Gunsmithing Difference in Remington LA and Magnum LA

[Coyote3]

For all you guys out there who do a lot of smithing, tell us all the differences exactly between a standard LA and a Magnum LA. We all know that the boltface is different, but how much difference is there in magazine box length, bolt length, ejection port length, action outside diameter, center to center from front and rear mount screws, feed rail width, etc... Just a few I can think of. Any takers so we all can learn and put in the old memory bank.

 

[Dans40X]

Re: Difference in Remington LA and Magnum LA

There are 3 Remington action lengths(basically)-
XP-100/600/660/XP-100R/Seven
Handle location=3.850"
Shorter rear receiver bridge than S/A's
Action screws= 1/4-28 front & # 8 rear

722/40X/700 S/A
Handle location=4.375"
1 pc scope bridge will interchange with above receiver spacing.
Action screws=1/4"-28 front/1/4"-28 rear/#8 center for ADL applications.

721/Sportsman78/700 L/A
Handle location=5.215"
Dimension/width between feed rails differs between .473"/.532"/.588" bolt face applications.
Action screws=1/4"-28 front/1/4"-28 rear/#8 center for ADL applications.

ADL/BDL mag boxes differ in height for different stock inlet/trigger guards.
SAUM & Ultra mag boxes are "windowed" for rebated/.532" case head clearance.

XP-100 & 40X receivers are faced from the Custom Shop prior to barreling.

All action diameters are not centerless ground, they are grained/sanded so diameters vary.

A 30-06 varies from a 300WM only by bolt face diameter & barrel profile=the receivers are machined identically.

 

[Coyote3]

Re: Difference in Remington LA and Magnum LA

So another words the difference between a Magnum LA and a Standard LA is the feed rail width and bolt face diameter?? By barrel profile, meaning where the taper on the reciever end start to taper for the contour??

 

[Cloud Peak 1]

There are also DBM actions which have very wide feed rails and cannot be converted to BDL for that reason.The R.U.M actions also have different rail spacing (.565' *varies some) as well as the feed ramp being moved forward.They can be converted to std magnum cartridge with no ill effects.The STD long action (30-06,270 etc )have same rail spacing as (7mm,300 win,338 win).540".The only difference in these actions is Boltface dia.All long action Mag boxes are same as well as ejection port hole spacing and footprint.

So another words the difference between a Magnum LA and a Standard LA is the feed rail width and bolt face diameter?? By barrel profile, meaning where the taper on the reciever end start to taper for the contour??

 

[George Az]

Thank you, one of the reasons this place rocks! Great explanations.