Thread: 7mm RM rechambering

Originally Posted by ChrisW

I dont believe 300NM class cartridges will fit in Tikka action. The cartridge is closer in size to .338lapua. It certainly wont fit in a Tikka magazine.

7mm with the right projectile will generally have better ballistics than the .300s. The only mainstream .308dia projectiles im aware of that has a higher BC than the 7mm 180 ELDM are the Hornandy 230 and 250gr A-tip projectiles, which only just edge out the basic (and cheap) 180ELDM. Hornady have not yet published the BCs for the new 7mm A-tips, but I have no doubt they will easily top the best BC 30cal projectiles commonly available.

The other thing to keep in mind is the twist rate of the standard barrel. It may not be sufficient for the heavy 7mm's.
The added velocity will offset some of the lack of twist rate, but will it be enough? Im not sure...would be borderline id think. (if we are talking 180ELDM)

@ChrisW Thanks for that authoritative advice. Norma state the 338NM and 300NM were designed to swap out in actions made for 338LM.

Do you think the 300NM would work well enough in the Sako 85 long range XL action or the TRG M10 ? Come to think of it. Are those in the pipeline as factory options ?

Originally Posted by Bagheera

@ChrisW Thanks for that authoritative advice. Norma state the 338NM and 300NM were designed to swap out in actions made for 338LM.

Do you think the 300NM would work well enough in the Sako 85 long range XL action or the TRG M10 ? Come to think of it. Are those in the pipeline as factory options ?

Yep, all those will easily fit in the Sako Long range XL action or the M10. Im not aware of any of the Norma Magnums coming as factory offerings but I do know 6.5PRC is in the works.

Originally Posted by 25 /08 IMP

Arthur Cleland will I think

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Originally Posted by Stocky

Let us know how that gets on with Greg.

Originally Posted by Spitfire

Dave Ward in Dovedale does. He’s doing one for me as we speak - 7-08 to .284 Win. The last one he did shoots 162s ELD-X into .5 MOA 5 shot groups. He knows what he’s doing.

Bit of an update, Dave Ward does, but doesn’t have the 7BM reamer. And Arthur Clealand does, and has quoted me $350 to rechamber, including a bit extra to get the reamer... bargain if you ask me

Originally Posted by Grimus

Bit of an update, Dave Ward does, but doesn’t have the 7BM reamer. And Arthur Clealand does, and has quoted me $350 to rechamber, including a bit extra to get the reamer... bargain if you ask me

Make sure you remember to make sure the thraoting is too suit the shorter tikka magazines. Ask Greg I'm sure he will have specs.

Originally Posted by Stocky

Make sure you remember to make sure the thraoting is too suit the shorter tikka magazines. Ask Greg I'm sure he will have specs.

@Stocky thanks mate yeah will do, have had a good look around and found that there has been two revisions of the CIP standard reamer, Rev B has a freebore measurement of .3645", whereas the original freebore of Rev A was .0631". I’ll confirm what I need with Greg.