Long Range Hunting Online Magazine

Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Berger Bullets


Using chronograph data to determine the best load????

LinkBack Thread Tools Display Modes
Unread 12-29-2005, 02:59 PM
Gold Member
Join Date: Feb 2005
Posts: 563
Re: Using chronograph data to determine the best load????

Okay, back from the range, muddy boots and all... [img]/ubbthreads/images/graemlins/frown.gif[/img] [img]/ubbthreads/images/graemlins/laugh.gif[/img]

Folks, I can't tell any difference. That doesn't mean that there isn't some difference--just that with the handloads and factory loads I was shooting, the ES would appear to eclipse any actual difference in free recoil velocity versus firmly held velocity.

Now. There's an additional surprise which we can chew up another gross of pencils over which I'll save for the end of this post... [img]/ubbthreads/images/graemlins/smile.gif[/img]

I first shot a little Model 34 Smith & Wesson .22LR (revolver), with a 4" barrel. Checked six shots (CCI Stingers), three with firm hold, three with as loose a hold as I could manage and still pull the trigger.

FH = Firm Hold, and FR = Free Recoil:

Average velocities...

Then I shot a 1911A1 45 ACP, using 230 grain surplus ball ammo. For the FR shots, I just put the butt of the pistol on a sandbag and used my thumb to compress the grip safety and my index finger to squeeze the trigger (yeah, don't try this at home!)... ES's were bad, but here are the averages of ten shots firm, ten loose...


For the record, one shot of the FH went 801 fps, and one shot of the FR dropped to 693. These two numbers pulled the averages pretty close. If I count those two odd shots out, it looks like:

FR...787 [img]/ubbthreads/images/graemlins/smile.gif[/img]

On to the rifles. These were shot off a bench, and for free recoil I just used my thumb behind the trigger guard and my index finger pulled the trigger.

On my pre64 Model 70 Winchester in .270 win. Load was 60.0 grains of Accurate Magpro with Sierra 150 grain Gameking:

FR...2772 [img]/ubbthreads/images/graemlins/smile.gif[/img]

6.5 x 55 Swedish Mauser, M38 Oberndorf. Load was 46.3 grains RL22 and Sierra 142 grain Matchking.

FR...2537 [img]/ubbthreads/images/graemlins/smile.gif[/img]

Please consider that this info is probably worth about what I charged you for it. But from what I saw today, when I was actually trying to figure out the effect of loose or firm hold on velocity, I have to recant my previous assertion that velocity can change all that much based on how firmly the gun is held. In fact, the crude little test I did today would seem to indicate that free recoil increases velocity as often as it decreases it--but I'm sure that's just a fluke...

I would still like to see some numbers from some other members who may take time to try this little experiment out next time they go to the range. There may be particular scenarios (certain gun, certain cartridge) where there is a more noticeable difference. I'm not at all familiar with the double rifles Bart mentions, so I can't really offer anything there...

Okay. For the surprise I mentioned earlier...

Why doesn't the POI on target change noticeably between FH and FR? It's supposed to. Everybody always says it will. [img]/ubbthreads/images/graemlins/confused.gif[/img] Granted, none of the rifles I tested today were shooting BR sized groups, but both were printing about 1.5 MOA with the loads I brought along. Holding at the same bullseye during free recoil seems to land the shots right in the group--even though the rifles were thrusting backward a good three feet (into my cousin's hands, who was standing behind the bench to catch the rifles during FR firing). I would have thought that POI would have been significantly different with FH versus FR. I would have to assume that with bug-holing BR rifles, the POI shift is more noticeable at 100 yards... But I'm glad no one asked me how that would have turned out before I did my little test today.

I would have been wrong twice! [img]/ubbthreads/images/graemlins/blush.gif[/img] [img]/ubbthreads/images/graemlins/laugh.gif[/img]

In any event, it appears that I was wrong once, so here I go... [img]/ubbthreads/images/graemlins/laugh.gif[/img]

Reply With Quote

Unread 12-29-2005, 03:06 PM
Platinum Member
Join Date: Jun 2005
Location: Yakima, Washington
Posts: 3,832
Re: Using chronograph data to determine the best load????GonHuntin


This is all very interesting but I think the original post has been forgotten, even though the results have been very interesting.

Remember that if you look at what buffalobob said you will easily see that free recoil would have only the weight of the rifle to resist rearward movement. Adding the shooters body, no matter how firm the hold, adds the weight of the body to that of the gun to resist rearward movement. The result would be that the rearward movement of the gun would be less with the body in the way but the velocity at which the gun moves to the rear is very minute compared to the speed at which the bullet travels forward.

