How does everyone do it? I read continually how one rifle is 0.5 MOA and another is 1 MOA, well how was that determined? When I really want to know how accurate a rifle is I use a bench vise. To me sandbags offer far too much shooter induced error.

For hunting rifles, which is all I do anymore with firearms, I consider 2 MOA off of sandbags sufficient. I will tell you however that is a composite accuracy of shooter and rifle. I would not say my hunting rifles are 2 MOA guns, they are almost certainly much much better.

So do you use a bench vise system or sandbags?

SRS

For my serious accuracy tests, I shoot prone from sandbags.

I had a load for my 30-06 which was shooting well under 1/2" at 100 yards, but when I got into the field, the recoil dynamics from the prone position were such that I couldn't get the same level of accuracy at 300 yards. Groups were barely 3 inches, or 1 MOA.

I redeveloped that load, using my OCW load developement method mentioned here and elsewhere, and now the rifle is a consistent 1/2 MOA performer from the bench, and from field positions up to 335 yards.

For this reason, I think that the rifle and shooter of that rifle have to be evaluated in the shooting positions most likely to be encountered in the field. As I found out, it is possible to get a super tight shooting load worked up from the bench, and find that it doesn't perform in the field.

As I type this, my right shoulder is throbbing from shooting my light, recoil-padless model 700 Remington 700 ADL at 400 yards. I've decided that for MOA accuracy at 400 yards (4 inches) scope cant and recoil control are the major limiting factors. I'm doing about 6 inches at this point, 1.5 MOA at 400 yards, which for deer sized game should be more than adequate. For varmints it isn't enough. Preliminary tests at 465 yards show me getting closer to 2 MOA at that range. A scope level might tighten that up a bit, but would look a bit out of place on the 1972 vintage Remington and period Leupold Vari X II. And shooting at game at near 500 yards with that rifle would probably be illadvised.

I agree that a vise is the best way to eliminate shooter error, but of course the only way to know how rifle and shooter (composite accuracy as you cleverly put it) will perform is to get to the field and start shooting at targets and recording the information.

Dan Newberry
green 788

[ 08-25-2002, 05:53: Message edited by: green 788 ]

I will not use any type of shooting vise due to the recoil of my rifles.I shoot off a shooting rest with sand bag under the front of my rifle and sandbag under the rear.I work at developing loads until I am certain that I have found the most accurate load for each rifle.My own hunting rifles are customs that will average 1/2" or better off of sandbags with my handloads.I would never consider hunting with a rifle that averages 2" as I may be required to make a shot in excess of 400 yards(average is probably 200 yards)and at 400 yards a 2" group becomes 8"(off of a bench) which leaves no room for shooter error or field conditions.

Stubblejumper,

I think you misunderstood me. My 500 AHR will shoot under 1 MOA in the vise. I can routinely hold 2 MOA at 100 yards on the bench and 3 - 4 MOA offhand. What that means is that the rifle is capable of 1 MOA, the shooter is capable of another 1 MOA from the bench and 2 - 3 MOA off hand. That is a rather simplistic explanation of the distribution, but I hope it serves to illustrate my point. Comversely, I have shot 1 MOA groups off hand with the 500 AHR! Guess what, that was nothing more than the law of averages going the opposite way of the 5 MOA groups I sometimes touch off.

I guess I have little confidence in sand bag accuracy statements. Back when I was a kid I used to shoot in some competitions and my rifle would should .3 MOA! I could shoot about .5 MOA or so. I make this statement based on this data. The rifles accuracy was derived from a rifle vise on a grounded bench shot into a target at 200 yards. I could routinely hit (9 out of 10) 12 shotgun shell hulls at 100 yards. Since these measure just over .8" in diameter I figured I was about .5 MOA capable shooter. Now that was a long time ago and I am NOWHERE near that capable anymore. I simply do not have the time, or desire for that matter, to practice enough. The rifle was a highly modified M70 30-06.

What is the recoil of you rifles like that you feel they cannot be vise fired? I have shot up to and including 50 BMG sniper/target rigs on a vise before. No problems to date.

