12 October 2002, 09:48
bobcUnique in big cases
I've been reading a number of posts in which warnings are given about light loads in big cases. I never load anything that's not in a reputable manual.
I've been shooting 'plinker' loads in my 375 H&H straight from Lyman's reloading manual, loads of 12 to (I think) 18 grains of Unique behind a cast lead 250 gr. Just mild, cheap, fun shooting. I am extremely careful to not double charge a shell or have the Bullseye out when I load. Are these warnings 'urban legends' about rumored explosions? Would Lyman be publishing these loads specific to this powder in a big case (as well as several other pistol/shotgun powders) if they were so dangerous? Everything I read in multiple sources says these are safe loads without fillers (I see more these days discussing which fillers are likely to blow you up).
By the way, I'm also loading up some loads with XMP-5744 which is designed to be used in big ole cases and light loads, so I'm not committed to Unique. It's just handy. Bob
12 October 2002, 10:03
Paul HBob,
I'm using 15 gr unique, CCI 250 over a 200 gr cast bullet in my 350 Rigby, which is essentially the 375 case necked down, and shortened a tad to 2.76" These loads clock 1400 fps, and are very accurate. I do not use a filler. BTW, the case is ~1/3 full with this charge.
I agree in being prudent with reduced loads, but from what I've read, the faster pistol powders are safe when loaded light. I have heard that the ball powders, specifically H 110 / W 296 are dangerous when loaded under max levels.
I presume that Lyman has tested the loads they list in their cast bullet manual. The data has proven good whenever I've used it.
12 October 2002, 10:06
Bill MI do NOT think these are urban legends, but have not personally seen/had a rifle explode due to "squib" charges. Not using less than the minimum charge listed "starting" load is very good practice. I know that the Winchester loading guide, for example, warns against using anything other than the EXACT charge weight/components for their 338 win mag loads, not to even use a different primer than specified.
One exception is H4895. You can use a reduced charge of 60% of max load listed for a particular cartridge, but not to go below 50% of max listed. This should yield a muzzle velocity of 1600-2100 FPS (depending on cartridge/bullet), and is only recommended for cartridges/bullets that list H4895 as a suitable propellent in their manual.
XMP-5744 is specifically designed for reduced loads.
Unique is often used in low velocity cast/jacketed bullet loads. There is a formula to calculate the charge weight based on bullet weight, but I do not have it handy.
Hodgdon also specifically warns that H110 loads should not be reduced nore than three percent under max load listed.
There has to be a reason that they warn you to avoid certain conditions, and they are the experts.
Be safe, Bill
12 October 2002, 13:33
<Don Martin29>I have seen a rifle explode from a reduced charge. It was because the previous load must have had no powder but for some reason a bullet stuck in the barrel and the next shot blew a 4" piece in front of me!
Lots of pistol loads in particular have small charges that don't fill the case. The .38 Special comes to mind.
So the small charge is another variable that must be managed.
I use a filler with light loads. I suppose the rifle can be tipped or held the same way each time but..........
When I load I stand up and look down into the cartridges in the loading block before proceeding with bullet seating.
13 October 2002, 05:26
Intel6I load 28 grs. of Unique in my .460 Weatherby with lead gas checked bullets and don't have any problems. As others have mentioned, it usually is associated with lighter charges of slower burning powder.
13 October 2002, 05:36
<eldeguello>You will have no problems with reduced loads using Unique, or other fast-burning powder, as long as you make sure to avoid a double charge, AND make sure you get powder in all the cases. What HAS caused problems is reduced charges of slow-burning powders in large capacity, small-bore cartridges, such as using 25 grains of H4831 in a .240 Gibbs or .257 Weatherby case, etc. And, in laboratory tests, such "detonation problems" have proven very difficult, if not impossible, to duplicate, leading some people to conclude such things never happen!!
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