3/27/10 - New 100 Yard Zero - Mixed Bag

After shooting through the chrony, I tried to reset my zero with the hand-loads on the .308.  Amazingly, I had to bring the scope up 20 clicks at 100 yards to get back to zero!  That is 20 clicks higher than the 168 gr. Black Hills 308 Match ammo.  It was very gusty at times, (about 3 p.m.) and my results were not very consistent.  I wonder if shooting the bullets so close to the ground was effecting the shots adversely.  From where I was shooting, the bullets were getting, possibly closer than 4 inches to the ground, about 20 yards in front of me.  It was making a ton of dust along the ground, which I haven't really had happening before.  I kept on shooting more than I normally would have to try to figure out if if was the wind, or interference from the ground, or just that my hand-loads are not very consistent.  I think I will be loading them hotter next time to try to get rid of some of the space inside the casings.  If you shake the bullets that I loaded last week (both the .308s and the .243s), there is more space in there than there is in the Winchester Super-X factory ammo.  I will need to compare with the Black Hills Match ammo on both the muzzle velocity and the amount of "empty space" in the casings.  As you can see, these groupings are not very good.  Some shots are okay, but overall, they are like 2 MOA groups for the most part.  I am not impressed.

3/27/10 Shooting Chrony

Today I bought a Beta Master Shooting Chrony.  I tested some of my loads and here are the results.

(In hindsight, I didn't get a large enough sample for most of these shots, so take it with a grain of salt.  The 308 group was only 3 shots, 243 group was 4 shots.  In later tests I ran 8-10 shots in the string and I think that is a better way to show actual performance.)

Savage .308 168 gr Sierra BTHP Match 42 grains IMR 4064:
     Low: 2620
     High: 2634
     Avg: 2624
     Extreme Spread: 13.69
     Standard Deviation: 7.54

Savage .308 Winchester Super X 180 Gr.
     Low: 2665
     High: 2691
     Avg: 2677
     Extreme Spread: 26.67
     Standard Deviation: 11.53

Ruger .243 Hornady 105 gr A-Max 41 grains IMR 4350:
 
     Low: 2856
     High: 2916
     Avg: 2879
     Extreme Spread: 59.19
     Standard Deviation: 26.24

Ruger .243 Winchester Super X 100 gr soft point

     Low: 3033
     High: 3077
     Avg: 3049
     Extreme Spread: 43.94
     Standard Deviation: 16.67

AR-15 .223 PMC 55 gr FMJ  ???

     Low:2722
     High2770
     Avg: 2749
     Extreme Spread: 47.99
     Standard Deviation: 18.35

3/21/10 - Wall of Fame

It speaks for itself.  These are the fruits of my labors.  Well, at least the fruits of my shooting labors over the last 6 months, give or take a few. 

3/20/10 - Reloading - Shooting the Bottoms

Today I spent the morning reloading at Dad's house.  We spent the night last night, and then later today, we went out to shoot at The Bottoms.  I loaded 100 .308s and 100 .243s.  On the .308s I used the Sierra 168 gr. match tips with 42 grains of IMR 4060 power.  I figured that would be a good starting point.  On the .234s, I used Honady A-Max 105 gr tips.  pushing the .243 bullets is 41 grains of IMR 4350.  Once I got going, it took me about 2 hours and 20 minutes to load 100 shells if I didn't trim the cases.

After loading, Dad and I drove to the Bottoms to see if it was too muddy, and to try to range out some of the distances with his car GPS.  Since it doesn't really give you accurate line of sight distances between way-points (because it is geared toward navigating streets), we went back home and tried to load those points onto his computer to figure the distance.  Well, that didn't work out too well.  We went back down with Karen and the kids and set up a target.  Using the mil-dots in my scope, I estimated the yardage to be almost exactly 500 yards.  I used data that I had for the Black Hills match ammo as a guide, and dialed 44 clicks into the scope.  It wasn't even close.  That shot was about 2 feet low.

We had a little wind coming from left to right too, so I was holding off the target to compensate for that.  Dad and Kaylee were by the target with 2 way radios calling my shots.  It was a little frustrating trying to figure out where these new handloads were hitting as far as elevation goes, but by the time I had shot 11 round, I was able to put the last 4 shots onto the paper as shown in the picture.  If I didn't have the wind messing with me, I think I would have had a very impressive grouping.  Take the two shots right by the bulls-eye for instance, and couple them with the one to the left 3 & 1/4 inches away.  That 3 shot grouping is well under 1 MOA, given the distance.  Those shots were achieved by holding clear off the cardboard to the left.  The shot to the right of the circle was one shot that I didn't notice any wind from where I was, so I held right on the bulls-eye.  After the shot, Dad told me they they still had wind at the target, hence the result.

