Determining velocity without a chronograph?

[DaveA37]

There are many very learned people on this board with much greater knowledge than I that may be able to shed light on my "pondering". Here's the sernio,

First, I do not have a chronograph. I got to wondering if there was a way to determine approximate velocity of a particular load WITHOUT the use of a chorny.

I'm using my Remington 700 with 280 Rem. cartridges and 140 gr. Accubonds bullets pushed by 54.5 gr of 4381 and WLR primers. I am getting (IMO) very good groups under .8 thus far

Anyone care to take a stab?

DaveA37

 

[Oldtrader3]

That is a light load, Dave. I am guessing that you are getting about 2750 fps with that load. If you believe the Ballistic Coefficient that Nosler publishes for this cartridge, you can get a fair estimate of velocity by duplicating their scope height, and measure actual drop for the geometric center of a group shot at 200 yards (or longer). Further is better and if you can go 300 yards, accuracy will be higher.

The equations for calculating drop are in your loading manual or you can just look up the drop at any yardage in the tables at the back of the loading manual. Find a table with drop that matches your actual measurents and voila! you have velocity numbers already calculated by computer.

 

[DrMike]

You can estimate velocity by measuring bullet drop, but you cannot determine velocity without a chronograph.

 

[JD338]

Dave,

You need a chronograph to clock your loads.
Although your light load shoots good, you should work up and see what it will do. It might shoot even better.

JD338

 

[FOTIS]

Only way I know is Quick load and that is only a prediction.

Get yourself a chronograph and call it a day...\

http://www.midwayusa.com/product/113204 ... hronograph

http://www.ebay.com/itm/Shooting-Chrony ... 2ec253527f

 

[Teknys]

If you are just "curious" then estimating by the methods already discussed will get you only an "estimate". Then that's ok.

Here is some "ifs" to consider:

If you are going to push loads you should really have a chrono to help you be safe. Knowing what would be over the top on speed and stopping if you get there to really check for signs of pressure and proceed slowly from there.

If any of your shooting is for accuracy (repeatable accuracy) then the chono can check your reloads by the deviation of velocity of a round of shots. IF your velocity is all over the place then review your reloading process to find where the variation is coming from.

If you are at all going to shoot longer distances where you will need to calculate the drop, it can not be done with out a chrono and knowing the avg velocity of the first shot from a cold barrel.

Yea - a chrono in my opinion is a must, a great tool.

 

[Oldtrader3]

This is certainly true. I use a chronograph for load development assiduously, because it tells me what I need to know in absolute terms and with science to back it.

 

[Guy Miner]

Dave - I've enjoyed the heck out of my chronograph. A CED Millenium:

http://www.cedhk.com/shop/products/CED- ... h-Set.html

Also believe that I've learned a lot more about handloading and the performance of various cartridges. Can't say that I've ever regretted getting one.

On the other hand, I hunted, shot and handloaded for many years without one, and did just fine. One thing I've noticed is that there has been a strong correlation between the velocity of loads published in the various manuals, and what I'm actually getting out of my hunting rifles.

An exception being some of the RL-22 loads Nosler has published - doggone they're getting some velocity! Must have been a great lot of RL-22, because as a rule, my rifles fall a little short of those velocities.

Otherwise though, my .308 and .30-06 sure track pretty well with the velocity predicted by Speer, Sierra, Nosler and Hodgdon... Your rifle might be different, but I'd put some confidence in the "book" velocity being at least close.

If you're getting good accuracy, and the trajectory is something you can live with afield, that's good enough to take a lot of game under a lot of conditions. The chronograph is just another tool, and a very useful one.

Guy

 

[bullet]

My signature says it all :mrgreen:

 

[SJB358]

There are many very learned people on this board with much greater knowledge than I that may be able to shed light on my "pondering". Here's the sernio,

First, I do not have a chronometer. I got to wondering if there was a way to determine approximate velocity of a particular load WITHOUT the use of a chorny.

I'm using my Remington 700 with 280 Rem. cartridges and 140 gr. Accubonds bullets pushed by 54.5 gr of 4381 and WLR primers. I am getting (IMO) very good groups under .8 thus far

Anyone care to take a stab?

