.243AI powder options, quickload request

[BallisticsGuy]

Got myself an 8-twist 26" pipe chambered for .243AI (Ackley Improved, 40deg shoulder) and ordered a crate of 108gn ELD-M's and several hundred Hornady cases and dies. Can't seem to get 115 DTAC's so the 108's will have to do. Use case is long range precision competition. I've been using .223 and .308 but I'm sick of .308 recoil so going to something a lot lighter kicking.

Given the long pipe and relatively heavy bullet and the overbore ratio (right up there with 7mm rem mag) I'm definitely going to be served by slower burning powders. H1000 seems to be well liked so it's looking like it wants really slow stuff suitable for highly overbore magnums running heavy bullets. I've had good luck with powders like US869 in some combos that are similarly overbore like 7mag with 180's. Curious if anyone has any data particularly for US869. Viht already has N550 data posted which looks promising but there's nothing out there about US869.

I fear US869 might be too bulky for the application but I'd like to see if someone could run a QL sim for me. I'm guessing charge weight would end up a bit north of 50gn based on the charge weights I'm running in my 7mag.

 

[Jud96]

I would try RL23, RL26, H1000, RETUMBO, and IMR 7977. All of those are slow burning powders that can give great results with the 108gr bullets. They are also temperature stable powders, not something you have to have in every situation, but it keeps everything relatively simple and the same throughout the year.

 

[ltrbuck]

I've got nearly identical of a setup, shooting 105 A-max's over H4350 very well.

 

[BallisticsGuy]

4350's looking hard to come by. I have a little H1000 laying around. I put in a request to Hodgdon to tell me about compatibility with US869. If there's nothing there I'll probably just get some more h1000.

 

[BallisticsGuy]

Well, that request to Hodgdon was particularly unproductive. Not just a no but the kind of no that says they really don't care either. However, doing some further research and some back of the napkin math I have a starting load figured out and a good idea of where the max should be. The high end is a pretty startling number for such a small case but it's the same way in my 7mag. Compared to the other powders, for which they both seem to share an affinity, US869 takes a gob of weight compared to h4350 h1000 and retumbo.

 

[Axl]

Well, that request to Hodgdon was particularly unproductive. Not just a no but the kind of no that says they really don't care either. However, doing some further research and some back of the napkin math I have a starting load figured out and a good idea of where the max should be. The high end is a pretty startling number for such a small case but it's the same way in my 7mag. Compared to the other powders, for which they both seem to share an affinity, US869 takes a gob of weight compared to h4350 h1000 and retumbo.

I have tried all the powders you list except us869 and in the 2 243ai's i load for H4831sc was the best performing with 105 grain bullets

 

[ATH]

I run Re22 with the 105s in my 243AI..mid 3200s. I do plan on trying Re26, and if that doesn't please me, Re23, and phasing out Re22 if results allow.

 

[Capt RB]

I ran Rl25 with 105 amaxs for awhile.3275 before I started to see any signs of pressure. Shot great in the winter but the bolt got sticky and a clear ejector mark the following spring. This is a shillen 8tw with win brass. I'm positive lapua brass would easily give you more speed. The amax and 107serrias shot extremely well with this powder. I have alittle bit of 26 left but I don't think I will try it in this case right now. Maybe when I get more I will though.
I have not used 869 yet so I cannot say. I am currently using H1000and loafing along at 3130 with my load. Shoots great and is not near the top at all. If I can get the kind of life that the 6cm shooters are getting I will be a happy camper.
Lastly H4831 has shot very very well in my gun also. It was a quest for better barrel life that lead me to Rl 25 and later H1000.

 

[BallisticsGuy]

After a bunch more looking around and some advanced google f00 I've found US869 will "work" sorta. Pressures are stupid low (39k) which is ok but it won't give particularly impressive velocities either (~27xxfps with a 105% load) and it'll bark loud and bright with a lot of un-burned powder exiting the muzzle. So can it, yes. Should it, not with 108's for sure.

I've got a 8lbs jug of RL23 coming in a couple days. Hopefully it works well. Alliants site seems to suggest it as well as y'all and some other folks. On the upside it looks like it'll also work really well with 162gn ELD's in 7mm Rem Mag.