I shot my first rounds of reloaded 450BM today. I started at 36.5gr of h110 and went to 40.6gr h110. The over all was 2.06 with hornady 240gr .452 xtp/mag. I had heavy sooting of the cartridge until I reached 40gr, but the only one that had no sooting was the highest load of 40.6gr. The last 4 that I shot had the same point of impact as the factory rounds, 40gr, 40.2gr, 40.4gr, and 40.6gr. The last 4 were also 1.1min of angle.
All of my shots were at 100 yds.
I could not be happier. My next batch will be 40.6gr.
For the most part what Randall is saying is true, buuttt, let me start by saying that the sooting (as described here in these posts ) is a very well recognized symptom of the 450b case not sealing in the chamber, because of low pressures, especially in the AR. Also, pressure signs with this cartridge, using the AR platform, are actually indeed very good indicators for deciding when to stop, one just cannot automatically discount Bernoulli’s Theorem and conventional wisdom does not necessarily apply, it does, but at much different pressure levels, that one might see with say, a necked cartridge. I repeat, I have never, nor has the vast amount of users of the 45 Pro, ever broken a bolt, using this cartridge/AR combo and this with primers and other indicators, that would scare anyone to death, but don’t ever load to this extent, ever, got it? If kinetic energy performance is the goal then back off the powder when standard signs start to show up.
BTW, on another note, how about that report about using resized 458 bullets in the 450b. What does that do for the Nay-Sayers who, out of ignorance, say that there are not enough bullets in the 451 dia. (golly, there are 451 bullets for every mission anyone can think of and they will penitrate or not, depending on your mission/choise, anything you want), compared to the 458 barrels, that can only use the limited 458 dia rifle bullets? We not only can use every and all Standard 45 cal bullets, regardless of dia, but we can use them with perfect safety and accuracy, and this is the big one, without changing the Terminal Effects of those Big 458 bullets one little bit, nada! One might expect jacket separation, followed by poor tissue penetration, but they’d be wrong. Question, what do you guys think the results will be, if one were to load 451 bullets into a case and barrel designed for a 458 dia? Humph, so much for the specious, crazy arguments, seen on some of the other boards. Now go teach them guys how you made a better dicision, with way more numerous options.
Just an update I called Hornady and talked to Mitch.
Nice guy and very helpful.
Confirmed all of my info and answered lots of questions.
He said H110 is the best powder and it is very close to the powder that they use in the factory ammo.
He also said that the 450bm should be loaded close to max published loads, because it seals the case to the chamber for better accuracy and smaller spread in fps.
I asked him about the 275gr Barnes and he said that the 300gr load data is the best to use. I kinda squeezed it out of him but he said i can load between the 250gr and the 300gr data but I must work it up and use a chronograph wile doing it.
Brush-up on pressure signs as they appear in 5.56 AR’s…
Now, the 450b is directly based off the .284win., and thus, turning or reaming should not be an issue, but what to do in the mean time? First, assuming you have full length resized and then trimmed to the factory standard of 1.700” (plus nothing, minus .003” and use the order given – resize and then trim), load a dummy cartridge and try the “THUNKING” test. Pointing the barrel down “drop” your reload into the chamber, it better have a decided Thunking sound when the mouth of the cartridge hits the end of the chamber. If it does not, take safety precautions and again full length resize and re-crimp, the reloaded cartridge; it’ll go “THUNK” now! Second don’t worry about squeezing the bullet a little in the resized loaded case; the bullet is a little over sized and the barrels are ever so slightly undersized and the dies (assuming they were made right) will not over crimp the bullet, so as to let the mouth of the case go pass the end of the chamber (remember we have the same set of problems with the 45 ACP). With that in mind put on a heavy tapper crimp, “NEVER any kind of roll crimp”, into the case, enough so the bullet is visibly dented, again don’t worry about denting the bullet, in fact you want to see a slight dent (you wouldn’t have to do this if you had the bullet sealing gum that Lake City uses, but normally we don’t, so not to worry). This will not affect accuracy at all and will assure proper bullet pull, and will stop any bullet travel, in the case, that can occur in the shooting/cycling process and still yield minute of angle accuracy and better.
Now, what to do about over pressure signs? It is very normal for under pressured cases to kick the primer out first, before the case releases, thus a flat or detached primer. It is my opinion; you may be very much under pressured. Randal gave numbers that say 35,000 to 37,000 psi are dangerous pressures (based on the program Quick Load), nothing could be further from the truth (no offence Randal, also none of the bolt thrust formulas are accurate either, more on that latter). We normally load the 45 Pro to 60,000 psi with 230 ball or FMJ flat points my favorite. Yes, I know that the 458Socom and the 50Beo are loaded to the 35,000 psi area, but then again those great cartridges do not have the barrel thickness the 450b has in the chamber area. Here’s my example, a “Mountain Rifle”, bolt action weapon, chambered for the 284win case has a SAMMI spec in the area of 63,000 psi and has a barrel chamber diameter the same as the 450b. The other proof is Bushmaster told me that twice they loaded to these pressures and fired 6000 rds + each time with no ill effect and my friends and I load to these pressures and have done so for years, normally. So, why does Hornady load for 38,000 psi, as they have quoted? They tell me the Lawyers won or that they did not want to over stress their SST bullet, which is designed for magnum muzzle loader velocities of around 2000fps and would blow up on deer, like a varmint bullet would do, if you pushed them as we can actually do. My personal loads in the 450b, for the 250gr. bullet START at 2500fps and go up, but then who can afford those bullets, sold in twenty packs. I’ve tried the 200gr SST and compressed a load of 296 and achieved 2800fps, with only slightly flatting of the primers. If you need a pointed expanding bullet, Barnes makes excellent 200 & 275 grain varieties.
As for “Bolt Thrust” with these pressures (70,000psi +), Wayne State University’s Engineering Dept., in a published article, I forget which gun rag ran it now, actually ran “MEASURED” test, not calculated and found that at these increased pressures, the bolt thrust was just a little less that the .223 case and this because of a effect known as Bernoulli’s Theorem, which basically tells us that necked cartridges have way more bolt thrust than straight cases and all the bolt thrust formulas are based on those necked cases, hence not at all accurate for the 450b. My Buddies and I have never seen a bolt failure and don’t ever expect to and we only use, what you might call, max loads, we don’t think they are but others might and we’ve never had a problem and together we have maybe a million rounds down range or certainly many, many, 100,000’s at least.
My recommendations? Assuming you will take proper safety precautions and use great skill, use WW296 for the lighter 200 grain Barnes, which is a pointed-hollow point bullet and AA1680 for the Barnes 275 gainers, which is also a pointed-hollow point. But consider the Hornady 230 FMJFP, which the Flat Point will disrupt more tissue than an expanded bullet does. The flat point doesn’t really expand and will penetrate straight through an animal, as opposed to going squirrely, as is the case with many expanded bullets, on occasion, even to turning 90 degrees in side of flesh, been there, done that. Your loaded length of 2.1” is way short too, load the 230’s to 2.2” (but not much more, you still have to hang onto the bullet) or longer and the pointed bullets to 2.250”, max is 2.260″, but you do need some clearance in the magazine. AA1680 & 230’s will increase your speeds and lower your pressures and still yield 2800fps, which is more than enough for any animal on this planet, if FMJ’s are used. In fact this combo has twice been to the Cameroon’s and has dispatched Cape Buffalo and Elephant, with reported ease. Keep in mind that this is with a version that is .070” longer, the 45 Professional. The standard 230gr hollow pointers are cheap and because of these highly increased speeds just explode on anything, making them good for home defense.