Simply put, the bullet accelerates so fast that it is out the end of the barrel before the gun has moved very far at all. This is proven by the fact that muzzle brakes work. The bullet, and the gas that is moving the bullet, get to the muzzle and the gasses and pressure interact with the brake before the mass of the gun has moved much, if any. This allows the brake to work.

This is probably why Dan didnít see the changes in POI that he expected to. Yes the free recoil guns moved a long ways back but I would think that the bullet was out of the barrel before much, if any, of the rearward movement of the gun had occurred.

What does all of this have to do with GonHuntinís original post? Nothing but itís interesting.

GonHuntin, I use a chronograph for every round I fire during load development and testing. This doesnít make it right or wrong, itís just that I want all available data I can get my hands on to make my decisions. I do not develop loads based solely on the chronograph data, my main goal is to develop the most accurate load I can. Drops are easy to figure, but itís really hard to hit anything at extended ranges with a fast, but inaccurate load.

Most of the time you are not going into load development blind. By that I mean that you are probably loading a cartridge/bullet/powder/primer combination that someone else already has used. You probably have data for that load. You are simply starting at a safe level and working up to an area that is known to be maximum under certain conditions, looking for the most accurate combo in your gun.

I use the ladder method and find it works best for me. I start low and work up. I hope to find one or more ďnodesĒ somewhere in the test that indicates to me that the gun ďlikesĒ that combination. Every round I fire is documented and goes into my notes. I also make notes of all pertinent field conditions every time I shoot. This is invaluable later on when you go from cold to hot conditions etc.

I also check for pressure indicators with every round fired. This is very important and combined with the other data you collect helps with what you are trying to accomplish. Just remember that with a custom action and quality brass, like Lapua, pressure signs may occur later than what you are used to seeing. Some primers will indicate different than others, some brass handles pressure better than others. Donít just keep increasing the loads and dropping the hammer. Be careful and analyze everything you know and everything you are being presented with.

I would expect to see the velocities climb as I increase the loads, but remember itís normal to see a round with an increased charge produce a lower velocity than the previous round fired in a ladder test. This is due to the ES that the different loads would produce. One load might show a velocity at the upper range of itís normal group ES and the other might show a velocity at the lower range of itís normal group ES.

I look for any velocity changes out of the normal. I donít expect to see the velocities start to drop and I donít expect to see a drastic jump in velocity that doesnít follow what has been occurring with the load increases so far. Remember you are probably working with a combo that has already produced a known velocity. You are just being careful and working up to an accurate, safe load in your gun.

At this point you canít be concerned with ES or SD because you are only firing one round per charge. You are simply trying to find the place where your gun seems to group 2 or 3 loads very closely. Later I take the loads in the nodes I have detected and load up several groups of each, in smaller increments, to try and find one that runs in the center of that node and is the most accurate in my gun. I am still concerned mostly with accuracy and am not looking for the best ES or SD.

When you get to this point and start testing, say at 100 yards and find a load that produces the best accuracy, you may find that it isnít the one with the best ES or SD. This quite often is the case as itís not written in stone that the lowest ES and SD will always produce the most accurate loads.

You then need to test your most accurate load at extended ranges. If I find a load that seems to be the most accurate at 100 yards and also have another thatís not the most accurate but has a much lower ES and SD, I will then go to extended ranges and shoot not only the most accurate load at 100 yards but also the ones with the lower ES and SD. I want to find out what combination gives me the most accurate load at extended ranges, not at very close ranges. Sometimes you will be surprised to see what the most accurate load is, in your gun, at extended ranges. Some load combos will tighten up at extended ranges and some will get worse, some will track as expected at extended ranges. You wonít know without shooting them all.

Now that you have found the most accurate load for you and your conditions you can now play with seating depth, primers etc. and it goes on and on and on if you want to. Just remember to only change one component at a time and do your testing with just that one item changed. Normally, if Iím happy with the results at this point, I will only change seating depth and try some different settings. I donít really like to seat bullets to engage into the lands unless I have to. I try to find a load that lets me start with the bullet just at the lands and then I will try seating in small increments off of the lands since most of what I load for is a hunting setup. Remember, if you do your testing at the lands and then decide you want to go into the lands, you must remember that this is going to increase pressures and you must make changes accordingly. You may find that certain types of bullets like to be seated into, at, or off the lands to a certain point. How much testing you do depends on how anal and picky you are at the time.

Just remember that you should be looking for the most accurate, safe load combo for your gun under your conditions. Velocity is not the determining factor and is actually way down the list for me, but it is another valuable tool and indicator that Iím glad I have every time I put a round through the chronograph.
Reply With Quote
Unread 12-29-2005, 03:46 PM
Platinum Member
Join Date: Jun 2001
Location: Potomac River
Posts: 5,070
Re: Using chronograph data to determine the best load????


