How much "Extreme Spread" is acceptable in competition?

[Mulligan]

View attachment 1065886 Here is a perfect example of what Dusty is referring to. You will see far more difference in type than weight

I will not be shooting targets, only recording chrono speeds on my labradar.
CW

 

[Mulligan]

very interesting
I take it it is a given that necks are clean inside and annealed as in any test changing only one variable at a time to PROVE the test
I had never considered primer weight
I am finally getting single digit es
but only at certain charge weights
usually during the seating depth test
which may be a fluke
I am looking forward to hearing(reading) your results
thank you

I will clean the inside of the necks with a brush, however I will not be annealing. I plan to load at the range, and do all the test firing with two pieces of brass.

CW

 

[Mulligan]

Ever get an unexplained flyer? Would you turn down a reduction of 25fps just for doing a little no-brainer grunt work? Thats enough to kick me out of the xring on ftr at 500yd, which I need to maintain to get all the help I can for crappy wind calls. While this degree of improvement may not be the norm, the effect is enough to motivate me to evaluate for myself.

If you look at the current scores at the nationals, dropping an x or two is not going to help.
Those are some seriously tight races!
CW

 

[CharlieNC]

Yes
I get a my share of fliers. I create a base load to compare to then one thing at a time.
IMO weighing primers is a final tune for that perhaps extra tiny bit.
I ask competition shooters if they weigh primers some do and some do not, does it help? No one I ask knows for sure what tiny difference they could make.
Jim

A number of top flight long range shooters whom I highly respect wrote about sorting primers to clearly improve accuracy. This was a year or so ago, and they dont post much anymore like a number of top shooters because they became tired of sharing their hard earned experience only to be challenged to provide proof.

 

[BoydAllen]

It seems to me that some of you fellows have failed to grasp the concept of what he is testing. This is only about how variations in primer weight affect velocity. You could shoot it into a dirt bank, with no target, during a wind storm.

 

[JFrank]

It seems to me that some of you fellows have failed to grasp the concept of what he is testing. This is only about how variations in primer weight affect velocity. You could shoot it into a dirt bank, with no target, during a wind storm.

Quite right indeed! Forgive me for interjecting

 

[jimmymac]

Shooter ability is the one variable you did not figure into all of the testing. I shot a friend's 6PPC LV rifle a couple weeks ago. No wind flags, not much wind. I shot a group with zero horizontal, and about 1 1/2 bullet holes of vertical. At 100yds, that gave me a .290" group. What does that tell me, other than the wind blows all the time here in Idaho? Was the rifle or the shooter at fault?

A .290 is big for a PPC. IMHO, if the rifle is tuned and regularly shoots smaller than that then it was you. With no wind flags, you don’t really know when you should be shooting or not. With the limited info you provided, I’ll go with the shooter being the limiting factor.

 

[Alex Wheeler]

Easy test. Color and shoot them at 1k. Share your results if you like to hear that you dont have enough scientific data or that you cant see a difference at 100 in a ppc!

 

[jim_k]

So what happened, Tom? I guess I can do the test myself, but you already did, and I think yours is likely to be more reliable than mine.

 

[denobravo]

I will clean the inside of the necks with a brush, however I will not be annealing. I plan to load at the range, and do all the test firing with two pieces of brass.

CW

we know carbon is lube
we know neck tension is affected by not annealing
If you are going to test , maybe use new brass
and just curious
how much neck tension are you going to use

 

[Mulligan]

Clay,

I'm not a statistical "type" so you'll have to pick through the other posters suggestions.


What I am is a straight to the point "type" lol. When I wanted to test this I loaded up a few of the lightest and a few of the heaviest. I fired them in alternating sequence at the same poa at 1000 yards. I don't look at the groups, but look to see if there is a discernible point of impact difference.



Tom[/QUOTE]

Right there with you Tom!
CW

 

[Mulligan]

we know carbon is lube
we know neck tension is affected by not annealing
If you are going to test , maybe use new brass
and just curious
how much neck tension are you going to use

We will have to wait and see which shooter I end up using. So far I seen one vote for the Dasher and I think one for for the PPC.
CW

 

[Mulligan]

Easy test. Color and shoot them at 1k. Share your results if you like to hear that you dont have enough scientific data or that you cant see a difference at 100 in a ppc!

I might have to move to Montana! I’m picking up what your putting down.

Besides, I’ve spent 4-6 weeks there each of the last few falls....wildfires.

You know, I discovered you have as many yuppies up near the Whitefish as we do in Telluride. Yaak was ‘bout perfect!
CW

 

[Liven The Dream]

Well from a Fellow F/TR Shooter (.308 ).
He had His perfect load with new Sierra 195 gr. Bullet . He took Silver in Rocky Mountain Match.
In tuning this load He found the Trick was Neck Tension ??

