115 Dtacs

[dcali]

I not smart enough to calculate the time of acceleration. Be very close to same considering on 50 fps and 8 gr difference in bullets. Let me know what your calculations say the time of acceleration is.

2 feet divided by 2900 fps =0.00068965517241379
2feet divided by 2950fps = 0.000677966101694915
Seconds inside the barrel.
Pretty sure you won’t be able to see any significant barrel wear. But shoot what ever you think is best for you.

Believe me, it's important. You cant just assume constant speed - it makes a big difference in barrel time. In any case, the point I'm making is that when you consider the cartridges you need to shoot a DTAC well, you're talking about a case that is bigger than a cartridge that shoots a 105 grain bullet well. That requirement is going to mean more powder. More powder and heavier bullets mean more barrel wear. That's a downside to the DTAC. I figured it'd be something the OP wanted to consider.

 

[6xcshooter]

Nah, all you have to do is keep records like Sierra did. The military has done all kinds of work on barrel erosion. It's not that much of a mystery - the way it happens is pretty well understood.

Whatever

 

[6xcshooter]

Believe me, it's important. You cant just assume constant speed - it makes a big difference in barrel time. In any case, the point I'm making is that when you consider the cartridges you need to shoot a DTAC well, you're talking about a case that is bigger than a cartridge that shoots a 105 grain bullet well. That requirement is going to mean more powder. More powder and heavier bullets mean more barrel wear. That's a downside to the DTAC. I figured it'd be something the OP wanted to consider.

Hmmm why don’t all the benchresters shoot the lightest bullets? Cause the benefits of heavier bullets out weighs a tiny bit more barrel life.

 

[urbanrifleman]

Hmmm why don’t all the benchresters shoot the lightest bullets? Cause the benefits of heavier bullets out way a tiny bit more barrel life.

Right?

 

[dcali]

Hmmm why don’t all the benchresters shoot the lightest bullets? Cause the benefits of heavier bullets out way a tiny bit more barrel life.

Benchrest shooters do shoot light bullets at short range for a lot of reasons. Long range BR shooters don't shoot light bullets, but they don't shoot DTACs or other 115s either. Because it doesn't make sense for their game. You won't find F Class shooters shooting them either - in part because of the barrel life relative to something like a .284.

The point is that there are tradeoffs to every choice, whether it's accuracy, ballistics, cost, hassle, availability, recoil or something else. The DTAC is no different. It's a VERY long for caliber bullet and you have to be conscious of what that design choice costs you.

 

[urbanrifleman]

Tubb gets quite a few rounds out of his barrels. And he stands on those suckers haha

 

[6xcshooter]

Benchrest shooters do shoot light bullets at short range for a lot of reasons. Long range BR shooters don't shoot light bullets, but they don't shoot DTACs or other 115s either. Because it doesn't make sense for their game. You won't find F Class shooters shooting them either - in part because of the barrel life relative to something like a .284.

The point is that there are tradeoffs to every choice, whether it's accuracy, ballistics, cost, hassle, availability, recoil or something else. The DTAC is no different. It's a VERY long for caliber bullet and you have to be conscious of what that design choice costs you.

for me I’ll take the accuracy and less wind drift trade off of the dtac over a few rounds less barrel life. For me the dtac at 2900 fps at 1000 yrds is 10 inches less over the Sierra 107gr at 2950 fps. 10 inches less might give me more in the 10 ring if I can flinch , jerk the trigger and blink at the right time. Hardest part for me is stopping my heart from beating as I squeeze a round off

 

[J.d. Popkes]

Ive shot the rebated coated dtacs in one of my 6xcs. It’s the best bullet ive put through it. Getting the correct free bore is the secret for shooting this bullet.

Hey will an 8 twist work with a DTAC, I’m at 5000’ elevation. Heard mixed reviews.

 

[Dgd6mm]

They'll jump a ton and still be accurate.

