Ramshot TAC load data 223

B

brians356

Beginner
Dec 3, 2012
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I have Ramshot TAC powder published load data from both 2009 and 2012 (ver 4.5) and noticed a big change in 223 Rem. 50-grain bullet data.

In 2009 they published Nosler 50-gr BT max load at 27.0 grs (3448 fps @54961 psi.)

Now in 2012 they omit the Nosler BT but do list the Hornady 50-gr V-max at max 25.0 grs (3391 fps @54990 psi.)

That's a full 2.0 grain reduction for ostensibly similar bullets!

I know this is a question for Ramshot product support, but I thought I'd run it up the pole here as well to elicit any comments or opinions. Have I missed some scuttlebutt? I bought the TAC several years ago but am just now getting around to loading some.

Brian
 
Differing lots of powder could easily account for such a difference. Also, there are slight differences in bullet length, seating depth and bearing surface between these two bullets. This would introduce some variables.
 
Sure, but 2 full grains difference in a 223 more than just raises an eyebrow. That's a full 8% difference. If different powder lots vary that much, I would find that alarming. I've been reloading a long time, and I've never heard of such a variation between lots. That is the one thing all powder companies strive to avoid.

Re: seating depth, bullet types, etc - those are always caveats in load data. But again, the difference discussed here is way out of proportion it seems to me.

But that's why I posted, I'm considering all opinions ...

Brian
 
You can witness up to ten percent lot-to-lot variations in powder burn rates. This is the reason hand loaders are cautioned to drop back ten percent whenever working with a new lot of powder, a different case or a different primer.
 
Well, what do you know? Nosler's latest manual lists max load at 27.0 gr TAC behind 50-gr BT.

Sooo ... Since this is the Nosler site, kind of have to defer to Nosler's data, right? :shock: That makes 25.0 grains my starting charge, not my max charge (as Ramshot now publishes.)

Incidentally, a couple other companies' reloading guides show max load at ~27 grains.

Thanks for the advice, chaps. I'm off to flatten some primers ...

Brian
 
I wouldn't worry about it in a bolt gun, but if you're shooting an AR you can easily break some parts.
 
Update:

I shot some 50 TNT groups last weekend, 26.0 gr TAC in Rem once-fired brass, neck sized only. Four different bullet jumps: .010, .025, .040, .055. The load is apparently light as there was significant primer protrusion and no signs of pressure on the case head. And shooting them, they were just obviously light loads judging from recoil and muzzle blast.

The degree of primer flattening was low but increased slightly, and primer protrusion decreased, as the effective case volume decreased (as bullet was seated deeper) but only moderate flattening even at .055 bullet jump (COAL 2.320 so still pretty long by most published standards.)

Best group (four shots 1/2" @100 yds) was at bullet jump .040, so I'll stay at b.j. .040 and start increasing charge in increments towards 27.0.

I did find some Sierra 223 (AR-15) data for TAC behind 50-gr bullets in 223 that maxed out at 27.5 grains, so I feel I will probably get to 27.0 at least with no problems.

Brian
 
Update:

I have not had much luck with TAC and the 50-gr TNT for accuracy. I got most promising result at 27.0 gr TAC and most promising bullet jump of .020". But groups were strung vertically on the order of 5/8" to 3/4" I am used to 1/4" groups in this gun using Sierra 53-gr Matchkings and H335, and Nosler 40-gr B.T. with H322.

So .. on a whim I switched to moly-coated bullets. I know, I know - no one uses them any more. But I ran out of my plain 40-gr B.T.s but had 750 moly coated ones purchased long ago, so I switched to moly. And if I was going to shoot ANY moly in this gun, I wanted to shoot ALL moly, so I moly tumbled my plain 50-gr TNTs.

Ok, so here's the issue: I mentioned earlier in this thread I got primer setback at my starting load of 26.0 gr TAC. By the time I worked up to 27.0 grains, the setback was gone, and primer flattening was "normal" per my experience.

Then I switched to moly bullets, exact same load of powder, bullet jump, primer etc. Now, suddenly I am getting significant primer setback again. Why?

