Thread: 7mm RM rechambering

OK, so this is a total pipe dream at this stage, but I’m looking at re-chambering my Tikka 7RM. I’m looking at 7-375 Ruger, or possibly 7-300 PRC.
The thought behind it is, I want to keep it mag feed-able, drop the belt, and increase range.

First question, can anyone recommend a decent smith for re-chambering? And also dies etc
Second question, has anyone got these calibres, and what are positives vs negatives of each.

Thanks in advance for any insights

The first question is what do you want to achive? If you want more range your better stepping up to a bigger .30cal. with 210eld's They suffer less in the wind and release more energy at range and yes I've got a 7mmRm. and shot it at range.

Cool. Kiwi Greg has a write up on the 7-375

I’ll be completely honest here... there is a lot of the “cool” factor coming in here, but what I want is to increase the range to point where I could possibly hit steel out to 1 mile. And if I’m up to it, cleanly take animals out to 1000m

Without a complete re barrel

Originally Posted by stevodog

Cool. Kiwi Greg has a write up on the 7-375

thanks for that mate I’ll look it up

To be honest you will waste a ton of money and end up with a rifle that won't sell for anywere what it cost.(been there, done that) Sell the tikka and buy one in any of the new 30 cal magnums, Yes you can hit steel with 7mmrm at a mile if theres no wind, you might want to talk to the guy's who do the toby shoot, but any wind and it's just a guess on your part.

Tikka probably not the best platform for such a chamber/calibre. Your 7mm RM is quite capable for animals out to 1000 yrds so long as you run the right pills and you/rifle are up to it and you can judge wind well. That applies equally to 30 cals too imo !
How many rounds thru the current bbl ? Whats the twist rate ?
You could risk spend some serious $ getting it done and end up with a dog.
If you want to go to any of the "big 7's", you really need fast twist 26in bbl.

Not keen on selling up,

Still brand new, only had 10 rounds through. Just about to work up a load with 162gr eld-x’s and RL22, see how that goes for speed/accuracy. If it doesn’t like the elds, I’ll try nosler 168gr LR’s. It’s just a standard 1/9.5” barrel so definitely not fast twist.

Check your mag length for the cartridges you are interested in for a rebarrel. Also, will the cartridges load and feed from your mag? And have you got a spare minimum of $800 for the rebarrel job (not counting the brass, dies, bullets, powder, etc)?

Originally Posted by Grimus

Still brand new, only had 10 rounds through. Just about to work up a load with 162gr eld-x’s and RL22, see how that goes for speed/accuracy. If it doesn’t like the elds, I’ll try nosler 168gr LR’s. It’s just a standard 1/9.5” barrel so definitely not fast twist.

If i were you and wanting to extend the range/hitting power of what you have. Id forget about mag feeding it, and look at running the 180gr eldm seated out as long as your chamber will allow. Im running them in a 22" barrelled 284 win at just shy of 2800, the 7RM will push them lots faster with the right powder and will give you alot more energy down range and im picking a windage advantage over the 162/168 at higher velocity.

Im shooting the 180s out of a old factory tikka M595 9.5 or 9.25 twist or whatever they are and it shoots them extremerly well. So your standard barrel will likely shoot them well.

If you want to rechamber it, id look at the 7mm Blaser Mag cartridge, i believe it can be done on a T3 no problem. and will give a handy powder increase over the 7RM and no belted case if thats important to you.

30/06 and be done with it.

Originally Posted by Grimus

Still brand new, only had 10 rounds through. Just about to work up a load with 162gr eld-x’s and RL22, see how that goes for speed/accuracy. If it doesn’t like the elds, I’ll try nosler 168gr LR’s. It’s just a standard 1/9.5” barrel so definitely not fast twist.

you can achieve more with your RM but need to go to slower burn rate powders like RL25 or 26, or AR2225, and like @GWH says bigger , higher BC pills like the 180 VLD's or ELDM's even if that means single feeding.
I believe the Duley's have even gone to RL33 in 7mmRM's with some success.

Talk to Kiwi Greg. As above 180 eld or berger 180. 7mag 2900-3000ish give or take. Your barrel twist is boarder line and will show at distance more than close. Just because it's stable at 1000 doesn't mean it will be at a mile. 30 or 338 cal would be better. Comparing figures of energy etc isn't comparing apples with apples. 7mm doing over a 100fps faster and 45gn lighter bullet doesn't mark a steel plate that I use. A 30cal cal going slower with the heavier bullet both of the same construction puts holes in it. On paper nothing between them. In real world there certainly is. Like comparing a v8-v6 4cyl with the same hp and similar toque . Put a hill in front of them and see who runs out of puff first