DaveA37

What 4831? IMR or H?

 

[SJB358]

Dave - I've enjoyed the heck out of my chronograph. A CED Millenium:

http://www.cedhk.com/shop/products/CED- ... h-Set.html

Also believe that I've learned a lot more about handloading and the performance of various cartridges. Can't say that I've ever regretted getting one.

On the other hand, I hunted, shot and handloaded for many years without one, and did just fine. One thing I've noticed is that there has been a strong correlation between the velocity of loads published in the various manuals, and what I'm actually getting out of my hunting rifles.

An exception being some of the RL-22 loads Nosler has published - doggone they're getting some velocity! Must have been a great lot of RL-22, because as a rule, my rifles fall a little short of those velocities.

Otherwise though, my .308 and .30-06 sure track pretty well with the velocity predicted by Speer, Sierra, Nosler and Hodgdon... Your rifle might be different, but I'd put some confidence in the "book" velocity being at least close.

If you're getting good accuracy, and the trajectory is something you can live with afield, that's good enough to take a lot of game under a lot of conditions. The chronograph is just another tool, and a very useful one.

Guy

Same boat as Guy..

Yeah, they must have had a super lot of RL22.. There is nothing that ever came close to the speeds they got..

 

[FOTIS]

What 4831? IMR or H?

+1

 

[Oldtrader3]

They do get velocity in the Nosler loaded ammo. My .257 Roberts with the 110 AB's clocks at nearly 3100 fps. That is really fast for a Bob with 110 bullets!

 

[clearwater]

The old Sharp handbook told how to calculate velocity using sound waves.

Also you can use your computer and a metal gong at a known distance to record the sounds and
the difference in time between firing and the time the gong's sound returns
and calculate the velocity. You need to know the altitude/air pressure. I compared a guy doing
this with my chrono and it was very close- within 25 feet per second.

 

[Oldtrader3]

Count seconds times 1125 feet per second at normal temperature and atmosheric pressures. Same as for lightning.

 

[DaveA37]

What 4831? IMR or H?

IMR 4831

The groups I'm getting seem to be fine out to 250 yards (don't have any more distance to try). Will see if I can do some work on this rifle/load when I get out to Wyoming where I can shoot for 2-3 miles.

Thanks for the help thus far.

Dave

 

[Antelope_Sniper]

I've seen velocities suprise by 300+ fps more then once.
Without a chronograph is just a guess. For $100.00 it's a good investement for any handloader.

 

[SJB358]

Here is some QL data.. This is what they project.

Cartridge : .280 Rem.
Bullet : .284, 140, Nosler AccuBond 59992
Useable Case Capaci: 60.112 grain H2O = 3.903 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : IMR 4831

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 92 49.05 2616 2128 40490 10608 96.8 1.291
-09.0 93 49.60 2645 2175 41810 10723 97.2 1.272
-08.0 94 50.14 2674 2223 43173 10833 97.5 1.252
-07.0 96 50.69 2703 2271 44579 10940 97.9 1.234
-06.0 97 51.23 2732 2320 46031 11042 98.2 1.215
-05.0 98 51.78 2761 2369 47530 11141 98.5 1.197
-04.0 99 52.32 2789 2419 49077 11234 98.7 1.179
-03.0 100 52.87 2818 2469 50674 11324 99.0 1.162
-02.0 101 53.41 2847 2519 52323 11408 99.2 1.144
-01.0 102 53.96 2875 2570 54027 11488 99.4 1.128
+00.0 103 54.50 2903 2621 55786 11563 99.6 1.111 ! Near Maximum !
+01.0 104 55.05 2932 2672 57604 11632 99.7 1.095 ! Near Maximum !
+02.0 105 55.59 2960 2724 59483 11697 99.8 1.079 ! Near Maximum !
+03.0 106 56.14 2988 2776 61424 11756 99.9 1.063 ! Near Maximum !
+04.0 107 56.68 3016 2828 63430 11810 100.0 1.048 ! Near Maximum !
+05.0 108 57.23 3044 2881 65505 11858 100.0 1.033 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 103 54.50 3030 2854 67111 11144 100.0 1.026 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 54.50 2723 2305 44762 11430 94.9 1.224

 

[Oldtrader3]

Man, those .280 Rem chambers must be all over the place! Given that this cartridge is .050 longer headspace than the .30-06. My Browning A-Bolt could easliy handle 55.0 grs of IMR4350 with W-W brass and the 140 gr Partition bullet. Coincidentally this is the same load that I use with the .270 (55.0 grs IMR 4350) and the 130 Partition which has the same sectional density and a shorter chamber.

