Barnes all copper, accuracy puzzle

[artjr338wm]

There are a few threads here on this board concerning Newtons laws and how they pertain to bullet accuracy that have prompted me to post the fallowing question:

Is there a most likely cause or defined cause that can be blamed for the fallowing accuracy problem many here have said plaque Barnes all copper ML bullets. The problem I speak of is the fact many here have shot the TMZs and Spitfires and found them to be capable of extremely good accuracy or at least acceptable accuracy at 100 yards only to have their groups open up dramatically and unacceptably at ranges of 200yrds.

I personally find this to be quite confusing as my 10ML-II shoots the 245 Spitfires awesomely well at 100yrds and the 290 TMZ although not as well as the Spitfires but still at 1.25" or better every time I shoot them at 100yrds.

So I can not understand how a load that shoots under 1" groups at 100yrds will "fall apart" so to speak and shoot 4 to 5" or even larger groups at 100 yrds using the same exact sub-moa load, unless the 2x longer bullet flight now allows some factor like Newtons law time enough to have a severe negative impact on the bullet.

As I'm in over my head in terms of knowledge as it applies to the laws of physics of saboted bullet flight, I need the input of those who are far better versed in these laws than I am.

I am basing my perplexity on the fact my two most accurate rifles both shoot under a inch for a three shot 100yrd group, same for 200yrds and in the case of my .338wm remain so all the way out to 300yrds, as that is the longest range I can shoot to with the use of a bench. I have shot both my most accurate rifles out to 400yrds and can hit a Colman fuel can at will using a large bolder for a rest.

So whats with the Barnes all copper ML bullets when shot in a sabot?.

Thanks,
Arthur.

[Richard]

Art.......Here is my take on it. (I know I will probably get bashed) If you shot or can shoot 3 shot 1.25 groups "all day" as some like to say, then at 200 you should be shooting 2.5" groups all day.........Providing you are in a dead calm under cloudy skies. Now lets add in a few "flies to the ointment": Your sighting now becomes more critical. What was easy to line up at 100 now becomes just a little harder at 200 yards. Now add in the mirage factor While some think lower power scopes eliminate mirage, they only cover what is there. You just are not seeing the movement as readily. So this in itself can cause point of aim problems to a degree. In .50 cal. as in most ML calibers, Ballistic Coefficient plain ole' just sucks. Factor in the decreasing velocity along with the wind (breeze) and you can see what is happening. Not to mention shooter error.
On the other hand, your rifle is firing a much higher BC bullet at faster velocities. Higher BC, lest wind deflection
Richard

[artjr338wm]

Good points, well taken Richard, but I can (this the simple truth not bs/brag) shoot 200yrd three shot groups under four inches seated shooting off of Stony Point shooting sticks with my beloved .338wm. Off the bench with my 338wm I stay under 2" for a 3-shot 200yrd group 90%+ of the time.

So that is why I am failing to understand how anyone who is shooting MAO let alone sub-moa groups at 100yrds will have their 200yrd groups increase in size by 4 or 5x, unless of course there are factors in play such as ones found in newtons law that I am not aware of.

I have yet to be able to shoot any of my Barnes TMZs or Spitfires at 200yrds of any amount to be able to draw any firm conclusions.

Case in point. I was able to steel away for a range session last Saturday and intended to spend 90% of my shooting time at the 200yrd range. As the 200yrd range only has one bench it can be hard to get. Well I was at the range literally as the gate was unlocked, but there was a large group of shooters already set up at the 200yrd range waiting for the appointed shooting time to arrive. I did not get to shoot at the 200yrd range until some seven hours later and then I only had time to shoot 2 three shot 100yrd groups as I absolutely had to be home by 4:30pm and this range is almost two hours from my home. Both groups were with the 290grn TMZ and 75grn/10X & Harv/CR for BT bullets. By know the wind as predicted had increased to 15mph with gusts to 25mph so not exactly ideal shooting conditions for a first time shoot at 200yrds. I still managed to shoot one group at 2.4" and the other was a hair under 3". Not bad all thing considered. But two OK groups a hunting load does not make by any stretch. Next trip I will get there a good 1/2hr before opening and an set up at the 200yrd range and simply wait till I can shoot.

