Home Forums Hunting & Shooting Ask The Gunwriters How to Work Up a Load Using a Burn Rate Chart.

Hello,

I have a ton of Ramshot TAC and I would like to use in my 45-70. According the burn rate charts it is right in line with what the 45-70 requires for maximum efficiency and compatibility but there isn't any published data listed. A call to Ramshot didn't yield any helpful info as they haven't done any testing with it. Also CFE223. That seems like it might be a tad slow for the 45-70 but "should" work. Would also like to play with these powders in the 338-06.

I am just wondering if there is a good reliable procedure how to go about using the burn rate charts along with published data to work up a load with powder that has a proper burn rate but no data provided yet.

Thanks,

Todd

No.

Get a cheap, break-open .45-70, an old tire, a length of cord and a cheap chronograph as a start.

You don't provide much information, action strength, bullet weight, construction, intended velocity, so guys are reluctant perhaps to help.
I will make a blanket statement though, just my opinion, ball powders designed to operate at .308/.223 pressure levels will not be an ideal choice for a straight wall case designed to operate at SAAMI 30,000...if you have a modern 1886 Win, they do feed them loads up to 50,000. If you stay low you will likely have wild velocity swings and boocoo unburned powder in the barrel. Perhaps your time would be better spent doing some powder trading. Do not be offended.

I’m a lot harder to offend than that. But,…. Most other 45-70 data revolves around powders that work well in .223 and .308 so I’m not quite sure I’m on board with your theory… but I’m not turning a blind eye either.



Thank you. Very useful thread.



I guess it’s settled then….


Thank you all for your time.

Todd

I've used several 1 lb cans of H335 in both .45-70s and .458 Win Mags. One of the very best for 400 - 500s. And... it's a ball powder - meaning more usable space in the case than H4895 or other stick powders. Yep, 2000 fps is safely possible from 400 - 405s in an 1895 Marlin 22", and 2150 fps from a 24", .458 using that ball powder and 500s from a 24". Not theory, but I've done it multiple times. H4198 is also one of the best for lighter bullets. You can also check Hornady and Barnes.

Bob
www.bigbores.ca

I was only semi-kidding with my reply up above. If I had an interest in using a powder I thought should work but had no proven data I wouldn’t hesitate to set up a remote control chronographing system with an expendable rifle, but many these days are reluctant to experiment…

For hot rod.45-70 loads I’ve used Varget for years with good results. As mentioned above, 4198 is often recommended as well. I’ve no experience with TAC, but it must be close to those two, I would think.

The burn-rate of TAC is very close to IMR4895/H4895, both of which have been used for reduced loads down to 60% of maximum charges for decades--though Hodgdon now recommends only H4895 be reduced that much, as they've found pressures/velocities become a little erratic in some cartridges with IMR4895.

But spherical powders are generally an entirely different deal. They're generally harder to ignite, and unless they fill the case at least 80% can be erratic, even with magnum primers. Compressed loads tend to work more consistently, no matter the primer.

Have used 42.0 grains of IMR4895 with bullets in the 400-grain range in my original 1884 trapdoor Springfield with excellent accuracy. Would not even consider trying the same charge of TAC.

Awesome. Thank you all again for your time. All very useful information without rhetoric.

My 45-70 is a Marlin CB with a 26” barrel so pressures will be increased a bit. I’ll forgo any experiments with it as it’s irreplaceable.

Todd

Yes, there is a method.

It’s called “start low and work up”.

Although I’ve never worked with the chamberings you’re dealing with, I’ve ventured into unknown territory with the .264 Winchester well before any published data was available for the slowest burning powders.

An old friend told me “when you have a .264 Winchester, you’ve just signed up to be your own ballistician”

I’ve experimented with eight different powders and multiple projectiles.

Enjoy the journey

The 26" doesn't increase pressure

Getting QuickLoad would be a good start if you want to venture into such territory.

The only load I've used in my 45-70 BFR were Marlin level loads with MR-223, an Accurate ball powder that's similar to 2230.

I used a Federal 215 and a 360 grain bullet; I'd have to find the box to get the charge but it's never hung or left much, if any unburnt powder.

It gets there "right now", from a handgun perspective.

Todd, I do it all the time.

A couple of basic caveats:
-Reference burn rate charts from several sources.
-Make sure the burn rate charts you reference are for the age of the powder you want to use.
-As John mentioned, be conservative when it comes to spherical powders in big volume cases.

Another approach that I use quite often is to establish a lower end charge weight with a 'published data' powder. Then, with the 'no data' powder (of similar burn rate to the known powder charge you've weighed), just use that measure setting. The volume and weight will change but it's surprising how close this gets you with a 'no data' powder.

Good shootin' -Al

I have three powder burn rate charts. They were independently derived - evidently. They don’t agree, except in a general sense. Be careful using burn rate charts.

Here is my Handi Rifle 45/70 work up test data after I did a max pressure analysis of the rifle [with the help of my father, the gun designer, and also help from a mechanical engineering professor]:
45/70 work up with; 405 gr cast with lube bands, CCI 200 primers, Win brass, old Unique [dirty] powder, chamber well lubricated between firings with CLP for max bolt thrust.

Quickload calculation of pressure and velocity with 405 gr, Unique

shot 0) 15 gr, 24,700 psi, 1271 fps, no shot fired, listed for Quickload reference point only
shot 1) 18 gr, 33,217psi, 1403 fps, primer looks fine.
shot 2) 20 gr, 39,435 psi, 1485 fps, primer is fine
shot 3) 22 gr, 46,133 psi, 1563 fps, primer looks flat.
shot 4) 24 gr, 53,334 psi, 1637 fps, primer is flat.
shot 5) 26 gr, 61,067 psi, 1709 fps, primer is top hat and flowing, action popped open and case ejected on firing

shot 6) 28 gr, 69,366 psi, 1778 fps, primer is top hat and flowing, case
head expansion .001", action popped open and case ejected on firing shot 7) 30 gr, 78275 psi, 1846 fsp, case head expansion .0015" action popped open and case ejected on firing, some leading in the muzzle.

shot 8) 32 gr, 87,841 psi, 1911 fps, case head expansion .0025", case head separating where case head is flowing into the extractor, action popped open, some leading in the muzzle, and case ejected on firing, primer is spreading out .010"

After this break action test I did similar work ups to the limit of rimmed brass on sav 219 30-30 and Stevens 410 with 45 Colt.
The 410 choke split with the 405 gr .458" bullets. The 410 stock butt was against concrete. The recoil forces splintered the 410 Birch stock wrist.

Justahunter,

There are plenty of suggestions and guidelines on the subject in the first BIG BOOK OF GUN GACK.

Awesome info and I appreciate all of the responses. I own all three Gun Gack books. I'll tear back into #1.

Thank you all again,

Todd