Tac powder

[buckey]

Anyone got a 5.56 load using 55 grain Hornady FMJ bullets and Tac powder that are not reduced loads but close to book loads that group well in your AR? Been playing with another brand of 55 gr FMJ bullets but have been less then impressed with the results. Thought I'd try what some consider the most accurate FMJ.
Thanks

[Unclenick]

It's easy to make an BTFMJ with poor accuracy so I suspect you'll find the Hornady or a Sierra will work better than an inexpensive brand (assuming that's what you've been using). Unfortunately, rifles are individual enough that you will have to find what your's likes best. A common problem is not seating primers adequately firmly. Also, you can try both standard primers and magnum primers to see if you get any accuracy improvement from one or the other. For military-sensitivity, Federal GM2205MAR and CCI#41 are standard and magnum, respectively.

[enstorm]

If this helps, 27 grains is the max load with 55 g fmj in my ARs, pressure signs show after that. Accuracy is acceptable, my goal was to duplicate NATO velocities as best as possible. So, you may want to tinker within the 27 g range. I have loaded Winchester but mostly milsurp fmjs with this load

[buckey]

Went all the way to the max, starting at 25.8 and just could not come up with a decent load. Groups hung around 2.75 to 3 inches at 100 yds, starting to wonder that the bullet's might be the problem?

[hounddawg]

just out of curiosity what twist barrel you running? I have 2 that are are 1-8 and love 69 and 77 SMK's. They outshoot anything below 60 gns. Unless you have a 1-14 or something try a heavier bullet with some Varget and CCI 450's

[P-990]

Originally Posted by buckey

Went all the way to the max, starting at 25.8 and just could not come up with a decent load. Groups hung around 2.75 to 3 inches at 100 yds, starting to wonder that the bullet's might be the problem?

Yes, the problem is your bulk 55gr FMJ bullets. Unless they're the Hornady offering, most 55gr .224" FMJ bullets just won't shoot better than 2-3 MOA, no matter your barrel or load.

Swap in some .224" 52gr Nosler Custom Competition or Sierra Matchkings and you'll see the difference right off. Even in a 1-7" or 1-8" twist barrel, either of those should absolutely hammer.

Anecdote: I had a batch of American Eagle .223 Rem 55gr FMJ ammo in my Colt M4gery that was so bad it would barely do 6" groups at 100 yards. I actually thought I might have had gun problems at first, then I remembered to try a batch of .223 match ammo I'd loaded with 69gr Nosler HPBTs and Varget. Presto! Sub-2" 10-shot groups.

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[FrankenMauser]

Use a better bullet.
Most FMJs are very low quality, and very inconsistent.
Use a Hornady FMJ, if you really WANT an FMJ in the load, and you should see things improve.

If you're just after CHEAP, then keep chasing your tail and jumping from bullet to bullet while wasting powder, primers, and case life.

Buy a reasonably decent bullet to use*, and most of your troubles should wash away...

*Name brand (other than Winchester), non-import, and, if possible, not an FMJ. The price difference is not that much.

[2ndtimer]

My mild plinking load with 55 gr FMJ bullet is 24.5 gr of TAC. But I get a lot better accuracy with the 62 gr HPBT Hornady from Mid-South Shooter's Supply with the same powder charge. Make sure your barrel is twisted 1 in 9" or faster. Some 1 in 12" twist barrels won't stabilize this bullet. It is only a bit more expensive than the Hornady 55 gr FMJ. Runs around $10 per hundred plus shipping, if you buy in bulk.

[buckey]

Have a shelf full of top notch bullets, been killing PD's for years out west and have shoot my share of bug hole groups. Can't find a thing wrong with this batch of FMJ's ( Not bent,bases look good, and weight is with in spec) and Rifles (3) are known shooters with decent bullets. 1/9 twist by the way,
Thanks

[Charlie98]

I found, in my early days, loading 55grn FMJ bullets that I could never do better than factory, so I really haven't loaded a 55grn bullet since. Besides the very nice 69grn SMK's for accuracy work, I got a quantity of 62grn BTHP bullets; they weren't much more than cheapo 55grn FMJ's, and less than the Sierras, so... happy medium. The 62grn bullet works well in all my AR's with whatever twist they have.

[buckey]

Like I said I've got a butt load of great bullets but was looking for a 55 gr FMJ load the shot with some degree of accuracy.

[Unclenick]

Originally Posted by buckey

Can't find a thing wrong with this batch of FMJ's ( Not bent,bases look good, and weight is with in spec)

Those factors aren’t the big players in FMJ grouping precision problems. The main problem is uneven jacket wall thickness, which you can't see from the outside and that unbalances the bullet. It's harder to form an FMJ jacket easily than it is to form a hollow point easily because you are forming the bottom of the jacket cup into a point rather than a flat base or a boattail.