This 140 gr Partition , .280 load chrono'ed at 2935 in my Browning 22 inch barrel with absolutely no pressures signs and rounded primers. Considering that I could beat this velocity with the 160 AccuBond at 3010 fps makes me wonder just how fast a 140 gr bullet can really go in the .280 Rem chamber if really pushed to SAAMI .270 pressures? However, I no longer have my .280 Browning rifle to test. Just musing out loud?

 

[SJB358]

Here is what QL says, loaded to 63K PSI and with a 22" barrel..

Cartridge : .280 Rem.
Bullet : .284, 140, Nosler PART SP 16325
Useable Case Capaci: 61.982 grain H2O = 4.024 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 22.0 inch = 558.8 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 63000 psi, or 434 MPa
or a maximum loading ratio or filling of 110 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

138 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Norma MRP 107.1 63.9 4.14 3133 98.9 63000 14079 1.028 ! Near Maximum !
Vihtavuori N560 108.8 63.5 4.11 3115 95.9 63000 14166 1.026 ! Near Maximum !
Accurate MAGPRO 109.0 66.2 4.29 3101 94.3 63000 14145 1.031 ! Near Maximum !
Alliant Reloder-22 109.1 63.0 4.08 3098 97.8 63000 13747 1.031 ! Near Maximum !
Bofors RP5/NP ~approximation 109.1 63.0 4.08 3098 97.8 63000 13747 1.031 ! Near Maximum !
Raufoss RA15 109.1 63.0 4.08 3098 97.8 63000 13747 1.031 ! Near Maximum !
IMR 7828 SSC 107.0 62.8 4.07 3095 96.3 63000 13703 1.019 ! Near Maximum !
ADI AR 2213 107.9 62.3 4.04 3078 96.1 63000 13536 1.019 ! Near Maximum !
Ramshot Magnum 110.0 67.3 4.36 3075 96.4 61312 13830 1.032 ! Near Maximum !
SNPE Vectan SP 12 110.0 67.1 4.35 3065 96.3 60698 13774 1.037 ! Near Maximum !
PB Clermont PCL 517 110.0 67.1 4.35 3059 96.1 60343 13770 1.040 ! Near Maximum !
Somchem S365 103.0 58.5 3.79 3058 100.0 63000 12006 1.042 ! Near Maximum !
Ramshot Hunter 100.9 59.6 3.86 3053 99.4 63000 12818 1.036 ! Near Maximum !
ADI AR 2209 104.8 59.6 3.86 3052 97.5 63000 12976 1.023 ! Near Maximum !
Rottweil R905 110.0 62.4 4.04 3052 95.8 62716 13250 1.034 ! Near Maximum !
Alliant Reloder-17 93.0 55.8 3.61 3052 100.0 63000 12165 1.025 ! Near Maximum !
Alliant Reloder-19 105.5 60.3 3.91 3051 97.6 63000 13067 1.030 ! Near Maximum !
Hodgdon H414 95.4 57.6 3.73 3050 98.9 63000 12829 1.038 ! Near Maximum !
Winchester 760 95.4 57.6 3.73 3050 98.9 63000 12829 1.038 ! Near Maximum !
Bofors RP14 ~approximation 106.2 60.7 3.93 3044 97.6 63000 12967 1.031 ! Near Maximum !
Norma URP 100.5 56.8 3.68 3037 99.9 63000 12354 1.042 ! Near Maximum !
Bofors RP19 ~approximation 100.5 56.8 3.68 3037 99.9 63000 12351 1.042 ! Near Maximum !
Vihtavuori N550 97.6 57.0 3.69 3035 99.9 63000 12488 1.047 ! Near Maximum !
