Adventures with NOE 246-105-FN

[Rick]

A few things wrong in your explanation Ian. First, not half of my "handguns" are large caliber slow twist. Many are bottle neck rifle cartridges in XP's, Contenders and others up to and including 308 Winchester or 30 caliber revolver, others including 6.5 TCU, 7 TCU, 30 TCU, 6.5 BR, 7 BR, 30 BR & more (I never did run cast in the 6 BR). Next I doubt you'll find many people that have done as much heat treating and heat treating experimenting as I have, have you read the articles I published on this? I'm also sure you've seen my posts on the result of crimp/neck tension testing, if not I could re-post it here. Yes, I shot handgun silhouette for 30 plus years using most of those cartridges.

I said in posts #14 & #16 in this thread that I haven't experimented with very low velocity using very fast powder or experimented with high velocity in rifles and that I wasn't talking to or about either. All that said probably 95%+ of cast bullet shooting/shooters is done within the parameters I mentioned, 800 fps up through 2,000 fps in numerous calibers, velocities, pressures, bullet weight/styles, action types etc. Not yet have I experienced the problems using tin that you mention.

Not likely that I will delve into the rifle high velocity testing, when that first came up on the CB forum it peaked my interest and I intended to, sounded interesting but it so rapidly turned into pure BS it squeezed all desire and interest right out of me and I dropped all thought of it.

 

[Ian]

I never thought about the difference between alloying up and using heat treat.

That's one of the golden keys to HV accuracy. Different alloys tolerate land abrasion differently, some handle high speed better than others.

Here's how I break it down in my mind, maybe it will help: First, figure out what sort of alloy percentages will give the friction characteristics required for your land pressure and linear speed, and then figure out how much toughness it needs to handle the powder pressure you're giving it from behind from primer spark all the way through to muzzle exit.

I wish there was a calculator for this, but simply not enough data and too many variables to make it exact. 50/50 WW and actual pure lead can be heat treated to different levels and really give some good performance in a lot of rifles. I'd say usually about 80% of full-on max jacketed velocity if you have your ducks in a row.

 

[KHornet]

In general I agree with Rick, as the majority of my testing for all cals runs between the 800-2000 fps he lists. I may go up to 2300-2400 for 22 cal pdog loads, but am not interested really in going much over that. I seldom cast for rifle below 18 BH, with the exception of range scrap (usually 10-11 bh ) in my experience for handgun bullets. Agree with Ian that I wish there was an appropriate calculator for this.

 

[Stonecrusher]

Made it back to the range today. 55-60 degrees. Wind pretty calm but gusts to 10-12mph. I double checked the bores of both rifles with a patch dampened with ATF and then dried them. No leading showed from last time.

Loads were the same as last time with the exception of heat treating the bullets at 425 deg for 1 hr then cold water quench:

NOE 246-105-FN sized to .2465" lubed with Ben's Red and a topcoat of BLL.
Alloy was COWW with 2% tin HT to approx 23 BHN
RP cases 15.0 gr RL-7 and WLR primer
OAL was 2.760" for A-Bolt and 2.820" for the 700

This is the 700. On the last target, bottom left shot was all me. I had a spastic moment. The other fliers I can't discount. Targets are in the order they were shot.




The A-Bolt:





I heat treated some more bullets yesterday and it will be a week or two before I can try them out. Some of the holes in the targets using 15.0 gr RL-7 look slightly oblong. I think the load is right on the ragged edge of stability.

I will work up to 20.0gr of RL-7 next time and see if they like more speed like JWfilip's rifle. I hope they will take it. I did notice that more of a lube star was forming with the heat treated bullets. I won't touch the bore before I shoot again. When I can get some H-4895 I will try that also.

I need to hurry, my wife wants to shoot. She doesn't have the patience for shooting groups and testing loads!

P.S.
I had an error in post #8 about my weight sorting. When I sorted I came out with two pretty destinct groups with just a few outside the range. So I seperated in two groups one of 103.4-103.6 grs and one of 103.7-103.9 grns. So, bullets were weight sorted into groups with +/-.1 gr.

 

[JWFilips]

When You heat treated the bullets How many day after were you shooting them? The reason that I ask is it still seems to take about two weeks age to stabilize them when you are dealing with the little bores.
What is the twist rate of each rifle If you don't mind.
Those center to centers look pretty darn good at 100 yards for just starting out. I would love to see 10 shot groups it would tell you & us more.
Stonecrusher: BTW My .20.1 gr load of RX7 was run through Quick Loads and it gave a listing of 1991 fps so Than is not really fast for a .243

I also have a "KickA" load of 10.1 gr Red Dot with this bullet If I had continued to play with it It probably would surpass the 2400 & RX7 loading groups.
I decide however to switch that testing over to American Select since I have more of it & it is a slightly slower burn.