All told, I ended up having to dial 61 clicks into the scope to get these shots.  That makes me really worried about the muzzle velocity of the bullets I loaded.  If my calculations are close, that means that I can't be getting more than about 2350 fps out of them.  That would not be good.  I really won't know until I get the rifle zero'ed at 100 yards (I didn't even attempt to do that today), and get a chronograph to shoot through.  I have really got to invest in one of those.

3/16/10 - Woman with a Gun - Kentucky Windage

The weather was so beautiful this afternoon that we decided to take a trip as a family to the range.  Karen, Kaylee, and Konnor all got to come with me to the range today.  Kaylee got to shoot a .22 LR for the first time in her life.  She liked that, but had a hard time reaching the trigger.  Karen shot the Glock too.  It's only the second or third time I remember her shooting a pistol since we have been married.  Some women wouldn't pose much of a threat to an intruder even if they had a gun.  Karen on the other hand,  well, let me put it this way; you wouldn't want to mess with her.  This is a warning to all:  she knows right where the gun is, she knows how to rack the slide to load it, and she could most definitely kill you with it!  She can put bullets on target, and she isn't timid when shooting.  She put two or three rounds in to a cup at about 17 feet, and then proceeded to unload the rest of the clip on some other target further away.  Not bad.  Not bad at all.

At the rate I am going, I will never have any bullets for the .308 (I need to reload), so I shot the cheap ammo out of the .243 again today.  I'm going to have to sit down one day and find out how much elevation I can get out of the Burris Scope that is on the Ruger, so that I can get some indication of how far out I can use the scope.  Right now, all I am doing is using the BDC reticle for holdover estimation.  Since I know pretty much exactly how to aim for the 425 yard distance, I haven't moved the scope knobs for a while.  Not exactly an exact science, but if I hit what I am pointing at, what difference does it make, right?  

While Karen and the kids went for little hike up the hill, I set up the first grouping.  I had a little wind, but I thought that it was mostly coming at me.  I should have known better.  Five shots, and only one of them even grazed the target.  I mean that.  I barely grazed the target with one of the shots.  The other 4 missed wide right.  I did end up seeing bullet marks in the ground behind the target which seemed to indicate the missed shots.  So after a long walk back, I set it up again. Armed with new information, I held about a 14 inch crab into the wind, and was able to get 3 of 5 generally on target as shown.  As to the location of the other 2 shots in this group, your guess is as good as mine.  Difficult to say whether this was a product of the ammo, or the conditions.  I doubt it was my mistake, but with a trigger like this gun has, I guess that is a possibility.  My guess is that the 2 close hits are a good representation of the consistency of the shots, and that the windage variability with the third shot is due more to atmospheric conditions, than the shooter on this one. 

Back to the .243 - 3/13/10

I'm out of bullets for my .308, so today I went back to the Ruger .243.  I've got a whole bunch of the cheap Walmart Winchester Super-X (crappier than all get out in my .308) 100 gr ammo, so I decided to use some of that up.  It was a breezy morning, and given the fact that I have lost all confidence in the Winchester ammo, I decided to shoot at about 110 yards (I don't know the EXACT distance for this one).  I haven't shot seriously at 100 yards for a while, so I figured it was a good change of pace, and would give me a good idea of how reliable the box of bullets that I was shooting was.  As seen in the picture, 6 shots were placed in a fair grouping for the distance.  Four of those shots, on the other hand, are definitely 1/2 MOA.  I cannot complain at the crap ammo when it makes those types of shots.  The stuff shoots okay out of the .243, but I will never buy it again for the .308.  In fact, now that I am getting more serious about precision shooting, I don't think I will buy any more of it all together.  

Even though the breeze was strong, it would die out every few minutes to be quite calm.  I didn't feel like I'd had my fill yet for the morning, so I took another target over to my 425 yard stump.  It's nice sometimes to just be outside on a walk to enjoy the morning, so I didn't mind the hike.  It is strange to walk that far, and then realize that the bullets you are about to shoot will cover that distance in about a half of a second (.473 seconds, but who's counting, right?).  

