More lube questions

[Marlin Junky]

I had a range day today and it was probably 10 to 15 degrees warmer today than it was the last time I was out. Stats with RCBS 30-180FN at 194+ grains and 16.0 grains of WC-820 were good but I got a lot of flyers. Can I blame this on my lube? Can someone please explain "lube purging" in detail?

Two 15 round strings w/ 30-180FN and 16.0 grains of WC-820 produced the following:

Using Fed 210:
ave: 1700
high: 1710
low: 1672
range: 38
std. dev: 9.1
% dev: .53%

If it wasn't for the 1672 fps round which was number 3 in the string after 4 fouling shots, the stats would have been:
ave: 1702
high: 1710
low: 1692
range: 18
std. dev: 5.2
% dev: .30% (it doesn't get much better than this even for 10 round strings)

with Fed 210M:
ave: 1700
high: 1715
low: 1675
range: 40
std. dev: 10.6
% dev: .62%
This 15 round string had two rounds clocking in the 1670's and none in the 1680's

BTW, I have been getting better stats using Fed 210 primers opposed to their 210M (match primers) each and every time I test them side by side with reduced capacity charges. The 215's on the other hand seem to produce better stats (In my experience with capacity charges of H380/H414/W760.

MJ

[felix]

Sound more like ignition problems rather than lube purging. A lube purge generally makes the following shot shoot LOWER, and usually just barely out of the INITIAL group. It will take an accurate gun/shooter to really decipher if it was lube purging or something else. The moral of the story here, is to assume lube purging as the last problem to solve, and ignition problems the first to solve. ... felix

PS. If a series of shots are climbing, and then suddenly a lower one, and then the progression starts all over AGAIN, then that is almost a certainity of sign of lube purging.

[Bucks Owin]

PS. If a series of shots are climbing, and then suddenly a lower one, and then the progression starts all over AGAIN, then that is almost a certainity of sign of lube purging.


Hmmm...

Explain lube purging please. I've fired groups that exhibit that tendency. Each shot cuts the previous but they climb about 1 caliber each shot for 4 or 5 shots...

Dennis

[Marlin Junky]

Felix,

I don't see how you can say I'm having ignition problems with stat's like these... especially the 15 round string using Fed 210's. Hang on for a few minutes and I'll post some targets.

MJ

[Marlin Junky]

OK... Here are the 15 rounds from the top string above. Are you saying Felix that lube purge can't be determined at 75 yards with iron sights? Is it more likely that these groups are the result of shooter error?

BTW, The bottom right group was the first one shot. Then I turned the elevation knob about a half turn.

[Marlin Junky]

P.S. The dotted circle is 1.5" in diameter

[44man]

I never put much faith in the SD or ES. Some of my best loads with the smallest also shot the worst groups. My worst flyers always seem to be blamed on the powder used for the caliber.
In my 45-70 BFR I use 4759 and almost never have a flyer. I have been working with 5744 lately and I am getting the same kind of flyers you are getting. The velocity is the same with both loads, same lube, primer, etc.
I find unburned powder in some cases and it is not reflected on the SD. Maybe a hotter primer will help me and will be tested next.
It has been my experience that when I get flyers like that, I switch powders until they go away. One way to determine if a powder is going to cause a problem is to find the best load, then load down and up a little around that load. If groups open a great deal or the group starts to walk away from the point of impact the good load hits, it is time for a change. This powder will get screwy in weather changes also.
One good illustration is 4227 in the .44 mag. If you shoot slow and keep the gun cool, the groups and SD, ES will be great. Shoot the gun hot or get a hot sun on it and velocity will start to climb like crazy, primers will flatten and the point of impact will start to drop until bullets hit the ground at 100 meters when shooting 200 meters. This happens with jacketed bullets so I can't blame lube. A switch to 296 cured the problem instantly. I would not even consider a different powder in my .44, .45, or .475. It works, it stays! Never get stuck on one powder until you have one that does what you want.
By the way, 4227 did NOT act up in the .357 max and was the best powder for it. Go figure!

[Marlin Junky]

44Man,

Group size doesn't necessarily correlate 1 to 1 with SD but with a proven boolit/gun combination, it should. I too have gotten great chronograph stats and lousy groups but that is usually attributed to poor bullet fit or improper alloy hardness with respect to chamber pressure.

Could barrel harmonics be involved at 1700 fps? If that's the case, I'll reduce the charge to 15.5 grains and check it out. I don't think it's the boolit because it has performed well all the way to 2100 fps with capacity charges of H414/W760.

The only other thing I've played with SLIGHTLY since the last range trip is gas check size. I was running the checked boolits through a Lee .311" die with annealed checks in place and the die wasn't touching the boolits but sizing the checks right at .311" (after polishing the die with emery cloth). Then I changed to .3100" - .3105" (with a polished Lyman .310" die) because the check, being fatter than the boolit, was opening up the neck and creating sloppy neck tension after it seated past the neck/shoulder junction. Maybe I should go back to my .311" die and try other ways to get a little more neck tension???

MJ

[StarMetal]

Marlin Junky,

I hate that aboiut gaschecks where they are bigger then the bullet. Annealing them, like you've done, helps some where the case of springback is the probably, but if your bullet is alot smaller then the die ( say like .310 and die is .311) then you must size in a die that is the exact size of the bullet if you want the bullet to fit the neck snuggly with total bullet contact in the neck.

I believe barrel harmonics are there with just about any velocity. You might try one of those harmonic dampners see if it improves. You could probably even fashion a homemade one.

Joe

[Marlin Junky]

Thanks for the input Joe, but I'll just adjust the WC-820 charge down .5 grains and see what happens. I also ran 18.0 grains of N120 (all else same) yesterday with noticeably less pressure (about .0005" to .001" less case expansion on newly resized brass) and the the results on the chrono and paper were both pretty bad. I figure if I can see the difference in pressure with the "mike" and on the primers too, it must be significant in terms of CUP. Conclusion, I really like WC-820 for reduced capacity loads in the 30-30 and am inclined to believe if I find the right charge, this combination should produce good result on the chickens, pigs and turkeys. I'm saving my H380-H414 for the rams. BTW, has anyone found a use for boolit shootin' with N-120?? It seems to need more pressure than I want to deal with in reduced capacity loads.

Regarding boolit diameter... I need fat .30s for these darn ol' Marlins, Joe, 'cause they "mike" .310" in the grooves. Their barrels are very consistent and of high quality from the chamber to the muzzle but these old Ballard rifled barrels are deeply grooved... almost .005" deep, actually. HEY! could that be why I'm having a hard time getting PB's too shoot well through them; i.e., too much base distortion! Wait a second, did I just have another EUREKA moment, or just a brain fart??

MJ