Best bullet weight for 280 Ackley improved with 22 inch barrel

[RockyMtnMT]

I have always wondered why pressure signs can show up quickly and seemingly early and below book max with Talley bullets. Is it the increase bearing surface that comes with an all copper bullet? Not being critical as I have had great success with Talley's.

Not familiar with Talley. Yes as a general rule all copper bullets have had issues with pressure. Barnes is the granddaddy of mono's. Their original bullet was a smooth baring surface. They shot great in some rifles and some rifles would build too high of pressure and others would have accuracy trouble. The age old question is how big in dia to make a copper bullet so that it will seal the bore but not make too much pressure. There is tolerance in bore/groove dia making some tighter or looser than spec. They made a change to the bullets by putting in grooves to eliminate some of the baring surface and relieve the pressure issues. Copper is harder than lead so it can't obturate to conform to the bore size like lead will. Lead will squeeze down in tight rifles and plump up in loose bores from the pressure of the charge behind it. So in loose bores the typical copper bullets will have trouble with accuracy as it rattles down the bore and over pressure in tight bores, and shoot great in the rest. Drive band bullets handle this better than grooved bullets but still have the issue. We solved this by making our drive bands on a radius so that the outside dia of the drive bands are very finite in actual material contact in the grooves. This allows us to cut our bullets larger in dia than caliber without creating extra pressure in tight bores yet still seal up on the loose bores. Hammer Bullets will show less pressure than conventional lead core bullets of the same weight and quite a bit less than most copper bullets.

 

[25WSM]

There is a fellow on this site that has the fastest 280ai I've ever heard about. I think he is getting 3050 from a 175 Berger with rl23. I figured he will be on this thread sooner or later. I still shoot retumbo from mine. 2900 and change but 1/4 moa.
Shep

 

[25WSM]

This is for the 175 accubond lr.
I don't know how you can get 300 more fps on it but some claim they do.
Shep

 

[Bob Wright]

While being attacked by a bazillion horse flys and gnat swarms, I managed to get thru group 5 of my 3 round tests. I lost concentration and shot round 3 into the target on the right. But just slide that one over and you get the
280AI, 143 Hammer Hunter, RE23, Fed215M primers, 3100 FPS, ES was 6fps
26" sporter Proof stainless
SAMMI length chamber (soon to be throated).
I plan on loading some lighter Sierras for trigger time, training for my g-kids, shoot the Hammers for kids hunts (lead free hunting only) and my desert muley hunts.

 

[Warrenoliver]

While being attacked by a bazillion horse flys and gnat swarms, I managed to get thru group 5 of my 3 round tests. I lost concentration and shot round 3 into the target on the right. But just slide that one over and you get the
280AI, 143 Hammer Hunter, RE23, Fed215M primers, 3100 FPS, ES was 6fps
26" sporter Proof stainless
SAMMI length chamber (soon to be throated).
I plan on loading some lighter Sierras for trigger time, training for my g-kids, shoot the Hammers for kids hunts (lead free hunting only) and my desert muley hunts.

What was the powder weight on that load? I'm planning to work up a good rl23 load for the 143 hammer hunter but can't find much info. Any pressure signs at that speed?

 

[Bob Wright]

What was the powder weight on that load? I'm planning to work up a good rl23 load for the 143 hammer hunter but can't find much info. Any pressure signs at that speed?

58.2 gr. No pressure here, but using the mag primers stopped erratic pressure anywhere during the ladder.
With a CCI BR2 primer it was erratic.
With Fed 215M:
59.0 light ejector at 3168 fps
59.5 bolt lift and increased ejector at 3172 fps
60.0 (Did not shoot)
So, I shot 3 shot groups starting at 57.4, .6, .8, 58.0, .2 and .4.
58.2 won, but there is not a wide flat area. Velocity variation is the real problem and if you look at the vertical in my target above, that is 6fps.
I still have work to do.
It also is the same with Barnes 145 LRX. A little velocity shows up dramatically in my rifle.

