Lets discuss "Accuracy"

[Team Sergeant]

Lets discuss Rifle Accuracy

What are your rifle accuracy demands? (And yes we can split hairs all day concerning hunting, tactical use and bench rest.)
What is the furthest shot you might attempt hunting? What shooting positions are you most comfortable in? Is your rifle accurized? Do you hand load? Do you know how to measure the bullet ogive ? Do you know what the first focal plane refers to?

Most folks never heard of internal, external and terminal ballistics. A good definition here:

1. Interior ballistics is the branch of the science that deals with the projectile while it is still in the gun.

2. Transitional ballistics is the branch of the science that deals with the motion of the projectile from the time it leaves the muzzle until the only forces acting upon it are due to exterior ballistics.

3. Exterior ballistics is the branch of the science that deals with the projectile after it clears the muzzle and throughout its time of flight.

4. Terminal ballistics is that branch of the science that deals with the impact, and force imparted on the target.

(Transitional ballistics IMO is external ballistics. )



How far down this rabbit hole do you want to go?

[Papa Zero Three]

Here's a good one.

https://youtu.be/hRAFPdDppzs

[mojaveman]

My favorite bangstick is a Winchester Model 70 Sporter XTR in .30-06. I also like the .243 because it has low recoil, shoots pretty flat and the deer in California are somewhat small.

Being that I don't reload and I am willing to buy decent ammo I am content getting 1.5 MOA accuracy with my rifles. I don't really like large objective variable power scopes and prefer using a 4X or 6X instead. MPBR with a 150gr projectile going 2900fps is about 285 yards so I don't think I would shoot any further than that.

I am most comfortable in the sitting position with both elbows resting on the knees. Other positions include standing with the right arm straight out parallel to the ground and the left arm supported on the chest. Prone supported is good too but you get dirty and see a lot less from down there.

The first thing I do with a new or used rifle is take it to the range. If it shoots decent I might not do anything. I usually then set the trigger at 4 pounds and sometimes bed the action or float the barrel.

I don't hand load because I just don't really shoot enough and as I stated earlier some of the factory ammo available is actually pretty good.

[(1VB)compforce]

Originally Posted by Team Sergeant

Lets discuss Rifle Accuracy

What are your rifle accuracy demands? (And yes we can split hairs all day concerning hunting, tactical use and bench rest.)
What is the furthest shot you might attempt hunting? What shooting positions are you most comfortable in? Is your rifle accurized? Do you hand load? Do you know how to measure the bullet ogive ? Do you know what the first focal plane refers to?

Most folks never heard of internal, external and terminal ballistics. A good definition here:

1. Interior ballistics is the branch of the science that deals with the projectile while it is still in the gun.

2. Transitional ballistics is the branch of the science that deals with the motion of the projectile from the time it leaves the muzzle until the only forces acting upon it are due to exterior ballistics.

3. Exterior ballistics is the branch of the science that deals with the projectile after it clears the muzzle and throughout its time of flight.

4. Terminal ballistics is that branch of the science that deals with the impact, and force imparted on the target.

(Transitional ballistics IMO is external ballistics. )



How far down this rabbit hole do you want to go?

Background:

Learned at 2ID Sniper while they were trying to get certified to be an official Sniper School (they never did get certified... remind me to tell you sometime about the HMMWV that probably ended their quest) I only hunt paper now. I loved the M21 system, but hated the Leatherwood ART II scopes because the elevation and magnification rings were aluminum and shaved each other.

Now my distance rifle is an AR-10 from DPMS (Panther Arms) that shoots <1 MOA from a cradle using Federal Gold Medal Match (FGGM). It's zeroed and confirmed at 300y using iron sights. No glass on it yet, I'll probably put a multi use scope like the Elcan w/ Dokter on it at some point. I use that distance out of habit, but should probably verify that the rise is the same as it was on the bolt actions.

To directly answer your questions:

I no longer have demands beyond the rifle being more accurate than I am. I don't ever like being in a position to blame the equipment for a miss rather than myself. It's my own fault I missed dammit!

I'd be confident of taking a shot out to 800-1000y against a non-moving target if I had a dope chart handy, but I don't hunt so haven't had the chance to make the call. (and I'm not sure how you talk the animal into standing still while I figure the windage ). Against a live, potentially, moving target I'd probably shorten that to 400-500y with confidence as long as I didn't have to lead a runner.

