Degrees Of Rifle Accuracy by Ian McMurchy

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Ian passed away just before Christmas, 2008. Read the tributes to this giant of a man HERE

 

[BountyHunter]

Ian

You have degrees of accuracy because you have no defined rules for groups or accuracy of measurements universally accepted across the board. Therefore accuracy is in the eyes of the beholder.

Some guys say that their gun will shoot .250. yes, one time out of 40, but the rest of the time it is at .750 or so. That is not a real .250 gun but that is the one pic that is always posted and quoted.

Now is that 3 shots, 5 shots, 10 shots or even 2 shots?

Is that measured with calipers or "eyeballed" or interpolated off "minute of bucket or minute of rock". We have all seen any of the above posted here and all over.

The short range BR guys have open challenges for "factory" rifles that their owners think that they are real .250 guns. Come shoot five .250 groups back to back in one of their matches and win some money. Guess what, no one has won any money yet on that bet.

The short range BR guys look at 5 groups of 5 shots and what is the agg.

The LR hunter and regular hunter tends to look at 3 shot groups and best ever shot. Seldom do we see the five shot group. The concern is here is first round hit.

So which is right or wrong. Once again, no universal answer.

You are correct the encores are amazing time after time too.

BH

 

[Mikecr]

For LONG RANGE HUNTING the right answer is always -first cold barrel shot -hits it's mark. That's what accuracy really is, and if group shooting at all, the spread should be taken to center of bull.
This is also from field rest and conditions only. No BR, no bench, no martini(shaken, not stirred). And finally, it includes shooting as a 'system' including strategy, ranging, stalking(with all equipment), condition measurement, calculations, corrections, timing, and the sense to know all is right before commiting(with your one shot) to hit your mark.

BR shooting is about PRECISION, CONSISTENCY, SPIRIT OF COMPETITION, and not at all about ACCURACY. In fact, most winning groups in BR are quite larger in MOA to their actual mark, and many BR guns would fair poorly in cold barrel accuracy. The equipment isn't designed for accuracy, the loads are not developed cold, and competitors rely on sighters instead of ballistics. The challenges are different.

I wouldn't rule out factory guns and factory ammo for accuracy potential based on poor grouping.
Forget grouping, it matters not.
Testing them in grouping is of no value as you are testing them -out of their element.. Far away from their design..
Instead, develop a cold barrel load, and shooting system, which you can rely on to hit nearest your mark. Do this with each gun in your safe and I bet you'll be surprised by the new order they fall into w/resp to accuracy.

There was a gunrag test that raised a stink a few years back. Several factory rifles and a BR gun built by Speedy. All shooting factory ammo. Speedys gun lost to the lineup, and of course this irritated many. Didn't surprise me at all.
I engage in a local accuracy contest each year(for the past 2). 1 shot at 200yds, 1"bull, off a feed sack full of dirt on a weathered(and warped) picnic table. You make it, you go to the back of the line. You miss, you're out. 1 winner takes all. It usually starts with ~35-45 shooters who prep for this way ahead of time but only one shoots at a time.
It went 9 rounds the year I won with a 26wssm custom. But last year I was whipped unmercifully(and so was everyone else) by a brand new Savage with Hornady 22-250 ammo. That surprised me, and another who had pre-demonstrated that he could cut a ragged hole all day with his LV6ppc. But it shouldn't have surprised us. We weren't hitting the center, the temps changed, the bag was packing, and timing between shots was ever changing(from hours to minutes). I'm sure it sounds easy, but nobody has won it twice in a row. And group shooting does not prepare you for this. It takes alot more work.

 

[edge]

For LONG RANGE HUNTING the right answer is always -first cold barrel shot -hits it's mark.

SNIP

This begs the question: How many folks shooting at long range fire a spotter?
( I am assuming that you are far enough away so that the sound of the rifle shot will not spook the animal....> ?? )

edge.

