I think I answered my own question. I shot some 400 gr cast bullets today using 4198 and 5744 powder. I started at 19 grs with the 4198 and 20 grs with the 5744. I increased the powder charge 1 gr for 10 rounds each. Action stayed open on all of the powder charges. Velocity was around 900 fps on the low end and at the high charges the velocity around 1400 fps. Lots of unburned powder — especially with 5744.
I noticed on the upper end of the charges, with both powders, that the cases had shave marks on the base (bottom) from the extractor groove in the bolt face. Indicating to me that two things were happening — 1. Chamber pressure was now high enough to seal the case against the chamber walls — 2. Chamber pressure was still high when the bolt was trying to open, most likely because the bullet had not exited the barrel yet.
Primers showed no pressure signs and actually looked very mild. I had used CCI 450 Mags (Small Rifle Magnum).
Velocity maybe needs to be at least 1700 fps (lowest velocity in Hornadys load data) to provide proper timing for bullet exit prior to chamber opening.
Hornady doesn’t have it — it was what I loaded up. I used 27 grs of Lil’Gun with a 400 gr. 45-70 bullet sized to .452. Velocities ran around 1550 fps. I feel that is too slow for proper unlocking of the action.
On another note — my load that I use for the 275 gr. Barnes is 35 grs of Lil’Gun. Velocity was about 2050 fps. Accuracy was 1 1/2 inches.
I shot 5 rounds today over the chrony. I used the 400 grain Speer, sized from .458 to .452. Used Lil’Gun and WSR Primers.
Charges and velocities are as follows:
1 — 27 grs, 1576 fps
2 — 28 grs, 1614 fps
3 — 29 grs, 1689 fps
4 — 30 grs, 1736 fps
5 — 31 grs, 1768 fps
Shots 3,4 and 5 all grouped in to .75″. Shot #1 was 3 inches below cluster and Shot #2 was 2 inches below cluster. Sweet spot must be 30 grains.
Charges #1 and #2 show nil primer flattening. Charges #3 thru #5 showed progressive flattening. ALL CASES SHOWED WIPE MARKS FROM THE EXTRACTOR AREA ON THE BASE AND SHOT #5 SHOWED EJECTOR SWIPE.
I would consider this data the upper extreme and would be very, very cautious about its us.
I just got back from the range and loaded up 8 (all the primers I had left) 405 gr loads. Using Lil’Gun, I started at 25.5 grs and in 1/2 increments went to 29 grs. I shot these at 100 yards. I borrowed a Chrono and here are the velocities that I got:
25.5 grs — 1387 fps
26.0 grs — 1435 fps
26.5 grs — 1498 fps
27.0 grs — 1499 fps (All three went into a 1 1/3 inch group)
27.5 grs — 1508 fps
28.5 grs — 1543 fps
29.0 grs — 1545 fps
I had no pressure signs. Primers looked OK. Sorry no Pics. This is 200 fps over the factory velocity for a Rem 405 in a 45-70. This bullet is not designed for high speed. I have shot them before in hot 45-70 loads and did have jacket separtation. Same thing happened with these. The bullet would mushroom and then split the jacket and the core would separate. Maybe a Speer 400 would work better.
I also chrono’d the 300 gr remington with 30.5 grs of Lil’gun and got 1857 fps. No jacket separation.
By the way — I also Chrono’d 240 gr hornady’s over 40.3 grs of H110 and got 200 fps variation in velocity. High was 2300 and low was 2100. Just like one of the previous posts said.
Your right about these bullets not being designed for the speeds you are at right now, to say nothing about the speeds yet to be achieved. I shoot some of these bullets out of a 458 win mag and sure enough, jacket separation is an issue. Bullet construction is always an issue. You must match the right bullet for your particular mission profile.
You might try these – http://www.castperformance.com/Categ…t=17&total=105 , (go one page up and down to see the entire line)
There are 14 bullets to choose from, 265gr-460gr, with 265gr-335gr .452” bullets. They are designed not to lead the bore at 3000fps and all are LBT flat points and the big deal is, they WILL NOT foul the Gas Tube. I wouldn’t recommend seating the middle of the bullet crimp grove to the case mouth, but seating the bullet out or short of the crimp grove (depending on your loading specifics) will do just fine. You won’t get jacket separation with these and the flat points will flatten anything you care to kill…anything/everything, period. They are shorter than the same weight copper jacket bullet (more powder) and competitively priced. The 265’s are reportedly at 2600+ fps and have killed numerous moose and two Bison that I know of, with efficient and very effective dispatch, with little (measured in mere feet) or no tracking at all. One gentleman is a shooter for the BLM and killed a bunch of cattle for them, one animal estimated at 2500lbs and reports absolutely in creditable results. Deer just don’t have a chance (Ok, a strange thing here, the non-expanding 45 cal bullets destroy way less meat than any 30 cal I ever used). Expansion is not necessary, as the Flat-Points disrupt much more tissue than an expanded bullet ever hopes too achieve and will penetrate where an expansion bullet can not venture. If you want cheap and these kinds of results, then go to 230gr ball bullets or better yet 230gr fmj flat points (I love the Hornady FMJ-FPs), and if you load SAFELY, some of you gentilmen will see 2800+fps with these. Don’t be concerned that the ball bullets will not expand, 45 cal is already a bigger diameter than a 30 cal gets after it expands, and will penetrate elephants, yes two…t
Here is a pic of 3 bullets. Each were shot thru 5 – 1 1/2″ pieces of spruce pine slabs stacked next to each other at 50 yards.
Bullet on left — 240 grain Horn. Went thru all the boards and was found laying on the ground. Wt = 211.7 grs, retained 88.7%
Middle — 250 gr factory. Went thru all the boards and was dug out of 6 inches of loose soil behind. Wt 238.2 grs, retrained 95.3%
Bullet on Right — 300 gr Remington [resized from .458?]. When thru 4 boards and was dug out of the last board. Wt 293.5 grs, retained 97.8%
I was really impressed with the factory round.
Good work, Great work, Wonderful work, but 97.8% bullet retention on a resized .458″ bullet to .452″? They are supposed to shed their jackets and obtain no performance what-so-ever and be downright dangerous, when you resize them that far, or that’s what the arm chair experts will tell you, as found on some of the other boards…wink. Problem is, they don’t have your cahones or are jealous or are just mad that they may have spent too much for an inferior product, well too bad for them, the guys on this board are interested in excellence, not hype.
The reality is, you have done for all who read this a great service and single handily shown just how versatile the 450 Bushmaster really is, can a 458 AR shoot 451 bullets? But a 451 AR can shoot 458 bullets and do them well, really well, wouldn’t you say? Now, we’ve only to show what the upper velocity limits really are. Keep going guys; we await your reports with baited breath, be careful and good shooting…t
Here is a photo — taken with cell, of a 240 gr Hornaday, Factory 250 grain, 300 gr. Remington (sized to .452) and 405 gr. Remington (sized to .452). The Remington’s were orginally .457/8.
Way to go Siringo!! Howz the thunk test with your re-sized 458’s? If it’s not real positive you may need to resize to 451 or even 450, with spring-back even 449 will come back to 451. I have shot 448’s, with the spring-back and they had perfect accuracy and performed on the Hydro test flawlessly, with NO jacket separation, what-so-ever! Of course you should minimally resize the 458’s only to the size where you start to hear the “Thunk”, when you drop them into a clean chamber..t
The sized right on to .452. Chambered fine. No bulge on case either as with the 240 gr. Hornadays.
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.