our chances of doing well. With those numbers I will be working a little to get that down under the 10 or lower area. Another guy shot nice flat elevation and for a 5 shot string (not really reliable as 10 or 15 shot strings are better but its all the ammo he had left) was a SD of 3. For long range shooting, its imperative that we keep the spreads and deviations down as low as possible. Shame we didnt get to test the 243AI for SD as I believe it would have been very good also.
For a varmint gun I personally wouldnt bother with mucking around with chronys aside from a quick velocity check. As long as it can put 3 shots into a cloverleaf at 100m Im generally happy with it.
My mate left his MS2 here for me to tune my gun with a bit more this week, and Im rather stoked with that! Got to get myself one as they are fast becoming the benchmark chrony around the world to work with. Accurate and can be used any time of the day without needing constant light conditions.
Now firstly I dont mean to sound rude but that F1 readings your getting probably arent worth the cardboard box the unit comes in. I have one and know of others that just couldnt get any reliable accuracy from.
Yesterday we set up on the 900m mound at the range and used a magnetospeed MS2 on a couple of rifles to tune loads for the queens prize. We shot strings of 10 shots and 2 sighters and recorded everything. Basically at the end of it, my rifle shot 58.8X at 900m in some horrible mirage. The two lost points were boils and change in mirage direction. A mate watched it closely and shot a 60.6 with his 243AI which was an outstanding effort. Best of all the elevation was probably 5 bullet holes high. He will be tough to beat in the queens we have coming up in a fortnight. My rifle that shot really well had a SD of 18. Im not happy with that, but I am happy with the way it shot. Quite often I have found a really flat shooting load at long range has poor SD and ES and have dismissed the figures a bit until recently. X ring elevation at 900m is very very good but we need repeatable velocities to maximise our chances of doing well. With those numbers I will be working a little to get that down under the 10 or lower area. Another guy shot nice flat elevation and for a 5 shot string (not really reliable as 10 or 15 shot strings are better but its all the ammo he had left) was a SD of 3. For long range shooting, its imperative that we keep the spreads and deviations down as low as possible. Shame we didnt get to test the 243AI for SD as I believe it would have been very good also.
For a varmint gun I personally wouldnt bother with mucking around with chronys aside from a quick velocity check. As long as it can put 3 shots into a cloverleaf at 100m Im generally happy with it.
My mate left his MS2 here for me to tune my gun with a bit more this week, and Im rather stoked with that! Got to get myself one as they are fast becoming the benchmark chrony around the world to work with. Accurate and can be used any time of the day without needing constant light conditions.
- mick_762
- 50 BMG
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Re: Reasonable velocity spread
Just bit the bullet so to speak, and bought the Magnetospeed V1, couldnt really justify the extra for the V2.
BUT, it was only $288 US delivered.
Fuck paying the prices the Aussie dealer wants, they are a bloody rip off.
Series 2 was $375 US, dealer wants AU$495.
BUT, it was only $288 US delivered.
Fuck paying the prices the Aussie dealer wants, they are a bloody rip off.
Series 2 was $375 US, dealer wants AU$495.
- Camel
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Re: Reasonable velocity spread
mick_762 wrote:Just bit the bullet so to speak, and bought the Magnetospeed V1, couldnt really justify the extra for the V2.
BUT, it was only $288 US delivered.
Fuck paying the prices the Aussie dealer wants, they are a bloody rip off.
Series 2 was $375 US, dealer wants AU$495.
Thanks for that Mick, answered the question that I haven't even asked yet. Whats the diff between V1 and V2, thanks. Not talking WW2 German missiles here.

- mick_762
- 50 BMG
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Re: Reasonable velocity spread
Camel,
From what I could understand, the V2 has updated sensors but is more designed for large barrel thickness (Over 1"), large muzzle Breaks and Suppressors.
Mick
From what I could understand, the V2 has updated sensors but is more designed for large barrel thickness (Over 1"), large muzzle Breaks and Suppressors.
Mick
- Camel
- Ultimate AusVarminter
- Posts: 12084
- Joined: Sat May 28, 2011 8:51 pm
- Favourite Cartridge: 20-222 6x47 rem, 250
- Location: Northern Riverina NSW
Re: Reasonable velocity spread
mick_762 wrote:Camel,
From what I could understand, the V2 has updated sensors but is more designed for large barrel thickness (Over 1"), large muzzle Breaks and Suppressors.
Mick
Thanks mate, onya

Re: Reasonable velocity spread
hi CZ, Some many years ago i thought that the Chrony was the thing that would make a good deal of difference in getting great groups .. I was badly mistaken , my guns for some years now have been known to produce vertical dispersion on a competition target at 1000yds of between 2inch and 3 inches for the whole 10 shots .. If you take the best recorded when shot at these 1K targets while using a chrono of approx 19 to 21 fps, the targets Should have had a larger dispersion than what actually occurred.. The reason is that i use barrel compensation results in my tuning process .. Please don't believe all that you read in regards to ES variations as the only way of looking at getting the best from your rifle, because it is in fact not just mathematics you need to consider ..JR.. Jeff Rogers
CZ550 wrote:G'day All,
Just spent a little time putting a few of the rifles and handloads through their paces over a F1-Chrony this weekend. There were some suprising (and disappointing) results there that's for sure.
I would just like to know - what do you deem as acceptable velocity spread on handloaded rounds? I was getting up to 55fps variance over a number of shots.
Thanks,
CZ550
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- .17 HMR
- Posts: 164
- Joined: Wed Jun 24, 2009 7:36 am
- Favourite Cartridge: .243 Win
- Location: SA
Re: Reasonable velocity spread
Thanks guys,
Some great words of wisdom there. I really just wanted to run my favorite loads over the Chrony to see what velocities they were roughly doing. Given that I'm really happy with the accuracy of the loads at the moment, I won't feel too dismayed at the velocity spreads seen.
Regards
CZ550
Some great words of wisdom there. I really just wanted to run my favorite loads over the Chrony to see what velocities they were roughly doing. Given that I'm really happy with the accuracy of the loads at the moment, I won't feel too dismayed at the velocity spreads seen.
Regards
CZ550