View Full Version : reloading fps question.
texasgunhand
03-10-15, 22:23
In your reloading manual they list FPS for starting and max loads. Does anyone know if thats at the muzzle or at what distance they measure at. I bought ammo and ballistics 5 book that list pretty much every factory load for all calibers out to 1000 yrds. Very interesting i was wondering what factory ammo flys at for my rifles now i can just look it up,kind lets me know what fps i want to get to etc.
its muzzle velocity
so long as your rifle has the same barrel length and twist rate as the test barrel you will be pretty close
I don't put much stock in those velocities. They're anywhere from mild to wildly overstated depending on the source. Plus, they often don't disclose the barrel length, which as I understand it, is often 24" test barrel.
waveslayer
03-11-15, 09:13
In your reloading manual they list FPS for starting and max loads. Does anyone know if thats at the muzzle or at what distance they measure at. I bought ammo and ballistics 5 book that list pretty much every factory load for all calibers out to 1000 yrds. Very interesting i was wondering what factory ammo flys at for my rifles now i can just look it up,kind lets me know what fps i want to get to etc.
Like they stated above, not very accurate if you are shooting a different barrel, brass even, primer, etc.. get a Chrono and document your results. The manuals are just starting points
People will tell you to be careful of load data/chrono data on the forums... but if you search around or ask here, there's almost no bad or dangerous data that I've seen posted by anyone.
texasgunhand
03-11-15, 12:28
I got the book at cabellas. It list 190 calibers. And 2500 different loads all factory. List barrel length,twist rate etc.
I know it cant be totally accurate becouse of to many variables , heat,humidity etc.
But it lets me know what say is the speed of an american eagle 115gr. 9mm as a starting point.
Its pretty interesting reading,if you wanted some info on factory loads.
The name is Ammo & ballistics 5 by Bob Forker.it list bullets drop , wind drift etc out to 1000 yrds if possible. List barrel length and twist rates ,saami maximum Pressure with the copper crush and transducer methods most barrel lengths are 24 but twist rates are different etc. I do wish the .223 was outa a 16 inch barrel but its just fun reading.
Thanks for you replies, I am looking into getting a crono. I need do to some research to see whats a good one without spending a ton of money..
I've got a copy of that book (e-book format). It is a good thing that you have that data for reference. It will become even more valuable if you do get yourself a chronograph like you seem to be thinking of doing.
If it helps with your decision, I use a ProChrono Digital from Competition Electronics. It was inexpensive (~$100) and is easy to use, which makes is a home run in my book.
waveslayer
03-11-15, 14:03
Get the Magnetospeed, worth every penny and is more accurate than majority of Chronos out. Get 3 friends together and go in on it. I did and so far no issues
The newer Magnetospeeds that clip onto pic rails and handgun dust cover rails are really cool. I have the straight barrel mount Gen 1 or whatever. So no SBR or Pistol Chrono with my unit.
waveslayer
03-11-15, 15:39
The newer Magnetospeeds that clip onto pic rails and handgun dust cover rails are really cool. I have the straight barrel mount Gen 1 or whatever. So no SBR or Pistol Chrono with my unit.
I attach mine to my rail on my SBR, works even better because no POS.
A reloading manual is a general guide to load within a safe range of charge weights with a particular projectile at a specific C.O.L. I have rarely measured the exact same muzzle velocity printed in the manuals when developing loads. I have seen different muzzle velocities from two bolt action rifles of different makes with the same barrel length. I have also seen the same weight and profile projectiles from two different manufacturers differ in muzzle velocity as well. Temperature, humidity, internal volume of brass and bullet composition are just a few factors that affect muzzle velocity. Unless you have identical equipment and conditions, your muzzle velocity will most likely vary from printed data.
Another factor that will affect muzzle velocity is age of powder. I am not referring to decomposing powder, but the difference in composition of the same brand name of powder. I had older reloading manuals published by powder manufactures that had recipes that were different for a particular powder when compared to newer manuals. A person who worked in the industry once told me that the same powder of different lots would perform differently, because it had "different octane." That is why ammunition manufacturers test powder frequently.
I recently finished using powders I had since the mid 1990's and used the manufacturers reloading manuals printed from that era. Newer manuals had different recommended charge weights. Once the old powders were gone, I tossed the manuals, because I believe the old load data does not apply to newly manufactured powders.
A reloading manual is a good guide to start load development safely, but a lot of variables can produce muzzle velocities that differ with reloading manuals when loading published charge weights. If anyone recommends a charge weight below the minimum published recommended charge weight, be very careful.
When you can afford a decent chronograph, it is worth it's weight in gold when developing precision ammunition. It is also handy to ensure you are meeting appropriate power factors when reloading for shooting sports.
If an experienced, trusted, reloader gives you a recipe it can save you a lot of time and money. As long as the load falls within the range of published safe loads, I'll try recipes for rifle and handgun that I have seen on M4C and other sites, but I verify the recommended load through the reloading manuals before trying the load. You have to be careful.
rcoodyar15
03-11-15, 17:02
Get the Magnetospeed, worth every penny and is more accurate than majority of Chronos out. Get 3 friends together and go in on it. I did and so far no issues
I have a shooting croney with the printer and everything. It works great but when you are shooting at a public range you have to get it all set up when the range is cold and if you need to adjust something then you are waiting once again for the range to go cold. It is a real PITA.