Once back at the truck, I set up the gun, and the shot again.  I concentrated on getting my breathing back to normal as I put in my hearing protection.  Here comes the wind again.  I have been dealing with wind in my shooting for the last few weeks.  It has definitely taken it's toll in accuracy, but I guess those are lessons that are important to learn.  I waited for a few minutes to see if it would die down a bit.  I could see the tall grass around the target swaying quite a bit, so I knew that the wind was even stronger at the target, compared to what I was feeling.  Once I noticed the swaying grass slow down, I used the same elevation hold that I used the last time at this distance with this gun.  I figure that the cross-hairs on the scope are fine for 200 yards, the next line down would be for 300, next line 400, next line 500...you get the idea.  Given that formula, I held the target in between two lines (what would equate for 450 yards generally).  I held on the right edge of the white plastic backing to compensate for wind, coming from the right to the left.  There was one of the seven shots that I didn't feel as confident about, and I was not able to see a single one of the shots from that distance. 

All things considered, (wind, and the amazingly long, hard trigger pull on this gun) I am pleased with the shots I placed.  A close look reveals that the 4 closest shots (in relationship to each other) are about 2.5 inches apart vertically, and about the same horizontally.  That almost exactly matches the 1/2 MOA grouping that I was able to print from 110 yards on the previous target (remembering that a 4.25 inch spread would represent 1 MOA at 425 yards).   It might not qualify for 1/2 MOA, but it is under 1, and I cannot expect any better given the ammo, wind, and factory Ruger trigger.  I was glad to see that my windage holding was just about right today.  That is an improvement over my last outing (with the .308), and that is what matters.

Turns out the .234 is no slouch

For all of you out there that have ever fallen asleep during a discussion of external ballistics, this is not the post for you.  Unless you are suffering from insomnia, and desperately need to get some hard core rest in the next 30 seconds, I suggest that you move on.  Those that didn't heed my warning and are still reading, now I can talk openly with you about ballistic co-efficients, windage, and foot pounds of energy without running the risk of scorn.  Doesn't it feel great that we can communicate on this deeply personal level?
Okay, down to brass tacks.  It turns out that the .308 using 168 gr. Sierra BTHP Match bullets shot from 2650-2750 fps will experience a bullet drop at 1000 yards of about 386 inches.  The ballistic co-efficient (hear after denoted as BC) of that round is .462-.424, depending on the velocity.  The .243 105 grain Hornady A-Max bullets I have, boast a general BC of .500.  I looked up the BC for the Sierra 107 gr. BTHP Match bullets and they fall in at .527-.495, (velocity dependent, from 2900 fps at the muzzle).  This higher BC means that the .243 will only experience a 309 inch drop in 1000 yards.  Not only does the .243 round out perform the .308 in the amount of bullet drop, it gets there faster.  Time of flight (here after denoted as ToF) for the .243 is 1.495 seconds, while the heavier, slower .308 takes 1.688 seconds to impact the target.  This flatter trajectory means that the .243 round will be more forgiving with regards to mistakes in the range estimation of any given target, than the .308 round will.
The particular .243 round we are discussing also out performs the .308 round with respect to wind drift.  If we examine a 10 mph wind coming at 90 degrees, the .308 round will drift 105.1 inches.  The smaller, faster .243 will only drift 81.1 inches.  I suspect this is due in part to the shorter ToF.
The one area where the .308 will out shine the .243 is the amount of energy the round has.  Assuming you can get your 168 gr .308 round to 2750 fps at the muzzle, you will have 2821 ft/lbs of energy.  The 105 gr. .243 round at 2900 fps, will give you 1961 ft/lbs of energy.  That means the .308 has 860 more ft/lbs of energy at the muzzle.  However, lets take a look at the 500 yard, and 1000 yard markers for a closer look at how each round bleeds energy.  At 500 yards, the .308 is down to 1271 ft/lbs.  That means that it has only retained 45 percent of it's energy.  The .243 round is down to 998 ft/lbs at 500 yards.  It has retained just shy of 51 percent of its energy.  At 1000 yards, the .308 round is down to 534 ft/lbs.  It has only retained 18.9 percent of the total energy it once had.  The .243 is down to 463 ft/lbs at 1000 yards, meaning that is has retained 23.6 percent of its total energy.  So although we cannot argue that the .308 round has more energy at all ranges, it is interesting to note that it bleeds off energy faster than the .243.  For the purposes of this discussion, I say that makes the .243 a more efficient cartridge with respect to external ballistics. 
If you are still awake after reading this, I congratulate you on the tremendous feat you have just accomplished. I suspect, that it was much harder for you to read this and remain coherent, than it was for me to write it.  I hope you learned something, because I sure have.  The .243 is no slouch, ballisticly speaking.