Bullet issues with .243 win in AR-10

Need help understanding what my gun is telling me. I have an AR-10 in .243 win. that I was planning to use for groundhogs out to 400 yrds. It has an Aero Precision upper and lower with a 16" Wilson Combat barrel with a 1:10 twist. I'm trying to get Hornady 58 gr. V-Max to group using various weights of Varget, IMR 4064 and RL15. The best group I can get is 1 1/2 inches at 100 yrds. Is the bullet unstable( too light) because of the short barrel, twist rate or is stability OK and i need to look at other bullets in the same weight range?
 
I’ve cut down two .308 barrels from 26” to 16” and all still maintain 1/2” groups at 100 yds and under MOA out to 600yds. I lost about 200 fps though.

I’m looking at the .243 or 6x68, but more than likely will stay with 18-20” length barrels which I will run suppressed. I’m planning to run the 58 v-max with a faster powder. Of coarse, it may not work out so I’m prepared to try different bullets, weights (lengths), powders, etc. I may even need to play with the bullet seating depth.

I would try a heavier (longer) bullet with those powders. I bet the 87 v-max and Fed 210 primers will work well with 4064. Might even need to try a faster powder with that short of a barrel, especially being in .243.

FYI- Contact Wilson Combat as Bill Wilson spends a lot of time with his products in the field hunting and range load development. He has been very helpful in the past and helped me with a 16” WC 6.8 SPC II.

 
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A simple test for AR accuracy issues, if you single shot hand feed a 5 rd group does it shoot better than a mag fed,gas operated group. If it does then you have issue other than the barrel/bullet compatibility.
 
Hornady bullets are always WAY more finicky to get to shoot in all my guns. Try a 55 grain Nosler ballistic tip. I had 6 loads that shot sub MOA in my BCA upper the first time I tested it. Guarantee I can’t shoot that tight with the hornadys. NBTs shoot tight in all my guns. Lightening up the trigger will help as well. I have a single stage CMC that brakes around 2.2 pounds.
 
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Hey spotstalkshoot,
Tried handfeeding and still had flyers. Best group I had was 1". Going to heavyer bullets. Trying 70gr. Nosler BT, 75gr Hornady V-Max and 87gr Hornady V-Max. Got these from a buddy of mine.
 
Seems like the single feed test excludes feed ramp/mag issues. A dummy round hand/mag fed and checked for length change will confirm enough neck tension and that the bullet seating depth is not touching the lands. Then a ladder test to find a powder load that minimizes vertical dispersion, then test for seating depth(Berger has a guide for this,works for all brands). This should produce a load that will shoot to you and your rifles ability. The rest/support of the rifle and your trigger technique will impact final groups.
 
best groups out of my RRA Predator HP are from 39gr Varget shooting Berger 64 gr BR Column at just under 3500fps..

65 gr V-Max also shot very well...with same load

77 gr Cutting Edge MTH in front of 40g H4350
 
Originally Posted By: Woodchuck HunterHey spotstalkshoot,
Tried handfeeding and still had flyers. Best group I had was 1". Going to heavyer bullets. Trying 70gr. Nosler BT, 75gr Hornady V-Max and 87gr Hornady V-Max. Got these from a buddy of mine.

Please post your results (good and/or bad).

For anyone, What kind of velocities are you getting from your handloads with the 70-87 grainers out of your 20” barrel lengths ?
 
Finished shooting all my loads today and the results are as follows:

No 70 gr. Nosler BT groups shot under an 1 1/2" using Varget, H4350, RL-15 and RL-17. This grouping was based on the most accurate loads from the Nosler Book. I also noticed pressure signs which I had before using loads in the mid 40 gr. area.

One 65 gr. Hornady V-Max group shot a sub MOA using 39gr. of RL-15. The other groups using IMR 4064 and Varget were around 1 1/2".This grouping was based on around 3500 fps using the Hornady book.

No 75gr Hornady V-Max groups shot under an 1 1/2" groups using IMR4064, RL-15 and H4350. This grouping was based on 3200 fps from the Hornady book.

My best results came from the 87gr. Hornady V-Max group. Two groups( 35.6 gr of IMR 4064 and 35.8 gr. of RL-15) had 1" groups and one group(35.7 gr. of Varget) shot a sub MOA group. The other group( 41.6 gr. of H4350) did not do well. This grouping was based on 3000 fps from the Hornady book. The Varget load I came up with myself based on burn rate.