Winchester WXR 110.0 62.2 4.03 3034 96.9 58966 13536 1.062 ! Near Maximum !
Accurate 4350 104.3 57.0 3.69 3033 100.0 63000 12342 1.058 ! Near Maximum !
Norma 204 99.9 59.0 3.82 3026 97.4 63000 12705 1.032 ! Near Maximum !
Raufoss RA4 103.2 59.0 3.82 3026 97.4 63000 12705 1.032 ! Near Maximum !
Bofors RP4 ~approximation 103.2 59.0 3.82 3026 97.4 63000 12705 1.032 ! Near Maximum !
IMR 4831 105.5 57.7 3.74 3019 100.0 63000 12098 1.050 ! Near Maximum !
Ramshot BigGame 93.8 55.3 3.59 3018 100.0 63000 11903 1.041 ! Near Maximum !
Hodgdon H4831 SC 106.5 61.5 3.98 3018 95.5 63000 12730 1.028 ! Near Maximum !
SNPE Vectan SP 11 93.9 55.4 3.59 3017 100.0 63000 11887 1.041 ! Near Maximum !
Somchem S385 105.7 61.0 3.96 3016 98.4 63000 12553 1.049 ! Near Maximum !
IMR 4895 90.6 51.8 3.36 3007 100.0 63000 11793 1.047 ! Near Maximum !
Bofors RP4 NT ~approximation 100.8 58.5 3.79 3006 98.7 63000 12340 1.043 ! Near Maximum !
ADI AP 2214 110.0 65.2 4.23 3002 95.4 59425 13142 1.046 ! Near Maximum !
Hodgdon Hybrid 100V 103.2 57.0 3.70 3000 100.0 63000 11398 1.041 ! Near Maximum !
Raufoss RA11 91.5 52.3 3.39 3000 100.0 63000 11763 1.047 ! Near Maximum !
Alliant Reloder-15 91.5 52.3 3.39 3000 100.0 63000 11763 1.047 ! Near Maximum !
Bofors RP11 ~approximation 91.5 52.3 3.39 3000 100.0 63000 11763 1.047 ! Near Maximum !
Winchester Supreme 780 103.7 62.5 4.05 3000 97.4 63000 12361 1.034 ! Near Maximum !
Norma 203B 91.9 52.5 3.40 2997 100.0 63000 11661 1.048 ! Near Maximum !
Hodgdon H4831 110.0 61.1 3.96 2995 95.1 61457 12644 1.040 ! Near Maximum !
IMR 7828 110.0 61.1 3.96 2994 94.9 56807 13330 1.069 ! Near Maximum !
Rottweil R904 103.9 58.6 3.79 2992 96.4 63000 12332 1.034 ! Near Maximum !
Hodgdon H380 92.7 54.1 3.51 2992 99.8 63000 11904 1.051 ! Near Maximum !
Lovex S070 100.0 56.5 3.66 2992 99.0 63000 12163 1.051 ! Near Maximum !
Hodgdon H4350 102.7 57.4 3.72 2990 98.4 63000 12086 1.037 ! Near Maximum !
IMR 4350 100.8 57.3 3.71 2989 98.5 63000 12067 1.037 ! Near Maximum !
Bofors RP5 NT ~approximation 110.0 64.1 4.15 2987 93.0 60029 12987 1.047 ! Near Maximum !
Bofors RP7 NT ~approximation 94.7 54.6 3.54 2987 99.1 63000 11796 1.025 ! Near Maximum !
Norma 203 old 93.1 53.8 3.49 2986 100.0 63000 11474 1.061 ! Near Maximum !
IMR 4320 93.4 52.5 3.40 2985 100.0 63000 11340 1.034 ! Near Maximum !
Rottweil R903 95.2 53.8 3.49 2981 100.0 63000 11392 1.061 ! Near Maximum !
Somchem S355 95.4 53.3 3.45 2976 100.0 63000 11390 1.055 ! Near Maximum !
Lovex S065 98.8 55.2 3.58 2971 99.6 63000 11752 1.051 ! Near Maximum !
Rottweil R907 97.6 54.7 3.55 2970 98.4 63000 11915 1.046 ! Near Maximum !
IMR 4007 SSC 94.5 54.8 3.55 2969 98.4 63000 11906 1.046 ! Near Maximum !