Custom 280ai build Q’s

[droppndrakes]

So I am planning out my first custom rifle build and I have a few gray areas where I could use some assistance.
After scouring the web I have learned a lot and come up with a list of parts I am leaning towards and I’ll follow the part list with a few questions.
Bighorn TL3 dlc Coated for AICS mags
Manners EH5 or EH5-A
Either Curtis bottom metal or manners mini chassis (both run with Curtis 3 round mag)
Proof 24” 8.4twist Sendero light, threaded with brake.
TriggerTech special

I was considering getting a barreled action with trigger installed from PVa or lri and dropping it into the manners mini chassis myself. Can I expect this to be inletted properly from manners for accuracy and finish concerns? I don’t want to sacrifice quality for this but I like the idea of the mini chassis and being able to Do it myself.

Next thing is the 280ai in AICS mags. Will this cartridge fit properly in the Curtis mags or AICS mags and feed correctly without bending lips? I don’t have experience modifying mags and If I dropped in a b/a myself I don’t want to have to deal with feeding issues.

Last question is should I just get the chamber cut to standard saami specs? I would be using copper creek to work me up some loads with the 160 or 168 AB but would also like to shoot factory offerings if necessary (Hornady 162 eldx Nosler 150gr AB). Would the 8.4 twist be appropriate for this? Seems like 1x9 is ideal but proof doesn’t offer that in the Sendero light config.

Thanks for any help! -Joel

 

[b6graham]

with the lego type builds there can always be issues, but you have to accept you may have to play with magazines, time triggers, etc

that's the cost you pay for saving money by not having a smith build it. you may have issues and maybe not

 

[droppndrakes]

Anyone else have any experience that could help me out?

 

[RogueTanker]

Minor lip bending will get you to feed from 300wm AICS mags. Nothing to worry about. Take a couple seconds. 30-06 mags will work without mods.

You can get 2950-3100 from 162's and 2750-2900 from 180s. Great round.

Tighter the twist is better, go with the 8.4. It'll stabilize pretty much everything. SAMMI spec is pretty much standard now I believe, so I'd use that for the chamber.

 

[B-P-UU]

With manners mini chassis, you won't be able to run the curtis 3 rd mags. I prefer proper bedding over mini-chassis.. they look cleaner and never have to worry about fit up. That said, lots of guys running them without issues.

My .280 AI had .100" extra freebore which setup the 168 bergers nicely in the case neck. If copper creek is building rounds, I'd run extra FB over SAAMI.. the little factory ammo I shot with this reamer shot really poorly though.

 

[droppndrakes]

With manners mini chassis, you won't be able to run the curtis 3 rd mags. I prefer proper bedding over mini-chassis.. they look cleaner and never have to worry about fit up. That said, lots of guys running them without issues.

My .280 AI had .100" extra freebore which setup the 168 bergers nicely in the case neck. If copper creek is building rounds, I'd run extra FB over SAAMI.. the little factory ammo I shot with this reamer shot really poorly though.

Thanks for your help! Manners is saying on their site that they work with the 3rd mags if you choose the gen 1 mini chassis.

 

[droppndrakes]

Minor lip bending will get you to feed from 300wm AICS mags. Nothing to worry about. Take a couple seconds. 30-06 mags will work without mods.

You can get 2950-3100 from 162's and 2750-2900 from 180s. Great round.

Tighter the twist is better, go with the 8.4. It'll stabilize pretty much everything. SAMMI spec is pretty much standard now I believe, so I'd use that for the chamber.

Ok thank you. Sounds like the mags aren’t a big issue either way.

 

[Supersubes]

With manners mini chassis, you won't be able to run the curtis 3 rd mags. I prefer proper bedding over mini-chassis.. they look cleaner and never have to worry about fit up. That said, lots of guys running them without issues.

My .280 AI had .100" extra freebore which setup the 168 bergers nicely in the case neck. If copper creek is building rounds, I'd run extra FB over SAAMI.. the little factory ammo I shot with this reamer shot really poorly though.

The Nosler/saami reamer has .100 freebore. Are you saying yours has .200? Edit: just re-looked at the JGS print, and it has zero freebore. Screw that! In fact the more I look at it, the more I don’t like it. Wacky things going on there.


OP, with the light weight components in your build, seem like traditional bedding would be the way to go imo. Also, aren’t the Curtis mags billet aluminum? I wouldn’t think they’d be friendly to altering the lips.


I’m building one of these for a friend on a r700/proof steel/ Manners eh2. Haven’t finalized the reamer yet, but the Nosler/saami looks pretty good. Waiting to take some measurements on a dummy
cartridge before I jump on it.

 

[B-P-UU]

The Nosler/saami reamer has .100 freebore. Are you saying yours has .200? Edit: just re-looked at the JGS print, and it has zero freebore. Screw that! In fact the more I look at it, the more I don’t like it. Wacky things going on there.


OP, with the light weight components in your build, seem like traditional bedding would be the way to go imo. Also, aren’t the Curtis mags billet aluminum? I wouldn’t think they’d be friendly to altering the lips.


I’m building one of these for a friend on a r700/proof steel/ Manners eh2. Haven’t finalized the reamer yet, but the Nosler/saami looks pretty good. Waiting to take some measurements on a dummy
cartridge before I jump on it.

Correct.. mine had .100" total and SAAMI has zero.

 

[Supersubes]

Correct.. mine had .100" total and SAAMI has zero.

Cool, thank you.