Crimping, Part 2

Crimping, Part 2

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Originally Posted by ar15barrels View Post
Don’t assume that the bullet moved during chambering.
It could also have moved forward during extraction.
Sharpie on the bullet is also in order to see if you find rifling marks.

If the bullet was seated firmly into the lands, the barrel will hold on to the bullet and yank it from the case.
They call this “breech seating” in the benchrest world.

Breech seating with loads designed for a bullet to jump will cause elevated pressures.

I tried several different degrees of crimp with the lightest crimp showing the most movement and the heaver crimp the least. I didn’t see any signs of the bullet getting into the rifling. The extractions were slow so I wouldn’t have to chase the things around the room.

These were Rainier 250 gr TMJ’s, pretty soft, it was not hard for me to mash the bullet with the crimper.

I tried a Hornady XTP 240 gr HP with the “groove”. Very slight roll crimp, factory case. Feed fine, bullet didn’t budge. Of course doing the same thing with a 284 case – Jam. Duh.

We now know why I was jamming. Now, whether my high pressures using the 284 cases was caused by large rifle primers, too much powder, too little crimp, tilt of the earth on it’s axis or all of the above, (probably all of the above) I still don’t know.

And at this point I’ve already spent way more on 284 cases, trimmers, reamers, pilots, gas and range fees than I would have on the equivalent number of factory rounds.

Don’t get me wrong, I’ve learned a lot, I’ve had fun, people have been very helpful and I’ve had a excuse to buy tools, what more could a guy ask… well I haven’t picked up any chicks… but I’ve still had hours of entertainment.

But I think there’s a point where ya gotta say “Dude, just go buy some more factory rounds! They’re straight wall cases dude, you can reload them a bunch of times before they wear out! Let somebody else take one for the team. You’re not cut out to be methodical, you’re having a tough enough time figuring out what works with the factory cases!. You just want to save a little money and have fun, don’t suck the joy out of it by going in over your head!

Know what I mean?

The Hornady XTP

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No, about 2.1″ AOL. Just to where the groove in the bullet starts to hit the case. Don’t ask me why there, it just looked like a good spot, and it gives the roll crimp die a little something to work with.

Like I said, I’m winging this whole thing.

As far as the 284 cases, I’ve had no luck at all. I’ve sized them but I can’t get the case wall the right thickness. A .452 reamer takes to much and leaves a good size shelf down in the case. I’m sure there has got to be a way to make them work but I’m not patient enough.

I’ve just been reusing the brass from the factory rounds. Thank goodness for straight walls, the cases are holding up well.

Montana Gold has some .452 250 gr 45 Colt bullets for a reasonable price, I’ve been thinking about getting some of those, but so far between the Barnes X 250 and 275 gr HP bullets, the Hornady 230 and 240 gr HP bullets and the Rainier 250 TMJ bullets I,m just confusing myself trying to figure out the loads.…/pricelist.tpl

Handload Comment

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I felt a follow up to request my for 450 Bushmaster reloading info was in order. With the help of more knowledgeable people than myself, trial and error, and by probably making all of the common mistakes newbie’s make, I’ve learned a lot about reloading and in the process come up with some viable loads ( I think).

I started by searching the web where I learned that the cartridge is based off of a Winchester 284 case trimmed at the shoulder. So lacking the availability of cases and factory dies for the 450 I bought a 284 sizing die, a .45 seat and crimper and a couple hundred 284 cases. After cutting them off at the shoulder and I found that my .452 pilot for my trimmer wouldn’t slide in the case without tremendous effort, so I brought out my torch to anneal the case mouth. After melting quite a few I finally figured out how to get them red hot without going too far, for the most part. Now, with a little lube, I could get the pilot into the case and trim them to length.

What I didn’t factor in was that the case wall is thicker at that part of the case, so when I tried seating a test bullet and inserting it into the rifle, it stuck and required some gentle tapping on the bolt to get it out. A case reamer is on order, but I’m setting aside the 284 case route and focusing on using the cases from my spent factory rounds. This would be a good place to say “duh”.

So, factory cases. I can de-cap and size them with the 284 die and seat and crimp with the .45 die. Starting with info from AR15barrels QuickLoad data I loaded up some rounds using WSRP primers, 250 gr Rainier FP bullets and W296 powder, staring 10% below the 31.6 QuickLoad recommendation
and working my way up in .3gr increments.

What I got was dirty incomplete burns with powder left in the barrel. After seeking advice I switched to magnum primers and increased my crimp. At 32.8 grs. of powder I got clean burns, moderate recoil and no signs of excess pressure. So I loaded a bunch and headed to the range.

Basically the bullets were all over the place, some even sideways. It was suggested that lightly plated Rainier bullets weren’t meant for higher velocity rifle rounds. Here’s another place to say “duh”.

The Hornady 240 gr. XTP/MAG bullets arrived. I loaded a handful starting at 32.8 increasing in .3 increments and headed to the range. I quickly started seeing signs of increased pressure, the primers were flattening out more with each step up, so I stopped at 34.6grs. Scratching my head, I’m thinking “hmmm, Hornady doesn’t use magnum primers, magnum primers might be causing the increased pressure even at loads way below the 38.5grs of whatever powder Hornady is using.” Another “duh”?

I de-cap all of my empty cases and load up a new batch using Small Rifle primers this time. Starting at 32.8grs I again go up in .3 increments till I’m at 38.8 grs, near 100% of what the case will hold once the bullet is seated, and head to the range.

After each shot I check the case. At 37.0 grains I’m starting to feel the recoil of the factory rounds and there is still no sign of excess pressure in the cases. The primers aren’t hardly flattening out at all. So I shot ’em all. The last primers didn’t look much different from the first. I even checked the soot inside the cases. They didn’t start to look light grey like the spent factory rounds until above 36.7 grs. of powder.

So here I am. I’m going to get a Chrony so I know what velocities I’m creating, then I’ll start to work on an accurate round for pig hunting using Barnes copper bullets. I might even try to salvage some of the 284 cases once my reamer arrives, but I’ve learned it’s best to solve one problem at a time. Another “duh”

It’s been fun, I hope I’ve been safe in my approach and not just lucky.

A W296 Starting Point

There is a massive, unindexed, pile of useful information about reloading the 450b on I will make a small attempt to index the info. Simply search for a powder or bullet or click on the tags.

This is the first about 250 gr Rainier FP with W296 powder:

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I started at 10% below the 31.6 gr. of W296 recommendation and worked my way up. The light loads cycled the action but left the casing a little sooty and didn’t flatten the primer, the recommended loads fired cleanly and flatten the primer and even a little hotter load was no where near the kick of the factory loads.

They did require magnum primers too.

This will be a very good starting point, thanks for the help!