That imbalance causes the center of mass (CM) to circle the bore axis as the bullet goes down the tube, analogous to a weight being swung around your head on a string. Then, when it clears the muzzle, the bullet’s CM is thrown tangent to the side of the barrel it was closest to at exit and away from the mean trajectory. The velocity of this radial toss is equal to the CM's angular velocity of rotation at the exit.

That drift fattens groups up nicely when the CM offset and location in the chamber are random. In funky 30 cal 147 grain NATO ball type FMJ's, I've seen that imbalance result in up to about 2.5 fps of drift away from the normal trajectory, resulting in an 8.6" group at 100 yards. More often, in cheap FMJ’s it is about a third of that. Drift at such low velocity doesn’t cause enough drag for air to slow it appreciably, so the result is group widening in proportion to time of flight to different ranges.

To find out if your bullets have the problem, there are four methods I am aware of. One is a bullet spinner based on Harold Vaughn's air bearing design that takes a couple of minutes to come up to speed with each bullet and uses a microphone transducer to detect vibration from the imbalance, though a guitar pickup and other methods should work fine. Another was used by Mid Tompkins as described on this board by member Bart B., which required a custom bullet holding collet used in a Dremel tool to spin the bullet fast while watching the Dremel’s current demand. Eccentric rotation of an unbalanced bullet increased the load on the Dremel tool, so current increased with it. The third method is the Vernon Juenke type device that uses a small inductive proximity detector to detect uneven eddy current loading by the jacket thickness while the bullet is rotated. The fourth is a horizontal torsion pendulum. This is a small v-trough suspended between two fine music wires under tension and coupled close to the balance point of the trough with a bullet lying in it. You rotate the bullet part of a turn and let it settle, watching for the angle of twist of the trough between the wires to change. It takes a little understanding to build one of these.

A less common issue, if the bullet looks good, is boattail eccentricity, but you can measure that easily. You can check boattail concentricity on a case or cartridge runout concentricity checker. If you have neither or yours lacks a suitable setup, place the cylindrical bearing surface portion of the bullet in a v-block with the tip up against a flat vertical plate or stop that you clamp to one end of the v-groove. Set the indicator anywhere along the boattail and rotate the bullet in the groove with your finger. You don’t want to see any runout.

[Bfglowkey]

The difference in price between the FMJ and the standard BTHP Match is 0.01 a round roughly....so 1.00 more per 100....difference in performance is 1.5 MOA on avg for the above reasons. I stopped trying with the FMJs. BTHPs from Hornady are a solid value. Just a opinion.

[Charlie98]

...was looking for a 55 gr FMJ load the shot with some degree of accuracy.

Yes, sir... but you miss the point. It's very likely you will not find equivalent accuracy with the 55grn FMJ bullet, it simply isn't designed or manufactured for it.

EDIT: I'm not saying you can't find a load or a specific 55grn FMJ bullet that won't give you the accuracy you are looking for, but it would be the exception, not the rule.

[FrankenMauser]

The most consistent FMJ that I found was the Hornady 55 gr.
If you want to run FMJs and have decent precision, I'd suggest running those.

Otherwise, pick one: Precision. Or cheapness.
You can't have both.

[buckey]

Lots of good points made, what I was looking for when I meant accurate was 1.5 accurate (Not Berger or Bart's accurate) Wasn't ever under the impression that FMJ under any body's name was going to shoot bug holes. Been trying to match what some of the factory fodder will do.

[2ndtimer]

Originally Posted by buckey

Lots of good points made, what I was looking for when I meant accurate was 1.5 accurate (Not Berger or Bart's accurate) Wasn't ever under the impression that FMJ under any body's name was going to shoot bug holes. Been trying to match what some of the factory fodder will do.

As has been said, then load the Hornady 55 gr FMJ with whatever powder gives the best accuracy - in your particular rifle. As I noted previously, I get comparable to the best factory 55 gr FMJ ammo with 24.5 gr of TAC, in my rifles. Yours might prefer IMR-8208XBR, or H-322 or Accurate 2230.
Or you might elect to spend the extra $1 per 100 bullets for the previously mentioned 62 gr HPBT HORNADY bullet and likely get results superior to factory 55 gr FMJ loads.
Frankenmauser nailed it, cheapness or precision, pick one. I chose to compromise with a cheaper bullet that shoots almost as well as the much more expensive bullets. YMMV.

[Emerson Biggies]

I have a Delton Echo AR. I load 23 grains of TAC with a 55 grain Hornady bullet. It chronos out to 2560 FPS which is fast enough to punch holes in my paper targets.
If you want to go fast use the load data on the canister. Why beat your rifle to death?

[buckey]

Not at all interested in reduced loads (see first post) just trying to reproduce some of the better (accurate) 5.56/.223 FMJ ammo.