243 AI searching for accuracy

[DLCrocket]

I have a 243 AI with a 1 in 7 match barrel from Criterion. Without going into all the details of how I uniform the brass etc., I've been trying to dial in Hornady 108 ELDs using H4350. Ive exhausted just about every combination of powder charge and seating depth possible. I had some loads with pretty type groups at 100 yrds but high SD and ES. The loads that had low SD and ES (not many) had bigger groups. When I tried the load with the best group and ES/SD at 200 yrds the groups fell into a 2" x 2" square. I want to get to a 500 yrd range so I want tighter groups at 200. Bottom line, trying to decide whether to try different bullets or different powder. With a pound going for $60 I'm running out of fun money so can't afford too many more combinations. Any suggestions are welcome!

 

[6MMsteve]

N555 and berger 108's or SMK 110's try that route just a suggestion

 

[koger]

I have seen a 6mmAI and 243 AI that would not group consistently, with BT bullets. When we went to flat base bullets, they shot tiny little bugholes. Just my experience.

 

[stork]

Re23 and 4831sc have worked very well with 112 Barnes and Lapua brass in my 7.5 26" Criterion's. Inside 7/8" at 500 yds. Just shot a few rds a week ago to check zeros at a variety of range gongs. No 5 shot groups, just a couple rds per distance.

 

[kyotekiller25]

I've often found a lot of times that low es/sd doesn't always translate into smaller groups or even the best shooting loads. I believe what the target tells me.

If I had a load that shot better downrange with a higher es/sd than a load with a lower es/sd, I would always go with the one that shot better despite what numbers the crono says.

A lot of my loads have an ES of 30-75fps and whatever SDs that translates to on any given day in a variety of my rifles. They still always seem to shoot an easy 1/2 MOA out to 500, and usually hold 3/4 MOA out to 1K for 3-5 shot groups.

 

[Capt. Oblivious]

Forget about looking at ES and do a proper load workup, I shoot with allot of 243AIs and Im yet to see one not shoot. H4350 is a good powder for 243AI and 108 ELDS are decent if your rifle is put together properly it shouldn't be hard to find a load.

Whats the load your trying now?

 

[ELR LVR]

1) 1:7 in my opinion is a bit fast for a 243 AI when likely an 8 twist is more optimal.
(gotta tailor everything around the bullet, and what it can withstand...this includes the speed)
---MIGHT work if you are using a HIGH QUALITY - cut rifled barrel ---- not a buttoned barrel
2) with that fast of twist, coupled with the velocity you are capable of .......
Ditch Hornady anything
---might be fine for a 6BR, but not for a 243 or faster, Sorry man
Sorry to be the bearer of bad news but.......
.......too many people are attracted to the Hornady ELD-M for their cost
They are nothing more than an updated A-Max
There is a very good reason they cost much less per 100, you get what you pay for
They save money by using less copper, which is too expensive for Hornady to spare.
I think they horde it in the back room just so they can make more bullets.

Hornady don't survive high velocities coupled high rpm, too much frictional heat generated there.
That when gyroscopically spun up fast, separates the thin jackets from their core..
Think .023" thick vs .030" (within the realm of bullets and heat, thats a big difference )
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Advice : You want accuracy? - Try some Sierra 107's or Lapua 105's or 115 DTAC
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Avoid even Bergers for the time being until you test the other 3, even bergers dont hold up well to
Fast and High Rpm, and if you do opt to try some Bergers, make certain they are
{TARGET bullets, NOT Hunting}
I comtacted Berger once, inquiring (basically to let them know their 6mm bullets werent living up to expectations)
Their response was : Well you're pushing them past their designed limitations.
That is a PC way of saying "you can't drive them very fast"
Ok then Berger, I Guess Sierra gets my money then, you're over priced anyhow.
Too bad Berger is unable to design durability at high velocity in with accuracy for the money they charge.
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Pic 1. (trying to use Hornady's - Notice the comet tail on the outer perimeter of the bullet hole
This is the jacket not being thick enough to be a thick enough heat sink to handle the heat and
angular momentum produced from the velocity generated from somthing like a fast .243
(You COULD, tune your load down to 3000 fps, but then why have a 243 AI?)
So you're gonna have a cartridge that is capable of 3300 fps, but then tune down to 3000 fps just to use Hornady's? Doesn't make sense right?

Pic 2. Sierra's - Notice complete jacket integrity kept from the virtue of using thicker jackets and tougher copper
Sierra = Gilding metal vs J4 jackets - Sierra = the tightness of what you seek.
These were all tested with the same load, showing a vast difference between the three
IE: I mean, why waste your time if accuracy is what you're after rather than explosive results?
4831 and Reloder 22 would be 2 other powders to try, I've had very good results with those powders
Here is some load data which may help with load info
If you try the 115 DTAC, Def try some H1000 with those, it's very consistent.

.243 Win + .243 AI Cartridge Guide

Shooter's Guide for .243 Winchester and 6mm .243 Win shooting, reloading, and accuracy. Bullets, powder, brass, accurate loads. Rifles and gear reveiws from champions. .243 ammo and ammunition reveiws. AccurateShooter.com is the best guide for precision shooting, with FAQ, Shooter Message...

www.6mmbr.com

 

[ELR LVR]

Why avoid Bergers and stick with Sierra for the time being until you get the bugs worked out???
Here's why, even with their Tote's Awesome 109 "Hybrid"
(That word Hybrid is a real "fisherman catcher" of an advertising term... rather than a fish catcher)
Now this example of the Berger 109 did not happen often, most the time they shot tight
IF.... I tuned down to approx 3200 fps.
but the fact that it happened even ONCE, is too much