 

[Retired shooter]

"when you consider the cartridges you need to shoot a DTAC well, you're talking about a case that is bigger than a cartridge that shoots a 105 grain bullet well. That requirement is going to mean more powder. More powder and heavier bullets mean more barrel wear. That's a downside to the DTAC. I figured it'd be something the OP wanted to consider"

Good evening all
All kinds of interesting information in the posts above, Thank You to all who have replied.

I understand what is said about needing a bigger case( more powder volume) to launch the 115 dtacs. The reason for my question is running the ballistics for the 115 grain projectile show a definite benefit over the 105/ 109 grain projectile when shooting well past the 1000 yard line.

My intent is to take the 6 ARC out to and past a mile for ELR shooting. ( already been done, however I want to do it also) When you all stop laughing, I would appreciate your thoughts regarding the 115 grain bulletts. Not only working with distance but will be in windy conditions. Calm in the AM at Spearpoint, gets windy in afternoon. That's why I am curious about the 115. I know both the heavier, and the lighter longer skinny bullet does funny things when subsonic, so is the heavier still going to have the advantage

Trying to get started on working out a safe but effective load for this objective.
Maybe some of you got your chuckle for the day.!

Thanks again

 

[dttheliman]

With 6xc at 1800yrds - they held .5 Moa , 29” 7 tw barrel running at 3080 fps , will say that was the top of the high node for accuracy, after 625 rounds the barrel opened up considerably with a bore scope the throat was just messed , also the ragged edge of where I could get too in terms of distance with any degree of predictability

 

[Retired shooter]

Any ideas as to the short barrel life.?

 

[6xcshooter]

Hey will an 8 twist work with a DTAC, I’m at 5000’ elevation. Heard mixed reviews.

Yes I’m at 6200 works for me. 7 or 7.5 be better. But my 8 t. Shoot s in the .1’s to .2’s

 

[6xcshooter]

"when you consider the cartridges you need to shoot a DTAC well, you're talking about a case that is bigger than a cartridge that shoots a 105 grain bullet well. That requirement is going to mean more powder. More powder and heavier bullets mean more barrel wear. That's a downside to the DTAC. I figured it'd be something the OP wanted to consider"

Good evening all
All kinds of interesting information in the posts above, Thank You to all who have replied.

I understand what is said about needing a bigger case( more powder volume) to launch the 115 dtacs. The reason for my question is running the ballistics for the 115 grain projectile show a definite benefit over the 105/ 109 grain projectile when shooting well past the 1000 yard line.

My intent is to take the 6 ARC out to and past a mile for ELR shooting. ( already been done, however I want to do it also) When you all stop laughing, I would appreciate your thoughts regarding the 115 grain bulletts. Not only working with distance but will be in windy conditions. Calm in the AM at Spearpoint, gets windy in afternoon. That's why I am curious about the 115. I know both the heavier, and the lighter longer skinny bullet does funny things when subsonic, so is the heavier still going to have the advantage

Trying to get started on working out a safe but effective load for this objective.
Maybe some of you got your chuckle for the day.!

Thanks again

Here’s my ballistics for what i shoot with dtacs. They dont go subsonic until 1850 yards. You can open the file with acrobat

 

[dcali]

My intent is to take the 6 ARC out to and past a mile for ELR shooting. ( already been done, however I want to do it also) When you all stop laughing, I would appreciate your thoughts regarding the 115 grain bulletts. Not only working with distance but will be in windy conditions.

You are asking A LOT from that case and bullet. I don't know what's fun for you, but for me, that would be basically an exercise in randomness. Given the freebore you're going to want to use for a 115, you could wind up with a barrel that's not very good at anything - you'll be jumping lighter bullets quite a bit. You may even have issues with a 7 twist. I don't know, but I'd look into it.

 

[Retired shooter]

You are asking A LOT from that case and bullet. I don't know what's fun for you, but for me, that would be basically an exercise in randomness. Given the freebore you're going to want to use for a 115, you could wind up with a barrel that's not very good at anything - you'll be jumping lighter bullets quite a bit. You may even have issues with a 7 twist. I don't know, but I'd look into it.

