Fallowing this thread, I tried some .321 boolets.
They chambered fine. Shoot great.
Problem I'm having is blowback. Neck all black with soot.
Yes, I've annealed the necks.
I've tried 2400, and IMR4198. 30/40 Krag loads. 200gr GC
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Fallowing this thread, I tried some .321 boolets.
They chambered fine. Shoot great.
Problem I'm having is blowback. Neck all black with soot.
Yes, I've annealed the necks.
I've tried 2400, and IMR4198. 30/40 Krag loads. 200gr GC
Yesterday I loaded some NuJudge boolits, a fattened version of the Lyman #314299 casting at something like .316" on the body. My caliper says the "bore riding" section of these is .308", and I'd gas checked these while running them through a .314" sizer. They're scrap lead water dropped, medium hardness and malleable. Tumbled them in liquid Alox, then dipped them in my homemade "Brown Thunder" lube. Following a suggestion here and elsewhere, I used new untrimmed 7.5X55 brass from Prvi Partisan for the first firing. With the .314" boolits they required an extra firm bump with the heel of the hand to finish locking the action, and the case mouths tapered enough after firing that I can't push a .314" boolit in by hand. Not restrictive enough to run pressures way up with a cast boolit, though. I'd used a very mild load of 7383 that averaged in the high 1600s I'd say. Haven't averaged the Chrony readings yet. My caliper indicates the case mouth opening is about .312", and though it's hard to measure on a taper, the O.D. right at the mouth seems to be about .336". Below the taper the neck O.D. is .346". My chamber is tighter than some. Next I'll trim the necks back until the taper is gone, which looks like it might take me all the way back to 53.5 mm, and see what the I.D. is there. An unsized Fat Thirty may turn out to be a good fit in the case neck, and I may have to go back to regular .30s if I still want to try paper patching. I'll see when I get the cases trimmed to length. As for shooting, I was trying to hit 100 yard targets. The closest sight setting is 300 meters, calibrated for a 1968 FPS boolit. So I found I had to aim at a point way under the target board near the ground. Hard to shoot tight groups that way with no aiming point. The windage is off. There's a scribed line on the sight and base that's staggered, and I bet if I get it realigned it'll be right on. I'm going to have to go climb up the bank to the 300 yard targets, looks like.
I found that to get rid of the chamber pinch taper on the necks, I had to trim all the way back to 53.5 mm. I chamfered the necks inside and out with the Lee tool, followed with the Lyman VLD chamfer tool on the inside. The inside diameter of these unsized fired necks is precisely .321". Fat .30 boolits will drop into them, but it would take some thin paper to wrap a .316" boolit to .321". I'm looking at the moulds I have that cast in the .309-.312" diameter range, with patching in mind.
The Lyman 323471 is an excellent boolit to size down for these rifles. You can size the bands down and taper in front of them in a properly fit Lee push thru die. They fit and shoot well that way.Quote:
Originally Posted by Ricochet
Thanks for the tip!
So it seems that IMR4198 is not working out.
I used to use Bluedot.
I changed to see if I could get rid of the blowback issue.
.321 cast chambers fine and shoots well at 50yds. 100yds not so good.
What is 7383 powder????
I'm collet sizing the necks to .319. Boolet is gas checked.
Necks have been annealed...again.
Not sure wht I'm getting so much blowback.
Any ideas?????
