Loading near maximum pressure

[Texas42]

I just got some Barnes TSX 70 grain. I was planning on loading them in 5.56 nato to shoot medium game, like deer. . . . anyway, I finally got to loading them. Barnes has load data for 5.56 nato.

For H335, min 21.0 grain, max 23.0 grains with COAL of 2.250"

I picked 4 fairly random powder measurements from 21.5 to 22.9 grains and loaded up a few of each. I want as much velocity as I can get, as these are for hunting.

I've never really been quite so close to maximum loads before. Any advice?

I measure each charge individually on a fairly new beam scale, and I was very careful with the OAL. I started to give a light crimp (i've been putting a light factory crimp in the plinking 5.56 I've been loading) to a couple, then decided not to.

BTW, these bullets are friggin huge. Too bad buck season is over, but I might get a chance to kill a doe or pig this weekend. I've got LC brass which are on their third loading.

Thanks.

 

[mage2]

Watch for over pressure signs, like splitting and primer odditys and etc.

I would also cross referance the load data with as many sources as you can. each book will show different numbers on max charges.
Crimping and using magnum primers can cause higher pressures so make sure to see what the "standard" of the book you are using is, meaning did they crimp? I personally dont think random is the best pattern to take, I would suggest starting at or close to minimum charge and working in .5 -1.0 grn increments load 3-5 rounds per variation and log everything.
Seeing that you have already loaded some rounds, start with the lightest and fire those first and watch for any signs of pressure. if you see any stop and back off some.

I know my rifle doesn't always like the max power loads and usually for a given round the difference in min and max isn't that much.
start small.
be careful if in doubt don't risk it. 200 fps is not worth your health.

Im sure you know this, what do i know im a newbie

 

[TexMex247]

If you are reloading for an AR, I highly recommend the reloading data from Sierra. Almost every max load listed exceeds all other published data. IME, nothing dangerous about it, just info tailored to the Ar-15. I will take a glance at em' when I get home and let you know about the H335 loads w/70 grain bullets. Don't know if the TSX is a pure copper bullet but if so, they may not tolerate the higher pressures as well as FMJs. Personally, I do tend to err on the side of caution and I agree w/mage about starting low and working up. The hottest loads are typically not the most accurate ones and a few FT/Lbs of energy may not be worth it. Anyhow, I will post some more info when I get home, hope this helps a bit - Texmex

 

[Texas42]

Yeah, the TSX is a pure copper bullet. VERY LONG. Rather spancy.

A Sierra loading manual probably wouldn't be a bad idea. : )

 

[Texasjack]

Because of the small diameter of the 5.56, there can be a lot of variance in the volume due to case thickness. So what works for one brand of cases may not work for another. Watch for signs of pressure.

As for the crimp, if the bullet gets slammed back into the case while in the magazine or during feeding, you could end up with problems. There's nothing wrong with doing a light crimp.

 

[TexMex247]

According to the data I have by sierra(AR specific for 69gr HPBT matchking) they list a max load of 23.8gr for H335 with a recommended starting point of 21.2gr. They also use a COL of 2.260, which I would stick to if you are using a lengthy bullet and pushing it near max. Ideally you would be using info specific to the TSX or a bullet of the exact same weight but 1 gr is close enough. Hodgon's website lists a max of 23.5gr for a 70gr Speer SP, so either way, you are in the safe zone. I think you can find the Sierra AR load data somewhere on the net for free. The same data by sierra(for 69gr HPBT) shows an "accuracy load"of 25.3gr of Varget. Also I just noticed that you are loading for the 5.56 nato and if you are using true 5.56 brass it may have less case capacity than regular 223 stuff so it may be a good idea to stay a few tenths below maximum. Curious to know how they shoot for you, so be sure and update this post after you put a few downrange. Good luck w/em'- TM

 

[Texas42]

I'm using the load data Barnes has specifc for this bullet (and Nato brass). I was lucky to have one of the two powders they had load data for (actually one of the reasons I got the 70 grainer).

I'll let you know how it shoots. I might pick up some Varget next time I'm in Buda.

 

[Texasjack]

Varget works very, very nice in the .223 - also in .30-30.

 

[texasislandboy]

and .308 for me

 

[Texas42]

Yeah, those 70 grainers under 22.5 grains of H335 worked wonders on a couple of spikes this past weekend. Shoot, one of the exit wounds was just over an inch in diameter. Pretty good for a "dinky 5.56x45 Nato." I would have liked to seen the bullet, but both went through the animal. I think I really like this load for hunting.

 

[mikeofcontex]

The closer you get to max, the more things that can go wrong. Variations in case capacity that will go unnoticed at medium loads will cause possible pressure issues when approaching max. Changing the primer becomes more critical the closer you come to max. Crimp or not, neck thickness, case length, and OAL all become more critical as max is approached.

My opinion... that last 100 fps just isn't worth the effort. If you obtain it and have to change anything, you have to start over. The game won't notice AND generally accuracy comes long before maximum performance.

Just one opinion and it's free.

 

[Dawico]

You will have pressure issues with full power loads, as military brass is thicker than commercial brass. Back the loads off to minimum to start.

 

[Texas1911]

You don't want to overdrive light bullets as they will tend to fall apart and not work as advertised. Barnes should specify a range of velocity that the bullets are suited for; hence the difference between .30-30 bullets and .308 bullets.

If you place the shot and the bullet stays intact, you will drop the animal. Good job running the 70+ grain bullets, the light stuff likes to come apart when it hits things.

 

[woolleyworm]

If you place the shot and the bullet stays intact, you will drop the animal. Good job running the 70+ grain bullets, the light stuff likes to come apart when it hits things.

The closer you get to max, the more things that can go wrong. Variations in case capacity that will go unnoticed at medium loads will cause possible pressure issues when approaching max. Changing the primer becomes more critical the closer you come to max. Crimp or not, neck thickness, case length, and OAL all become more critical as max is approached.

My opinion... that last 100 fps just isn't worth the effort. If you obtain it and have to change anything, you have to start over. The game won't notice AND generally accuracy comes long before maximum performance.

Just one opinion and it's free.

An opinion that I'd be more than happy to 2nd ! I would suggest loading up some H335 and Varget and perform a ladder test with each powder. I'd much rather have a highly accurate round vs a highest velocity round. Unless you're looking at going out past 300yrds, a couple hundred fps isn't going to matter much. Find the most accurate load for your particular gun and you'll be better off in all situations.