I wonder if the Anvils are not the problem some Higher or lower in the Cup ???
I will have give this more time to set in ..

I have been testing my .308 F/TR with Varget and 185 Berger J-Nots , I have had a great deal of trouble with Grouping ??
Great number on the Crony . Change Seating neck Bushing and Primers CCI 450 and Wolf SRM the Primers made little to No difference …

I switched to H4895 and got 5 shot group of 5/8" at 200 yards ???? As stated by many H-4895 has a Bigger push over Varget plus pressure .

I will test German Salazar's go to Powder in coming days IMR 4320 ????

Barrel Burner at Work

 

[Shawnba67]

Gotcha, thanks Joe
CW

Wear a glove, depriming is one if bigger sources of lead expose in reloading.

 

[Alex Wheeler]

I might have to move to Montana! I’m picking up what your putting down.

Besides, I’ve spent 4-6 weeks there each of the last few falls....wildfires.

You know, I discovered you have as many yuppies up near the Whitefish as we do in Telluride. Yaak was ‘bout perfect!
CW

Yep we are still too close to the west coast!

 

[fredo]

we know carbon is lube
we know neck tension is affected by not annealing
If you are going to test , maybe use new brass
and just curious
how much neck tension are you going to use

The concern this gentleman is alluding to, is legit.

If the test is to compare primers, you must 'control' the brass as a constant, best you can...
With subsequent firings, necks are gonna work harden & affect bullet release. Which, in turn, can & will affect both velocity, and POI. So, just sayin...in order for a primer test to be scientifically sound (valid), the brass issue needs addressed...

Most efficient way I see doing that, would be to use brass from a sample of 1x fired, fully prepped. 1x fired will allow brass to form to your chamber, and allow for a minimal resize that you can control...

Before that first resize, neck turn all brass to uniform thickness, and trim to same (nominal) case length

Finally, weigh sort those cases to help insure a consistent case volume.

Once you have enough of that 1x fired 'near perfect' brass, then you can use them for your primer test. And, fire each only once! This is the only way to help isolate the brass itself from skewing the data your are collecting to compare primer weights...

If you use the same brass, over and over, you are invalidating the test you worked so hard to set up!!!

Wish you all the best! You've got more patience than I to do this kinda stuff, so curious to as to your results. Just remember garbage IN / garbage OUT, so make sure your brass 'control' is in place. Otherwise, your test will not be valid...

 

[BoydAllen]

I disagree completely. All that would have to be done with a single case is to alternate weights of primers as a single case was loaded and fired.

I interviewed the fellow that won this year's IBS 1,000 nationals (who won four out of seven traveling trophies) and he used brass that may have had 15 to 20 firings on it that had only had been annealed one time early in its use. He told me that he used it because it still felt very consistent when seating bullets. Unfortunately I did not think to ask him if he had had to adjust his load based on the number of firings.

There are many possible sources of variation in velocity, by carefully weighting all charges, putting them in containers, and loading a single case at the range, IMO we have the best chance of eliminating variations caused by differences in cases' hardness, and neck ID condition. A simple brushing does not remove all powder fouling, nowhere near.

What is being looked at is the difference in the average velocities produced by light and heavy primers. Based on the OP's preliminary results there is a significant difference that could have an effect at the longest ranges.

It is my impression that among 1,000 yard benchrest shooters, weighing primers is not uncommon. I used to think that this was probably just silly overkill. Right now, it looks like I was wrong. Testing this at long range based on group size introduces the issue of positive compensation that reduces the effect of velocity variations. If we simply want to look at velocity variations, a chronograph is the best tool.

 

[fredo]

Just stating the obvious that, in scientific test, one must eliminate and/or account for, any/all potential variables that may skew results. Without that, there can be no way to attribute results of the test to any one variable, much as we'd like to...

Explaining away variables is convenient, especially when the results of the (flawed) test are already assumed to be valid. And, even more so when some amount of success has been achieved, based on that (flawed) data...

Unfortunately, "because the shoe fits" is not a step in the scientific method.

 

[BoydAllen]

Just stating the obvious that, in scientific test, one must eliminate and/or account for, any/all potential variables that may skew results. Without that, there can be no way to attribute results of the test to any one variable, much as we'd like to...

Explaining away variables is convenient, especially when the results of the (flawed) test are already assumed to be valid. And, even more so when some amount of success has been achieved, based on that (flawed) data...

Unfortunately, "because the shoe fits" is not a step in the scientific method.

So, tell us of your properly done test, and the results. Your post seems more than a bit vague. Saying that something is obvious hardly qualifies as a proper challenge of a procedure. I think that the test of the validity of results is whether they are reproducible, using the exact same procedure.

You have offered exactly no proof of your assertion of the faults in his method. You only say that they are obvious.