<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: StanwoodSpartan</div><div class="ubbcode-body">More loads for the 6ai?? How bout anyone shooting the 115DTAC's with H4350? </div></div>
personal opinion but for a big case like the 6mm Remington with a small .243 neck pushing a very heavy 115 grain bullet, I'd look at the slow powders like H4831sc, H1000 and Retumbo.
All the loads shot within 1 MOA except the 53 gr load and I had a lot of barrel mirage. I'm not happy with the SD numbers, but it is fire-forming so.....
I resized the 280 AI brass, bumped shoulder back .002" I decided, for no particular reason to try the Sierra 175 SMK. I again chose H4381SC from recommendations by others. I decided to jump these .020 and will get closer to the lands as I go. I also loaded 5 differing charge weights among the 50 rounds, but I loaded 5 rounds with a 200 primer and the other 5 with a 250 magnum primer for each charge. 1200' elevation 35%humidity, 97-103 degrees. Oehler chrono 8 ft from muzzle.
The 57.0gr load looks like the primer is starting to flatten, but no other signs of pressure. What velocity should I be getting with the 175SMK? I was thinking tops would be around 2875fps... Thoughts?
I was thinking of doing the same type of test, but jumping the 175SMK .010 and beginning with 56.5 and work my way up to around 58.5 or until I see some pressure signs... Thoughts?
With a quality barrel like that, run the charge up until you see signs of too much pressure then back off .3-.5 grains then play with your seating depth. I haven't found a reasonable charge weight shooting 168 bergers or 162 Amax's that I couldn't tweak the seating depth to get them to shoot sub 1/2 MOA.
I'm running 61.5 grains 4831SC with the 162 Amax's btw and they are right around 3000 fps if not a little under. Never messed with the SMK's (yet).
Shot some more 280AI same weather conditions and elevation. Same shootin-rig too, of course. Oehler @ 8 feet. 5-shot groups, etc. blah, blah blah.
Jumpin' the 175's 0.010, H-4831SC, CCI 200/250 primers and 175 SMK
57.5gr, 200 primer, had previous data in chrono so no data, group: 0.716 MOA
57.5gr, 250 primer, ES: 09, Vel: 2774, SD: 04, group: 0.605 (4 in one hole last shot doubled the group size).
57.8gr, 200 primer, ES: 66, Vel: 2778, SD: 25, group: 0.548
57.8gr, 250 primer, ES: 22, Vel: 2798, SD: 08, group: 0.564
58.1gr, 200 primer, ES: 29, Vel: 2784, SD: 13, group: 0.318
58.1gr, 250 primer, ES: 29, Vel: 2814, SD: 10, group: 0.386
Looks like the recipe is getting better. But, I've decided to go with the 162 Amax, so all load data after this post will be on that bullet.
For the next 20 rounds, I tried Hornady's Superformance since it was next on the burn-rate chart. All I can say is... wow. Same bullet, same 0.010 jump.
No, the ES numbers are not a typo. The groups opened up initially because the firing pin began sticking/hanging a little. It felt like there was a delay from the time I pulled the trigger and the firing pin struck the primer. Had another shooter drive and he experienced it too. We disassembled the bolt, cleaned up some excess oil and it was again operating normally. Needless to say, I was impressed with the Superformance's velocity, but that was where the good impression stopped. Guess I have some fire-forming powder.
6mm AI rem case 52.5 grain Imr 4350 ,remington 80 grain hp,rem 9 1/2 primer 3700 fps. same thing with sierra 85 grain shoots but shows too much pressure.51.5 imr 4350 with horn.87 grain bthp 3590 fps. remington 722 with a 22 inch hart barrel
I am looking for a few pieces of either 6mm AI or 257 Roberts AI brass. I need at least 6, but no more than 10. These can have bad primer pockets as I won't be loading them to shoot. I am trying to test magazine function for a project.
Win formed brass
47.5gr H Varget
120gr Nosler BT's
running 3350 with chronograph about 7yrds from muzzle.
This load worked to get through hunting season, I'm now in the process of working on 162Amax load now.
The 162's show substantially more promise and initial tests with varget and 4350 both are proving very accurate. With Varget velocity is 2700 with 41.5gr with room to come up and with 4350 2580 with 45.1 also no pressure but fairly compressed.
26"Brux, 1-8 HV, .253 Neck, .077 Freebore
75 gr. A-Max
Lapua, fire formed, trimmed to 1.743", 3x fired, .248 neck bushing.
24.9 gr. IMR 8208 XBR
COAL 2.500, (.020 off lands<span style="text-decoration: underline"> in my chamber</span>)
Come-ups from 100 to 200 yds. jive with a QuickLoad MV prediction of 2965.
Temp, 68 f, Alt., 1200 ft.