 

[Buffalobob]

For a hunter, in order to develop a load you must use some criteria to determine the precision of a load in striking the target in the same place repeatedly. A group that is two inches left and three inches down during load development does not bother me because I have knobs on my scopes. Shooting groups is how most of us do it. The 0.148 inch 3 shot group I shot last Sunday was fired over a 30 minute time frame. In other words each and every shot was cold bore. The way I shoot half MOA past 1K is the same - 10 -20 minutes between shots. I detest load development because it is a tedious business requiring nerve racking patience.

I beleive that Darryl Cassel and his shooting of spotters tries to hit at least 100 yards away from the elk. I have never found an elk dumb enough not to know it was shot at (brake or no brake) if you actually shoot at it. The last shot I took on an elk was about 1425 yards and the whole herd took off. I would love to find a dumb bull who would let me get a second shot. The same can be said for the antelope I have encountered. Even when you have a clean miss at 1400 yards and a braked rifle of small caliber they run like crazy. The last antelope I killed clearly knew I had shot at him but he didn't know where I was located because of the brake and actually ran from 1000 yards to about 800 yards.

 

[Forrest Ebert]

Rifle Accuracy !

Ian,
I like what you said about 1/2 " groups out of the box! I purchased a Tikka 7mm-08 for my girlfriend matte black finish put a Burris Fullfield 2 scope on it with the Tikka rings provided with the gun and have shot just about all the factory ammo available and can't even come close to the FACTORY GUARANTEE of 1" but now with handloads and some run of the mill Hornady 139grn. bullets and some 760 powder we can get .625 and less groups at 100 yards.
I don't know maybe like the Vanguard MOA. The Tikka was picked for handloads only !

 

[Rustystud]

Degree of accuracy of a rifle..

A "good" factory rifle, with "good" ammunition, and "good" scope, rings and bases, with a "good" rest and finally and most importantly a "good" shooter should be able to get 1. moa accuracy from a factory rifle.

Trouble is today we are short of the "goods". Quality has gone south when price has gone north. Good shooters are far fewer than a few years ago.

I build custom rifles and last night I tore down a Remington 700 5R milspec from the custom shop. The owner had fired approximately 400 rounds through this rifle. The best group he had acheived was 1.5 moa at 100 yards. I found the upper lug was not engaging by over .020. At the owners request I am truing the action and rebarreling with a 26" Broughton 5C 1:10 barrel. When this project is finished I hope to have a sub .5 moa rifle.

Weather my customer can shoot is another story. That is why I will do some load development and shot his rifle before he picks it up.
Rustystud
A/k/a Nat Lambeth,
Custom Guns and Ammunition.

 

[burnley]

This is a thread for discussion of the article, Degrees Of Rifle Accuracy by Ian McMurchy. Here you can ask questions or make comments about the article.

The author will have this thread automatically notify him of posts so that he can join the discussion. Here you can ask questions or make comments about the article.

An HONEST article

 

[Buffalobob]

I would add a comment on forcing a child to eat boiled okra. They don't like the slimey stuff and if you do make them eat it they will throw up on the table. Some days it is hard to be a parent.

Some rifles don't like boiled okra either. I shoot a 308 40X and it has a special match chamber suited for the 175 SMK . Dave King had a recipe on a box of ammo and that is what I use and I have never experimented with trying to improve it. That rifle will shoot the 175 SMKs into what ever group the shooter is capable of. Apparently, it will shoot down into the1s or 2s for people it likes. It seems to like my daughter, but appears to have a grudge against me. It refuses to shoot Accubonds under 1.5 MOA and it justs throws up all over the table when you feed it Nosler partitions. I cannot get the partitions under 2MOA.

 

[edge]

Keep feeding it the boiled okra, someday it will grow up

edge.

 

[Chopaka81]

MikeCR,

I love that shooting game/contest you discribed. I have just forwarded that to members of my gun club, my hope is that we can get some calendar time in late July/August to do a shoot that you discribed.

Way Cool!!! gun)

 

[johngfoster]

An HONEST article

I thought so too. I've owned 2 Remington 22-250s. Both shot between 2 and 3" out-the-box with factory ammo. My second one I had bedded and trigger adjusted down to 2.5lbs. What a difference that made! Just with these two "mods" my groups shrank to 1 to 1.5 inch consistently. I then had the lugs lapped and trued. Now it will shoot hand-loads around 0.5" most of the time. I did once get a 3-shot one-hole group, and happened to shoot a fly on my target with the 3rd shot. However, it will NOT do this "all day".

