Need help with 450 Bushmaster loads.

[NordicRX8]

http://www.precisionbullets.com/

Anyone ever use these coated "black" bullets?

The home page states "You can fire our bullets at over 2000 feet per second with no leading and no copper fouling and no messy lubricants."

Cheaper than FMJ, if the 230gr black bullets can withstand the higher velocities, I may have found the most practical plinking projectile to use with the 450 Bushmaster.

[BD1]

Notes:
-The Quickload predicitions do not track the H110 chrony data very well. I may have a slower lot than that used to set up the program.
- After seeing the extreme velocity spreads from 36 through 38 grains I really put a hard double crimp on the 39 and 40 grain loads. This helped somewhat, but the extreme spread is still hugh. it was making me doubt the chrony so I shot some of my tried and true 6.5x55 loads over and got and ES of 17 with an SD of 7 for a ten shot string, so it's not the chrony. I'm wondering if the small rifle primer is up to the task? At 40 grains I'm getting quite a muzzle flash and concussion out of the brake indicating a lot of the charge is burning beyond the muzzle. In general the LilGun did much better.
Approximate group size is to the right.

BD

.450 Bushmaster, 16" barrel
H110 under the Hornady 250 grain FTX 45201

36 Grains Quickload predictions Group size
AV 1904 fps 2014 fps 5"
ES 224 37,444 psi
Sd 89.44

37 Grains
AV 1949 fps 2068 fps 4"
ES 250 40,723 psi
SD 91.6

38 grains
AV 1978 fps 2121 fps 3"
ES 292 44,300 psi
SD 93.34

39 grains
AV 1949 fps 2156 fps 1 1/2"
ES 165.9 45,945 psi
SD 93.34

40 grains
AV 2131 fps 2209 fps 1 1/2"
ES 170 49,909 psi
SD 58.78

[BD1]

Another attempt at getting the spreadsheet to post:

.450 Bushmaster, 16" barrel						
H110 under the Hornady 250 grain FTX 45201						

36 Grains			Quickload predictions			Group size
AV 1904 fps			2014 fps			5"
ES 224			37,444 psi			
Sd 89.44						

37 Grains						
AV 1949 fps			2068 fps			4"
ES 250			40,723 psi			
SD 91.6						

38 grains						
AV 1978 fps			2121 fps			3"
ES 292			44,300 psi			
SD 93.34						

39 grains						
AV 1949 fps			2156 fps			1 1/2"
ES 165.9			45,945 psi			
SD 93.34						

40 grains						
AV 2131 fps			2209 fps			1 1/2"
ES 170			49,909 psi			
SD 58.78

[BD1]

More data. My experience with H110 in the 16" barrel, using Hornady brass and small rifle primers was not good. The data is falling way off the quickload predictions, velocities show extreme variations and accuracy is poor. There is ample indication of combustion beyond the barrel. Something is amiss here. I'd be interested in hearing from anyone else who's has some data for these powder/bullet combinations.

Next weekend it's on to cast boolits on top of LilGun.
BD

16" .450 Bushmaster				
H110 behind the Nosler 250 grain 43013				
COAL 2.10				

39 grains		Quickload Projection		
AV 1997 fps	2095 fps		Approximate Group
ES 193.8		39,015 psi		1 1/4"
SD 91.37				

40 grains				
AV 1992 fps	2146 fps		
ES 219		42,233 psi		3 1/2"
SD 91.37				

41 grains				
AV 1916  fps	2196 fps		3 1/2"
SD 543		45,702 psi		
SD 226.79				

42 grains				
AV 2065 fps	2228 fps		2"
ES 420.4		47,154 psi		
SD 133.5				

Notes:				
My only explaination for the eratic velocities in the 				
39 - 41 grain loads is that the bullet was being moved 				
forward.  I crimped the 42 grain load as hard as I could				
and that improved things somewhat.  But this was still a 				
poor load.  I cannot recommend H110 in the 16" barrel for 				
these 250 grainers.  Fireball was impressive, accuracy sucked

[Siringo]

H110

ALL of my loading for the 450 is done with Winchester Small Rifle. When using H110 and at Hornady's max charge -- my velocity variations were 200 fps. There is a post way back from another that had the same experiences.

It is because of this that I switched to Lil'gun. Check Hornady's website for the new data. Basically they say the LG is the way to go. Also, I had tried other primers and they did not match the accuracy or velocity I got out of the WSR's. The CCI SR Mags where 100 fps less.

I have always suspected that the SR primer can not adequately light large charges of H110. Also, seems that quick load does not take into consideration primers. Seems that it assumes that it can all be lighted properly. ?????

[Wildcatter]

Just a thought to get you thinking..