One thing I found rather intriguing was the fact this. I shoot the 290 TMZs in the fallowing load:
75grns RL-10X
290 TMZ
Harvester yellow CR sabot for BT bullets
Fed 209

And the 245 Spitfire in the fallowing load:
245 Spitfire
76 grains H-4198
Harvester yellow CR sabot for BT bullets
Fed 209

After I got home and looked over my targets I discovered that these two different bullets shot with different powders had 95% same or a near exact same POI. I laid one target on top of the other and they differed less than1/2" in direction. Although I doubt it, if this holds true out to 200yrds, it would be nice that I would have the option of a 2450fps load or a 2600+fps load to use as I see fit.

Be well,
Arthur.

[wilmsmeyer]

Art,

Good shooting so far. I think some folks here feel my 200 yd results are poor too. When I was shooting the Spitfires and TMZ's by the truckload, my 200 yd groups were never something to write home about....4-6 inches. However, my 100 yd groups are only occationally under 1 inch and usually closer to 2 inches.

So...my 200 yd groups actually corralate quite correctly to my 100 yd results. The slight opening up is due to much of what Richard said above IMO.

Back to "poor" groups. A 5 inch group centered in your desired POA will give you a 2 1/2 inch margin of error up-down-left-right. For deer and for me that pretty much means venison in serving size portions will come easily. I love the tiny groups and appreciate the folks who spend $1000 on a gun/scope and $2000 changing the gun from a 2 moa shooter to a 1 moa shooter. I just never needed that to do what I need my gun to do.

If I intended to be able to kill deer at 300-500 yds, things would have to change. However at these ranges, trajctory and exact yardage...coupled with needed ballistic plex's...AND a shooting house with sandbags make solid MOA performance not a neccesity for me. My hunting is from hang-on stands and off shooting sticks. 200 yds is a long shot.

I will agree with your contentions that a MOA load should not "fall apart" at 200 yds. The answer lies more with our poor BC's, wind effect and target picture IMO. Try this as you increase ranges:

If you shoot at a 1 inch square or dot at 100 yds, then shoot at 2 inch square or dot at 200 yds....using the same magnification. Your sight picture will appear the same...including any wobble you are having at the bench.

[dougedwards]

I am not sure but I don't think that the 290 grain TMZ has that bad of a ballistic coefficient compared to other 300 grain bullets that we shoot. It may have a lower sectional density but it is a long and pointed cylindrical type of bullet which should do ok cutting through the air. I think that some of the problem with the long copper bullets is that they weigh much less than their lead centered, copper plated counterparts thus making them less stable in flight. I had to find just the right load combination to get them to consistently group well without the occasional keyholer. We probably would do better if we were shooting through a barrel with a faster twist rate. Maybe some of the guys with the new Pac-Nors will have some experience with shooting the all copper bullets and can chime in.

I would suggest that you try backing off of your heavy charge of 75 grains of Alliant 10X and also use a vegetable wad underneath the bullet but with the two groups that you experienced in the wind I wouldn't touch anything yet. It is a good start and I look forward to seeing what you can do without the wind to contend with.

Doug

[bigmoose]

To me this is a puzzle, I only have access to a 100 yard range, The longer shoot Ive taken on game is 128 yards [w/muzzleloader] 290gr. Barnnes TMZ FB, shoots sub-MOA groups, Why would they open up greatly. If I had a range, I would try this, set up a 100 target, than in line set up another target a 200 yards, that way you would if, its the shooter or the rifle. If I had to guess, I'd say the shooter. [Sabotless}
Wilmsmeyer,
since you have your own range, if you would, you will be the perfect candidate to run this test.
Don't you like folks who volunteer other folks to do the job It should be a shooting offence.

[rexxer]

In a couple weeks I will be trying some all copper bullets sabotless at 100 and 200 yards.

[wilmsmeyer]

Send me your gun Bigmoose and I'll see what it can do at 200 yds. Already know what mine does. ;D

[bigmoose]

Wilmsmeyer,

One of the first thing, you learn in the Infantry, I never give up your weapon.