My theory is the moly bullets produce lower chamber pressure, like a lighter load, and anecdotal evidence I have gleaned over the years says moly bullets produce lower velocity than plain using the same loads.

Speer's reloading manual says that primer setback is caused by one of two things - excess headspace, or too light a load. Since I am using cases fired several times, and only ever neck sized, and bolt closure is firm (indicating shoulder really could use setting back a tad) I know headspace isn't an issue. (BTW rifle is a stock Rem 700 VS.)

Has anyone ever heard of, or experienced, such significantly reduced pressure from moly bullets, and/or experienced primer setback when switching to moly bullets?

Brian
 
I would go with 26 grains of TAC and a 50 grain BT or Vmax. I use TAC in my .222 and it is just deadly. It should work sweet in the .223.

LT
 
So ... you're saying 27.0 grains is too much, and causing the primer setback?

I am not seeking an accuracy load suggestion, I am asking about the curious reappearance of primer setback when switching to a moly coated bullet.

To review:

Using plain copper 50-gr TNT, I had primer setback at 26.0 grains TAC (indicating light load.)
Primer setback disappeared by the time I progressed up to 27.0 grains TAC.
After switching to moly coated 50-gr TNT, the primer setback reappeared (still at 27.0 grains)

Brian
 
Ok, chaps, I got my answer. None other than David Tubb wrote:

"... if we take one specific load that uses an uncoated bullet and simply replace the bullet with a moly coated bullet, velocity will drop. For instance, let’s say a .243 produces 2900 fps with an uncoated Sierra 107 gr MatchKing. The load is 41.5 gr IMR-4350. Replace the uncoated bullet with a moly coated Sierra 107 gr MatchKing and there will be an approximate velocity loss of 40 to 50 fps,,1-2 percent). Pressure, however, will likely fall from approximately 52,000 psi to 49,000 psi, or lower,about 4 -5 percent reduction)."

That's all I need. I will now start inching up my power charge until I see normal primer flattening, no primer setback, and (I hope!) better accuracy.

Here's the web page at accurateshooter.com where I found the Tubb quote, plus some information published by Norma on the effects of moly:

http://forum.accurateshooter.com/index. ... 029.5;wap2

Brian
 
Update:

My previous TAC load with non-moly 50-gr TNT bullet was 27.0 grains, and accuracy was not stellar (1/2" at best.)

After switching to moly bullets, I got primer setback.

Yesterday I shot groups at grains 27.2, 27.4, 27.6 and 27.8. Primer setback gradually receded, and when I arrived at 27.8 grains, group size suddenly shrank. (More groups to be shot at around 27.8 grains and a bit more when the weather breaks.)

Note: I had originally stopped at 27.0 grains not from pressure signs, but because that seemed to be a "max" load behind a 50-grain bullet according to the various TAC data I was able to search out at the time (happily more is published today.) There was one reference to 27.5 grains behind a 50-gr, but it was too much of an outlier for my taste - consider that Ramshot publishes a 25.0 max load today (revised way down from their initial load data.)

But with a moly bullet in my particular rifle, even 27.8 seems below max - primers not very flattened, no extraction signs. The TAC powder is now up to the base of the neck at 27.8 which I like, but nowhere near compressed since these TNTs are not even quite halfway down into the neck, even with a .040" bullet jump.
 
Brian,

First whenever I'm using different components, other then what's listed in the reloading manuals, and approaching near max loads, I use a chronograph. Pressure has a direct relation to velocity and while many people use other means of excessive pressure signs when developing a load is by no means a reason not to use a chronograph or own one since they're readily available and rather cheap in relation to the entire cost of reloading.

Second point I'd like to make is from many years of using and reading about the use of Moly-Coated bullets vs. Standard Jacketed bullets. This point is most applicable to the erroneous conclusions and claims made about molybdenum disulfide bullets' superior performance over std. copper-gilded jacketed bullets. The drop in pressure and velocity measured with moly-coated bullets vs. identical non-moly-coated copper jacketed bullets when with the exact same load isn't due to a reduction in friction, which some claim to believe. The real cause and effect is due to the hot gases, which vaporize the molybdenum causing a the temperature of the propellant gases in the process to drop by about 400 degrees from 6,000*F.