DC
Thank you Sir,
I have been told before that it was not on a high list of anyone's priorities. If it was easy anyone could do it. Heard that one before.?

Had a well known gun shop build me a 26 in Bartlein 7.25 twist stainless barrel, we talked about this idea of one mile, his opinion was it will be an awesome gun at 1000 yrs. That's good my local range is limited to 625 yrs. Will be going to spearpoint several times a year mainly to spot for my son. Being retired ( meaning less cash flow) buidiing a larger caliber gun was not in the picture. I am not in to competition, my shooting if for fun. I enjoy the challenge.

Have measured distance to lands, know how much bullet will be seated in the case, know what COAL I can use if I were to mag feed, also have Bob sled so I can single feed. Have not done any reloads yet to determine actual velocity, have only fired factory loads. 2700 fps. for 108 ELD match.

So with this long winded explanation of a old farts idea of long range, small caliber attempt, it appears ballistics wise the 112 / 115 grain will be a good option.

Was curious about the DTACs compared to Bergers, at least the DTACs are available.

Thank you to all.

 

[davidjoe]

I have a 600 yard 15x3 Fclass match tomorrow and I’ll put them head to head against 110 A-Tips, same gun. The A-Tips only appear shorter as seated because they need to be jumped for best accuracy, whereas the DTACs are not finicky and when a given a choice I’ll favor more case volume.

Whichever bullet seems to shoot the best, pattern plus the conditions at the time, will get shot in the third and windiest match. .243, Manners F-Class, 40-X single shot.

 

[Retired shooter]

I have a 600 yard 15x3 Fclass match tomorrow and I’ll put them head to head against 110 A-Tips, same gun. The A-Tips only appear shorter as seated because they need to be jumped for best accuracy, whereas the DTACs are not finicky and when a given a choice I’ll favor more case volume.

Whichever bullet seems to shoot the best, pattern plus the conditions at the time, will get shot in the third and windiest match. .243, Manners F-Class, 40-X single shot.
View attachment 1431723

Thank you DJ
Good luck tomorrow
Let us know the results

 

[swd]

"when you consider the cartridges you need to shoot a DTAC well, you're talking about a case that is bigger than a cartridge that shoots a 105 grain bullet well. That requirement is going to mean more powder. More powder and heavier bullets mean more barrel wear. That's a downside to the DTAC. I figured it'd be something the OP wanted to consider"

Good evening all
All kinds of interesting information in the posts above, Thank You to all who have replied.

I understand what is said about needing a bigger case( more powder volume) to launch the 115 dtacs. The reason for my question is running the ballistics for the 115 grain projectile show a definite benefit over the 105/ 109 grain projectile when shooting well past the 1000 yard line.

My intent is to take the 6 ARC out to and past a mile for ELR shooting. ( already been done, however I want to do it also) When you all stop laughing, I would appreciate your thoughts regarding the 115 grain bulletts. Not only working with distance but will be in windy conditions. Calm in the AM at Spearpoint, gets windy in afternoon. That's why I am curious about the 115. I know both the heavier, and the lighter longer skinny bullet does funny things when subsonic, so is the heavier still going to have the advantage

Trying to get started on working out a safe but effective load for this objective.
Maybe some of you got your chuckle for the day.!

Thanks again

Are you shooting this out of an AR or a bolt rifle? I’m thinking the only way it might work is out of a bolt rifle with a very long throat to regain some powder capacity. DTAC’s are long bullets and without a really long throat it will just use up lots of powder space and you don’t have any any extra as it is.

 

[Retired shooter]

You are correct this is being done with a AR gas gun, that's the other part of the equation, people say it can not be done. However it has already been done. Just not by me. I want to do it occassionally.

Dont recall the numbers, distance to lands, or jam, have it figured and recorded downstairs, I have some mags that I can load longer than book length, and have Bob sled I can single feed with, problem is limited pressures and figuring out a safe load.
Thank you.