Have you tried that type of test

[ET]

Art

I have my own pet theory of why all copper bullets are harder to group at 200yd than 100yd. using sabots. The main factor IMO is related to gyroscopic stabilization (RPM-Spin Rate). I will be focusing this attention on my 200-XPB this year. This weekend I hope to get my new Vortex sighted in and hopefully have a chance to produce a decent group with them (200-XPB) at 90-yds on a makeshift range. Then when the 200yd range opens that I shoot at I will then find out if my theory holds any water.

If you are wondering why my thinking is going this way here it is.
The strongest contact supporting the bullet in the bore area is the lands. Let’s say that is approx. 1/3 the bore area of the ID circumference. With bullets that have better obturation properties this contact point with the lands can be increased and should provide a proper Stabilizing Spin Rate. Now with a bullet that doesn’t obdurate as well this contact point wouldn’t be as strong and possibility of slippage could occur affecting the spin rate. This may possibly be off set with providing a better grip between sabot and bullet. I plan on using a raised cannelure to see if there is a difference seen at 200yds.

If not then I have to wonder on 2-other possibilities that I am not ready to reveal just yet. There may be some chuckles on the first possible theory. ;D

Ed

[wilmsmeyer]

So, with your theory....how is it possible for greatness at 100 and mediocrity at 200+? Not sure I'm getting it? Spins just enough to produce groups at 100 but not at 200?

That is a tough sell to me.

Here are what I consider more likely factors:

1) bullet is subjected to wind longer from 100-200 then from 0-100.
2) Mirage distorts sight picture more at extended range.
3) Vertical speads are more pronounced with ML bullets at longer range

Most of us that shoot 1-2 inch groups at 100 aren't missing a 6 inch circle at 200...that I know of. There are only 5-6 people on this board that even claim 2-3 inch groups at 200 yds with any load....saboted or sabotless. Yes, some very good groups get posted....but the norm isn't MOA.

Are we reading way too much into this?

[dougedwards]

Apr 9, 2009 20:31:14 GMT -5 wilmsmeyer said:

That is a tough sell to me.

Here are what I consider more likely factors:

1) bullet is subjected to wind longer from 100-200 then from 0-100.
2) Mirage distorts sight picture more at extended range.
3) Vertical speads are more pronounced with ML bullets at longer range

How are those three factors only related to all copper bullets? Isn't the expressed problem that 290 grain all copper bullets are different from other bullets that we shoot in that they fall way off in accuracy after the 100 yard mark? The Barnes Originals don't exhibit this characteristic yet we still have to deal with wind and mirage while shooting them.

What do you think it is about the 290 grain TMZ that causes it to become unstable at longer distances? Another question that would come to mind is concerning the 250 gr TMZ. Does it seem to exhibit this same characteristic? It might be many things that come into play here but I don't see how wind and mirage have any more effect on the Barnes than say a 300 grain SST.

Of course there are many practical things that escape my understanding so this wouldn't be the first time but I am scratching my head no this one?

Doug

[Tarheel]

I know when Barnes first started out, they had some concentricity issues with rifle bullets. IMO if the spin slowed enough to de-stabilize the bullet, wouldn't some of the bullet holes be oblong

[ET]

Wilmsmyer

Not trying to sell a theory but express one that I will be looking into by trying something to see if it’s related. I did mention “I will then find out if my theory holds any water”

Your factors mentioned should apply to all bullets if that’s the case.

But the factor you are not mentioning is velocity decay where any instability MIGHT be amplified or more readily shown.

I’ve started with a theory and now hope to prove whether it’s related or not. It’s a starting point as to possibly why such a difference is seen with copper bullets at longer ranges.

“Are we reading way too much into this?”

Maybe? But if one doesn’t look deeper into details or possible remote factors how can one find an answer or understanding to what is happening?


Ed

[ET]

Apr 9, 2009 21:28:33 GMT -5 Tarheel said:

I know when Barnes first started out, they had some concentricity issues with rifle bullets. IMO if the spin slowed enough to de-stabilize the bullet, wouldn't some of the bullet holes be oblong

Good question. I agree but don't know what percentage lower of the required spin rate for a particular bullet would immediately produce this result.
But now your mention of bullet concentricity could possibly be another factor to contend with.
Thanks for pointing that out.