Tests to prove this point were conducted by Harold Vaughn and were reported in High Power Rifle Accuracy Before You shoot by Douglas E. Arnold of Arnold Arms and others that have reported on this same subject. He stated the molybdenum disulfide melts at 4,802*F and the energy consumed was consistent with the reduced pressure measured (lower by 4,500 psi) and 50 fps less velocity. (This burnt mess adds to even more accumulated fouling in the bore.)

Another claim is that moly-coated bullets improve accuracy is also false. If this were true you'd see every manufacture producing moly-coated bullets, the fact is they don't should speak volumes about that myth.

But the final claim regarding using moly on bullets has to do with barrel fouling. The claim that coated bullets create less fouling in the bore then non-coated bullets is in my opinion and many others just another layer of material within the bore that will need to be removed! When viewed through a bore scope there isn't just burnt powder residue and copper but burnt black baked-on multi-layered coating of molybdenum, copper, and powder residue. Which will require JB Bore Paste and Kroll Oil used alternately with Sweet's 762 Copper Solvent to remove these built up baked on layers within the bore.

I wouldn't recommend shooting moly-coated bullets to anyone. I understand you not wanting to toss those bullets away, but the amount of extra time you'll be spending to clean your barrel doesn't seem worth the trouble to me. I can attest to the facts above that using moly-coated bullets was a waste of my time and did more harm then good because of the extra cleaning required. That extra cleaning was just more wear on the lands edges caused by the clean rod jag covered in JB Bore Paste. There was no trade off there, so why bother?

I've developed safe loads before that used one manufactures bullet with a different bullet/powder not found in their own manual but in another reloading manual. As well as about a bakers dozen Wildcat cartridges. I still look for any signs of excessive pressure also but I stay within the expected velocity level for the given bullet weight/powder and cartridge. Rarely do I ever see these signs anymore, which is why a chronograph is so important. Honestly most of the time the powders used average slower speeds then what's listed in the manuals, but I have rarely found the most accurate load at the maximum velocity level attainable within a given cartridge. Besides the brass will last that much longer as well as the barrel life.

I'm only saying this because I've seen what can happen when things go terribly wrong developing a load at or above a maximum. Even reduced charges can have horrible consequences, so tread lightly Brian. It's rarely worth an slight accident when a accurate load can be developed at 85% of the velocity curve.
 
Thanks longrangehunter, a lot of good information and opinion in that post. I had read about the propellant gas temperature drop explanation vs reduced friction elsewhere.

I have not personally experienced any issues with bore cleaning or moly buildup in barrels after shooting a lot of moly bullets in rifles chambered for 222 Rem, 6mm Rem, and 250 Ackley. Nor have I yet experienced a drop-off in accuracy over time with any of these rifles. I have not sent thousands of bullets down their bores, but certainly many hundreds.

Incidentally, re: the 50-gr TNT load results detailed above, I took a closer look at the fired cases, and even at 27.8 grains (max load tested so far with the moly bullets) I am still getting slight primer setback of about .003". In cases not having excessive headspace (as is the case here) this could reasonably be considered a sign of a light load (insufficient pressure.)

If this is caused by the effect of moly lowering combustion gas temperature, that would be nice to know, but that would not suggest a dangerous condition, would it? (Unless someone took this load and blithely reverted to a plain copper bullet on top of it, assuming it was a safe substitution.)

Re: chronograph: Are you looking for a sudden spike in velocity along the progression of charge increase? Or something else?

Your further comments welcome.
 
In my AR with 77 MK @ TAC 24.5 with CCI small Rifle Mag Primers or CCI 41

Or 62 gr @ 26.0
 
Alaska,

Did you by chance intend to post your comment in another thread? I cannot relate it to the ongoing discussion here.

Forgive me if I missed your point. :oops:
 
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