I prefer prone supported or seated unsupported. I'm accurate kneeling, but never feel comfortable in it. Standing is my weakest for accuracy, especially in long strings. Seated I go cross legged and packed tight with the same arm positions as prone. I use my forward (non-shooting) elbow as a support rested on my left knee. Kneeling I rest my weight sitting on my rear foot/ankle with it crossed under me. Standing I do my best epileptic seizure imitation and try to time the pull

My rifle hasn't been bedded or accurized beyond the production specs. I'd love to go for an AI rifle sometime and see what I can really do now.

I don't hand load, I use FGMM. Never learned how and now, for killing paper, don't care. FGGM is good enough for any application I would use it for. I promise my personal accuracy isn't good enough any more for <.5 MOA variance to make a significant difference in my results.

Yup, but have no need to do so.

Yup maybe not the actual definition, but the practical use. First focal the reticle is magnified when the scope is adjusted, second focal the reticle stays constant. Changes how you range something using the scope. First focal can also obscure the target unintentionally at distance.

[mark46th]

My hunting rifle is a Model 70 in .270 Win that I bought at Walmart 10 years ago. I put a Nikon Buckmaster 3-9X40 scope on it. Best inexpensive scope I have ever found. I reload so for this one I use 140gr Barnes TSX bullets for pigs, mostly. My back up is a Rem 700 in .308. I use 168gr Barnes TSX bullets. It also has a Nikon Buckmaster. Both of these shoot 1MOA or better. I also have a Rem 700 in .338 Lapua Mag. It is on an AICS chasis, has a Timney trigger and S&B 5-25X56 glass. Load is Lapua brass with 300gr Matchking bullet and 92gr of Retumbo. It is zeroed at 600 yards. I haven't been able to group it due to there being no 800-1000 yard ranges locally.

[HOLLiS]

I do not bench rest any more so high accuracy is not practical for hunting or killing cannibalistic dirt clogs with their paper allies.

Hunting for elk, a gallon milk jug at 600M. A .338 Win Mag has about 2,000 ft pounds of energy at 600M. Good Elk Medicene

For Cowboy Action shooting, sufficient to hit the target.

IMHO, it depends on the needs of the shooter.

I use hand loads, IMHO more accurate than commercial loads.

My Ruger Mk II .308 on basic hand loads clover leafed at 100M.

I hate bi pods, either off hand, kneeling for hunting. Chicken wing works.

I do not measure ogive, I set bullet seating, where I have 0.030 free bore left, for long distant hunting.

I also use a Chrono to check bullet speed and chamber pressures. I prefer powder that burn a little slower with same bullet speed as one that burns a little faster.

I do fiddle with my main shooters for accuracy. My Mod 70 .338 Win Mag, is bedded (thought not needed for hunting), I recrown as needed. I like a trigger with a crisp release at about 2.5 pounds.

Furthers shoots off the bag with iron sights, 1000M. Hunting I am a lot more conservative. I am not into wound animals.

Focal plane............ I use two settings, for Mil dot 200M for others cone of accuracy where my POA/POI will be within the kill zone. Does not really answer your question. I rarely change magnification. Where I live there are not many long shots. So I adjust for those shots. At higher magnification I will, range my rifle before going hunting. (Range, adj POA/POI to the distance that I think I will be shooting, and use Kentucky windage to adjust as needed.)

[Team Sergeant]

Originally Posted by HOLLiS

I do not bench rest any more so high accuracy is not practical for hunting or killing cannibalistic dirt clogs with their paper allies.

I must admit, I've sent many of those "paper allies" to the great recycle center over the decades. No matter how many holes you punch in them they just seem to come back in greater numbers.

The fight continues......

[Old Dog New Trick]

Been reading this all day...don't have much to offer but wanted add something about "Transitional Ballistics" and the effects of those cool things at the end of the barrel or not.

Any gun/bullet can be more accurate than the shooter but some guns are better than others because of the way they let the bullet fly (Exterior Ballistics) or the last touch. Because after all, it's the last thing the gun can do well or not so much.

Barrel crown, be it standard round, 11-degree taper or recessed has a tremendous effect on how the gasses are expelled evenly around the bullet as it leaves the barrel and can ultimately affect flight. Is recessed better than tapered? I don't know but a cheaply finished crown or damaged crown will make even the best rifle junk.