It appears to me as though I should focus on the 87gr. Hornady's and start ladder tests. Any thoughts?
 
it appears to me that instead of randomly picking loads out of the book to "test" with... or going by someone elses pet load.... you need to try a proper load workup.

first - thats not testing. thats just throwing darts at a board blindfolded and hoping one of them hits a target. you're gathering data - but only one small data peice of a wider data set and trying to make accurate judgements on just that one peice of info.

second - thats just not safe. especially in a barrel that is relatively unknown.


you need to pick a bullet and powder, do a proper ladder and test with that combination.

if that turns out to be unsatisfactory... then try another combo and do a proper ladder with that combo.


i have yet to shoot a single ladder where at least one random charge (regardless if its a noted "best accruacy tested" load in the book) did not shoot a 1.5-2" group at 100 yds.

EVERY barrel is different and thats why we do the kind of load developement testing we do.
 
for example if i wanted to test your 58gr vmax with varget this would be the ladder i would test.

i have a preference for 3 round groups for initial testing, so i would load up 3 each of the following charges and shoot them low to high while watching for both accuracy nodes as well as pressure signs for safety reasons. i also typically go 9 charges down from max for convienance and saving projectiles as i'm personally only concerned about the upper half of the charge range anyway. If for safety reasons you want to go lower down the charge range withinn the published data and shoot more groups... i wont discourage you from the practice.

so my initial ladder would look like

44.2 gr
43.7 gr
43.2 gr
42.7 gr
42.2 gr
41.7 gr
41.2 gr
40.7 gr
40.2 gr

once i found the accuracy load out of those, then if need be you can fine tune by doing a 2nd smaller test with a finer powder charge variable. for example if 42.7 was the best group of those but i wanted to try to refine it or determine how wide the accuracy range was for margin of error reason i might test the following


42.3
42.5
42.7
42.9
43.1

having a chronograph to know your ES/SD numbers will help in this greatly.





but again - i'm suggesting that you simply need a more methodical testing method to follow instead of just random testing and hoping for a good result from that.


you usually cant make good decisions with half of the information presented to you - especially if you dont know if the information you have represents the better half of the data or the lesser half that you dont need in the first place.
 
Plant One has excellent advice.

I think you have too many powders and bullets in your mix making your quest way over complicated and your method way unscientific. What you have going on is a huge project and expensive with a poor likelyhood of finding a great load.

You initially wanted to use 58 Vmax. Focus on one bullet and one powder and make it work.

I don't know how you selected the powders you chose for testing, but I'd do more research first on temp stable powders for light 6mm bullets. 243 is similar to several other 6mm cartridges so research powders for those cartridges too. My research led me to IMR 8208 XBR and it's fantastic with 55gr bullets in 243 and other 6mm's at near max loads. I'll bet you a cheeseburger 8208 will work better than Varget or 4064 or R15 for light bullets (and probably for medium and heavies as well).
 
I always clean between bullet or powder type changes. As noted you need to develop or follow a load testing procedure. Certain bullet/powder combinations tend to work in specific cartridges, but that doesn't preclude the need to test. Find the powder charge that shows the least amount of vertical dispersion, than seat depth test. I know this is elementary, but load testing with a bipod probably not the best and never allow barrel contact with bags,rests.
 
I wouldn't struggle with one bullet too long. Try several different bullets in that weight range a grain or so off of max at book length and see if the rifle favors one. That's the beauty of the 6mm....lots of bullets available in that weight range.
If you find one that shows a a horizontal or vertical pattern adjust oal and powder up or down .2 grains at a time to see if it responds.
 
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Honestly, I don't think it's a bullet or powder issue yet. I think you should start with a jump test to see what seating depth your gun likes before you do anything else.
 
If you slow down the Vmax with less powder, you may get tighter groups. I've seen lower velocities produce tighter groups for "light" bullets in multiple guns and different caliber sizes, multiple bullet manufactures and multiple powders. The quickest way to test this is a ladder test. With a light bullet like a 58 gr Vmax, you may not be able to adjust the seating depth closer to the lands where your gun may shoot it better. I tried to get 55gr Varmageddons to shoot well in two different 6mm Creedmoors. After multiple tests, I could only get them to shoot well if I slowed the velocity down. There is no benefit to shooting 55gr bullets at slower speeds so I decided to go with 80gr Ballistic tips and 115gr Bergers
 
Yep I pick two or three powders and a ladder test them .2 grain increments from minimum to maximum charges. Eventually you’ll find a load that will put all three in the same hole at 100 yards if you do your part and the gun is capable.
 
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