I haven't been able to find much load data on frangible bullets and really didn't know what to expect for accuracy. My goal was to get 1) reliability, 2) lock back on last round and 3) reasonable accuracy. We plan to use these on steel targets between 7 - 50yds.  

50yds using 3x scope. Forgot to bring sandbags and a spotting scope so I wasn't able to see where they hit until walking up to the target. Time was rushed and I wasn't able to finish a last set of TAC-TX with the 300blk. This was my first time to the range since Covid hit and we were limited to four 15 minute firing sessions before you get ushered off. They clear the area, spray the benches and the next group comes in. Took 2 weeks to get a weekday time slot. Weekend slots are a month out.

1) All loads fed, fired and ejected as normal.  
2) All loads locked back
3) Both 223 powders had the best groups with the highest charge weight, even though the velocities were quite different. 107gr Sinterfire seemed to duplicate a TAC-TX bullet POI more at the 20.0 charge weight as well.  

223 - I was getting inconsistent seating depth while the bullet ogive was deforming as the bullet was being seated. I since picked up a 223 M die to open up the necks a little more for these soft core bullets. I've started using the M die in the Lee APP this weekend and it seems to work well.  

* 223 50gr brown tip pull down frangible from American Reloading

16" Hanson Premium SS barrel (BA) 223 Wylde, with a A5 extension, Kynshot RB5007 buffer and Tubbs 308 spring.








* 308 107gr Sinterfire pull down from American Reloading

8.5" KAK 300blk barreled pistol with a DD spring, std buffer and carbine length tube. No brace.

I forgot to turn on the Labradar on for the Tac-tx at 18.0gr, then the battery died after finishing the 18.5gr string. Range time was over too, so it didn't really matter...



Last shot on 20.0gr was just off the right side of the target. These are under 2" at 50yrds which is good enough for what we plan to use them for.

I never could get any sort of accuracy out of the 50 gr. .224" frangible pulls I got from RMR a few years ago. Slow or fast, they all key-holed at 25 yds or less out of various barrel lengths and twist rates. I suspect I got a bad lot, which is why they were pull-downs in the first place.

I've been using them up for close-range drills and when the last rounds are gone, I will be glad.

Are yours brown tipped?

I'm assuming the brown tipped bullet I loaded is a pull down from the MK 311 Mod 0 produced by Federal. From the picture, it looks like a compressed load.  
https://www.thefirearmblog.com/blog/2019/09/25/federal-awarded-12-9-million-mk311-mod-3-delivery-order/

The barrel I used is a 1:8 twist.

I bought some plated 110gr 30 carbine bullets from RMR and they flew like rocks at the target. No resemblance of a group at 25yds loaded in 300blk. They also came apart around 1500 fps. Copper shreds were in the linear comp. Not a fan with RMR because they told me in an email they could hit a softball consistently at 100yds in 300blk and could push them over 2000 fps. Later they included a 1500 fps limitation to their listing of the bullet.  

Yes. Those are it. I would not call them brown tip though. The tip is just exposed frangible core material.

I could never get an accurate load with frangible bullets.

You might have something different. These have a brown polymer tip. They were also listed as brown tip when I bought them... I'm color blind so probably I'm not the best person to judge this otherwise.

No, that is the frangible core formed into a tip... Not polymer tipped, although it could be argued that the frangible material is polymer since IIRC there is some sort of plastic in the mixture...

Although not a great pic, you can see on the two rounds in the middle, that the core and the exposed tip are the same material and all one piece.

"Brown Tip" is commonly referring to the 5.56 "Optimized" load with a solid copper projectile, like the right-most cartridge in this pic...

Attached File

What's interesting is that the center 50gr tip seems to be a FMJ. What I have is an exposed tip more like the 62gr bullet to the right of it.

I've seen the MK 311 Mod 0 (aka AA40 and RRLP) referred to as a purple tip in some cases. These are definitely not that.

I just loaded up a couple hundred more last night. They are a compressed load with 25.0gr of IMR4895. I find the bullet pushes the bullet back out of the case slightly so the OTBL isn't consistent. I noticed this in the first loading session, but with not as much variance and thought bullet deformation was the reason. I used a drop tube that time.  I've got more to load tonight and will setup a drop tube to work along with the powder measure.

Here's the packing label that came with the order in case someone wants to order. They haven't been available since around the beginning of summer.

It's just a crappy pic. The 50 gr. and the 62 gr. are constructed the same. Cut one of yours lengthwise and you will see.

I ended up using W-748 in my loads because I could not stand to hear the crunching of the IMR type powder when seating those very long projectiles... I pulled down a factory original round and it had about 26.5 gr. of a ball powder that looked very similar to W-748.

Yeah, I'm looking at the pic on a better computer and can now see the jacket ending exposing the core material at the tip.

This thread on the subject seems to confirm your suspicion the powder is W748. https://forum.cartridgecollectors.org/t/aa40-5-56mm-frangible-ammunition/10428

I've got a lot of IMR4895 so that's why I'm using it. AA2520 was a lot faster at the same weight and no crunching, but I don't have much of it left.

