243 win loading advice

[Disfunctional_Engineer]

I'm wanting to start to dabble with 243win and powders I have on hand. The powders I have I'd like to use for the heavy stuff are Ramshot Magpro and IMR 7828 (non SSC.) Gun is a 1:8 twist 18" barreled AR-10 for what difference it makes. I also have an 8lb jug of IMR 4064 and a small amount of H414, a bit over 1 lb H335, BLC(2) and some AR-Comp but I don't think any of that is really serviceable for 105gr Nosler Custom Competition bullets looking at load data.

I've never done compressed loading before and the load data I'm seeing from Hodgdon indicates the 7828 is a compressed load as max. Anything I need to be conscious of with that? Kind of makes me nervous tbh.

I also have a ton of 80gr Winchester JSPs I'd like to make into more of a plinking ammo I got via an estate sale. There's load data for 7828 as well but I think they'd work fine with the 4064.

Any opinions on where to start would be appreciated. Probably just looking to punch some paper mostly.

 

[larryh128]

You would absolutely not want to use 7828 in an ar-10. Much too slow. Out of that lot I would look at AR comp. 4064 I have no experience with. AR Comp works great in 308, so being basically the same case it should work fine in a 243. Plus AR Comp was designed to run in gas guns.

 

[Disfunctional_Engineer]

Interesting on too slow. I'm guessing function problems?

 

[larryh128]

Interesting on too slow. I'm guessing function problems?

Yes, H414 would probably work seeing it's 4350 speed but you would definitely need a mag primer. My primer choice in the 6.5 Creed in an AR-10 has been a CCi 34. Hardest cup that I've found and good results.

 

[Disfunctional_Engineer]

I took the load data I could find for 105s and this is the list I came up with (slow to fast based on a burn chart from Western I believe it was. YMMV)

Retumbo/RL25
H1000
Magnum
Magpro
PP4000MR
N-560
RL22
IMR 7828
Noma MRP
H4831
H4350
IMR 4350/RL17
W760/H414
H380
Varget
H4895

Looking at this list the H414 is probably about the fastest I'd want to run with 105s. Varget leaves a solid 100FPS on the table maybe even 150-200FPS. 105s aren't the heaviest within the weight the caliber but they're certainly up there. That theroetically should have a (positive) impact on dwell time. I think starting off with the H414 is a good choice, transitioning to RL22 and then 7828 if it looks like things are going well. H414 may also be a good choice for my progressive when I get there because it's a ball powder.

If I get another barrel I'm also presuming a + length gas tube could help as well? Any recommendations there? I have an 18" as mentioned but am thinking I'd like to do 20" next time and maybe go 1:7 instead of 1:8 but I think I'd be past the limit of mag feeding at those bullet weights. They make +1 to +3. In terms of AR-15 etc. I tend to prefer the longest gas tube length possible because from what I understand it makes the gun softer shooting and less finicky about ammo.

 

[GIXXER2000]

I use 4831 but in a bolt gun good case fill and sd hangs around 8.5. Not had any issues with being temp sensitive and I live in NW AZ and its hot.

 

[larryh128]

Interesting on too slow. I'm guessing function problems?

I have some AR comp/130 gr data at home. I can look it up if your interested.

I use 4831 but in a bolt gun good case fill and sd hangs around 8.5. Not had any issues with being temp sensitive and I live in NW AZ and its hot.

4831 is a great powder for a bolt gun but too slow for a gas gun. Doesn't mean you couldn't , you would just get better results with a faster powder.

 

[Disfunctional_Engineer]

130gr 6mm bullets? I think you're talkin 6.5 creed not 243. As a broader question how much variance is there from the top to the bottom of this list? Is it a fairly linear rate change or is it something where there's an inflection point and it goes from moderately slow to zomg slow?

 

[larryh128]

Yes, u are correct. My brain went creed in an instant. Usually what is being talked in a gas gun. My opinion for what that's worth, on a gas gun it's what cycles the action without being overly violent or just too slow to effectively cycle it. And that doesn't mean that gas can't be adjusted for any powder to work but why bother when there are powders that are going to be painless. And adjusting for a powder that is either too slow or too fast is far from painless.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

I run H414 for 243Win through my bolt gun w no issues. I don’t reload for semi auto though.

 

[Disfunctional_Engineer]

Did a bit of testing today. nothing big as I had the kid with me but I did get to test H414, IMR 7828 and Magpro. I loaded 3 rounds, min, between min and max and max. H414 and 728 seemed good but Magpro is definitely too slow. Brass pics pending.