Post by: Rob on September 09, 2009, 03:38:04 PM
But I have been trying to work up loads for a .204 ruger. I have I have data for 60 shot groups consisting of 285 individual shots taken over 5 different days. Average of about 4.75 shots per group. After pulling out a the Factory loads and two fliers, I end up with 52 groups made up of 253 individual shots or 4.85 average shots per group. The measurements are taken at different yardages which further complicate the data.
When faced with so much data and so many variables, I found it very difficult to do "like for like" comparisons of shot groups taken at different yardages. So as I was pulling my hair out over printouts of pivot tables from excel, I thought I would try to bring the data down to a common value for comparison
For example, look at the first table below and quickly try to tell which of the groups are best?
I tried applying an MOA rating to each of the groups, but even that was difficult and it is hard to sort text from best to worst. My solution was to level my groups and categorize them with a #. To do so I gave each group what I call an "EQ" Value, or Equalization Factor. The EQ is derived by taking the group size and divided it by the yardage, multiplying that by 100 and rounding that # to the nearest half number. So Eq=(Group Size/Yards)*100 Rounded to the nearest 0.5 This could be roughly equated to comparing all shots at 100 yards rounded to the nearest half inch.
Look at table #2 with two new colums. First I leveled the group sizes to 100 yards by multiplying the group size by the yardage and dividing by 100, then I round that to the nearest 0.5 so I have easy #'s to look at.
(By the way, the excel formula to round a # to the nearest .5 is "=mround(REF,0.5)" where "REF" is the cell that you are trying to round. if you wanted to round to the nearest whole #, you would change the 0.5 to 1 and so on)
If All I had to look at was the first three columns, that analysis is difficult. but by looking at the last column, I can easily see that groups 1, 2, 3, 5, 6,7 6 and 10 are better than 3, 4, 8 and 10. May not be a very exact way to look at the data but it sure simplified things. It is basically a way to calculate a form of MOA rating rounded to the nearest .5.
In table 3, you can see my EQ values for the 60 shot groups. Roughly 33% are under 1 inch groups at 100 yds, 50% are around 1 inch groups and the remaining 17 % are over 1 inch groups.
Post by: littlebuf on September 09, 2009, 07:02:05 PM
Post by: JoshT on September 09, 2009, 07:08:24 PM
Dude... you're using MOA... except where you called a 2" group and a 3" group at 300 yards both "1"...
Measure the group (C to C... or Outside to Outside - bullet diam.)... and devide by 1% of the yardage... that's MOA (or close enough). This is your magical "EQ Leveled"... and using Excel it would be very easy to sort the data based on this number. Then you wouldn't assume that a load that shot 3" at 300 yards was equal to one that shot 2.25" (30% better).
Post by: Rob on September 10, 2009, 08:55:36 AM
"It is basically a way to calculate a form of MOA rating rounded to the nearest .5."
It is not exactly MOA because it rounds in an unusual way as you pointed out.
The calculation has made it pretty simple for me to quickly look at a bunch of data and calculate it in a formula in excel rather than do it manually. Which is why I thought I would share...
Not trying to pull an Al Gore and state I invented the internet!
And yeah, work is a bit on the slow side... I'm leaving end of the month and I have pretty much finished up all I need to do before I go leaving me with a bit of extra time.
Post by: JackOfAllTrades on September 10, 2009, 09:58:36 AM
Calculating MOA of fired shots at given ranges is your best indicator of consistant accuracy.
Now... develope a pivot table for POI vs POA for cold barrel shots vs warm barrel shots with noted temperature of barrel at mid span.
That ought to keep you busy for a while...
-Steve
Post by: Rob on September 10, 2009, 01:34:13 PM
By rounding, you actually made a few groups appear to be equals when in the data, they are not.
Calculating MOA of fired shots at given ranges is your best indicator of consistant accuracy.
Now... developed a pivot table for POI vs POA for cold barrel shots vs warm barrel shots with noted temperature of barrel at mid span.
That ought to keep you busy for a while...
-Steve
POI/POA warm vs cold would be easy to do. Barrel temp would be easy if you could measure the temp and record it.
The rounding is, and is not, giving false info. Depends on how you use it.
It will assign a 1.0 value to any group size that after normalized to 100 yards that falls between 0.75 and 1.24. So yeah, it equates a 3/4 inch group the same value as a 1 1/4 inch group.
The problem I was solving for was trying to make sense of a large data set. Trying to look as 60 set of data grouped into 1/8th inch groups was causing me to spend more time understanding the data than interpreting it. By rounding them to the the nearest 1/2 inch I was faced with 4 groups of data (0. .5, 1, 1.5, 2) rather than 16 (1/8, 1/4, 3/8, 1/2, etc...)
