Greetings,
Another thought. I believe that the Bergara barrel has a one in nine inch twist and I see that Hornady specifies a one in eight inch minimum twist for the 73 grain ELDM. Perhaps testing with a different projectile might be wise.
GPM.
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Greetings,
Another thought. I believe that the Bergara barrel has a one in nine inch twist and I see that Hornady specifies a one in eight inch minimum twist for the 73 grain ELDM. Perhaps testing with a different projectile might be wise.
GPM.
Try some 55gn projectiles to see if it will group better if not sell it.
Yep, grab a few different factory loads and try them out. I feel that that projectile might just not suit that rifle, I think that stability wise it's length over weight and that would seem to be a pill that's on the longer end for mass. It might be on the verge of stability - in that it's flying straight through the paper but giving the mini-wobbles on the way?Quote:
Originally Posted by outdoorlad
There seems to be a lot of info missing here, especially in your case prep process. You say you suspect consistant ignition may be an issue, what do you base that on?
How clean is your barrel? You will always get a bit of speed variation as the barrel heats up.
How do you size the brass?
It looks like you have vertical and horizontal dispersion. Velocity changes should only give vertical.
How accurate is your powder charge?
Is the powder measured at one sitting, does it sit in the thrower day to day.
What sort of rest are you shooting from? Are all the screws torqued correctly? Is your scope OK.
The poor grouping and the velocity spread may not be related but may be separate issues.
Everyone is trying to help but I just think there's too many possibilities with the info at hand
Yes agree... Part of the reasoning behind the suggestion of trying some factory loads - isolate out if it's ammo related or platform-related. If all ammo does it, then it's a rifle or shooter related factor. If the rifle shows a distinct preference for a type of factory ammo, then it's either a component issue, or a reloading process issue.Quote:
Originally Posted by johnd
Greetings
No sign of Tentman today. He is either on his way to Geraldine to get some counselling on chronograph withdrawal from MD or he has had good results yesterday and he is waiting for us all ti stick our necks out so he can cut us down like ripe wheat. Time will tell.
GPM.
Sorry, been socializing and shooting, wot a great weekend!
So here is a target I shot Saturday in very difficult conditions with a gusty, swirly wind across the range. I always make an assessment of how I feel (some days I just know I won't hold to 0.5 moa) and environmental conditions . . . . And Sat had at least 0.5 moa variation built in!
Attachment 251687
This has 10 shots of 73gn reloads ( top centre) 6 rounds of Fiocchi factory 55s (top right) and 10 rounds of Sako factory 55s (bottom left). So yes it has been shot quite a bit with factory ammo. Yes it will mostly put 3 rounds of reloads of factory ammo into 12mm - 20mm groups but we all know 3 shot groups don't tell us much about a rifles accuracy, maybe a kind way to describe 3 shot groups is that "they tell us a rifle is ok to hunt with as long as we are not to fussy.
My reloading techniques are sound, I have other rifle/cartridge combinations that reliably shoot 0.75 moa and without being fussy with things like primer seating depth etc.
I have shot to 300M with the 73s, no sign of stability issues . . . and anyway stabilized or not twist rate won't on its own cause an ES spread.
So looking closer at today's target, the ES is down to 50 fps . . . . Almost acceptable for a 223, 25 fps would be better. The changes made from the 100 fps ES results, I have polished the inside of the bolt body, and made up a firing pin bush that fits inside the mainspring. I have also been focusing on primer seating depth, ensuring I feel the primer seat, then compress the anvil. So some progress I think.
Thanks for suggestions, remember all I'm trying to do is get the ES down at this stage, I think the rifle can eventually be tuned into something pretty good, but there are maybe several more steps to go to get there . . . .
Hmmm. I still think your focus on ES isn't addressing the primary issue - you can have single digit ES and shotgun level accuracy. Those groups are fairly equivalent in pattern and size if not point of impact on the target - if it was mine that would be a sign for me.
If you are needing better on target grouping/performance than this, I don't think your answer lies in this rifle even if you succeed in reducing the ES. However, if this is a personal challenge/project thing, please keep posting the results as it will be interesting to see where you get to with it and if the group sizes shrink if you can get a reduction in ES.
Greetings,
So to summarise the rifle shoots quite well in 10 shot groups which are always larger than 3 or 5 shot groups. Velocity indicates book max pressures once barrel length is allowed for and the projectiles are stable to 300 metres at least. If we did not know what the ES and SD were we would be happy. Now I would be the last person to suggest aiming for perfection was not a noble goal but the law of diminishing returns does apply here. Be happy with what you have but it is still noble to strive for better. The choice is ours and ours alone.
Regards Grandpamac
Haha - great post and yes you are 100% right. Really I am happy but I am just seeking to improve and learn. I've decided I'm too old and tubby to be competitive at PRS, I find F and FTR a bit codified and so that sorta leaves me to find other things to do - trolling 3 shot group methodology etc. and getting the most bang for my buck from what I have at hand!Quote:
Originally Posted by grandpamac
I'll stick my neck out, I don't think the issue is related to ES. Take the bottom right target as an example. The Sako factory load.... 10 shot group (6 recorded velocities that I can see) largish vertical dispersion but only 35 fps ES (I'm not gonna do the SD math).
Leave out the windage variation as you say there was variable wind, perhaps this is the limit of the setup?For a short, handy little rifle, call it good.
Me too.Quote:
Originally Posted by Tentman
GPM.
I'm with you, maybe less neck at risk here haha but you get the idea. Plenty good for most if not all .223 work, and it's not a super dooper out there shooter's caliber so. Having said that I've been known to swap bits like barrels, stocks and triggers out when I can't make a rifle go as good as I think it should.Quote:
Originally Posted by johnd
Have you tried seating them deeper in the case? Some projectiles like some jump especially eldm and eldx!
an update on the 6CM velocities i mentioned in my rifle on the first page:
I kept the main load the same but pulled the expander mandrel out of the F/L die, sized with the usual 2 thou bump. Then used a mandrel (actually the mandrel from a .243win Lee collet die) to expand the necks in a second stage.
The accuracy might be slightly better, which was always good but the velocity over approx 20 shots is now SD 8.5 & ES 30. So definite improvement. I'll skim turn the necks and see if that helps more (because i can and i like tinkering).