Just got my magnetospeed V3 from the UPS man. Looking forward to using it.
Now the one caviat to using the magnetospeed is it can change your POI much like a barrel tuner would. I only plan to use it during load development to establish what my actual velocities are. Wouldn't reccomend sighting in or shooting groops with it in place.
I have a shooting croney with the printer and everything. It works great but when you are shooting at a public range you have to get it all set up when the range is cold and if you need to adjust something then you are waiting once again for the range to go cold. It is a real PITA.
Just got my magnetospeed V3 from the UPS man. Looking forward to using it.
Now the one caviat to using the magnetospeed is it can change your POI much like a barrel tuner would. I only plan to use it during load development to establish what my actual velocities are. Wouldn't reccomend sighting in or shooting groops with it in place.
If you see differences in muzzle velocity measurements for the same load between the magnetospeed and a standard chronograph, please let us know. That would be useful information. Bear in mind that when shooting through the sky screens at a chronograph positioned 15 feet from the muzzle you have to correct for distance.
waveslayer
03-11-15, 17:17
If you see differences in muzzle velocity measurements for the same load between the magnetospeed and a standard chronograph, please let us know. That would be useful information. Bear in mind that when shooting through the sky screens at a chronograph positioned 15 feet from the muzzle you have to correct for distance.
You will only see a 2.5-3.5 fps difference roughly at 15' from the muzzle not much to worry about. But with the two chrono's side by side watch for larger deviations in muzzle velocity like 10 fps or so, as an example. I tested mine and I had a lot of inconsistencies using my F1 at 15'. Using the Magnetospped I had mostly 1-8 fps SD for all my loads. I hand load all of my precision ammo so now I feel better knowing I'm in the single digits with my SD u like the poor results I was getting from my F1. In addition to the sewed results when you have a guy shooting next to you
You will only see a 2.5-3.5 fps difference roughly at 15' from the muzzle not much to worry about. But with the two chrono's side by side watch for larger deviations in muzzle velocity like 10 fps or so, as an example. I tested mine and I had a lot of inconsistencies using my F1 at 15'. Using the Magnetospped I had mostly 1-8 fps SD for all my loads. I hand load all of my precision ammo so now I feel better knowing I'm in the single digits with my SD u like the poor results I was getting from my F1. In addition to the sewed results when you have a guy shooting next to you
I have a light target load for a rifle that measures an average velocity of 1801 fps at 15 feet from the chronograph. When calculating true muzzle velocity with RemShoot software, it indicates the muzzle velocity is 1845 fps. I have tested other loads that RemShoot calculated at greater differences in muzzle velocities.
As a point of reference - military ammo mfr's like LC measure their ammunition for muzzle velocity at 78 ft from the muzzle.
waveslayer
03-11-15, 17:39
As a point of reference - military ammo mfr's like LC measure their ammunition for muzzle velocity at 78 ft from the muzzle.
That's out there, they might as well as go 100 yards and at the muzzle to get a real BC. Too bad the Labradar only works out to 100 yards "technically" if the could make it so you can set it up 1 at the muzzle and 1 at 300 yards would be sweet!
I ran my Magneto against Pappabears (the one Masan mentioned, I think) and it reconciled pretty good.
As a point of reference - military ammo mfr's like LC measure their ammunition for muzzle velocity at 78 ft from the muzzle.
I read that 78 feet was their standard, but use 15 feet which gets me just beyond the muzzle blast.
At 78 feet I might hit my chronograph. :D
Most chronographs (standard type) will give much more accurate readings if you tape a piece of plain white paper to the diffusers.
waveslayer
03-12-15, 15:46
Most chronographs (standard type) will give much more accurate readings if you tape a piece of plain white paper to the diffusers.
Or install some cheap LED lights to them, that works well and enables you to shoot in all lighting conditions
interesting read in regards to chronographs http://appliedballisticsllc.com/Articles/ChronographChapter.pdf
this is from Brian Litz, and the whole book is a good read for anyone who wants to shoot long range
waveslayer
03-12-15, 16:24
interesting read in regards to chronographs http://appliedballisticsllc.com/Articles/ChronographChapter.pdf
this is from Brian Litz, and the whole book is a good read for anyone who wants to shoot long range
Awesome read
interesting read in regards to chronographs http://appliedballisticsllc.com/Articles/ChronographChapter.pdf
this is from Brian Litz, and the whole book is a good read for anyone who wants to shoot long range
That is a great link. A chronograph comparable to mine showed an error of 25-50 fps low, which coincides with my experiences. When using RemShoot to correct for distance from muzzle to skyscreen, the author's conclusions are definitely on point.
waveslayer
03-12-15, 17:40
That is a great link. A chronograph comparable to mine showed an error of 25-50 fps low, which coincides with my experiences. When using RemShoot to correct for distance from muzzle to skyscreen, the author's conclusions are definitely on point.
Yep the man, the myth, the legend... Bryan Litz seems to know his business! Nice thing about the Magneto speed that he even mentioned was the zero need to have any light to use it. I have used it for some night shooting to get some good data and DOPE
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