 

[travelr47]

Degree of accuracy of a rifle..

For hunting purposes, I agree with the post above, the first shot from a cold barrel HAS
to hit where I'm aiming! If that first shot is a flyer and I can't get the barrel to shoot at
POA on the first shot from a cold barrel and the second shot next to it, I'll replace it.
Fortunately, so far, I haven't experienced a situation where this has really been an issue,
I'm usually able to place three shots within an inch of where I'm aiming (first shot cold barrel, second & third shot after). Only speaking for myself, a one-inch group @ 100 yds
(3-shots), is normally all the accuracy I need for a hunting rifle. To get this level of accuracy from a factory rifle normally involves bedding the action and floating the barrel. If the trigger is terrible I call up Timney and order a replacement. If the barrel can't get the job done, the barreled action is sent off to get a new barrel. I bought a M700 SPS, chambered for 308 Win I'm currently working with. So far I've replaced the factory stock with one from H-S Precision, and the trigger with one from Timney. I haven't given up on the barrel just yet, but decision time isn't far away. The good news is that the rifle only cost me the same as if I'd bought just the M700 short action.

From my perspective hunting only requires one accurate shot with good shot placement
to fill my tag. Over the last ten yrs or so, I've rarely needed to shoot more than once.
I attribute this to good shot placement, excellent terminal performance of the bullets I
use, and the good judgement not to take a shot that I'm uncomfortable with, as much
as I do to the accuracy of my rifle.

Target accuracy is a bit more precise though. Several shots are fired in a string and the
barrel (and shooter) have to be able to hit the 'mark' repeatedly regardless of a hot or
fouled the barrel becomes, or position required. Consistency becomes as important of a
factor as barrel accuracy. From the first shot fired to the last, regardless how many
rounds fired, over whatever time limits imposed. Consistency won't necessarily produce
the smallest groups, but should limit 'flyers' to shooter error.

Then there is the question of distance. One load might produce sub-MOA groups at
100-yds, but open up quite a bit out to 300 or 400-yds. OTOH, another load might
produce 1.25" group at 100-yds and at 300-yds or further, tighten up to MOA or sub-
MOA. Between the two loads, I'd prefer the latter.

The shooter with the sub-MOA at 100-yds might think his load is very accurate. And
it is out to 100-yds. But it is important that the load is tested over all the distances
required at a target match, or hunting situation before assuming the load is accurate.

I'm a firm believer in practice, practice, practice. Both at a range as well as at home
dry-firing with snap caps.

 

[drbobc]

Response to Ian

Accuracy is an issue of four basic factors: 1) the rifle; 2) the sights -- usually a scope if long distance is involved; 3) the embedding of the action to the stock; and 4) the shooter. You cannot separate them into discrete topics very easily. Years ago I remember vividly getting a Japanese Ariska rifle rechambered for the 6.5 Gibbs wildcat. Barrel was short and the recoil was horrific. I would shoot it about 6 tomes and the peepsight would fall off the rifle. No one could have shot the rifle with any accuracy. At the same time I had a 1917 enfield rechambered for the 30-338 winchester magnum. Was done by the Kuharsky brothers (inventors of the B&L scope mount) and the rifle would cut bullet holes at a 100 yards. Was amazingly accurate. I now have a host of Weatherby Mark V rifles with 2 of them having properly embedded stocks. They are unbelievably accurate both the 240 that is about 50 years old and a new custom stocked 30-378. What makes them so accurate? Attention has been paid to all details. Jim Clark has worked on the stocks and embedded the actions. In other words, 3 of the 4 factors have been taken care of. I am the 4th and have been shooting for nearly 45 years. Fortunately I am not of small stature being 6 foot 3 and 225 pounds. I use quality components and can easily handle recoil. Shooting tight groups is not a factor it is an essential. For awhile I could not shoot worth a **** but cataract surgery has solved that problem. I can now see perfectly so most of the 4th problem has been corrected also.