TAC 30 revisited

[stagpanther]

Periodically I scan my safes for "lonely guns" that haven't been fired in a while and I came across a build I did using ARP's 30 Herret--which thankfully H decided to change the name to TAC 30--the only drawback to that name being that Burris also calls one of their scopes that. Checking my load data I noticed I had done very little load development--part of the reason being that this is still a "non-SAAMI wildcat."

ARP's description of the barrel does give some useful loads--but I decided to take a closer look at "projected performance" and see what the cartridge really had to offer. From my perspective--the real competition for the TAC 30 is the 300 blackout and the 7.62 x 39--they are collectively the "bantam 30's that doublestack and reliably feed." The TAC 30 should be able to reach velocities of 2600 to 2700 fps with 125 gr bullets--that clearly leaves the 300BO in the dust; and while I have "pushed" some 7.62 x 39 loads to just shy of 2600 fps--I haven't been able to stabilize the bullet well in either an AK or AR47 at hot velocities. I expect that on average the TAC 30 will have about a 200 fps advantage over the x39--maybe more when you take into consideration that the "sweet spot" for the x 39 is usually in the 2300 to 2400 range (at least that's been my experience with the AK and AR47). That may not seem a whole lot--but when I did comparisons using ballistics calculators the TAC 30 bullet should theoretically remain quite potent to 300 yds and beyond; whereas most typical x 39 ammo I wouldn't feel confident using on medium game past 150 yds.

From left to right for comparison--the 300BO, the 7.62 x 39 and the TAC 30:

[ed308]

Sweet hunting cartridge from what I've read.

BTW, my .224 Valkyrie is finally built. Need to finish setting up my reloading bench and make some ammo. Plan to hit the range and test it soon.

[stagpanther]

BTW, my .224 Valkyrie is finally built. Need to finish setting up my reloading bench and make some ammo. Plan to hit the range and test it soon.

Good luck--and don't get frustrated if there are "teething pains."

[stagpanther]

After checking out some of my bullets--I discovered that the 125 gr accubond is an ideal fit for "ergonomics" of the tac 30 case; essentially you can seat it as long as your magazine and well will allow. I decided to load up a low-end load of 28 grs using 8208 xbr--a powder that has always given me outstanding results in other similar sized cartridges but maybe not as efficient in the tac 30--especially considering the small primer cases. I also ordered a few hundred new 6.8 cases--all of my tac 30 cases are reformed from very old and well-used SSA brass that has been reused countless times through a number of different 6.8's. Three of the shots formed almost a 1-holer, but then a shot (which on labradar showed a large velocity deviation) went way wide, though I'm sure I pulled it some as well. Unfortunately all the velocities were anemic turning in an average velocity of just 2200 fps. I'm sure I can get a boost in the velocities--but not without going into "compression territory."



My top-secret stash.

[greentick]

ARP TAC 30 bbl is on my list, glad he's keeping them around.

[stagpanther]

The Tac 30 is still basically a reloader's proposition. my opinion is that the SSA 6.8 brass is the best there is for it; it seems to have a slightly higher capacity than other brass I've tried--and is also very tough. Hardest part is trimming down the neck length when reformed--and making absolutely sure you do not bump the shoulder back too far. Using Hornady's 30 herret die--this means turning the die so it's around an eighth of an inch +/- or so above the shell holder. What works for me is a case length of around 1.57" and a base of shoulder at about 1.27" +/- .

[stagpanther]

Went out again today and tested more loads--once again a couple of charges in the vicinity of 2200 to 2300 grouped sub MOA--but the powder just doesn't deliver enough velocity--even when I started to compress the charges. Time to abandon the 8208 and move on.

[stagpanther]

I need to make a correction to the case measurements above. Even though I'm signed in and I created the thread--for some reason I'm not being allowed to edit my own posts (except this one).

Anyway, The tac 30 is a wildcat--which means you'll need to figure out the proper head spacing for your particular build--which is not very hard to do. H has some very useful guidelines for doing that.

I mention all this because recently I was testing several different loads--but was getting wider than usual standard deviations in my velocities. Other than that, everything was shooting fine and there were no pressure signs. Nonetheless my gut told me something wasn't quite right, and thought maybe my headspace might be off a bit--allowing for a less-than-good seal of the case to the chamber. Turns out my suspicions were correct and my shoulder base was being bumped back too far and I had to "bring it forward" somewhat. The message is--ignore my measurements above--you need to confirm the proper headspace measurements for your particular set-up.

[ed308]

Does that leave with a short neck for seating the bullet? It's that way on my TAC 6.

[stagpanther]

Does that leave with a short neck for seating the bullet? It's that way on my TAC 6.

Length of neck is a bit shorter than the diameter of the bullet--but it is no problem whatsoever, it grips the flat base and short spitzers with no issues--other than if you seat a bullet with the base of ogive starting to go down the neck. Most of the bullets I use can seat all the way to whatever the mag will allow--in the cavity back mags I can take the 125 accubond (which is about the best bullet I've tried so far) to 2.32. Using a resized SSA case that also gives extra space for more powder. Just like the parent 6.8 spec--the tac 30 generally is a very reliable feeding cartridge in the AR action.

[stagpanther]

I just got in a few hundred cases of SSA 6.8 virgin brass directly from Nosler--I'm hoping it's the same stuff that SSA used to make prior to their acquisition by Nosler. These cases will be my first ones formed from scratch for the tac 30 instead of the very old "retreads" I've been using up until now.

[stagpanther]

My first batch of reformed but unfired tac30 brass from the SSA stuff--perfect! It's really worth it to spend the extra money on virgin brass instead of resizing used (different cartridge) brass IMO.



My trials with reforming brass have shown so far that the SSA is still superior to the other stuff I have--including some virgin Hornady 6.8 brass that I purchased. The SSA brass tends to be stronger in the head and mid-case area--allowing it to remain more likely to chamber without "stickiness." Resized brass from fired 6.8 brass from brands other than SSA I've noticed tend to be more prone to expansion in the head/base areas. I take a 30-30 resize die, remove the spindle and size the whole body of fired 6.8 brass in order to take out expansion in the lower part of the case, but the more "fluid" brands of brass tend to have "memory" of the 6.8 chamber and will be tough to eliminate that expansion altogether.

[stagpanther]

Recently I bought a couple of boxes of 125 gr cutting edge Maximus bullets just out of curiosity. I did a preliminary batch of cartridges driven by CFE BLK but had some trouble shooting--the gun and cartridges worked fine--the problem was me holding the gun steady. I'm not going to draw any conclusions on accuracy because I did not have the gun well balanced while shooting (I could get 2 or three impacts very close but invariably threw a wide flyer). It's a very promising combination that I will definitely do more work with--I was generally getting velocities in the 2600 to 2750 fps range without even getting into compressed loads or any signs of pressure (that's not to say I might not have been running the pressure up anyway). Using my labradar I noticed consistency within charge groups was excellent--some of the smallest deviations I've ever seen. Another less scientific observation--I noticed that the bullet's impact destruction into the berm behind my target was noticeably more violent and destructive than any other bullet I've tried so far on the tac30.

[stagpanther]

The higher-end load was right about MOA (with an obligatory flyer) and I plugged it into a calculator, the numbers are pretty impressive for an AR15 based cartridge. Labradar only tracks to 100 yds--but the numbers I got (in winter time cold I might add) were very close to what the calculator projected to 100 yds.

[brasscollector]

Move aside 7.62x39. Finally a 30 cal ar15 worthy of building.

[stagpanther]

Move aside 7.62x39. Finally a 30 cal ar15 worthy of building.

ARP is the place to get it.