I picked up some 45gr in 223 a while back from frangiblebullets.com. Worked up a load using WC-844. Was pleasantly surprised by the accuracy of these. Was not expecting much out of them but ended up getting around 2 moa from them. This was with 25.5 gr of WC-844. They were easy to seat with no bullet deformation. Locked back and fed fine.

Just checked and they have these in stock if anybody is looking. Although the price has gone up a good bit since my purchase in August. Also picked up some 9mm. Also in stock now. For some reason the price has dropped a little on them.

I saw those yesterday when researching the bullets I'm loading. Good to know they're accurate for that price. How much were they charging before they raised their price on the 223?

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Using a drop tube reduced variability in seating depth for the most part. I forgot to mention I'm loading mixed brand cases, so I'm sure neck tension isn't very consistant either.

It was $97.60 for 500 .223 back in August. Now at $126.50.

Also ordered 100 9mm for $31.50. They are now $26 for 100.

My order for 500 223 and 100 9mm somehow got mixed up and they sent 500 9mm and 100 223. I contacted them and they sent the 400 missing 223 and told me to keep the extra 9mm.

Still trying to work up a load for the 9mm. So far having issues with them not cycling or feeding well. But at least I have plenty more to play with.

Sounds like a company that supports their customers. My thumbs up for them.

We shoot steel with 9mm and 40S&W at about 15yds with lead bullets and haven't noticed anything coming back at the shooter. We have experienced some splatter when someone is about 45 degrees off to the sides behind the shooter some 25-30yds away. A friend we were shooting with thought it was a gnat flying around before realizing what it was. Always wearing eyepro so haven't had any issues

If we decide to shoot steel at close range, I'll keep that company in mind.

I was impressed with their service.

That is good to know that 15yds is fairly safe. We may decide to shoot closer though.

I've shot lots of the American Reloading pulled 50gr frangible "brown tips".  Specifically, in government speak, they are the pulled bullets from SEMI-JACKETED FRANGIBLE MK 311 MOD 0 5.56 cartridges.  I call them brown tips to differentiate from other 5.56 frangible bullets, as that is what they look like to me, but I realize they really don't have a separate tip, just tarnished copper showing.  I got mine when they were cheaper and more available.  Glad I got them when I did.

My observations and experience with them:

They need a fast twist.  1/9 accuracy sucks.  Some 1/8 shoot them fine and some 1/8 shoot poorly.  I use 1/7.  Maybe they'd shoot good in slower twist if the velocity was increased, but I have no need to try that.

If the AR likes them, they are capable of 1 1/2" at 100yd.  My Ruger Precision 5.56 will do 1 1/8" at 100yd with them.

I too have problems with a uniform oal when reloading.  I shoot for a 2.25" oal, measure each loaded round, gather up all the ones over 2.26" oal and simply seat them a little deeper.

I started out low with IMR4895 and WW748, working up until the rifles functioned and I got the best accuracy.  It ended up for me that 23.5gr IMR4895 and 23.5gr WW748 met my goals.  Since I have plenty of 4895, that is what I use, but worked up WW748 as a backup load.  Some of my rifles prefer CCI 41, some prefer Wolf KVB223M, and some like both these primers that I use in AR's.  In my opinion, I am not using a hot load.  For example:  my XCR-L 7.5" pistol gas system is normally set on "1" for ball ammo; it needs to be set on "4" to function with the frangible bullets in 70 degree weather and "6" when it's cold (for Florida).  

For a steel target test, I put a 3/8" AR500 steel plate inside a brown single layer corrugated cardboard box used for shipping.  I shot the steel plate through the box at 12yd, wearing face, double eye, and head protection, firing multiple shots.  Opened the box and looked.  None of the bullet fragments penetrated through the sides of the box.  A few pieces did stick into the box sides, but could not be felt from outside the box.  Mainly it's the jacket material.  The core mainly turns to "dust" with a few larger chunks on the ground.  My steel targets are normally shot at 35yd.  I have no fears of shooting at steel at that distance with these bullets.  Have also shot plain steel at 35yd.  Out of a 16" bbl on plain steel, the bullet MIGHT be creating a tiny dimple, or it might be just a buildup of the copper core where the bullet hit.  Out of shorter barrels there is just a smear where the bullet hit.

Here's a couple of velocity averages I'm getting all with 23.5gr IMR4895:

16" Tavor: 2739.5fps at 10' from chronograph
10.3" Daniel Defense Mk18: 2344.9fps at 10' from chronograph

I keep throat wear records on all my .223/5.56 barrels.  These long frangible bullets don't wear the throat any more than other jacketed bullets.  

I like them...people noticing them at the range can think that are armor piercing from the darker tip.  One also has to caution shooters not to shoot at steel that close with regular ammo, lest there be target damage or bounce back of bullet parts.  

I used a 1:8 twist to get the data in the OP. The velocities were taken at the muzzle.

Must be a lot of crunching with 23.5gr in the case.