Ed

[Dave W]

I don't have the answer as to why they don't shoot as well out of my gun as a jacketed bullet, but after 100's of rounds and dollars, I am confident in saying they do not shoot as well at 200yds as jacketed bullets in my gun. I'm almost 100% sure I have never shot a sub MOA 200yd group with a all copper, it is a struggle to get them under 3" at that distance. I have shot plenty of groups under 3" at that distance with the 250 SST and the 300 Rem. Barnes solids are the reason I stopped testing at 100yds.

The 195 will shoot in the .45, but I can't get them to group in my Savage like a SST, big difference in barrel quality of course.

I think about all the bullets we shoot are out of round, SST's, Parkers, and the Barnes all coppers. Maybe-if, the jacketed bullets obdurate they are more stable at longer distance, but it still does not explain how the 195 "which is also out of round according to one of the notables here" shoots so well at long distance in the .45.

There are guys over on MM that claim excellent accuracy at 200 and farther with Barnes solids in BP guns so I'm not sure speed or pressure has any bearing on the subject, especially if these bullets do not obdurate. Maybe the twist rate has a bearing since the BP guns seem to be rifled slower than the MLII, someone that shoots BP or subs in their MLII could answer this.


It has been noted many times how different these guns are as far as what shoots for one guy, does not shoot for the next, maybe the answer is that simple. Art and Danno and a few others like the guy who recently posted his gun averages something like 2.5" at 200yds, maybe their guns are some of the few that like them and the rest of us are SOL.

[screwbolts]

First off I must say that I have never shot a solid Copper or brass bullet.

Have any of you been able to recover a bullet from snow or water? does the bullet actually obterate upon being fired.

Is the Copper TMZ ( did a search and found it is tipped) holding the sabot well, i saw they are .451.

would it help accuracy, if you very lightly Knurled the bullet shank. just enough to give it a texture. This might help the bullet grab the sabot and better transfer spin from the rifling. If you just push a saboted bullet threw the bore what do the pedals look like compared to fired? I have often pushed a knurled bullet threw and looked at the sabot, no knurling marks transferred to the sabot. shoot the same bullet and sabot and now the inner surface of the sabot hase the knurl patter deeply engraved in the pedals.

What does your fired sabot look like, even with my hard cast the base of the pedlal do show widening, that indicates obteration to me

Ken

[whyohe]

IMO these are all good factors. but i am more inclined to agree with dougwards. the OL of the bullet and its sectional density are the 2 factors that differ it from jacketed bullets. if i rember right, the longer the bullet the faster the twist needs to be to keep it stabilized. it might be spinning fast enough at 100 yards to keep it stabile but the spin degrades enough that at 200 yards it becomes unstabile due to the slower twist AND possibly the sectional density being less its spin degrades even faster than its lead core counter part. just a though.

[artjr338wm]

Wow!!! what a thought provoking discussion we have going here. Last time I observed this much over my head fact and theory I was watching the history channel and they went from theories on how our solar system was formed fallowed by a discussion on the possible existence of parallel worlds.

But seriously, I am quite surprised, pleased and impressed to the point of feeling humbled by the examples of the laws of physics as they apply to ballistics as expressed by many who responded to my question.

I do wonder some times if as ET says if we are "reading to much into this", but I discount that possibility as I have seen pics posted of literally dozens of 200 yard MOA groups shot with SSTs, and other bullets as well as to many 300yrd groups at or vary near MOA shot with several different types of bullets (in factory barreled .50 cal 10MLs) but I simply do not recall EVER having seen any pics posted of TMZs or any .45cal all copper Barnes ML bullets of MOA 200yrd groups let alone MOA 300yrd groups. I might be mistaken, but I simply don't recall any.

I personally have five saved saved targets of shooting 245grn Spitfires at 100yrds that for would make any center fire rifle owner do back flips in celebration (and the fifth target is still under 2"), that I have refrained from posting because #1- I wish to first determine how they will shoot at 200 because I do not want to influence anyone to run out and buy them based on my posting my limited results of 100yrd groups.
#2-Even though I have one IMHO VG 3 shot 100yrd group and four bordering on excellent, this shooting was all done while developing a accurate load, and do not consider it to be conclusive. So until I can shoot enough at both 100 and 200yrds, say 10 three shot 200yrd groups, my posting pics of my best 100yrd 3-shot groups would be more a example of bragging than actual sharing of information helpful to others.

