Questions reloading for a TC Dimension

[Tuxie]

Years ago I committed to the Thompson Center Dimension platform, and being that I have three boys coming close to hunting age i've snapped up enough stock & receivers, barrels, and LH/RH bolts to allow them to transition from lighter recoil to magnum calibers if they choose too. For those unfamiliar with the TC dimension, in my opinion, its probably the coolest ugly bolt action rifle you cant find anymore. Its a interchangeable component system that allows one stock/receiver to switch through 11 calibers from 204 ruger to 300 win mag, that fall into 4 different bolt families. I've only been reloading for about 3 years, and only playing with my main caliber 30-06. Ive been wanting to toy with some of the other barrels I have but there are a few aspects i'm confused/nervous about. My 30-06 load i'm currently using has been proven to be very accurate and reliable. When I change barrels and then change back and use my old stock of handloads do I have to be worried about the seating depth (Im less concerned about this one as I will recheck my Max CBTO to my rifle notes), and secondly my biggest jump in accuracy gains came with only neck sizing and only using those handloads for that specific rifle. My thought is that if I necksize only for a specific reciever / barrel combo, and I take said barrel off and then replace it at a later date, compare my Max CBTO and its the same, I should be safe to use those handloads developed for that specific reciever / barrel combo. I would love to hear your thoughts on this one. I have taken to time to try and research this question on my own and did not come up with any answers.

Tuxie

 

[Coyotefurharvester]

I have a Dimension also, love it. I have A.B bolts and 204,223,22-250 barrels. Since the barrels are/were/could be purchased separately from bolts and receivers, I consider them interchangeable. But I only have one receiver. Any difference should be limited to the bolt face depth. Shouldn't take but a few minutes to see if two A group bolts are close(couple thousandth) using a spent primer in a sized case. The stock maybe a bit fudly but are very useable with a rail scope mount with thermal/night vision scopes. I change barrels/A,B families in the field and even pull barrels for cleaning. Reinstall and shoot my hand loads with no issues/changes. There will very likely be a scope adjustment needed when changing barrels. I don't have the cantilever mount, my receiver has a one piece EGW rail. When I change barrels/cartridge I need to rezero the scope, this has been as little as 1" center to center. I have removed and installed same barrel and saw No poi shift. Any other questions let me know, had my barrels threaded for direct thread suppressors. I full length size, neck sizing COULD be an issue between two different same cartridge barrels, simple fix find which barrel requires most sizing and use that sizer(FL) setup for both barrels. You have get lucky and neck size will work for both.

 

[Homerange]

An old trick for getting the younger ones used to the larger calibers was to use 150gr 30.30 FN projectiles in a 308 or 30/06 for that matter downloaded to 30.30 velocities where they'll still perform well at most normal hunting ranges while youngsters develop recoil tolerance and accurate shot placement.

For them to develop these skills it's very important not to let them get bashed around at the bench so pad them up and ensure the hold the forend to minimize recoil.

 

[Tuxie]

Thanks Coyotefurharvester for all the good info, and I think the TC dimension was a extremely underrated platform. I actually like the look of them, though I realize that was a major complaint by many. My plan with my neck sized handloads would be to fire them with all the exact same components they were loaded with, the only difference would be the barrel was removed and then replaced at a later date. I believe the risk to be minimal but there is a chance of getting a case jammed in the receiver.

Homerange, I totally agree. My first rifle as a teenager was a 30-06 and it did leave a crescent moon shape on my forehead. My current plan is to move them up from a .22 to the .223 barrel, then my two younger ones will eventually graduate to a 7mm-08, my oldest will have to make the jump to a .270 win with a reduced recoil load that I will be working on this spring. I do have a SKS and I believe the recoil from the 7.62x39 is pretty close to the 30-30. I wouldnt get them hunting with that gun but would get them used to the recoil.

Tuxie

 

[Coyotefurharvester]

Zero chance of problems if using loads developed for a specific barrel. Removing and reinstalling a barrel in the dimension platform is what the system was designed for. Just use the system tools,follow the instructions. Do mine in field, range and prairie dog shooting, NO issues ever with ammo, all my barrels are sub moa easy. Inspect the trigger assembly pins(2) I have installed a McCarbo spring and noticed the pins are loose fitting. I actually used some of the wife's nail polish so I wouldn't lose one. I haven't built a click sheet for each barrel because I have also switched optics occasionally. Last was 4-20 stac to night vision for winter coyote, from summer prairie dogs. Looking for a 30/06 barrel.

 

[Homerange]

Homerange, I totally agree. My first rifle as a teenager was a 30-06 and it did leave a crescent moon shape on my forehead. My current plan is to move them up from a .22 to the .223 barrel, then my two younger ones will eventually graduate to a 7mm-08, my oldest will have to make the jump to a .270 win with a reduced recoil load that I will be working on this spring. I do have a SKS and I believe the recoil from the 7.62x39 is pretty close to the 30-30. I wouldnt get them hunting with that gun but would get them used to the recoil.

Tuxie

Rather than just download also consider using lighter projectiles than is the norm for any caliber especially if your quarry isn't large framed or heavily haired.
For some years I've used 120's and 130's in 7m-08 and 308 at near max loads and had great success with them on mid to smaller deer. Far more pleasant to shoot at the bench too than 150's and heavier.

There's lots of good info on all manner of calibers and projectiles and their terminal performance here:

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