Interesting development in 450 Bushmaster-land. Calguns was insistent that a side crimp is needed for our beloved cartridge. But a quick perusal over at our favorite .450 Bushmaster forum gives the following insight:
450+ wrote:Thanks guys for the quick responses. I would like to use the 45-70 modification but I’ll need to get the die and hunt down a machinist, so the tubing cutter modification seemed like the best start for now, something even I could do. Plus I just received my Lil’Gun and am aching to load up some 230gr FMJs. MOA accuracy would be sweet but realistically I’m loading up for plinking, hunting, and defensive purposes. “Minute of grizzle,” as wildcatter has coined, is good for me, anything else is just gravy.
If no one has a picture, am I right that the longer screw is simply to hold the nut, or is it for something else? Does there need to be a gap inserted between the two “handles” and that’s why a longer screw is used?
I guess I don’t get why I can’t just dull the crimper and get to crimping, leaving the factory screw/bolt alone.
You can, the drill is not required.
Did you get the Hornady die set? If you did it comes with a taper crimp, there is no requirement for any other kind of crimp. I called and talked to the Hornady folks about making a side crimp and they were kind of at a loss as to why people want one. They said the factory ammo is all done with a taper crimp and they feel it does a good job.
There seem to be twoe reasons that people are looking for a side crimp style die/tool.
1.) so far with some testing (a small testing pool) it seems to give more consistent pressure, and therefore more consistent velocities which will help tighten up vertical spread.
2.) shooting lighter bullets like the 185 grn bullets. They seem to be so light that they leave the case before all the powder is burnt. A tighter crimp would help with that.
Your 230 grn bullets should not have a problem with number two.
So you are really GTG on reloading without any other tools, a side crimp is not a requirement.
I’ve set up my side crimper for the 275 gr Barnes bullet with a 2.25″ AOL. I’ve got it crimping .190″ down from the case mouth. This catches the bottom cannelure but not much of the base of the bullet, that’s the widest part on the these and I didn’t want to mess with the sealing of the bullet in the barrel.
you can see this deforms the bullet a fair amount.
Without the side crimp it only takes one good whack with the inertia puller to move or dislodge the bullet. With the side crimp it takes 3 good whacks to dislodge it.
I’ll let you know how this effects the ballistics next time I make it to the range.
Here’s another style of crimp. This too will stop bullet creep dead in its tracks, its a type of side crimp. After you’ve pretty much decided which bullet you like most or the trade-offs you are willing to except, you can have Lee Dies; make up a Lee Factory Crimp Die that crimps well south of the case mouth, just like the side crimp I use (your going to have to tell them how far south on the case you want it and how much crimp is required, hey, this is all custom stuff here). Or, I bought a Factory Crimp die for the 45-70, cutting off the base of the die and shortening that crimp plunger do-dah (heck I don’t know what they call it?), this let the case go well above the top of the die, before the crimping action took place, which then placed the side crimp way down the case, where I wanted it anyways. This is very slick and quick for reloading and much less time consuming than the chemical bonding. Of course, this will require some minor machining.
I repeat Gentlemen; most sooting usually is a function of not enough pressure. The question to ask, is why? Could be not enough powder, not enough bullet pull, or the powder burn rate is to slow, or the sum of all of these symptoms at the same time. Assuming everything else is safely reloaded to spec; these suggestions usually are the major culprits. Low pressures can cause the case not to seal in the chamber and can become so bad that the gases escaping down the sides of the case can cause the case to collapse from the side. I’ve never seen this in the 450, but it is always possible. A little sooting, at and around the case mouth is Normal and is seen in all rimless straight cases (45acp/9mm etc.). Using faster burning powders, ala, ‘lil gun/296 and others, usually keeps sooting to a minimum. AA1680, needs a stout crimp and allot of powder to seal properly, but then a little sooting can still be visible, but this should cause you no alarm and AA1680 has the additional benefit of driving the speeds up.
Something else about crimping vs. bullet creep, consider. Using a drill motor, I have chucked up the cutter of a hand held tubing cutter (every hardware store has them)and with a stone have nicely rounded off the sharp cutting edge. The cutter on the tubing cutter usually is held to the tool with a screw. Take the cutter out insert a longer screw; put a jam nut on the opposite side and you are now ready for the drill/lathe chuck. Any kind of stone will work; anything from one from the front yard or a chunk of cement, to something you buy from the hardware, just so long as it is on hard side. Now you have a nice little tool to roll a heavy crimp into the bullet at nearly any location you desire (Because we head space on the case mouth, you must stay well away from the case mouth. The crimp is best done towards the bullet base, but not on the base, bullet bases are critical to accuracy.) and is as good as any, so called standard roll crimp, something we cannot use at our case mouths. It will very slightly shorten the case length, so don’t get carried away. Keep the crimp fairly consistent, that is to say, location and pressure. Measure the final case length to see if you made it too short or have not put on enough crimp. Pull a couple of bullets and look to see if you have dented the bullet sides, you actually want this denting. This type of crimp is particularly useful when using solids. I put a groove into the solid at the spot I want to roll the crimp into, using this method. Lead based bullets do not need such a grove, as the crimp squeezes into the side of the bullet. Those long heavy bullets seem to thrive with this method of crimping, of course I still tapper crimp. After a little practice The Side Roll Crimp, as I am wont to call it, is easy to do and to keep somewhat consistent and accuracy is not adversely affected, even if you aren’t particularly consistent, yea even sometimes accuracy is made better.