IMR 7383 is a milsurp powder. Made for the short .50 caliber cartridge for the spotter rifle mounted on the old 106mm recoilless rifles. Much smaller and less powerful than the .50 BMG. That cartridge was supposed to match the trajectory of the 106. You'd aim at the target and fire a .50 to check. It had a tracer and exploded with a flash and puff of smoke. If it hit the target, the 106 was immediately fired. 7383 is an odd powder. A jug that holds 8 lbs of most powders holds 7 lbs of 7383. The grains are black through and through, unlike most powders that have a dark graphite surface coat and are translucent yellowish or greenish inside. It is almost flashless but makes lots of smoke and soot. In the original spotter cartridge 120 grains of 4831 was used. In later updates 110 grains of 7383 gave the same ballistics, which will give you an idea of its burning rate. Maximum average chamber pressure was 38,000 PSI. I have hypotheses as to how this powder is different from other IMR powders, aimed at minimizing flash and optimizing burning for that modest pressure, but I have no authoritative data on its composition and characteristics. My lot of 7383 seems in my limited testing to act something like 4350, but the bulk limits the amount the case will hold. In most medium size cartridges with standard weight bullets it won't quite reach the velocities that most powders will. You can't load enough in most cases to reach maximum pressures and velocities. I've tried compressing it hard and recommend strongly against it. Pressures do appear to rise very rapidly when it's compressed. I find it very useful in cast bullet loadings for old military rifles in the .30 caliber-8mm range. It is sooty, you'll have to scrub hard carbon out of the throat after shooting it a lot especially with jacketed bullets, and in most of my loads it doesn't reach a pressure level that will completely burn it so it leaves a lot of partially burned grains. My Chrony collects lots of those partially burned grains. It also makes a strong ammonia smell that I've never smelled from any other powder. It seems to come from the surface layer that burns off first, because in most loads the ammonia smell is all in the exhaust cloud that blows out the muzzle and what remains in the bore and cartridge case smells like regular IMR powder smoke. I've had fellow shooters exclaim "Couldn't you find any smellier powder?!" One of my hypotheses is that the ammonia smell is a clue to nitroguanidine being used to reduce the flash, as it commonly is in artillery powders. It's an eccentric, quirky powder, but it was very inexpensive when I bought it and it serves my purposes well. YMMV.
Hello,
some maybe useful info: for M1889 rifle I use RCBS 7,5x55 NECK die, for FMJ .308 bullets (aka GP90/23 cartridge) I use expander ball .306, and for cast G-C .321 bullets (GP90) I use expander ball .319, made from cal.8mm expander.
I found, then best accuracy and less speed standard deviation (8fps) is about the speed as original Swiss GP90 cartridges had, so about 1900fps for my 235grs bullet. For example, same cartridges with lower load and 1700fps have higher speed standard deviation (20fps). I think the same load as original had could offer the best expansion and sealing of the case in the chamber throat. It could be the solution for Mr. abunaitoo blowbacks - to use higher load.
I can recommend ACC5744 powder, and the load 28 grs.
Bye Ales
Thanks, Ales. I've read lots of your posts while searching the Web for info pertinent to loading the 1889.
I have my first batch of "real" 7.5X53.5 loaded. I had to go all the way down to that length to eliminate all case neck pinching in my chamber. The I.D. of the fired case necks after trimming off the pinch is .321", best I can measure with my calipers, and .323" sized 8mm boolits can't be pushed in by hand. They accept .316" boolits patched up to .323" easily in the press and hold them snugly. Even though I chamfered the cases, I had to flare them a little to start the boolits. Smartly shoving the rifle's operating handle forward would chamber them and remove the flare, but I held them upside down in the top of an 8mm Mauser Lee Factory Crimp Die to remove the flare after trying that. Now they chamber smoothly. As this light load of 7383 gave a bit more erratic velocities than I like with the initial firing of the .314" gas checked lubed boolits, I used polyester fiberfill in these. I spent too much time getting it all figured out and done to try shooting them this weekend. That will likely have to wait till the next one.
