Posts: 27
Threads: 6
Joined: May 2019
Posts: 222
Threads: 13
Joined: May 2016
Your rifle may not like the SST bullets. There have been others that have said SSTs weren't the most accurate bullets they have shot.
Or the rifle doesn't like the SSTs with the CFE behind them. It could be one or the other, or both.
You could try going up in length as long as the mag allows it just to check that possibility and satisfy your curiousity.
My experience with CFE was that it is way too temperature sensitive for my use and for my Grendels I'm now sticking with 8208 XBR.
Your loading practice seems to work for your other loads so that probably isn't a factor.
If it was me I would change powder first and see where that takes you.
Posts: 480
Threads: 60
Joined: Oct 2020
My rifle doesn't like the SST bullet... CFE223 works great with the 120gr, 123gr ELD, Sierra 123gr MK, Lapua Scenar
123gr, and the 120gr Barnes Match Burners bullets...
30.0 grains OAL 2.260...
Posts: 7
Threads: 3
Joined: Dec 2016
CFE223 has been very accurate in my Larue barrel with 123 grain HPBTs from Midsouth. Ive found in many calibers that some bullets just shoot better in a given barrel. Id switch bullets and try something else. I was not a fan of CFE223 in my 5.56 loads but it gives me great velocity and accuracy in the Grendel. I havent had the greatest luck with SSTs in several calibers.
Posts: 4,287
Threads: 156
Joined: Jan 2017
2475 to 2505 is the node area for the 20" howa. So I'd say your 30.6 is the load.
As for the 1.58 group which is the best one you show, could there be something else affecting group size I wonder.
The 123 has more recoil than the 90 gr.
What kind of stock setup do you have, and how heavy or light is the trigger. If you're using the plastic stock, it's pretty useless imo, this rifle needs a better stock to really free float.
And it is possible that the sst-your rifle don't get along, have you tried the 123 eldm, 120 nosler. Better yet get some 120 sierra hpbt and try them.
Eldm will work as a hunting load if that's your goal.
I have had trouble using the sst myself. I've switched to the 120 nosler and the 100 ttsx. I have plenty of cfe but for now I'm not using it either very much, these 2 - ttsx and either xbr or h335; and 120 nosler and AR comp, are my go-to's right now. for 20" ---
wait, I do have a load for the sst and eldm in CFE but for some reason the only place I find it is in my spreadsheet, don't recall being able to get the results I want from it, but I do have one. As for 20" my AR/20" is now "in the game" (120 nosler/ CFE and Ar comp both) but the howa is sitting on the sidelines, letting the AR stretch its legs.
Oh, one other note, sometimes a primer switch can get you better grouping, I've been using the federal 205 in the howa but 450's (cci) in the AR. Plus a field crimp for the AR.
There's a good group in there somewhere for the howa, but might not be that sst/cfe combo is all I'm sayin'.
"Down the floor, out the door, Go Brandon Go!!!!!"
Posts: 27
Threads: 6
Joined: May 2019
Ok so I have 123 Nosler CCs, 123 ELDMs, and maybe one more
my immediate thought is to load 5 each over 30.6 CFE 223, adjusting the COL to hold the same cartridge base to bullet base dimension (i.e. the same powder volume) and shoot groups over a chronograph at 100. Maybe also try 5 SSTs with a Fed 205M. I think this would cover all my bases and also finish this box of SSTs. If they all shoot poorly, its me/the stock, if the other two shoot better than the SST its the bullet, and so forth.
Posts: 1,238
Threads: 51
Joined: Dec 2017
Snarf Wrote:Ok so I have 123 Nosler CCs, 123 ELDMs, and maybe one more
my immediate thought is to load 5 each over 30.6 CFE 223, adjusting the COL to hold the same cartridge base to bullet base dimension (i.e. the same powder volume) and shoot groups over a chronograph at 100. Maybe also try 5 SSTs with a Fed 205M. I think this would cover all my bases and also finish this box of SSTs. If they all shoot poorly, its me/the stock, if the other two shoot better than the SST its the bullet, and so forth.
Change bullets or powder, some barrels just dont like certain combos!