SRS

SRS,
The truth is that most 1/2 minute rifles are rifles that will, now and then shoot a 1/2 inch group at 100 yards. Or they will put a significant number of there shots into a half inch and the flyers are disregarded. To me a true half inch three shot rifle is one where the shooter can, on any given day, say "watch this" and shoot a 1/2 inch group or at least have a reasonable expectation of doing so.
A live varmint rifle that will consistently beat 1/2 inch for 5 shots is still not real common. A hunting rifle that will do the same is probably non-existent.
Anyone who has been involved in BR shooting for any length of time knows how difficult it is to keep a rifle working at the 1/4 moa level or better yet we always hear of the 223 Savage that shoots .2 all day long. Strangely, when this rifle shows up at a match the aggregate is usually more like .650.
Whether or not the hunting rifle really shoots 1/2 inch doesn't really matter in the end though does it? Really, as long as the rifle shoots well enough that the hunter is confident of making his shot it is good enough. If the hunter wants to believe his rifle always shoots 1/2 moa it probably does no harm.
If a person is shooting a target rifle it's a different matter. If he is shooting at a .5 moa x-ring then that rifle real does have to shoot .5 or better if he's to have a chance at a perfect score. If he's shooting a 308 in Hunter class BR he will have to shoot into about .375 every time and be perfectly centered to shoot a 50-5x.
To shoot a 50 with no x's a 3/4 inch rifle should suffice. I have watched a whole bunch of 3/4 inch hunting rifles try and fail at this by the way. And usually by a substantial margin.
Now I have seen some really nice groups fired and have fired a few myself. I have seen 375s shoot 3 shot groups that were well under 1/2inch. I shot a .400 inch group (4 shots. I chickened out and didn't fired the fifth) with a 45/70 Marlin. This was a pretty solid 1 inch rifle by the way. One of the best shooting hunting rifles I've ever had. A customer once fired 4-3shot groups under 1/2 inch with a 280 I barreled for him while I watched. This seemed to be a pretty honest 1/2 inch three shot rifle. But most 1/2 inch rifles don't seem to do this under scrutiny.
In general then, when somebody says they have a 1/2 inch hunting rifle I think it should be like that .280 and shoot repeated 1/2 inch groups at will. In reality when a shooter tells me his rifle shoots 1/2 inch I know it's probably a pretty good shooter and there's a chance it will produce a 1/2 inch group and it probably won't shoot a terrible group.
When I hear of a 1/2 inch varmint rifle that should mean a rifle that will put 5 shots into 1/2 inch on demand anytime. It will probably mean a rifle that has a pretty good chance of producing a 1/2 inch group and will certainly put most of the shots into 1/2".
When a BR rifle shoots 1/4moa then that rifle had better shoot 1/4 inch or better anytime the wind ain't blowin'.
When I say my long range rifles shoot 1/2 moa I mean that I can shoot 10 shots and if conditions are good those shots will hit within 1/2. I presently have one LR rifle which I feel may be a legitimate 1/2moa rifle. With it I have put 15 shots into about 6inches at 800 meters and just last night fired a five shot group of .650 and a ten shot of .9 at 200 meters.
I have a 308 Norma with which I have shot a bunch of groups under 1/2 inch (3shots) but I don't say it is a half inch rifle because I'm not certain that I could produce that 1/2 incher on demand. I'm not certain because I've also shot some 1 1/4 inch groups with the same rifle.
So when I'm told of a 1/2 inch 300 mag I'm not disappointed if it shoots one inch and I'm impressed if it really does shoot 1/2". I'm really impressed if it does it often. I've been impressed but I havn't been really impressed very often! Regards, Bill.

srs-What kind of vise do you use that can hold a heavier recoiling rifle?I have tried the varminter vise type devices and found that I can shoot just as well off sandbags as with these devices with a lot less hassle.When I say a rifle shoots 1/2" I mean that if I go out and shoot five groups and average them out the result will be 1/2" or better.Some groups may be 3/8"and some 5/8" but the average will be 1/2".

Firing a rifle from a vise adequate to hold it is the only way to ascertain rifle accuracy independent of the shooter's ability.

One of the biggest problems I have with the way most benchrest shooters evaluate a rifle's accuracy is they seem to factor out shooter induced error, essentially assuming that shooters don't make mistakes. I've been asked, with regard to my own rifles, "Okay, so you shot a few 1/2 MOA groups. Big deal. What does your rifle average , Hmmmm???" This makes no real sense in view of the fact that the shooter is nearly always the biggest wild card, and largest limiting factor in the composite accuarcy (I'm stealing your nomenclature there SRS!) of shooter and rifle. I can take a legitimate .2 BR gun and commence to trashing its average simply by shooting poorly.

So the question should be: "Okay, what do you and that rifle average?" That's a fair question, and that makes sense.

To fairly judge the accuracy of any rifle, it would have to be fired independent of human error. If you want a rifle's average that's the only real way to get it.

When folks are under scrutiny, human error nearly always escalates. I call it the "gameshow syndrome," so named because of the gameshow contestants who often miss simple questions they well knew the answers to because of stress.

I think there are a lot more 1/2 MOA rifles extant that most of us realize. It isn't their fault that they belong to folks (like me!) who often blow shots...

Dan Newberry
green 788

I have seen allot of guys that say they shoot less than one inch groups, but then can never do it while I am watching.

I have never got a 1" 5 shot group at 100 yards.

I got a 1.05" once.
That rifle will average 1.4" groups with hand loads from a benchrest.
But that rifle is a .223, and they are twice as accurte as other rifles for me.

When I'm trying to determine accuracy of a load/rifle, I like to shoot 5 10-shot groups. My heavy (17 lb) 30-06 usually puts 10 shots in about .8-1.1 inch, with 8 of the 10 under .4"

I feel a 10 shot group allows for a flyer or two and still 7 or 8 "groupers" to demonstrate probable accuracy expectations.

MM