T/C Dimension Rifle - Caliber Conversion

[awpk03s]

Anyone with some experience in Thompson Center Dimension rifles?

I’ve read a lot of favorable reviews on them for as far as a budget/basic bolt rifle for hunting and the like.

They are set up to be quick change barrel/caliber setups, you can change out the barrel/bolt/magazine to switch calibers.

CDNN is blowing them out, and I ordered one (LH) with a 2 caliber set, 30-06 and .223 Rem. for $499. I don’t have extremely high hopes or anything, just looking for a quality basic bolt rifle to have my kids learn on or take hunting.

My question though, I can get a third barrel in .243 Win for $149. It takes (and comes with) a different magazine, and they say you also need to buy a different bolt for that “family” of rounds (243, 7-08, 308). Of course by the time you buy the dedicated bolt you’d be better off buying a whole nother rifle.

I don’t understand why the 30-06 bolt won’t also work for this? The cartridge head is the same isn’t it? Yeah I know short action and long action, but with all these calibers the action is the same no matter what, I’m guessing long action all the time like a Tikka I guess - so I would think the bolt itself is same length in all variations also?

So, if anybody has one of these, and can comment please do. If I’m missing something in this, please let me know that too I would really appreciate!

PS - I called CDNN and asked same question they didn’t know. I called S&W/TC and asked and that guy had no idea what case head dimension even was, they just wanted to sell another part.

 

[Action Guy]

I have a T/C Dimension in .223 Remington. I bought it simply because I was intrigued by the concept. In the end of 2017 when they were giving $75 rebates on them is when I purchased it, so the investment was not great. I had no need for it at all.

I always planned on other calibers to fully realize the potential, but the cost of a barrel, bolt and magazine in the second family (wanted 7mm-08) was about 2/3rds the cost of a second rifle. When I added the bridge mount to the system so the scope would stay with the barrel/caliber, it really was not much less than a complete new rifle. Oh well, novel idea anyway.

Kept hoping for a deal on barrels and/or bolts to pop-up, maybe an end of year rebate again, never happened. After T/C discontinued the Dimension at the end of 2018, I kept a close eye on the market for deals, such as from CDNN. When suddenly I could not find barrels at all, I felt lucky to finally find a fair price for the barrel and bolt from different suppliers. Just last month, CDNN started blowing them out, oh well, I overpaid to ensure I got at least another caliber. I'll quit hoping for a .260 Remington barrel.

To answer your question, I cannot say for sure, but it most likely the C family bolt for the .30-06 has a longer bolt stop groove than the B family bolt. This allows the bolt to come back further in order to grab the round from the longer C magazine. Their bolt faces would certainly be the same, lengths are the same because the receiver is the same. If I were to bet, I would guess the C bolt would work with the B family of cartridges but come back a little further than necessary for a B cartridge. Just speculating though. Perhaps some else knows for sure.

If you care or are interested, here are my personal experiences with mine:

1. .223 Remington twist rate is far too slow at 1:12 and is 1 MOA as claimed, but only with bullets below 50 grains. Hopefully I can find a hand load combination to get 50-52 gr bullets to do at least 1 MOA.
2. Quality seems pretty good for a $500 rifle. The bolt is extremely well made, as is the barrel. This is where the true manufacturing cost is at which is why the caliber change is almost the cost of a complete rifle. They do not feel cheap to me.
3. It is a fairly light weight rifle and easy to shoot. Does not feel right in the prone, but the stock is not a prone design: oh well.
4. The barrel change is easy enough and the tools supplied work as described. Again, a neat idea.
5. Zero does shift for my .223 barrel about 1 MOA when removing and replacing the barrel with the bridge mount that carries the scope with it.
6. Trigger pull is not terrible, but not great either. I adjusted mine to as low as it would go and had to settle for around 3.75 lbs. About what I would expect for a $500 hunting rifle. Breaks clean, so I'm good with it.
7. Magazine capacity at 3 rounds is too low for me, even for a hunting rifle. Especially so for a .223 Remington.
8. It is ugly as hell. This should not be heald against it, and I don't. FN PS90s and FS2000s are horrendous to look at, but when you shoot them, you understand why they are shaped the way they are. Ergonomics explains the Dimension's strange look. An old adage I learned in the military: "If it looks stupid but works, then it's not stupid."

Now about the 7mm-08 Barrel and bolt:
I cannot comment on their accuracy, zero retention or function just yet. When I got the bolt, sold as an accessory, it did not have an ejector spring in it. Not hard to figure out after an initial cleaning and noticed the ejector button had no tension. I assumed it was stuck down from debris or excess lube so I punched the retaining roll pin to free and clean it. No spring. Disappointing but not the end of the world. That was last week. T/C was informed and is shipping me a replacement spring, free of course. No dispute or hassle from them: they just dropped it in the mail. It should arrive late this week or early next. Good customer service can quickly make up for simple QC oversights, in my opinion.