Having said that, I used to do it that way too!  Lately Ive been trying it their way!
https://youtu.be/QwumAGRmz2I
They say a picture is worth a thousand words! You can scroll down to the last page in this paper for an eye opener! At least it was for me!
https://storage.googleapis.com/wzukusers...istics.pdf
Posts: 4,287
Threads: 156
Joined: Jan 2017
Downloaded this to read later. One thing near the end however caught my eye, as it is a key part of how I've been doing things.
Get a dispersion of shot-loads/MVs to cover your expected MV range, to get the curve (actually a linear curve fit) of MV vs charge load for that particular combo in that gun.
His variation study of shots-grs powder vs MV confirms that linear curve exists.
At that point I narrow myself into looking at the range of a more or less known node-velocity (OBT) for that barrel length. Chris Long theory. I have those nodes in an xls I developed.
That's why I earlier said that I think OP will find something that works in the 2475-2510 range for his howa-20" hb. Once you find an acceptable SD (I try for <10, ES in the teens), the remainder is to find a primer (if you have that option) and an OAL that gives the best groups.
Getting that curve for powder etc combo in YOUR gun is the key starting point.
I know other guys use other means, which is ok AFAIC... this is my way. Seems to work for me.
ps, in general a different bullet (same class), even a different powder (with a similar pressure curve and speed) doesn't affect this approach by very much.
"Down the floor, out the door, Go Brandon Go!!!!!"
Posts: 27
Threads: 6
Joined: May 2019
Harpoon1 Wrote:Change bullets or powder, some barrels just dont like certain combos!
Having said that, I used to do it that way too! Lately Ive been trying it their way!
https://youtu.be/QwumAGRmz2I
They say a picture is worth a thousand words! You can scroll down to the last page in this paper for an eye opener! At least it was for me!
https://storage.googleapis.com/wzukusers...istics.pdf
Ive seen the video and Im pretty well bought in
I agree that a 5 shot group isnt enough to call a load development complete. However, theres no way for shooting more bullets into a 3 group to make it get smaller. So I dont see the larger sample size being required to rule out a load, unless Im missing something?
Obviously the small sample problems do apply to the SD calc that led me to settle on 30.6 as my charge weight, but now Ive got 15 rounds over the chronograph and its holding steady.
I will re watch the video and read the document you linked and see if they address the problem of ruling out
Posts: 1,238
Threads: 51
Joined: Dec 2017
06-14-2023, 03:24 PM
(This post was last modified: 06-14-2023, 10:26 PM by Harpoon1.)
Quote: However, theres no way for shooting more bullets into a 3 group to make it get smaller. So I dont see the larger sample size being required to rule out a load, unless Im missing something?
They actually say that in the podcast. 3 or 5 shot groups wont tell you if its a great load but it can tell you if its a bad one!
I dont compete, only hunt and plink, usually under 300 yds. So I couldnt care less about having low ES/SDs or a powders temperature sensitivity. Typically load and shoot one 5 shot group. 3 shot groups are just not enough, IMO. If that looks promising, then Ill load another 20 and see how it holds up. .75 MOA/5 shot group is my starting cut off at 100, anything bigger than that, I keep switching powders until it meets my threshold!
Posts: 27
Threads: 6
Joined: May 2019
Harpoon1 Wrote:They actually say that in the podcast. 3 or 5 shot groups wont tell you if its a great load but it can tell you if its a bad one!
I dont compete, only hunt and plink, usually under 300 yds. So I couldnt care less about having low ES/SDs or a powders temperature sensitivity. Typically load and shoot one 5 shot group. 3 shot groups are just not enough, IMO. If that looks promising, then Ill load another 20 and see how it holds up. .75 MOA/5 shot group is my starting cut off at 100, anything bigger than that, I keep switching powders until it meets my threshold!
You know now I think I recall hearing them say in that podcast that changing powders is really the only way to accomplish any major changes in load performance...
Posts: 1,238
Threads: 51
Joined: Dec 2017
Snarf Wrote:You know now I think I recall hearing them say in that podcast that changing powders is really the only way to accomplish any major changes in load performance...
Powder, then projectile! As I remember it! 
Posts: 67
Threads: 5
Joined: Aug 2019
CFE 223 wouldn't shoot good out of my gun velocity all over the place tried 90 to 123 grain bullets .Went to xbr8208 and all was well for my gun.
|
