Range report 445 SM

[gunther66]

Reamed a 44 Mag barrel to 445 SM using the new reamer from the GBO forum. Removed the pilot as it would not enter the bore or the muzzle.Haven't slugged the bore yet but it has to be tight as the pilot was only .424 by my calipers.
First thing I noticed was the recoil must have doubled over the 44 mag! Next, the Chrony showed an average vel of 2076 fps with starting load on the Dan wesson website of 29 grs H110 and 240 gr JSP.
Accuracy has degraded somewhat. 2 3/4" groups at 50 yds. This was 3 to 4 shots in 1  1/4" and a flier or two opening the group.
The other observation is that the primers (WWLR)were quite flat and cratered just a little..and this is a starting load.
Thus is going to take some more work.Maybe I should have just stuck with the 444 Marlins?
Does anyone have a favorite load for this cal? G66

[bikerbeans]

G66,

I checked two sources and both list 29 grains of H110 as a start load with the 240 grain HP/XTP bullet.   33.0 grains is shown as Max.  One source used Fed 210 primers and Starline brass, other didn't identify the primers and I think Starline is THE brass for the 445SM.  The OAL from both sources was 1.925".  Maybe check to see if your bullet is into the rifling?  Since the pilot didn't want to fit down your barrel maybe time to slug your bore?   Might also want to check the headspace on your gun since if that is good it would take a lot of pressure to flatten out a large rifle primer.

BB

[yukondog]

Not sure but it seems like I heard that CCI primers are harder than Win.. Might give them a try and see if that helps.

[quickdtoo]

The Hornady 8th lists 29.6gr H110 start for the 240gr XTP-HP @ 1.925" COL, 32.8gr max, in IHMSA brass w/Fed 155 primer. I think BB hit on the likely cause with the headspace issue, deep rim cuts are common on H&Rs, may cause flattened primers within safe pressures.

Tim

[gunther66]

Anything is possible at this point.I cut the chamber to zero headspace,then realized the case was headspacing on the case mouth, then cut the chamber about a thou deeper.The case then sat that thou below the breach.No cutter marks on the existing rim cut,but the cutter was touching it.
My loaded rounds drop freely into the chamber with no resistance and extract by just elevating the barrel after the action has been closed.fired cases come out easily also.
was using WW large rifle primers.I have CCI LR,will try them next.  G66

[bikerbeans]

SB1 or SB2?

[gcrank1]

Recoil impulse like that is likely to widen groups alone.......
Make sure the stock bolt is well torqued.
Regardless of book loads, given other pressure signs, reduce the load.
Sounds like fun  .

[bikerbeans]

G66,

Take an MT brass and insert it backwards in the rim cut, make sure the ejector/extractor isn't interfering.  This makes it easy to see if the rim cut is too deep without the case mouth or bullet getting in the way.   If you used an unsized or uncrimped brass to check the chamber while reaming and then roll crimped during loading the mouth would probably then not contact the end of the chamber.

BB

[gunther66]

I moved the barrel to it's original SB-2 frame when the chamber was lengthened.The extractor was removed for recutting the chamber.
Anyone here checked the velocities of their 445's in a rifle? 2076 fps av. is nearly up there with the 444 and I already have that.
I will trim a couple thou off a few cases and see if it makes any difference.  G66

Never saw it mentioned here...What is the correct torq for the stock bolt?

[quickdtoo]

http://www.gboreloaded.com/forums/index.php/topic,133235.msg1098502998.html#msg1098502998

I use Win. 296 in all my loads,you should see what the 180's do with a fullhouse load. My Marlin 444 does 2275 fps with the 265 gr. bullet and the 445 is a little over 100 fps. slower. The Handi barrels are about .006" larger than they should be in the chamber area,so you'll probably get some swelling in the brass.The 445 reaming tool did'nt even touch the chamber sides when I reamed mine and Lik2hunts barrels. I'm pretty sure I used 32 grs. of 296 with my load,but I'm not sure about that.It may be that you'll have to start out lower and work your way up.Our rifles shot 1" to 1 1/2" with these loads. The 240's will do 2250 fps.  Digger

(Win 296 and H110 are the same powder)

[bikerbeans]

445SM = 444M Lite

[Ditchdigger]

I'm not sure,but I think I rememeber reading that the 445 does not like reduced loads. I use 296 with a not quite max load and get 2266 fps with the 240 gr. bullet. The 300 will do 1977 fps with a not quite max load .( .7 less than max) Mine likes the 265 gr. bullet at 2160 fps.   Digger

[gcrank1]

I'll bite........
Everything I have, and have had in over 30yrs. of messing about handloading, has responded to downloading. I have done most of this with cast lead bullets, plain base, where high velo can be problematic with my basic, cheap & easy WWt alloy.
The real issue with the H&R 44M barrel may well be the slow twist, downloads often need extra rotational speed to stabilize, as does longer/thus heavier, bullet design. If you arent getting groups with your download, try a shorter bullet. If cast, make sure it's dia. fills the throat, regardless of the barrel groove dia. (most throats are at least groove dia., if yours isnt that is a whole nuther problem). Jacketed is more forgiving, but it is still best to fill up the bore to prevent gas cutting of the grooves getting past the bullet sides. At least they dont 'strip' the rifling or lead, so many like using them; for me, I cant afford them. My old Shikari 44M shot everything from RB plinkers on up to full house factory magnums and it had the 'slow' twist, IIRC.
I guess the reason for the long case might be to make a 'more efficient' cartridge compared to the 444 or 45-70 , more akin to the 45ACP vs the 45Colt. It seems that higher pressures and more felt recoil is part of the result?
If I wanted a 'flat' shooter there are a whole bunch of better cartridges than these brick throwers, but I do like big bores.
I think if you have a good chamber with a decent throat and leade into the rifling, and a decent bore, you should be able to make it shoot slow or fast, it just may take a little more fiddlin' with the bullets.

[Ditchdigger]

gcrank,the bullets stabilize by revolutions per minute,the faster the bullet is pushed the faster it spins.Thats why some bullets will self destruct when pushed to fast. the bullet is spinning so fast that it will tear itself apart.  Digger

[gcrank1]

Yes....agreed that does happen on occasion, at least Ive read about it.
My reference is regarding bullet stability (or rocket, or football, etc), a certain amount of spin is required to make a projectile of X dia and Y length at V velocity stable (bullet material, thus weight for the length is another matter, just talking regular bullet materials here). If you have too little twist for the velo, marginal to no stability, increase the velo in the twist and you sometimes can stabilize. The problem with big bore calibers is that your tolerance for recoil, or overpressure for the platform may be exceeded before you achieve it. Increase the twist and for that reduced velo, or more, it will be stable, even if sub-sonic. In my experience, err on the side of a bit too much twist for the longest, heaviest bullet you intend to use, than not quite enough, if you are 'building up a barrel'. With factory barrels you dance with who ya brung; Im only suggesting not giving up too soon on reduced loads if that is what you want as an option for playin', Ive been doing it happily for years (YMMV).