For my purposes (trying to select a load for a rifle based on the group sizes) this made sense. For scoring yourself or trying to track your improvements, this makes no sense at all and a true MOA rating is better. (this is why I said in the first post that is it a form of MOA).
The problem of rounding to the nearest 1/2 can be solved by changing the excel formula and having it round to the nearest quarter. That takes about 3 mouse clicks. here is an expanded data set with the rounding set to .25 rather than .5. definitely more accurate data, but more data groups to look at.
Post by: Rob on September 10, 2009, 01:38:38 PM
Post by: Rob on September 10, 2009, 01:45:09 PM
Post by: JackOfAllTrades on September 10, 2009, 02:16:12 PM
I think I would look back at loading increments of Varget with the Vmax to attain ~4,000fps which seems to be the sweet spot for your barrel/that bullet.
Is this what you were thinking also?
When I work up a load, I set in with one bullet and load increments of powder charge to get the most accurate combination. Then I play with OAL/seating depth for the most accurate combination. I'm certain that you're only comparing results from once fired brass fireformed from that chamber and that you're adjusting cartridge length, verifying concentricity at the neck and bullet of a loaded cartridge?
Then I select a different bullet and do the same thing until I've got loads I like.
All at one distance to target. Bullets will behave differently at various speeds during time of flight taking into account cross winds and such at longer ranges.
You've got data from factory loaded cartridges, different bullets with different powders and charge weights with incomplete reference to velocity. What I look for in accuracy is often derived from the velocity numbers and trends of tighter groups in relationship to the velocity differences. A chronograph is your friend and should accompany you with every range trip if you're looking for the utmost in accuracy from that rifle.
-Steve
Post by: croix on September 10, 2009, 02:35:14 PM
Post by: Rob on September 10, 2009, 03:15:51 PM
My favorite part of this whole thing is the gun named Lorraine :chuckle:
There is a very specific reason I chose that name too... Can anyone guess? It is a bit obscure, but has it's roots in Washington State.
Honestly I'm a brand new re-loader so I'm up against a steep learning curve on all this and I am sucking up any advice that is offered so I appreciate that. I do have a chorny, but if I'm shooting with friends I can't set it up (have to be on the public side of the range and they don't allow them). Also if I am just going to shoot for an hour or so, then taking the time to set up the Chrony is a bit intrusive. But you are 100% correct, that data is pretty important.
As I understand it, for each bullet/gun combo, there are 5 variables to play with that will impact grouping and velocity(primer, brass, powder type, powder charge, OAL). did I miss any?
Primer:
-I am shooting CCI SR primers and with the scarcity of primers these days, that is pretty much a fixed variable for me.
Brass:
-My brass is all over the board. Some of it has been fired, most of it was brand new at one time or another. I have Rem and Win brass. Not sure I know what this means "verifying concentricity at the neck and bullet of a loaded cartridge" but I do validate cartridge length and inspect each case prior to priming and loading.
Powder Charge:
The faster loads seem to shoot pretty good, and I'm not seeing signs of high pressure at max recommended loads so I have decided to stick with max loads for now. This may be a bit backwards based on what you have said.
This leaves Powder type and OAL as the main variables that I have been playing with. Trying to play with both at the same time is just complicating matters I have come to see. Having FPS averages for these would help. but in lack of that, here are my observations:
Varmint Grenade
o The Varmint Grenade data is limited and there is no smoking gun that says one specific OAL is better than another.
o There is a slight indication that the VG's like 2.24 and 2.3 OAL as the V-Max's do, with the shorter and longer OAL's having the larger group sizes.
o The Varmint grenade is also a smaller data set leading me to believe I need a larger sample size.
o As far as powder goes, pretty clear winner here. The RL 10X seems to outperform the W 748.
V Max
o The V-max's seem to like the shorter OAL's 2.24 and 2.3 are the favorites regardless of powder.
o All the powders seem to shoot well.
o I eliminated the Varget as both the N 140 and W 748 seem to outshoot it.
o I would like to see more data on the H 4895 as I only have 4 data points total.
So my thinking is, I need some more data points with more constants. I plan on loading up 160 more shells:
For each of the following bullet/powder combos, 20 in 2.240 and 20 in 2.300 OAL's
Varmint Grenades: R10X
V-Max H 4895 W 748, N140
I will also be striving to get the chrony set up for all the future sets.
Post by: JoshT on September 10, 2009, 04:52:34 PM
Make sure you're shooting the same brass with all the loads that you're comparing... stick to the Rem. or the Win... but don't mix them. Internal capacities vary quite a bit between manufacturers... so the same load could vary drastically between the two types of brass.