OK, I have some data now. With my original load of unsized, untrimmed Prvi cases (that pinched down in the end of the chamber to a .312" opening after firing), NuJudge 200 grain boolits (similar to #314299 but fatter), sized to .314" and checked, CCI 200 primers and 2.8cc (about 33 grains) of my IMR 7383 powder, no filler, I got an average of 1670 FPS. I don't have QuickLoad, but the online Powley Computer's rough estimate for that is 18200 CUP. With the necks expanded and unsized, unchecked NuJudge boolits paper patched with a triple wrap of office exam table paper to .321" and lubed (as were the naked ones) with my homemade "Brown Thunder" waxy lube, CCI 34 primers, the same 2.8cc or ~33 grains of IMR 7383 and a snug tuft (around 1 1/2 grains) of polyester fiberfill, the average velocity was right on 1800 FPS, which the Powley Computer estimates at 21,200 CUP or 22000 PSI. I should be able to easily step it up to match the velocity of the original GP90 or even the GP90/23 while staying well below the pressure rating of the 1889. These numbers may not match your rifle if you have an 1889, its chamber and bore dimensions may differ from mine, and if you have IMR 7383 from a different lot, it may burn at a different rate. Start low and use a chronograph to check while observing pressure signs. Mine appears to be quite low. I can't say too much about accuracy. I'm just learning the hold-under to get the boolits on paper at 100 yards with the 300 meter sight setting, and I'm aiming at a pointless area at the bottom edge of the target frame under the target, also estimating windage compensation. Speaking of which, we had 20-25 MPH winds at the range today. So, while I got a few lucky tight clusters like a 5 shot 2 3/4" X 1 3/4", my groups weren't always printing in the same area and some were pretty strung out. I feel the rifle's capable of shooting a lot better than I can now. Time to patch some more boolits and load up the next step! :D
By the way, my 1889 has an extremely tight bore - .2965 minor, .3035 major, and .300 across the slug. Am rather worried about finning, but when I get the chance I'll chuck some 314299's down it to see what happens.
Why 314299? Well, it's what I have on hand, and is big enough to meet the cavern of a throat that these things have without making a transatlantic flight.
I don't have any recovered boolits. I expect they look funny, with the whole length of the nose and shank engraved with the rifling through the patch and the shoulder obliterated, with the grooves very much narrowed down. The gas check shank should help prevent finning back to the base of the boolit.
Where is the NOE Group Buy for the boolit mentioned on the first page>
I looked in Active Group Buys and couldn't find it.
Thanks!
I was lucky in that my 89 has a throat just a tad larger than my 1911's & K31. I need to sort out some brass just for it but haven't worked with it that much yet.
I did do some initial load testing and came up with this. BTW, I order almost all my Swiss's from Simpsons.
A few gunshow ago, I picked up a factory box of those rounds. I made a post on them.
They have rifles that shoot almost the same round. It's called a 50cal BAT.
If it's like IMR4350, it must be a slow powder.
I try to use med to fast for my cast loads.
Quote:
Originally Posted by Ricochet
Just happen to have some AA5744. I tried it in a few different calibers and couldn't get a good load out of it.
look to be a little faster than IMR4198.
Closest boolet I have would be 321/250gr.
I'll start with 24.0 and work up.
Quote:
Originally Posted by Wdog01
Hello abunaitoo,
yes, try it and please report your results here. Load 24 grs of ACC5744 is good start, I call it my target load, and my maximum, military load, is that 28 grs. No other filling to the case! I use ACC5744 and this load 28 grs for more older (cca. 1870-1890) rifles, all with cast bullets, and for my earlier big surprising this load is universal and perfect in these old rifles and several different calibers from 8mm to .50. Yes, seems little faster like IMR4198, I think this ACC5744 is the fastest rifle powder from Accurate.
Bye Ales
And , as independent promoter of ACC5744 ... :-) ... I can place original producerīs powder description from some older Accurate manual:
XMP-5744
Our XMP-5744 has proven to be an extraordinary powder! XMP-5744 is a short cut, extruded, double
base rifle propellant. Its burn rate is between our No. 9 and 1680. XMP-5744 is not intended to set new
velocity records. What it will do, however, is allow you to shoot reduced loads, without fillers, in just about
any cartridge, especially the older, low pressure, rifle cartridges. IHMSA shooters take note, it is also useful
in large capacity handgun cartridges.
XMP-5744 has some very specific design criteria. First, it is double base with a high percentage of
Nitroglycerin. This gives the propellant a high energy content. It also promotes consistent ignition even
with low volume powder charges in the large capacity ‘‘old timers’’ such as the 50 Sharps. In fact, the 50
Sharps was used in some of the development work for this propellant. Nitroglycerin contributes to excellent
shelf life and reduces the effects of humidity and temperature.
Second, XMP-5744’s short length provides uniform metering so you can spend more time shooting
and less weighing charges.
Third, XMP-5744 has a relatively low bulk density. This contributes to its ease of ignition. In fact,
ease of ignition and consistent velocity, regardless of powder position in the case, are the two main criteria
we set in manufacturing new XMP-5744.
Bye Ales