Just TWO-shot groups to start?

[AlNyhus]

Maybe so, but I'm not set up for that and probably never will be.

All you need is sized and primed cases, a way to put powder in the case and seat the bullet.

Throw your charges at home into vials. Take your press and a couple 'c' clamps to the range and clamp it down. Put powder in the case, seat a bullet and shoot.

 

[Bill Norris]

Two shots testing anything will tell you as much as three will even if the third shot goes in the same hole with one of the other two. Group is still the same as it was before you shot the third shot.

 

[Kracken McGraw]

If you have confidence in your bench technique why not? Your testing in small charges or seating depth increment anyway, it should tell you what’s going on.

 

[c_bass16]

I heard that shooting, the first time out with the rifle, only TWO rounds (and two groups) per combo during load development was a good way to save a little money and barrel life...as in...if the first 2 shots didn't produce one hole or at least a bughole, why bother shooting a third?

Opinions?

Two shots won't tell you if a load shoots well...but it will absolutely tell you if it DOESN'T

This is how I start load work up. 2 shots up to pressure looking for patterns, either vertical or horizontal.
(if 3 consecutive loads get progressively tighter, that's what I look to focus on when I eventually start doing develpment)

 

[Andy Work]

Two shot groups are fine for a rough in, then fine tune with more.

 

[Webster]

If you flip a coin twice and get two heads, would you stop and declare it a two-headed coin?

I think the way I first heard this expression it was worded better. If you do the same thing over and over and get bad results do you think repeating it will evenually give a good result?

 

[Ccrider]

I’m not the sharpest tool in the shed but I’ve learned to tune power nodes with two shots per increments.

Ok. Tell the unknowing what the two shot groups show? Where did tune end up?

 

[450BM]

Ok. Tell the unknowing what the two shot groups show? Where did tune end up?

Simple, they show you if you want to continue or not.

 

[JEFFPPC]

I have been doing it for years.

 

[BoydAllen]

What it all comes down to is the quality of the rifle, the ability of the shooter, conditions and the related equipment. I have a friend who shoots his competition short range rifles very well. He does his initial powder charge testing, on days when the wind is suitable, over flags, off of a concrete bench, with excellent rifles, shooting two shot groups, You can see the groups change with the powder charge. On the other hand, with a lesser rifle I think that more shots would be appropriate....but who is interested in "lesser rifles"?

 

[JEFFPPC]

If your first 2 shots go in a hole shot another 2 shot group with the same load if they go in a hole your on to something. Next day repeat, if you get the same results you have found a winner more than likely.

 

[KMW 1954]

...if the first 2 shots didn't produce one hole or at least a bughole, why bother shooting a third?

Opinions?

I guess the better question is, are you capable of shooting that consistently? I know I am not that good.

 

[K22]

If I was a cyborg, two shots might be reliable. But even off the bench with a high-quality front and rear rest, I still submit, shooter error can come into play to give unreliable data, at least for me.

With that said, I have used 3 shot groups to bracket loads for further testing but before I accept a load as my go to load for full scale production, I qualify the load with 3, 5 shot groups, often shot on different days.

However, each of us has their own method so there I more than one way to "skin a cat". The one absolute I would suggest however is do not use a lead sledge in load development.

 

[Bill Norris]

If I was a cyborg, two shots might be reliable. But even off the bench with a high-quality front and rear rest, I still submit, shooter error can come into play to give unreliable data, at least for me.

With that said, I have used 3 shot groups to bracket loads for further testing but before I accept a load as my go to load for full scale production, I qualify the load with 3, 5 shot groups, often shot on different days.

However, each of us has their own method so there I more than one way to "skin a cat". The one absolute I would suggest however is do not use a lead sledge in load development.

Yes verification with 3 to 5 shot groups after the test is needed.

 

[KMW 1954]

With that said, I have used 3 shot groups to bracket loads for further testing but before I accept a load as my go to load for full scale production, I qualify the load with 3, 5 shot groups, often shot on different days.

I follow this same concept. Then once I have one I like I load that one again and also one each side of it and test 2 or 3 times to assure it repeats.

I don't qualify as a "High Master" so I need more shots.

 

[RabbitSlayer]

I do 3 shots and I pick one or two that look good near the velocity I want. Then I load 25 of each and fire a 5 shot fouling group and a 20 shot group. The more I do this, the more I find that those smaller changes to the load don't matter much once you get a larger sample. If these small changes do matter a lot, it takes a bench gun and a better shooter than me to see it.

 

[Webster]

I heard that shooting, the first time out with the rifle, only TWO rounds (and two groups) per combo during load development was a good way to save a little money and barrel life...as in...if the first 2 shots didn't produce one hole or at least a bughole, why bother shooting a third?

Opinions?

Why would you think a good load would show 2 shots touching. If the rifle and load are capable of shooting a 1/2" group the 2 shoots would be 1/2" apart.

 

[dgeesaman]

Two shots that make a bad group are always bad. Two good shots don't mean it's good. Even with 3 shot groups there are some 'lucky good' groups. As long as you keep that in mind, it can be useful for tuning.

 

[foxguy]

What seems to be working pretty well for me. Before going out to shoot I research on this site what bullet seems to be shooting pretty well in the Caliber I am going to be testing. I also research the general seating depth that the bullets like. I research the preferred Powder that the caliber likes. Now I know the bullet, Powder that I want to test. I select a mid-range Powder Charge and go onto seating testing. I find the Lands with my bullet and start from there. Some bullets like to be seated into the lands and some Bullets like to be seated off of the lands. My research on the bullet has usually identified to me which direction to start testing.
I will test seating with the mid-range of the preferred powder seating into the lands or off of the lands whatever the Bullet generally likes. loading 2 shots of each seating depth and shooting on a pretty windless day usually early morning. I will have 6-10 seating depths to test, and the target will usually tell me what seating depth that the bullet likes. After determining the preferred seating depth, you can try increasing your powder charge in .2 gr increments (I do 2 shots of each charge initially) and see if an increased charge can tighten the group more. Some larger calibers you can increase you powder charge by .5 gr increments.

Good luck, the 2 shot group testing has been working for me when shooting in very mild wind conditions.

 

[CharlieNC]

Why would you think a good load would show 2 shots touching. If the rifle and load are capable of shooting a 1/2" group the 2 shoots would be 1/2" apart.

Exactly. My point with flipping a coin twice and stopping if two heads came up was to simply illustrate that some historical experience/knowledge must be available in order to develop a rational criteria. Fewer shots are required for a precise BR rifle vs a hunting rifle.