After reading and digesting all this information concerning all copper Barnes ML bullets, I am inclined to agree with the theories that there simply must be some thing about the Barnes bullets themselves causing the accuracy to so significantly degrade at 200yrds VS 100.

I also strongly feel we shooters as a whole get way to caught up in the quest for MOA at all ranges we shoot at and all to often forget about the "other MOA as in "Minuet of Animal" Last time I looked shooting benches are far and few between in the deer/elk woods.

I also am inclined to think that the fact we are shooting muzzleloders might not actually be causing this phenomenon to occur but it I strongly believe exacerbates it because of the problems of loading consistency, or better stated "Inconsistency" inherent to all muzzleloders.

So based on the information I have read stated here, I'm beginning to think that there is a strong possibility that a link exists between the Barnes all copper bullets themselves might just have a design aspect (at this point I am not willing to go so far as to call it a actual "design flaw" as in all fairness we are shooting them way beyond the velocities thay were designed for) that surfaces and is directly proportional to flight time of the bullet, and the fact we as muzzleloders are subject to loading variable inconsistencies and will never be able to have the same control over these same exact set of variables as do when we reload metallic center fire rifle cartridges.

Does that make any sense to anyone or is it time to alter/change my Meds?

[rexxer]

If you look at Dave D's group at 300 you will realize that the Barnes can be shot quite well with sabots. I'm thinking the copper bullets might have to load real tight shooting sabot less. I have some 275 xpb that look like they should be an excellent bullet shooting sabotless. I believe the all copper bullets will obturate a lesser amount than a bonded lead bullet so it must be engraved deeper when initially pushing it down the barrel.

[Dave W]

Apr 10, 2009 19:44:29 GMT -5 artjr338wm said:

So based on the information I have read stated here, I'm beginning to think that there is a strong possibility that a link exists between the Barnes all copper bullets themselves might just have a design aspect (at this point I am not willing to go so far as to call it a actual "design flaw" as in all fairness we are shooting them way beyond the velocities thay were designed for) that surfaces and is directly proportional to flight time of the bullet, and the fact we as muzzleloders are subject to loading variable inconsistencies and will never be able to have the same control over these same exact set of variables as do when we reload metallic center fire rifle cartridges.

Something to ponder about pushing them faster than intended.

On the old board a guy who owns one of the Ultimates mentioned that he got a hold of some TEZ's before they were released to the public. According to his post, the 290 was under MOA @ 300yds. The 300SST over 4 pellets in one of those guns shoots around 2300+, over 5 pellets approx. 2500fps. He did not mention how many pellets but I'm guessing 4 pellets since the two guys that posted about the Ultimates were using 4 pellets for best accuracy with the 300 SST. So, is it the bullet, the powder, the gun.


The best accuracy I got with the TEZ's was by knurling with a coarse set of files, getting the diameter up to .453. I did this because I thought maybe the bullet slipped in the sabot. Unfortunately the load blew sabots intermittently, never tried shooting them like that with another powder to see if results were any different.

[bigmoose]

Reading all these opinions has got my head spinning, here is what I know, no speculating, no conjecture, no maybe.
I know this becauce I have shoot at least 500 plus 290 gr. Barnes TMZ. [SABOTLESS[
1. Tightnees in loading, even hammering, stuck bullets,down the barrel, had no effect on accuracy. When I first realized this I call Rick, and asked him how that could be.
2. 290gr. TMZ are super accurate. I don't know how many rounds I have fired in 60 plus years of shooting, but I have more one hole groups with Rick's rifle, 290 TMZ 53 grs. H4198, wonder wad. The TMZ are resized to 449.5 and knulded up to .450.5
3. After recovery from firing in penetration test the the base mik's .459.5 bullet weight 287.8
What law of physics would destabilize, an object that flies so true at 100 yards?
At any rate each of us must be guided my our own experiences, mine is the the TMZ at 100 yards is super accurate. If the chance arises, I would not hesitate to use it at my self imposed max range on big game 250 yards.