Once it does arrive, I'll get the second caliber going and see how it shoots. Planning on reloading for it, so as long as it does close to MOA with some factory stuff, no big deal there.

I think this system would be great for a younger shooter who wants to grow into a more powerful cartridge after starting with a lower recoiling caliber such as .243 Win. Or if you wanted to travel light on a trip and carry only one gun case but several calibers for different kinds of hunting while on the trip. Also, if having serial numbers was restricted like in other countries, this concept would mean you could have as many "rifles" as you wanted under one serial number, even if the cost per barrel is 50% the cost of complete rifle. However, it appears as though the Dimension will not survive in the US market for whatever reason. After about 5 years, T/C has discontinued it. I applaud them going out on a limb trying something new, nonetheless.

If I did not have the rifle and spare barrel and bolt now, I would definately be buying the system from CDNN now. For the price, it is hard to go wrong, in my opinion. Perfect for kids just starting out or as a spare truck rifle.

Just some thoughts,

Action Guy

 

[awpk03s]

Great feedback - thanks for the time to document that!

Makes sense on the B/C bolt family, and how the bolt stop functions (probably makes more sense when I pick up the rifle tomorrow, haha).

I was not planning on doing the bridge mounts, but maybe just re-zeroing or offsetting the scope with the barrel changes, but CDNN is selling the bridge mount so cheap I may be tempted to try one.

I’ll think about the 243 too after I look it all over. I don’t think it would be any safety or accuracy issue, so I may give it a whirl.... knowing they’re discontinued and the parts are going cheap kind of makes me want to get as many options as I reasonably can without getting stupid.

 

[awpk03s]

Well I picked up my Dimension rifle today from the FFL. With a few minutes to unwrap and give it a once over, I am impressed, especially at this price.

The rifle was 30-06, and my conversion barrel/bolt was supposed to be .223 Rem, however, CDNN shipped me a barrel and bolt for 22-250.
Initially I was miffed, but then I considered that 1:12 twist on the .223 wasn’t that optimal for the bullets I shoot anyway, so maybe it’s not a loss. Plus.... the ‘B’ series bolt for the 22-250 is the right one for .243 Win.
So I accepted the transfer and went with it; and then ordered the .243 Win conversion barrel from CDNN. A win win I guess.

Never had a 22-250 before so I guess I will have fun with that.

 

[Action Guy]

Can you tell if the B and C bolts are the same except for the bolt guide/stop groove?

T/C may have changed the size or dimensions of the bolt head slightly along with the barrel extension so a B bolt can only go into a B barrel. Perhaps done to sell more bolts or to keep it simple for the Fudds of the world.

The missing ejector spring I was waiting for arrived yesterday, two weeks after requesting it from T/C. Already installed and the new caliber is ready for the next trip to the range to begin evaluation.

AG

 

[awpk03s]

The B and C bolts are indeed except for the length of the bolt stop groove.

I’m anxious to get some glass on it and some rounds fired. The more I handle and inspect this, the more I like it. As you mentioned, the barrel and bolt are beautifully machined. The action is smooth. It’s not as nice as a Tikka, but it’s a darn sight better than a Savage/Remington/Ruger in its price range. The stock is ugh, but it doesn’t feel cheap or flimsy at all, it’s pretty stiff in the right places and it just feels good to hold and shoulder.

I did order a couple spare magazines, and a barrel change tool, since they’re discontinued, it’s hard telling what future availability will be.

 

[Action Guy]

Well, if there is good news, the magazines are shared with the T/C Venture which is still in the line. They only show it in short action lengths, though.

 

[BROWNBEARHUNTER]

I have a T/C Dimension in .223 Remington. I bought it simply because I was intrigued by the concept. In the end of 2017 when they were giving $75 rebates on them is when I purchased it, so the investment was not great. I had no need for it at all.

I always planned on other calibers to fully realize the potential, but the cost of a barrel, bolt and magazine in the second family (wanted 7mm-08) was about 2/3rds the cost of a second rifle. When I added the bridge mount to the system so the scope would stay with the barrel/caliber, it really was not much less than a complete new rifle. Oh well, novel idea anyway.

Kept hoping for a deal on barrels and/or bolts to pop-up, maybe an end of year rebate again, never happened. After T/C discontinued the Dimension at the end of 2018, I kept a close eye on the market for deals, such as from CDNN. When suddenly I could not find barrels at all, I felt lucky to finally find a fair price for the barrel and bolt from different suppliers. Just last month, CDNN started blowing them out, oh well, I overpaid to ensure I got at least another caliber. I'll quit hoping for a .260 Remington barrel.