Hornady uses a WW297 product and before the panic I've seen it on the net for sale. 297, as you know is slightly slower than 296. H110 vs 296 - there is not any real difference, but I use 296, but only because I've got a ton of it. The crimp is usually the key and there is no better crimp than my side crimp. At the low pressures, I am looking at here, there is probably considerable case sooting, which means the case is not sealing in the chamber from the low pressures. It is true that 110 doesn't play well at the lower pressures. The algorithmic calcs on QL might be a little shy because of the lower true pressures (the sooting thing again) and not enough crimp, but heck your getting all the crimp you can get for a tapper crimp. My rec's are to go for case head expansion of at least .001" (my persona standard is .0015) and use the side crimp, and stay with 110 for just a little longer. Once the sooting stops, I think you'll start to get better over-all performance. Try feeding the cartridge, by hand, all the way into the chamber is see if the sd goes up, this should confirm the bullet pull problem you suspect. But just to get you further thinking, the factory loads I've shot, soot the case terrible and gave tremendous accuracy, go figure..


Safety First..t

[Siringo]

Yes, bullet pull is important. I am using a modified Lee factory crimp die, but only to put a crimp much like the factory rounds. After I size the cases, I tumble them again and also after the tumbling, I clean the inside of the case necks to remove any residue from polishing or left over lube. This seems to help quite a bit. I found that when I sprayed my cases for sizing, I also sprayed the inside of the case -- no point in lubing the bullet while seating! Cleaning that out should help provide more consistant bullet pull. My bullet jump when feeding is no worse than the factory ammo during chambering.

There is a good write-up about bullet jump in the AR15 w/5.56 ammo in the new Sierra Manual. Happens even with the 223.

Final note -- I have shot up a box of the new FTX's using a max load of LG. The velocities that I got were around 2200 fps out of a 16 inch barrel. Factory out of my gun is around 2050 fps. Accuracy was not as good as the factory rounds, but pretty close. My overall length was set as the same as factory.

[pitted bore]

A question for those shooting and reloading the factory cases: With a first-fired case from a Hornady factory cartridge, how do 250 gr FTX bullets fit in the case mouth?

After factory cartridges are fired in my custom-reamed chamber, an FTX bullet will enter the mouth of some of the cases with very moderate finger pressure, and with other cases considerable force is required. None of the fired cases will permit the bullet to drop freely into the mouth. (The cases have not been resized, but are fresh from firing.)

In my experience, first-fired factory 45 ACP and 45 Win Mag cases do not expand sufficiently to permit any insertion of a bullet. With conventional bottle-neck rifle cartridges loaded to factory pressures, the case neck expands sufficiently to allow bullets to drop into the case. However, I'm seeking some comparison of the bullet-fit phenomenon with factory 450 Bushmaster cases fired in factory-reamed chambers.

Thanks.
--Bob

[Siringo]

They slip in -- not easily though. More like a slip fit. Upon firing though the case will spring back some.

[BD1]

Mine also will "slip fit" into a fired case.* Snug, but they do slide in there. I am also using a modified Lee FCD die. When I say I'm putting on a "hard crimp", I'm using that FCD to put a visible body crimp into the bullet .01 below the mouth, and then I'm using the Hornady crimp die to bring the case mouth back into the bullet and smooth out the slight bulge below the body crimp.

I loaded a dummy round, using my 300 grain LRNFP (cast) boolit, under a live FTX round and fed it from the mag that way three times on Sunday. COAL went from 2.098 to 2.101. About the same variation that I get seating the Noslers with the hornady seating die.* However, that boolit has a lube groove placed so that the Lee FCD crimps into it, which really seems to help. I'm hoping that the heavier boolit with a more effective crimp will give me more consistent ignition.
Of course there is no cannelure for the body crimp to "seat" in, I'm pressing into the side of the bullet. Even with a hard crimp I'm getting velocity spreads of 160 -180 fps and a big muzzle flash from the brake. I really think it's not getting lit well.

Unfortunately due to the current primer shortage Remington 7 1/2s are the only small rifle primers I have on hand.I gave the rifle a good cleaning last night in preparation for the shift to cast boolit loads. No sign of any wear to the anodizing on the bolt lugs at all. No real copper fouling. There was some soot from the H110, but that is to be expected.

I had been shooting off the bench with a lead stock weight in. Unfortunately the recoil has pounded the stock weight forward to the point that it is binding the buffer tube so I had to take it back out. I may wind up drilling the stock so I can pin the weight when it's in there as it does make the long bench sessions more pleasant. In combination with the recoil pad and gentry brake the rifle is pretty enjoyable to shoot.