In my .204 (looooong gone by the way) the Hornady 39 grainers shot the best... though I only tried those and the Sierras... don't know that the varmint grenades do anything for me, they have a BC roughly equivilent to a ping pong ball.
I haven't found a gun yet that I can't find a load for in 50 or so rounds... certainly less than 100... and my accuracy standards are pretty high for "varmint" type rounds. Load development isn't rocket surgery...
Post by: JackOfAllTrades on September 11, 2009, 10:43:31 PM
Quote
You're WAY over thinking this thing man. Pick one bullet... one powder... and one OAL. Find the charge that shoots the best, then play with the OAL a little to see if groups improve. If your results don't yield an acceptable accuracy outcome, switch powder and start again, or switch bullets and start again.
Make sure you're shooting the same brass with all the loads that you're comparing... stick to the Rem. or the Win... but don't mix them. Internal capacities vary quite a bit between manufacturers... so the same load could vary drastically between the two types of brass.
Josh saved me a BUNCH of typing..
-Steve
Post by: Rob on September 12, 2009, 10:51:37 AM
Thanks for the input.
I have the loads all set, so I'll shoot them over the next few days and see what happens.
I normally don't shoot well enough for thinkgs like brass type or minor OALK changed to make a noticable difference. Thsi gun shoots quite well so I can actualy see the difference which has been fun.
Post by: JackOfAllTrades on September 15, 2009, 12:00:25 PM
You should be able to match (at the least), and probably cut that group size. Also, you should be able to talor your loads to the game/ranges you're hunting. That's what hand loading is all about. If you're just hand loading to save money, you're missing the big picture. I don't care how fast a bullet goes, but if you can't hit anything with it, it's useless. Having a varmint rifle for little ground squirels at 300yds, with some of the 'poor' groups you list is not worth owning/reloading for. So, you should strive for accuracy that at least matches factory ammo, or just not reload for that toy at all.
Differences in brass does matter! And the more you shoot, you will learn to shoot better. As you get better, you'll demand more from yourself. You'll demand more from your rifle. You can't do that with variables in your ammunition. :twocents:
There is a line where you need to back off.. No, your rifle/ammo/shooter isn't capable of groups smaller than the bullet diameter. :chuckle:
-Steve
Post by: Rob on September 15, 2009, 02:40:40 PM
I reload for three reasons. Cost, accuracy and pleasure. (no particular order). I expect better results from reloading than factory rounds. I also find it fun to sit down at the bench and reload for a few hours. Certainly the cost is offset by the time it takes to re-load so if I did not have fun I would just buy ammo. I'm new to reloading so I do not expect to be a pro after only a few months of loading.
I only have 8 data sets for factory ammo. The Remington Actutip’s do perform well, but I think overall my re-loads are doing as good or nearly as good. That ¼ inch group was pretty cool though! They were definitely better than the Hornady factory rounds. The first table has my data for the factory loads.
I am now tracking brass type and primer in my data.
I know this gun will shoot 1/4 inch groups or better at 100 yards if I work on it. The factory 3 shot bench target they sent with the gun was a single hole group probably .22 caliber in size...
I did hit the range on Saturday and I shot 16 5 shot groups.
four groups for each of the following config:
-Barnes Var Gren RL 10x at 2.240 OAL
-Barnes Var Gren RL 10x at 2.300 OAL
-Vmax H4895 at 2.240 OAL
-Vmax H4895 at 2.300 OAL
I got Velocity info on half of the sets. I had issues with my chrony half way through the day and it took several sets to correct it. For those sets I was able to get Velocity info on, within each set, the readings were within 1.5% of each other in all but one of the sets (one was 2.25%). (FYI I calculated this by taking the max reading minus the min reading as a percentage of the average reading-not sure if that is how others figure it out or not). I interpret this to mean my loads are pretty consistent.
Largest group was 0.875, smallest was 0.375, average across all groups was 0.6.
A table is listed below. My conclusions are:
-The 32 grain V Max seems to outperform the Barnes with only 2 of the 8 Barnes groups coming in under a half inch vs 4 of the V-max. I think once I shoot up the bullets I have, I am done with Barnes for the 204.
-The worst performing round was the Barnes V grenade in 2.300 OAL
-The best OAL was the V Max in the 2.240. (2.240 was better for Barnes too)
So next steps:
I have 80 more shells to shoot in the V-max. 40 in the N140 and 40 in W 748 (both powders have 20 in each of the two OAL's).
My prediction is that the W 748 with an OAL of 2.240 shooting 32 grain V max's will be the shell I choose.
Then I'll load a bunch of those up and head of to Wyoming for a little bit of varmint hunting. When I get back I’ll start seeing how they shoot out at 300 yards. (will try to play with that before I go to Wy time allowing)