Most science comes from observation. We have all ridden around in the back of pickup trucks as kids and thrown rocks at mailboxes, road signs, any cow close to the road or anything else that struck our teenage interest. I was trying to get people to associate what they personally knew as a fact with what I was saying. And in the process keep the discussion interesting enough to read.

The reference to deer hunters in trucks is because I was so disgusted with what happened to me yesterday. Many of the back roads are frozen sheet ice and I was blackpowder hunting in a new area and decided to park my truck at the bottom of the mountain and walk up the icy road to the saddle and then hunt the sunny side of the mountain. I did not see another hunter in the woods but was constantly having to step off the dead end forest road to avoid the road hunters sliding their trucks into me as I walked along. It was a two mile walk and I got to the top and sure enough all the deer had bedded down on the sunny side of the nountain. I didn't kill any deer but it was good to get out into the woods and explore a new place.

Glad you enjoyed the discussion.

PS. 786 or who ever -- That is the greatest picture of eating crow. I have saved it so I can use it sometime.
The Smokin Fur Rifle Club
Reply With Quote
Unread 12-29-2005, 03:49 PM
Platinum Member
Join Date: Feb 2005
Location: Nevada
Posts: 2,782
Re: Using chronograph data to determine the best load????

green 788,
I for my self do appreciate your efforts, your actitude and willingess to find answers. Thank you! Bless You!

Jesus Christ the same yesterday, and to day, and for ever.

Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!!

---> As promised, God Sent His Prophet to us!
Reply With Quote
Unread 12-29-2005, 04:39 PM
Join Date: Dec 2004
Location: El Reno, OK
Posts: 1,922
Re: Using chronograph data to determine the best load????

Thanks buffalobob. I really thought this was correct but either I am just to lazy or not smart enough to put it the way you did!!!

788 and BartB,

This has been a very good discussion. I, as well as others, gained alot of respect for you and everyone invlolved. We actually behaved like adults and not 2 year olds!!

It's been fun. Great job everyone!!
Reply With Quote
Unread 12-29-2005, 05:52 PM
Gold Member
Join Date: Jan 2005
Location: Searcy, Arkansas
Posts: 700
Re: Using chronograph data to determine the best load????

Bart B.

The way I got the .00072 number is as follows. 3000fps X 12(inches in a foot)=36000 inches per second. 26 inches divided by 36000 = .00072 seconds.

Actually that number is technically incorrect, but I felt it was close enough for our discussion. You are correct that the bullet is accelerating as it travels the 26" length of the barrel. Starting at 0fps and exiting at 3000fps. So, the actual time would be more than .00072 seconds..........but not much!

Thanks for weighing in on the subject. This is what I really like about this site [img]/ubbthreads/images/graemlins/smile.gif[/img] This has been a fascinating discussion with several opinions expressed but no one started name calling. Everyone just seemed to enjoy the discussion and try to learn something. And as usual on this site someone who really knows what he is talking about steps in provides the answer.....Thanks!

I know we all got a little off topic on this one, but it sure was fun [img]/ubbthreads/images/graemlins/grin.gif[/img]
Reply With Quote
Unread 12-29-2005, 06:08 PM
Gold Member
Join Date: Feb 2005
Posts: 563
Re: Using chronograph data to determine the best load????

Definitely off topic, in more than one direction! But this has been very enlightening. The lack of a significant POI shift issue was a serendipitous discovery that I'll not forget. [img]/ubbthreads/images/graemlins/laugh.gif[/img] Amazing...

But on the velocity thing... The only thing to do was to test the idea before we took this thread to a dozen pages mulling it over. It appears that the effect is negligible--but no one seemed willing to bet the farm on that [img]/ubbthreads/images/graemlins/wink.gif[/img] until we had some actual data (crude as it may be) to pour over...

A friend of mine from Sweden has a saying, which translates to English something like "Trust your own observations rather than relying on what others tell you." That's good advice, and seemingly pertinent here.

Reply With Quote


Thread Tools
Display Modes

Similar Threads for: Using chronograph data to determine the best load????
Thread Thread Starter Forum Replies Last Post
Load data .243 Ackley varmit load please ballie Reloading 5 02-22-2011 01:49 PM
Millennium Chronograph Versus Pact MK IV Timer & Chronograph Eaglet General Discussion 10 03-31-2010 11:28 PM
How to determine "best" load for long range shooting bgordon Rifles, Bullets, Barrels & Ballistics 8 11-05-2009 01:17 PM
chronograph & load development? dewiseman Reloading 4 07-04-2009 09:12 PM
Test results from 338 ST *pics and chronograph data* Black Diamond 408 Rifles, Bullets, Barrels & Ballistics 16 04-24-2006 10:08 AM

All times are GMT -5. The time now is 10:13 AM.

Powered by vBulletin ©2000 - 2016, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2015 Long Range Hunting, LLC