Range Report 0.2gr= difference between 1.5 MOA and 0.25 MOA???

[bodywerks]

Working up a load for my new savage fcp HS precision in 308. I did about 20 rounds of break in using the shoot, clean, shoot method on the same day of load work up. Then i started with a clean barrel and shot 5 foulers, then three 3 shot groups of different loads, starting with 43.1gr of varget under 175 smk's and going up in .2gr increments from there:
43.1 = 1.5 MOA(100 yards)
43.3 = 0.25 MOA
43.5 = 0.8 MOA
Then i took a break, cleaned the barrel, shot 5 foulers, then:
43.7 = 1.1 MOA
43.9 = 0.45 MOA (consequently, my go-to for my last savage)
44.0 = 1 MOA (but two bullets went through the same hole)
Anyway, does this look like a typical work up or more like inconsistencies in the barrel or shooter? Based on the shape of the groups, the 43.3 and 43.9 varied only in windage (and mirage was a heavy left to right flow) and yielded the best groups. The others varied more in elevation and windage.
So, am i seeing myself up for failure expecting 43.3 and 43.9 gr loads to be my primo loads? I guess i question the ability of .2gr to affect a group by over an inch...

 

[Captain Kirk]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

I'd try a few more in the 43.9-44.1 charge weight, I just think you need more data. Could have been a little shooter or mirage as well. Its not comon for a loads to vary that much with +/- .2gr, you need more data. If you have a chance you may want to run your loads over a chrono at the ame time, just gives you that much more info.

Kirk R

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Thanks. I do have a chrony so I'll try that. 44gr is already a good bit above max for varget under a 175gr bullet, so if i don't have an accuracy node in that range I'll probably go down from there. I'm going to try three consecutive 3 shot groups of the 43.3 and 43.9gr loads to check for consistency.

 

[victorz]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

What's your twist rate and barrel length ?

I have good luck with 44.1 Varget and 43 Varget, FC brass, CCI Br2, 2.80 OAL. from my CZ550 Varmint 26" ,1:12 bbl and SSG69 P2 1:12, 26" bbl.

I load up to 45gr of Varget with no problem, but I do feel the kick is much harder.

 

[TiroFijo]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

While everyting is possible, I second the "I think you need more data" motion

In a 308 class cartridge 0.2 gr won't normally (ever?) change the groups from 0.25" to 1.5", and I don't think that any "normal" rifle will group <span style="font-style: italic">consistently</span> into 0.25" either.

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Thanks. I do have a chrony so I'll try that. 44gr is already a good bit above max for varget under a 175gr bullet, so if i don't have an accuracy node in that range I'll probably go down from there. I'm going to try three consecutive 3 shot groups of the 43.3 and 43.9gr loads to check for consistency.

 

[Early Cuyler]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bodywerks</div><div class="ubbcode-body">Thanks. I do have a chrony so I'll try that. 44gr is already a good bit above max for varget under a 175gr bullet, so if i don't have an accuracy node in that range I'll probably go down from there. I'm going to try three consecutive 3 shot groups of the 43.3 and 43.9gr loads to check for consistency. </div></div>

Are you getting pressure signs at 44gr of Varget? I'm tinkering with Varget under a 178 Hornady BTHP and barely got flattened primers at 45.9gr. I do have cratered primers, but my DTA cratered the primers at 43.1gr too as well as Black Hills factory loads.

 

[Casey Simpson]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???


Study these two topics.

Barrel whip

Optimal Charge Weight

 

[George63]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

statistical error due to the small sample size - if you shot 10 rds of each charge weight those groups would end up closer to the same size

not that there is any need to, you got the data you need - it is highly unlikely that a larger sample size would reverse the size relationship between the groups

 

[caustic]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

add ladder test to the study topics list

 

[KYpatriot]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

You are not seeing real group changes like that with .2 grains of powder difference. Start over. Make sure your ammo is consistent first...weigh every charge (i use a beam scale for this) and use a comparator to make sure you have the same length to the ogive for every round.

Load twice as many rounds so you can do the test twice if you need too. Shot the groups round robin style. By round robin, I mean shoot one of the 43.7 at one dot, one of the 43.9 at the next, one of the 44.1 at the next and so on. Wait a minute or more between shots. Focus hard on fundamentals, same body position and trigger pull for every round.

The key is consistency and to take as much of your error out of the equation as possible so you can see how the groups vary based on powder changes. If you shoot well and do this right, you will see a small group slowly grow into a larger group and then back down to a smaller group again as you go up in charge weight, this pattern will repeat until you are happy with velocity or you see pressure signs.

By the way, I shoot 45 grains varget under a 175smk in FGMM brass. Every rifle is different so be careful, but i doubt you are seeing pressure signs at 44 grains.

 

[Captain Kirk]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

If you have the ability to take some of your loading gear to the range you could arrive to a good load MUCH faster. I have a forster coaxial and a cheap powder dispensor mounted on a portable table, all brass is prepped and primed so its just dump the powder and seat the bullet. I will run every load over a chrono but will have no idea what the charge weight is, just looking for a accuracy node and watching velocity and pressure signs. Once you achieve the desired velocity and accuracy you can even tweek with seating deapth, check velocity the entire session. Once you get home you dump another charge from your dispensor and see what the weight was for your proven load and your done.

