# OK Gurus!! Opinions!!



## THE JAMMER (Aug 1, 2005)

Some of you may remember a post I did on the "Fickle 243 load" thread where I talked about a great load I developed and a .302" group I shot with my Colt HBAR, and Charlie congratulated me and asked if I thought I could do it again. Well here are the results.

Picture #1 is the picture of the original .302" group I shot using 25 GR of VV 140. Picture #2 is a group I shot the same day using a load that had everything the same but used only 24 gr of VV 140-- .56" not bad.

Picture #3 is trying to call Charlie's bluff and duplicate the .302". Didn't happen. Opened up to about an inch. However picture #4 is that same day shooting that 24 gr load. .45" but 4 shots into .090". Flip flop.

Now my question: the first day I fired these two loads it was about 60 degrees, and the muzzle velocities were about 100 fps apart. The second day I fired them it was 85. The muzzle velocity of the 25 gr load on the first day was almost the same as the muzzle velocity of the 24 gr load on day two- I'm guessing because of the increased temperature- higher pressure- more velocity. The difference between the two loads on the same day is almost 100 fps.

Can a change in temperature/change in velocity really make that much of a difference in accuracy? From my data it appears that the magic velocity is about 2650 fps, whether it comes from 24 gr or 25 gr. If that's the case are certain loads only very accurate at a particular temperature??

What do you guys think???

THE "HAPPY WITH BOTH OF THEM" JAMMER


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## CoastalOutfitters (Aug 20, 2004)

the new super "computers" that the long range snipers carry will ck for temp, , baro pressure, wind and actual position elevation , so .......must be a yes 

another thought..........on extremely cold days, like close to 0 or below, shotshells do not get the velocity that they do on a warmer day


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## THE JAMMER (Aug 1, 2005)

I know they plug in temp as one of their variables ( I do too with the two computers that I have), and they do that because of the change in impact point as a result air density (cold air is denser and gives more resistance), and velocity change. My question is will that significantly affect the accuracy of the round. The accuracy of one of my rounds went 3 times larger, and the accuracy of the other was cut way down.

Also what I forgot to say in that five into .45" and 4 into .090," the "flyer" was my third shot and I called it right after the shot before looking in my scope. I knew I had pulled it, and I called "up and right." Which is what it was.

Thanks for the input coastal.

THE JAMMER


CoastalOutfitters said:


> the new super "computers" that the long range snipers carry will ck for temp, , baro pressure, wind and actual position elevation , so .......must be a yes
> 
> another thought..........on extremely cold days, like close to 0 or below, shotshells do not get the velocity that they do on a warmer day


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## CoastalOutfitters (Aug 20, 2004)

you can throw a few other wrenches in there........with base loads etc, being the same........

same brass or same age brass

are you neck sizing only or full length , case neck trimming to hold brass LOA same

cleaning primer pocket holes ea run

same time of day, ...........alot of coffee , tobacco, tea , etc........


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## Ernest (May 21, 2004)

Far from a guru, but I'll tell you what I think. 

Assuming, decent scope/decent trigger/constant wind, big picture, its a numbers thing. 

We have all scanned up a load, shooting five shot groups (or even three shot groups), got a nice tight one, and then when reloaded, its not what we expected. So, I consider any initial results, until repeated with say five groups of five, to be merely preliminary. A starting point for further investigation. 

I don't think you LOA or brass length is going to play much of a role. That Colt likely has a long throat and long chamber, so unless you are single feeding, the jump is huge and brass length no big deal. 

I'm be surprised if a temp delta of 25 degrees - from 65 to 80 - had that big an impact on velocity or accuracy, everything else being equal. N140 is single based (as I recall), so it should offer a decent degree of temp tolerance. 

Further, I'd bet the margin of error on your chrony is such that 4% is barely significant. Particularly with a small sample size. 

I'd load 23.9/24.1 at 10 each. Then, I'd load 24.8 times 10, 25 times 20 and 25.2 times 10, and see what shakes out. Shoot them in five shot groups. Then again, I believe any trigger time is time well spent, so I'm not shy about trying different loads.


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## CHARLIE (Jun 2, 2004)

As a very old song says

"meanwhile Im still thinking"

My belief is this and certainly not a guru. I think sometimes we make mountains out of molehills. I think sometimes we expect way too much out of our hardware. I think if we shoot a lot then sometimes that one holer will happen. To be able to repeat it is sometimes a problem. 

Charlie


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## 27contender (Dec 22, 2008)

I agree with Charlie.

I have shot 3 one holers out of the same gun in only 39 shots total. Two different loads (one load did it twice) two different days, almost got two of the one holers on the same target but I guess I got a little flinchy to the tune of 2" or so. I was gonna get it framed. Hey, I may never do it again.

I did keep the piece of paper.