 

[Warrenoliver]

58.2 gr. No pressure here, but using the mag primers stopped erratic pressure anywhere during the ladder.
With a CCI BR2 primer it was erratic.
With Fed 215M:
59.0 light ejector at 3168 fps
59.5 bolt lift and increased ejector at 3172 fps
60.0 (Did not shoot)
So, I shot 3 shot groups starting at 57.4, .6, .8, 58.0, .2 and .4.
58.2 won, but there is not a wide flat area. Velocity variation is the real problem and if you look at the vertical in my target above, that is 6fps.
I still have work to do.
It also is the same with Barnes 145 LRX. A little velocity shows up dramatically in my rifle.

Bob,

Thanks for the great info. This should really help me with working up a load. I have recently switched to the federal magnum primers so that info is especially helpful.

Warren

 

[Plinker147]

[

There is a fellow on this site that has the fastest 280ai I've ever heard about. I think he is getting 3050 from a 175 Berger with rl23. I figured he will be on this thread sooner or later. I still shoot retumbo from mine. 2900 and change but 1/4 moa.
Shep

The 175 elites have less baring surface the similar 160-168 gr bullets thus can achieve some better velocities. I have seen this in other caliber elites too. Probably a long barrel too.

 

[dougduey]

I hope you find a factory load that works well for you. I just picked up my new .280AI. I built mine off an old Remington action I wasn't using and a Brux barrel I picked up off this site.

I quickly did some load testing this past weekend and I can tell it's going to be a shooter. I started with 160 Accubonds and 168 Berger HLVDs. All I have on hand is 4831SC, so nothing screaming on velocity, but extremely consistent. I fired 9 different powder charges of 3 shots each with the 160 Accubond and not a single group was over .75" at 100 yards. I am going back this weekend to see if I can push it a bit hotter. I was sitting at 2856 and 59.1gr of powder. I think I have room to go as there was no indication of pressure. This was out of a 24" barrel. I love this caliber so far.

H4831sc is a great powder in the 280 AI. Might not be a fast and as sexy as some others, but extremely temp stable and reliable. You should be able to hit around 2925 fps, which is a sweet spot for the 160 gr bullets in the 280.

 

[dougduey]

I have some RL23 but am having trouble finding load data for it. Mind sharing yours? Currently I'm shooting 169 ABLR with either IMR4350 or H4831SC
Thanks

I spoke with Berger a few weeks ago about load data for the 168 gr Classic. COAL 3.330"
RL23. START: 54.5 gr 2601 fps
MAX: 60.5 gr. 2864 fps
RL26. Start 56.5 gr. 2640 fps
Max. 63.0 gr. 2951 fps
N560. Start. 56.0 gr. 2631 fps
Max. 62.1 gr. 2929 fps.

 

[dougduey]

What was the powder weight on that load? I'm planning to work up a good rl23 load for the 143 hammer hunter but can't find much info. Any pressure signs at that speed?

I hit a good node just under signs of pressure from 63.8-64.1 gr. I hit pressure at 64.5 gr. I have a match chamber, so the throat is long. My COAL is 3.474". ES with new brass was 12 with 3268 fps average. ES with 1x fired brass is 4 with 3264 fps average. Fed 215 M primer.

 

[dougduey]

There is a fellow on this site that has the fastest 280ai I've ever heard about. I think he is getting 3050 from a 175 Berger with rl23. I figured he will be on this thread sooner or later. I still shoot retumbo from mine. 2900 and change but 1/4 moa.
Shep

Man, that is screaming. Those are velocities I would expect out of my 7 STW, not the 280 AI. Actually it's faster than what I'm getting in my 7 STW.
I know Lance is getting around 2970 fps with that bullet/powder combo.

 

[25WSM]

Lance has a fast one too.
Shep

 

[25WSM]

I get just over 2900 in mine with Berger 168s.
Shep