I have been able to find a go to load in under an hour using this method, no going back home wondering what you can do to pick up the process and you are saving a lot of loading componants.

Kirk R

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Thanks for all the info guys. The group (if you wanna call three shots a group) measurements i posted were actually just guestimates while i was trying to keep myself awake on a 24 hour roadtrip. I got home today and actually measured them and all but the 43.1 load were quite respectable for a factory stock rifle. Turns out the groups are as follows:
43.1 = 1.25 MOA
43.3 = .24
43.5 = .75
43.7 = .47
43.9 = .55
44.0 = .58
Thanks for all the info and suggestions. I love striving for accuracy. I have a chargemaster 1500 that i usually use, but when it comes to working up a load I use my digital scale and hand trickle the charge until one granule causes the scale to turn to the desired charge weight. It's not as accurate as using a .02gr $300 scale but it's pretty close.

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Oh, FWIW, i am using a redding match bushing neck Sizer die (with the button, considering getting rid of the button) and a redding micrometer bullet seater. I did measure distance to the lands in the chamber and i seat my bullets to be about .010" off, resulting in about a 2.813coal.
These were also factory new hornady brass that i only neck sized prior to loading.

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Pics in case it matters. Don't have the 43.1 pic but it sucked anyway:

43.7 below

Two shared the same hole on the horizontal cross hair

 

[TiroFijo]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

In my opinion, this is just a typical case of random load/rifle dispersion + external variables commonly encountered with 3 shot groups.

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

I think you're right. I'm still gonna load several more 43.3 and 43.9 rounds and shoot groups through a crony. 43.9 worked well in my last savage so it should hopefully do well in this one.

 

[Josh Elam]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

I would shoot it all again with at least 5 shots per group. I like doing each test twice with 5 shot groups. After testing today I plan to go back out and redo it at 300 yards. Either way you have a shooter.

 

[timelinex]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

What brass are you using? With Winchester brass and 175smk, my load in my savagr is 44.8gr. 44gr would have been a very mild load.
As long as you aren't planning On shooting too long distance though,, sounds like the charges you found will do, accuracy wise.

 

[caustic]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

shoot more then one set of each group, test sample is too small to ensure it was not you.

NO 3 shot groups , 5 shot min.

 

[wadebrown]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

I would shoot more than 5 fouler shots unless you were experienced with that barrel and knew it settled down in 5 and I would not be cleaning between as you did.

 

[Greg Langelius *]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Load development requires adherence to the Scientific Method. That means that testing must allow only one variable at a time.

Testing different seating depths, primers, and powder charges all together is an inevitable invitation to absolute confusion.

My order: charges, primers, seating depths; bearing in mind that once one variable is set, preceding ones might improve with review. I.e., once charge is set, and then primers are set, try a little variance in charge weight with the newly-set primer. Some further improvement might emerge.

Once you have your recipe, test it rigorously. Never entrust a long term handloading spec to a hastily developed load recipe.

Greg

 

[alpha6164]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

There is no way that assuming all other variables were same that 0.2gr difference would make a difference from 0.25 to 1.5MOA. And the proof to that is i have pulled Federal Gold and Black Hills match ammo and there is difference of up to a little more than 0.5gr in the same box of ammo and obviously all shoot sub-MOA. So there is no way that 0.2gr can change barrel harmonics that much. Not to say you are not a consistent shooter, but unless you got your rifle in a rest there is no way to take your own errors out of the equation.

 

[Greg Langelius *]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

My experience suggests that with FGMM both shooting well and demonstrating what a handloader would consider unacceptable charge weight variances; there has to be some other critical variable at work here.

My guess involves bullet pull force/neck tension. Somehow, I'm guessing that Federal has managed to get their neck tension/pull force up to a degree of consistency that most of us are simply not seeing. Don't ask me how. My best guess is that there is some sort of coating involved.

Greg

 

[mdesign]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

I wish I really understood neck tension and how to measure and control it. I have consistent wall thickness and a reasonably controlled annealing process but I wish there was a low cost way to know and understand it better.

I've reloaded for many years but really do not feel like I know this part of the process, how to test it and how to know if it is affecting my load.

 

[wvlapua]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

Looks like your rifle shoots best fouled with 8 shots.

 

[bodywerks]

Re: 0.2gr= difference between 1.5 MOA and 0.25 MOA???

All very good info. I'm starting over with load development, as it had been a year since i had shot when i first did this load work up. I need to get my basic shooting technique back. I know it's off because i can't keep control of the muzzle jump and spring shots like i used to. Im going to try the ocw method on a rest and see where it takes me.
Wvlapua you are right. For some reason these savage barrels need a lot of foulers. I seem to shoot high and right for the first 7-10 rounds and then it finally settles in. What sucks is the tightest groups I've ever had almost always seem to be in the first 10 shots. Fml.