Forming loads 280rem to 280AI

[pods8]

Any favorites out there for loading up some "plinking" rounds while fire forming with bullets?

I just picked up some new RP 280rem brass here and I plan to shoot 139/140s while forming. From what I've read it seems like a mid range load of a faster powder does best while forming? Due to availability I was thinking IMR4350 would be a likely one I'd be inclined to use. Depending on the given bullet in the 139/140gr range max tends to be 52-53.Xgrs per various reload manuals. Would a ~51gr charge seem like an appropriate mid range load for this purpose? (I'd load a few starters in .5gr increments lower to fire first as my typical procedure to work up to a given charge to account for all the variations that can cause a hot load).

 

[cahunter805]

51gr would be fine. I load forming loads to touch the lands. Most forming loads tend to shoot pretty good accuracy wise also.

 

[pods8]

I'm presuming no point in trimming to a uniform length at this stage (brass is 2.530-2.535 currently which is under the 2.540 max) and just do so after fire formed and actual load development is starting?

 

[Jokostel]

When I started fireforming a few cases to AI... I simply grabbed my 280 Rem handloads off the shelf, chambered and fired them...
No double shoulder/headspace issues, nothing negative...
Just came out a LOT different than when it went in...gun)

 

[pods8]

Yeah I'm not anticipating headspace issues, the smith is chambering it traditional and backchecking it against 280rem brass. I had gathered up some 280rem ammunition but I also just picked up some 280rem unfired brass that I will need to load up (thus the discussion of best practice when loading specifically to fire form). I just sized the necks to take out the shipping dings and measured them up to see length (2.530-2.535 range). If I was loading for accuracy on 280rem I'd trim them all uniform and start load development. In this case the first firing is just to from so I presume I don't need to bother trimming (since none are over max length) and just uniform up the length afterwards. Thus my second query.

I do look forward to seeing the transformation.

 

[Jokostel]

Yeah, don't bother doing cleanup unless its flat out unsafe... until the "transformation" is complete.
A good quick propellant charged from 280 rem data is best

Oddly enough, when I was doing that with my Patriot 280AI..... it was literally throwing a 10 shot .2 moa group with 56.5 Rl19 and a 140 Remington PSP bullet...
Craziness man... craziness.

The AI is one hell of a cranker for me... I've settled on A 140 CT/Ballistic Tip with RL17 and a 215.... doing 3220 avg. VERY impressive for a 24in pipe.

 

[pods8]

Right on, I'm quite looking forward to it. I'll be running a 24" as well.

IMR4350 is findable (alot to be said these days...) and medium speed for 280rem so I was thinking that with some 139 hornadys (low cost and typically fairly accurate for me in 7-08).

For load work I was planning to start out with RP brass, 9 1/2M primers, IMR7828SSC (still haven't seen any 4831SC around) working with 145-150gr bullets initially.

 

[Jokostel]

Any 7828 has been love/hate for me...
Honestly, if you can score RL17/22 I think you'd be MUCH happier, unless you want to run 170-180s...
BTW, 61gr of I 7977 with a 171 Barnes Match Burner does 2880 in that same rifle...

 

[pods8]

Any 7828 has been love/hate for me...
Honestly, if you can score RL17/22 I think you'd be MUCH happier, unless you want to run 170-180s...
BTW, 61gr of I 7977 with a 171 Barnes Match Burner does 2880 in that same rifle...

I already have the 7828SSC so I figure I'll see how I like it initially (I've seen just as much if not more griping on RL22).


The new IMRs actually didn't cross my radar till just the other day, I've been reading up on them a bit.

 

[Jokostel]

Admittedly, I was skeptical on IMRs new propellants...
More smoke and mirrors to make a sale and complete with Hercules/Alliants new speeds.
I7977 is the only one I have tried.... and so far... it seems to be about 5-7% slower than 7828SSC....
stuff (to me anyways) looks VERY close to Retumbo in kernel size.... and smell... Probably the copper fouling detergents... who knows...
Let me know what you come up with ...

 

[pods8]

Seems like it'd be getting a bit slow then for 145-150s I'd think then, no? From what I've gathered in research 7828 turf is already a full to slightly compressed charge.

 

[Jokostel]

4350/4831 class propellants unless your going 150/168/171s.....
gun)

 

[pods8]

Yeah still looking for some H4831SC. I have IMR4350 around if I don't like what the 7828 is doing and haven't found the H4831SC. IMR7828SSC seemed like it offered a full case and solid velocity for the 145-150s I'm starting with so I figured I'd give it a go and see how accurate/stable it is.


BTW, staring at a pile of components ready to go and still waiting for rifle delivery is making me **** antsy... gun)