There's definately room out there for someone to market a stock designed for the AR thumpers.
BD

[Siringo]

Alternate powders

What does quick load say for alternate powders to H110 -- stick, flake, ect. Maybe some of these would be easier to ignite than ball powders.

What about using a limb saver slip on pad?

[BD1]

Quickload likes LilGun, 296, VV110 and H110 for the .450 B in about that order.

One downfall of Quickload is that it does not address primers, or ignition, only percentage of combustion. So It can't really predict a load that's not lighting off well. It's telling me that a 40 grain charge of H110 should be 98% combusted by the end of the 16" barrel. My eyes and ears, and chronograph are telling me different.

LilGun performed much better than H110 in my rifle, but I still had variations in velocity of over 100 fps, and standard deviations over 50. Other rifle cartridges I have significant experience with are the 6.5x55, .270 WBY mag, and the .223 with heavy bullets. In those three a good, accurate load usually has velocity variations under 20 fps and SD values in the single digits. When you look at the velocities involved, the percentage variation is much smaller in comparison. Of course they are bottle necked cartridges using much slower powders. But even my .44 mag in a six inch revolver doesn't produce velocity variations like this.

When I get through the initial work ups with the Hornady factory brass, I'll start into some cut down .284 brass. That should tell the story on the primer size issue.

BD

[Siringo]

Bullet Tension

This is the article I mentioned that is in the Sierra Manual. While it applies to the 223, I think it is appropriate for any cartridge in a semi-auto.
Bullet Tension.jpg

[BD1]

Siringo, that article is a pretty good explanation.

Compared to the .223, In the .450 B the situation is greatly exagerated.

First; due to the bullet weights involved, the enertia of the bullet in the .450 is greater relative to the bolt mass and velocity.

Second; due to the diameter of the round, neck tension, (amount of "grip" as a result of surface area in contact with the brass), is much less in proportion to the enertia generated.

Third: being basically a straight walled case, any movement of the bullet results in a much greater percentage of case capacity increase when compared to a bottle neck round.

I had some issues with bullet jump on chambering in my DCM when I first went to the moly coated 77 grain sierras. After a loading or two the case necks would get slicked up by the moly. I was able to address it by dropping a smaller bushing in the neck die, and using a Lee factory crimp die. Before I went to tri-focals I could keep that rifle under 1/2 inch @ 100 yards all day off the bench using that factory crimp. As I get older my vision is getting worse and that rifle really should get a flat top. Just can't bring myself to do it.

In trying to prevent bullet jump in the .450 I'm crimping the body to the point that I'm swelling the bullet, and case, on either side of the crimp. It seems to prevent the bullet jump, but it's not helping the accuracy potential of the bullet, and I still get velocity variations, with the occasional real low velocity shot, so it's not an ideal solution. A bullet with a real cannelure placed for proper seating depth would help. It's possible that proper neck tension using the thicker .284 cases may help as well. Someone, (Forstner?, C&H?) used to market a little cannelure tool. Maybe we should try that? Something like the Barnes triple shock might provide the chance for a good crimp also, but I can't imagine sizing a .458 solid copper slug down to .451.

By body crimping into the lube groove on the cast boolit I seem to be able to control bullet jump pretty well. I'm hoping to get the chance to find out this weekend.

BD

[Siringo]

BD1 -- I thought by your post that the bullet was jumping .003 inches -- I think that was factory. That would be in line with what the article says.

My main plinker bullet is a Hornady 240 gr. XTP Mag (.452 diameter). I crimp into the bullet cannelure at the rear most edge -- to minimize the jump. Seems to work OK as my velocities are consistent and accuracy is very good.

Corbin Swaging sells a groove tool that would work. I have been toying with getting one.

Regarding the Barnes -- there are a couple of relief grooves that you can crimp into. But these are expensive bullets (made for the 460 S&W -- .451 diameter)

One thought here is the factory ammo does have some jump. However the accuracy is great and very consistent velocities. My point is "0" jump may not be necessary -- as long as it is minimal AND this is only for one chambering. Repeatedly chambering the same cartridge and checking the jump is counterproductive. Yes, the bullet will continually move forward -- much like a bullet puller. Usually, the round is chambered only once and then fired. However, in hunting situation, the same cartridge may be chambered several times over the course of the season. In this situation, I do use the same cartridge, but chamber softly and use the forward assist to make sure it is chambered properly. I check to make sure it is locked up properly so when the 30 pt buck comes by -----.

I think someplace in all these posting was reference to gluing the bullet in. If I recall, the military -- even for its match ammo -- used a mastic that helped to keep the bullet in place and make them waterproof. I may be incorrect here, but I also recall that they bullets without the "glue" would just slide into the case. I have often wondered how loctite would perform. They make a special product for bearings or very close tolerance pieces. Hummm!