Need help with 450 Bushmaster loads.

[Slash2]

I have been reloading the 450B for a couple of months now and I have my best grouping using H110 27Gr., Rem. 71/2 small rifle primer and Hornady 250gr HP/XTP (.452) . I have the bullet seated in the grove at 2.018" O.A.L.
They are grouping at .5" at 100yds. from a bench and are moving at 2120-2125 fps.

Are you really using only 27grs, or did you mean 37grs?

I had my dies made by CH Tool & Die and work great. I also have a set of Hornady dies but the group veries some time the groups are good and the next they are bad .75-2". I belive it being cause by the design of the die. It has that floating bullet seater and crimper thing which does not give the same resualts for each round. I have been playing with the crimp on the Hornady dies but still not impressed.

I've been wondering about the crimp too, I've backed off the seating die so the roll crimp doesn't come into play and then I use the separate taper crimp die, Does the CH Tool & Die seater use a separate crimper or is it all in one? Are you using a roll or taper crimp, and how much crimp are you using?

My CH Tool & Die dies are consistantly great .5" all day long. I also have modified my barrel a bit. I removed the comp and cut off the the threaded end to my it leagel in NY. I 90 degreed the barrel end and put a 45 degree crown on. I can say enough about how accurate these 450's are Im impressed. I purchased a second one just to see if its a fluke but it also holds .5" group.Cool!

So are you saying the second one holds the .5 group unmodified?

I gotta tell ya, .5 groups, that's impressive!

[ar15barrels]

I gotta tell ya, .5 groups, that's impressive!

That's so easy anyone could do it...

Only fire one shot and your group will measure 0.45"

[Slash2]

That's so easy anyone could do it...

Only fire one shot and your group will measure 0.45"

X2!

[mdbrownell]

I meant 37gr. I hit the wrong key. And I used 5 shot groups and the second guns barrel is also modified to stay legal in NY. Getting .5" group is not that big a deal from a bench rest. When you shoot a .5" standing using nothing but your arms is impressive.

[mdbrownell]

ar15 barrel bender you are right 1 shot = .45", 5 shots= .5 lets see you try it.

[jagermaster]

ar15 barrel bender you are right 1 shot = .45", 5 shots= .5 lets see you try it.

He is just joking around.

A .5in 5shot group is impressive we would love to see picks.

Would you tell us more about your reloading prosses, like slash asked about your crimp.

What did you purchase your gun for hunting, target, or other?
I got mine for white tail, they grow big in Mississippi.

Edit: Have you used any other bullets other than the 240gr xtp/mag, and if so how did they do.

[Slash2]

I meant 37gr. I hit the wrong key. And I used 5 shot groups and the second guns barrel is also modified to stay legal in NY. Getting .5" group is not that big a deal from a bench rest. When you shoot a .5" standing using nothing but your arms is impressive.

ar15barrels joke aside, I think a 1/2" 5 shot group from a bench rest is still pretty impressive at 100yds, especially knowing what kind of kick is coming your way each time you pull the trigger!

Thanks for the info. I don't think I'm going to be able to modify the end of my barrel, but I might take the Izzy "brake' off to see if it makes any difference one way or another. I've had it off before just to look, and they sure didn't do a very nice job of finishing the barrel end.

[Siringo]

The floating seating die from Hornady is supposed to assist in bullet alignment during seating. I have not found any variation in seating depth with my dies. However, I am not sure how straight the reloaded cartridges are compared to the factory rounds. There are signs of a bulge on the reloaded round that does not seem to exist on the factory round - even though the OD diameters are the same between the two.

I do not use the seating die for crimping, but the supplied taper crimp die. I too am wondering how much crimp is required. I have noticed that if the bullet is not crimped enough, upon chambering, the bullet would move forward (if crimped in the forward portion of the crimp groove). This would have an effect on the accuracy. This even happens with the factory ammo. I was running the rounds in and out to test magazines and after a time or two the cartridge OAL would change -- growing longer. The bullet has enough mass and the bolt speed is high enough that upon chambering the effect is that of an inerta bullet puller.

Here are some measurements using my Hornady dies:

1. After one firing, sized and expanded -- Inside diameter of case =.450"
2. After one firing case wall thickness = .0135
(neck tension = .002")
3. OD at edge of crimp = .476"
4. Case is somewhat tapered in bullet area, but OD just before crimp in .480"

Based on these measurements, I am crimping into the crimp groove .002" (240 gr)

Note that the crimp edge on the factory round is .477". So the factory is crimping into the 250 gr bullet .001".

The factory loads are very accurate. Using the same bullets, primers and powder -- the single most significant item to duplicate factory accuracy is the reloaded round has to be just as straight. I do not have a way to measure the runout, maybe some of you can. Also, I know my measurements are a thousand or two off factory, but it was with my caliper just to show a difference. Based on the factory drawing, they are crimping into the bullet .001".

[shomstead]

ar15barrels joke aside, I think a 1/2" 5 shot group from a bench rest is still pretty impressive at 100yds, especially knowing what kind of kick is coming your way each time you pull the trigger!

Thanks for the info. I don't think I'm going to be able to modify the end of my barrel, but I might take the Izzy "brake' off to see if it makes any difference one way or another. I've had it off before just to look, and they sure didn't do a very nice job of finishing the barrel end.

After your second divorce you don't notice the kick anymore.

Thanks you all for the great info in this thread. I'm off to the range with
my first batch of .450 reloads!

[Slash2]

Thanks you all for the great info in this thread. I'm off to the range with
my first batch of .450 reloads!

Have fun! Be sure and fill us in on how it went! (provided your shoulder isn't too sore for you to lift your hands to type)

[MudBug]

Has anybody considered using the Cast Performance bullets? Maybe the 360 grn or 395 grn bullets? These are being used in 460 S&W magum loads at velocities that kinda compare to what might be seen from the 450b.

http://www.castperformance.com/Categories.bok?category=Cast+Performance&searchpath=5&start=17&total=105

[ar15barrels]

Has anybody considered using the Cast Performance bullets?

If you intend to shoot a lot of lead bullets in a gas operated gun, make sure they have gas checks.

[MudBug]

If you intend to shoot a lot of lead bullets in a gas operated gun, make sure they have gas checks.

Gas Checks right?

[ar15barrels]

Gas Checks right?

Yes, the bullet standing up has a gas check on it's base.

[MudBug]

BTW, I have no idea how those would perform for anything, I just know that the 395 gr bullets are the biggest .452 bullets I've found that seem to be made for these kinds of velocities.