To answer your question, I cannot say for sure, but it most likely the C family bolt for the .30-06 has a longer bolt stop groove than the B family bolt. This allows the bolt to come back further in order to grab the round from the longer C magazine. Their bolt faces would certainly be the same, lengths are the same because the receiver is the same. If I were to bet, I would guess the C bolt would work with the B family of cartridges but come back a little further than necessary for a B cartridge. Just speculating though. Perhaps some else knows for sure.

If you care or are interested, here are my personal experiences with mine:

1. .223 Remington twist rate is far too slow at 1:12 and is 1 MOA as claimed, but only with bullets below 50 grains. Hopefully I can find a hand load combination to get 50-52 gr bullets to do at least 1 MOA.
2. Quality seems pretty good for a $500 rifle. The bolt is extremely well made, as is the barrel. This is where the true manufacturing cost is at which is why the caliber change is almost the cost of a complete rifle. They do not feel cheap to me.
3. It is a fairly light weight rifle and easy to shoot. Does not feel right in the prone, but the stock is not a prone design: oh well.
4. The barrel change is easy enough and the tools supplied work as described. Again, a neat idea.
5. Zero does shift for my .223 barrel about 1 MOA when removing and replacing the barrel with the bridge mount that carries the scope with it.
6. Trigger pull is not terrible, but not great either. I adjusted mine to as low as it would go and had to settle for around 3.75 lbs. About what I would expect for a $500 hunting rifle. Breaks clean, so I'm good with it.
7. Magazine capacity at 3 rounds is too low for me, even for a hunting rifle. Especially so for a .223 Remington.
8. It is ugly as hell. This should not be heald against it, and I don't. FN PS90s and FS2000s are horrendous to look at, but when you shoot them, you understand why they are shaped the way they are. Ergonomics explains the Dimension's strange look. An old adage I learned in the military: "If it looks stupid but works, then it's not stupid."

Now about the 7mm-08 Barrel and bolt:
I cannot comment on their accuracy, zero retention or function just yet. When I got the bolt, sold as an accessory, it did not have an ejector spring in it. Not hard to figure out after an initial cleaning and noticed the ejector button had no tension. I assumed it was stuck down from debris or excess lube so I punched the retaining roll pin to free and clean it. No spring. Disappointing but not the end of the world. That was last week. T/C was informed and is shipping me a replacement spring, free of course. No dispute or hassle from them: they just dropped it in the mail. It should arrive late this week or early next. Good customer service can quickly make up for simple QC oversights, in my opinion.

Once it does arrive, I'll get the second caliber going and see how it shoots. Planning on reloading for it, so as long as it does close to MOA with some factory stuff, no big deal there.

I think this system would be great for a younger shooter who wants to grow into a more powerful cartridge after starting with a lower recoiling caliber such as .243 Win. Or if you wanted to travel light on a trip and carry only one gun case but several calibers for different kinds of hunting while on the trip. Also, if having serial numbers was restricted like in other countries, this concept would mean you could have as many "rifles" as you wanted under one serial number, even if the cost per barrel is 50% the cost of complete rifle. However, it appears as though the Dimension will not survive in the US market for whatever reason. After about 5 years, T/C has discontinued it. I applaud them going out on a limb trying something new, nonetheless.

If I did not have the rifle and spare barrel and bolt now, I would definately be buying the system from CDNN now. For the price, it is hard to go wrong, in my opinion. Perfect for kids just starting out or as a spare truck rifle.

Just some thoughts,

Action Guy

Would you happen to have a stock for a T/C Dimension? I broke my trigger guard off and have a hunt coming up in 3 weeks. Thanks--JIM

 

[Action Guy]

No. I only have the one on the single rifle I own. Finding an aftermarket replacement is going to be impossible. Your only hope is to reach out to T/C.

 

[BROWNBEARHUNTER]

No. I only have the one on the single rifle I own. Finding an aftermarket replacement is going to be impossible. Your only hope is to reach out to T/C.

Yes is sure is brother ! May have to buy a complete rifle to get a stock!!

 

[awpk03s]

I often considered getting a Boyd’s TC Venture stock (think it includes a metal trigger guard) and inletting it for the Dimension. Mags are the same. I think the action footprint is the same. Just need to mill out for the barrel nut clearance, and get creative for retaining the magwell interchangeability.

That project never made it to the top of my list and I’ve since sold the rifle and barrels. But I still think it could be done.

 

[BROWNBEARHUNTER]

I actually sent the stock to STOCKDOC. The way the conversation went he can make it look new. I'll let you know when I get it back. Thanks so much my friend !!!!!