Long Action .257 Roberts A.I.

[Capt Nag]

I know this subject is a horse beaten half to death. I read, listened, and took as much advice as possible then had a .257 Roberts A.I. built on a .270 Howa 1500 action. Hey, it's been my dream gun; what can I say?
My question is when guys recommend going with the Long Action, they never talk about feed issues.
I placed my action in a MDT Chassis. It uses AICS magazines. The problem I am having is MDT says a 30.06 mag would work, but I'm finding that the round isn't sitting high enough in the rear of the mag for the bolt to reliably pick it up. So, once in a while, the bolt skates over the round.
I phoned MDT asking for magazine recommendations, and the 30.06 is the one they say should work.
We tried "Tuning" the mag lips, (btw).

So when one builds on a long action, assuming they're using a regular rifle stock, with drop out floor plate magazine, (like a Rem 700 BDL), are there any problems like this?
I'm at the point where I'm ready to junk that chassis system and mag and go back to basics.

Any thoughts on this issue? Thanks

P.S. I'm almost thinking if the mag had a block or spacer in the rear of it, the round would sit a bit more forward making it easier to be caught by the bolt. Just a thought. One other thing comes to mind.....Since the head space for a .270 & are 30.06 are the same, [.473'], I'd think a mag for a .270 might work better, only because it's OAL length is a wee shorter. Again, more food for thought.

 

[Phil Rizzo]

Is there another type follower for your mag?

 

[std7mag]

Ok, first things first.
What you are calling "head space" is actually the rim diameter.
Headspace is the distance from the bottom (or face) of the case to a predetermined distance on the case ( usually somewhere on the shoulder). It's where a certain length & certain diameter meet.

So in this case the 30-06, 270 Win & 257 Roberts AI are all in the same class of rim diameter. 0.473"

The case lengths and taper of the cases is vastly different.

My 257 Roberts AI is built on a Savage 111 that was originally a 270 Win. This rifle has the hinged floor plate, swing down magazine.
No issues with feeding.
Nor would I expect any had the rifle originally been a 30-06.

I'd ditch the AICS and chassis and use the original stock and magazine.

 

[P7M13]

I have two MDT chassis. Their mag well is sloppy (up/down *and* side to side), especially with metal AICS mags.
Try a Magpul.
Inside the mag well, take a look at the inserts for mag travel end stops. Can they be adjusted?
Good luck

 

[VinceMule]

The solution is to modify the magazine follower, get a different brand of magazine, or go back to factory equipment.

A 1/2" rat tail file will make quick work of modifying the Magazine follower, Drop the case down in the front.

 

[Tiny Tim]

I've seen mags with a rear spacer for short cartridges ( but no one i know or can contact). Not certain if purchased or modified, but they seemed to work.

 

[Capt Nag]

I have two MDT chassis. Their mag well is sloppy (up/down *and* side to side), especially with metal AICS mags.
Try a Magpul.
Inside the mag well, take a look at the inserts for mag travel end stops. Can they be adjusted?
Good luck

A Magpul is on the way. My criticism of the MDT metal mag is identical to yours. I'm not certain there's another latch; one that might push the mag up higher. My several conversations with MDT were not helpful in this matter either. Oh how I regret going the the route with a chassis.

 

[Capt Nag]

I've seen mags with a rear spacer for short cartridges ( but no one i know or can contact). Not certain if purchased or modified, but they seemed to work.

Agree, that that's the solution. But like you said, where to get one is the question.

 

[Capt Nag]

Is there another type follower for your mag?

MDT says no. A spacer in the rear that could set the case closer to the barrel would be helpful.

 

[Capt Nag]

Ok, first things first.
What you are calling "head space" is actually the rim diameter.
Headspace is the distance from the bottom (or face) of the case to a predetermined distance on the case ( usually somewhere on the shoulder). It's where a certain length & certain diameter meet.

So in this case the 30-06, 270 Win & 257 Roberts AI are all in the same class of rim diameter. 0.473"

The case lengths and taper of the cases is vastly different.

My 257 Roberts AI is built on a Savage 111 that was originally a 270 Win. This rifle has the hinged floor plate, swing down magazine.
No issues with feeding.
Nor would I expect any had the rifle originally been a 30-06.

I'd ditch the AICS and chassis and use the original stock and magazine.

You are right. Sorry for the incorrect nomenclature. My brain is a little fryed with all the case measurements. Sounds like moving this chassis on would be the easiest way to go. There's a lot of "dough rey me" in it. AICS mag was $80 by itself.
I'm gonna try a Magpul mag first.

 

[Capt Nag]

The solution is to modify the magazine follower, get a different brand of magazine, or go back to factory equipment.

A 1/2" rat tail file will make quick work of modifying the Magazine follower, Drop the case down in the front.

I like that! Hate to ruin a $80 mag though. Gonna try a Magpul mag first.

 

[lancetkenyon]

.30-06 and .270Win mags are identical. They don't make a different mag for the .270Win.

Primal Rights makes a spacer and follower for the SA Accurate mags to run cartridges like a 6BR and 6GT. I bought a couple and swapped them to run my 22GT rounds, as I was having similar issues. Maybe contact them and see if they make a similar system for LA.

Hawkins makes spacer systems for their Hunter mags too, for the same reason. But they only work with their Hawkins Hunter DBM and Hunter flush mags.

 

[Capt Nag]

OMG! Thank you so much for that info. I'll get ahold of them. That looks like my ticket

 

[Capt Nag]

.30-06 and .270Win mags are identical. They don't make a different mag for the .270Win.

Primal Rights makes a spacer and follower for the SA Accurate mags to run cartridges like a 6BR and 6GT. I bought a couple and swapped them to run my 22GT rounds, as I was having similar issues. Maybe contact them and see if they make a similar system for LA.

View attachment 508265

Hawkins makes spacer systems for their Hunter mags too, for the same reason. But they only work with their Hawkins Hunter DBM and Hunter flush mags.

On the phone with them right now. Only 6BR is available at this time .
Great idea though.