Then there are all those things we screw onto the ends for various reasons: Flash Hiders, Muzzle Brakes, Compensators, and last but not least Suppressors. They all have an effect on the bullets "exterior ballistics" for better or worse.

Lastly, barrel length and twist rate for a given cartridge and powder charge. Some are too short, too long or too slow to adequately send the bullet down range properly. The end result is a loss of everything from accuracy to "terminal ballistic" effect. The wrong combination will make a great rifle bad or worse - unreliable.

Just my $0.02 to the discussion.

[HOLLiS]

Originally Posted by Team Sergeant

I must admit, I've sent many of those "paper allies" to the great recycle center over the decades. No matter how many holes you punch in them they just seem to come back in greater numbers.

The fight continues......

My hope is, we will preserver against the deadly onslaught.

[HOLLiS]

Originally Posted by Old Dog New Trick

Barrel crown, be it standard round, 11-degree taper or recessed has a tremendous effect on how the gasses are expelled evenly around the bullet as it leaves the barrel and can ultimately affect flight. Is recessed better than tapered? I don't know but a cheaply finished crown or damaged crown will make even the best rifle junk.

My two penny's worth.

Crown is all about concentric. Recess protects the crown where the bullet leaves the barrel. Off concentric crown will push the barrel this way or that. A pitted rifle barrel will not. The Crown will. IMHO, The Crown is a big part of accuracy. Bedding a rifle action is a very small part. In best rest, every 0.0001 improvement is a must.

When I re-crown, I like reset. It protects the crown.

We had three bran new mod 70s, One would not group. (1") Finally we recrowned it, and it was sub 1".

[jw74]

Any thoughts on the value of 'blueprinting' or truing the action?

I am curious if this is a gunsmith money-maker or an essential aspect to squeezing accuracy out of a rifle.
I have seen the change that a re-crowning can bring and wonder if blueprinting is the same.

I changed barrels to a different caliber on my hunting rifle and had it done at the same time so I can't say if the blueprinting was valuable but I suspect switching the factory plastic for a quality stock did more for accuracy than any other tweak.

[Papa Zero Three]

Originally Posted by jw74

Any thoughts on the value of 'blueprinting' or truing the action?

I am curious if this is a gunsmith money-maker or an essential aspect to squeezing accuracy out of a rifle.
I have seen the change that a re-crowning can bring and wonder if blueprinting is the same.

I changed barrels to a different caliber on my hunting rifle and had it done at the same time so I can't say if the blueprinting was valuable but I suspect switching the factory plastic for a quality stock did more for accuracy than any other tweak.

Yes, it does make a OEM gun a lot better as everything is square and or trued up, something that doesn't happen on factory production built guns. If you're replacing a factory barrel, you might as well have the Smith true the action while it's apart as it's worth the few extra dollars.

[longrange1947]

Just to throw some crap out there, transitional ballistics is a form of external and is actually more pronounced in some barrel twists than others.

What it really effects is a near range zero. Remember that the bullet crosses the line of sight (LOS) twice, once on the way down range and when, hopefully your LOS and POI coincide on the target. With some barrel bullet combination, your grouping potential at say 35 meters is worse than your grouping potential at 200. Reason is Transitional Ballistics and this is when the effect of the rifle is still present and before only external forces effect the bullet.

Clear as mud?

[longrange1947]

An ideally stabilized bullet is under spun at the muzzle, and when it gets to the intended accuracy range is properly spun. The bullet will become over spun at longer ranges.

In most bullet/barrel combinations, this is not an issue, but in some, the bullet "wobbles" around its flight path and the wobble becomes less and less until the bullet settles on that flight path. This causes problems with near range zeros.

The second problem is that the precursory column of air forms a mach disc that can upset some bullets. This requires the bullet to be over spun to maintain accuracy, another problem with transitional ballistics.

[HOLLiS]

Originally Posted by Brush Okie

So at times a bullet will be less stable near the muzzle than farther down range? I have heard mixed opinions on this. Good to know. I read the 303 British Enfield supposedly did this but never heard this from a reliable source. Thanks

IIRC, there is moment of destabilization when a bullet speed cross the the speed of sound. I believe more of a issue with people who shoot black powder.

Working on memory, so I may be off.

The transonic problem:

https://en.wikipedia.org/wiki/External_ballistics