R


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## Ernest (May 21, 2004)

I would suggest - good scope, good trigger, good technique - the Colt HBar with a free float barrel is capable of consistent .50 MOA performance with the right loads in decent conditions. So, generally speaking, I don't think you are expecting too much. 

Is it a Comp Hbar or Match Target or other? Model number? A 6700 should do it. Maybe not with 68/69's, but it should do it.


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## THE JAMMER (Aug 1, 2005)

It's a pre ban 6700 comp HBAR. Scope Leupold 4.5x14 mil dot; timney 3# trigger, and FANTASTIC TECHNIQUE. LOL.

I agree with everything all have said, as I have also experienced this many times- load shoots great one day, and not so great a week later. And trust me these were not the only times I have fired these loads-- many many sets of 5.

I just thought it was interesting that with two identical loads, except for one grain of powder, that they would flip flop their accuracy like they did with the only variable changing being the temp/velocity. Especially having the lower powder weight at 85 degrees group the same or better than the higher grain group did at 60 degrees. Like has been said you wouldn't think only 20 degrees would make that much difference, but the measured muzzle velocity of each load varied by about 80+ fps-- and those velocities were an average of the 5 shots.

We have a fantastic group of reloading/shooting talent on this board, and I for one continue to learn from everyone on here, and greatly appreciate everyone's inputs.

By the way I just put a Magpul PRS stock on that HBAR. Looks great and I'll shoot it this weekend.

THE JAMMER


Ernest said:


> I would suggest - good scope, good trigger, good technique - the Colt HBar with a free float barrel is capable of consistent .50 MOA performance with the right loads in decent conditions. So, generally speaking, I don't think you are expecting too much.
> 
> Is it a Comp Hbar or Match Target or other? Model number? A 6700 should do it. Maybe not with 68/69's, but it should do it.


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## CHARLIE (Jun 2, 2004)

Hang in there Jammer it will happen again but, week after maybe not... Thats shootin

Charlie


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## Ernest (May 21, 2004)

Sorry, I was not clear on how many times you had shot those loads. 

See, I've adopted my wife's group evalution system. Its improved my groups considerably. It includes: 

that one don't count, cause I was not really ready to shoot; 

I was just practicing for a good group later; 

discount that one, cause my mind was wondering a bit; 

I think that shot was someone else shooting my target, my bullet disappeared before it reached the target or maybe hit a bird or something; 

Obviously, equipment failure cause last time this weapon shot much better groups; 

If three of them are close, clearly those fliers are defective bullets. Who loaded these? Did you weigh each bullet? See, thats it. 

I thought my glasses were about to fog up; 

I forgot what part of the reticle was the point of impact; 

I was concentrating so hard on my breathing, that I got impatient, and so I decided to just shoot that one just to be done with it; 

I'm pretty sure that ammo was intended for a different caliber weapon; 

I thought maybe a spider was trapped in my ear muffs, so I just hurried thru that group so it would not burrow into my brain. 

And, my favorite - you intentionally gave me the crappy ammo while keeping the good stuff for yourself. Look, your ammo is bright and nice, while mine are kinda dull. LC 99 must stand for last chance before you throw it away causes its junk, and why am I forced to shoot this old stuff anyway? I'd do much better with modern, new ammo. You know there were defense cut backs under Clinton in '99. Probably saved money with crappy brass. 

Try it. Nothing but bug holes under this system.


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## CHARLIE (Jun 2, 2004)

Very good Ernest I liked it.

Charlie


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## THE JAMMER (Aug 1, 2005)

Ernest,

That was awesome. I'll have to say that you included several which I have used in the past, but there are bunch of new ones in there which I can't wait to use in the future.

*MAGNUM LOL!!!*

THE JAMMER


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## CoastalOutfitters (Aug 20, 2004)

i rushed my shots

my barrel sure is getting hot, do you notice the mirages too ?

i just swabbed the bore . these are test shots


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## CHARLIE (Jun 2, 2004)

Somehow my trigger has developed a creep. 

Oh I mixed up the ammo somehow

Oh I shot the wrong target

That muzzle break on the 300 down the way made me jerk

I forgot my ear protection

Where are my glasses

let me hurry and get this shot off


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## THE JAMMER (Aug 1, 2005)

The cease fire buzzer just sounded, and this is the last shot of my last string, and if I don't get it off, I'll have to wait another entire relay to get my target.

BOOM! Yeah I knew I'd throw it!!

THE JAMMER


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## davidb (May 10, 2006)

Some of the bench resters will adjust loads up and down with temperature swings or at least have a cool and hot weather load. Some will also adjust powder charge for elevation differences.

Me I am still trying to get the spiders out of my Ear Muffs.

The biggest variable is always the Nut behind the Butt.

Doubly true in my case.


Forgot to add the only useful part of my post: With that light a load just the way the powder sits in the case will affect ignition and velocity a swing of 100fps would not be unusual.


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## CHARLIE (Jun 2, 2004)

Compressed loads...

Charlie


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