Best load so far with this bullet, <3/4" at 200. I will load more and shoot through the chrono.
I was working with my 223 Ackley today with good results.
I have an APA trued 700 with an 8 twist 5C Broughton bedded in a McM Remington hunter stock by SAC, HDMR G2 @ 21x.
Ran all loads through my can, off a bipod at about 110 yards.
Sunny, intermittent 5-7mph breezes.
Hornady 75 Amax, hBN coated, 1x LC 09 brass, Wolf SR primer, IMR 8208 XBR 2.525 OAL which is into the lands pretty good in my rifle.
I was having some driver error, this powder really seems to want to shoot knots, so try not to wiggle.
I don't know if it was my can, but the cold bore shots tended to me .5-.75 moa outside of the subsequent group.
Those were discarded in the measurement as they were not indicative of the accuracy that followed.
Fireforming 24 grains IMR 4895 thrown from a Lee perfect powder measure 8 shots CTC .362" ATC .127"
The clear winner of the day, 26 grains:
These loads were not safe in Lapua brass.
I has several pierced primers and had to back down to 25.6 grains to approach the accuracy seen in the 26-26.2 range using LC brass.
The Lapua weighed 2.7 grains more than the LC and the powder was higher in the case with like charges.
.250 AI (.250-3000 or .250 Savage) Great kids/ladies gun. Fast, accurate, and recoil is minimal.
CCI 200 primer
100 gr. Barnes TSX
.0060 off lands
23.5" Shilen barrel on Rem 700 SA BDL
.401" 5 shot @ 100 yds.
CCI BR-2 primer
100 gr. SMK
.0050 off lands
.304" 5 shot @ 100 yds.
Very low recoil and accurate. My new 1000 yd. steel ringing round.
CCI 250 Mag primer
60.3 gr. Alliant RL22
100 gr. Barnes TTSX
.0050 off lands
28" Lilja barrel on Rem 700 LA BDL
.383" 5 shot group @ 100 yds.
Looking long and hard at building a .260 AI or 6mm AI for some long range shooting/medium range hunting. Need to figure out whether to go up or down in bullet diameter. I have .224, .257, .277, .284, .308 covered. I see two gaps in there....maybe fill both over time!
Winchester brass fire formed
26" 1-10 Douglas barrel
56.5 gr. reloader 19
Bullet .008" off lands
190 gr SMK
don't remember exact COAL
2795 fps 18 es
shoots 1/4 moa @ 100 holds 1/2 moa out to 1000 in calm conditions
Interesting new data from the range today, 78 degrees Fahrenheit, DA 1950 or so. The Magnatech chronometer gave me 2875 fps muzzle velocity (see earlier post). But on the range today I measured come-ups at 200, 300, 500, and 600 yards and entered these into Shooter. The adjusted velocity from Shooter tells me I have 3050 fps velocity.
It was a little (5 degrees) hotter today than on the day I zeroed, and I shot slightly faster today so the barrel temp was probably higher. SO, take all the velocities you read about with a grain of salt, as I think there are too many variables to make any meaningful comparisons. There could also be Magnatech or Shooter errors (or the loose nut behind the trigger errors).
My match load is 47.2 GR. RE 17 in Rem Brass with Rem 9 1/2 and Sierra 123s
Out of my 8.5 twist 29" Krieger barrel I get 3250 FPS. This is a really good barrel, and it shows. It's not unusual to get 3 round groups of 1/4" I've used this load to 1100 yards and have found it really easy to hit steel. Please note, this is a MAX LOAD in MY RIFLE. I know some folks will baulk at the Rem. Brass, I started out with Lapua, and at some of the matches, you don't have a lot of time to pick up brass... Hurts my feeling when I lost a piece of the expensive stuff, not when I loose the cheap stuff. Also, the Rem. Has slightly more capacity. I neck turn brass, and sort bullets. My load regime is nearly the same for my benchrest rifles. This has been an excellent round for most of the tactical matches I've participated in.
Guys, as with any Max data, please work up with caution!
142 grn Sierra MK 48.0 grns of H4831SC(slightly compressed) CCI BR LR primer Norma fireformed 260 brass yields 2940 ftps. Surgeon action, 26" Broughton 8.5 twist,barrel shot suppressed. bullet .015 off lands. Warm load please as with all load data work up with caution.
Wayne thank you for your data, wanted to try some 120s.
I would start at 47.5g and work up. My 243AI has an 8t 28" barrel and with 50g of the H-1000 the 105 HyBred touching the lands is doing ave 3160 5 shot group with an sd of 8. I am still doing load work-up because I don't want to have to single feel when I have such a nice mag fed action. So we will see over the next few weeks if these Burgers like to jump. Best of luck with your "load chasing".....Rick