I think things are getting better Keep up the good work
Jim

 

[Rick]

When You heat treated the bullets How many day after were you shooting them? The reason that I ask is it still seems to take about two weeks age to stabilize them when you are dealing with the little bores.

The size of the bore isn't what requires more or less time for heat treated bullets to age harden. How quickly or how slowly they achieve final strength (BHN) is determined by the Sb percentage. The higher the Sb the quicker they will achieve final strength. Like wise the less Sb the longer the age/time curve. Another way to say that is a 2% Sb alloy will take longer, possibly 2+ weeks, a 5% Sb alloy probably 2-3 days. After that they will continue to age harden very slowly for some time but not all that much. They will also age soften but very slowly. I tested heat treated 30 BHN bullets after 10 years and they were still 25 bHN.

 

[JWFilips]

Rick, Yes I fully understand ...but what I think I was getting at was the smaller bores are more sensitive to the age of the hardness in general : Lets say you run a test 4 days after heat treating Then you run a second test with that same batch 8 days after heat treating etc. The sub .30 cals seem to be more finicky with changes like that then is let's say an 8mm rifle ( At least this has been my experience). The large calibers seem more forgiving

 

[Stonecrusher]

When You heat treated the bullets How many day after were you shooting them? What is the twist rate of each rifle If you don't mind.
Those center to centers look pretty darn good at 100 yards for just starting out. I would love to see 10 shot groups it would tell you & us more.
Jim

The bullets fired today were heat treated sixteen days ago. One week after treating they were the same hardness as at two weeks, according to my redneck brinell testing.
As for twist, the A-Bolt is 1-10" and the 700 is 1-9" or 1-9 1/8". Whatever Remington was using in 1976.

If I can get rid of the fliers I will be pretty happy with the groups, both rifles being sporters. When these bullets age I am going to work back up the powder charge. Would like to get back to 2,000 fps but it won't hurt my feelings too bad if I can't. This bullet at 1,600 fps should carry well enough to 200 yds and that is as far as our range goes.

When I get closer to what I think I will be using there will be 10 shot groups. The point is to get something consistent so we can have fun putting some lead downrange.

 

[JWFilips]

The reason I mention 10 shot groups is Flyers ...yes can be in the loading but more often then not, I feel it is inn the trigger finger!
My 8 MMM GEW98 can rip ragged holes in the water months but I don't like shooting it now because it is cold & dark .... and "I am" no where as accurate with my shots as I ate in the brighter warmer days of spring & summer.
The more bullets you throw at a target the more the percentage tells the tale..Cold Dark, Hot Cold...Neck tension, powder weight etc...It all sort of balances out.
I have fired 40 rounds at times at a 1/2" bull ( sights adjusted to hit above or below the sighting area) a number of times and that told me more then 50 - 5 shot groups

I'm surprised at the A-Bolt: The design of that 105 grain NOE was to be used only in a 1-9 ...so I think you are doing very well.
Sorry I questioned you on the heat treat cure time..... ( Old Cast Boolits site Type question! Forgot, only the best are here!)

If you are ever interested in over all ( many. 243 Bullet ) data PM me !
Jim

 

[Stonecrusher]

Jim, I think some of the fliers may go away soon. I am working out of brass that had been fired quite a few times with jacketed and I annealed the necks, timing it by spinning in a drill. My consistency is probably far from perfect so the neck tension should be more uniform the next time through the brass.

I am still kind of new to this rifle casting, it was only a few years ago that I bought my second mold for rifle casting. First one was about 1990. You know how it is, the more you learn the more you realize you don't know squat.

I am kind of surprised at the A-Bolt myself. It has always had a tendency to shoot about 1/4" smaller than my 700 with anything it gets fed. Those are the targets that I noticed some obrounding of the holes. That is another reason I would like to get the velocity back up.
Nice to be called the best; but I don't believe it. I tell the people at work "I'm not the best there is but I am the best you got". Thanks for the PM offer for data. I may take you up on it. There are a couple other molds I am interested in.

 

[Stonecrusher]

Finally got back to the range last weekend. Had some success. Using the COWW's HT to 25.3BHN I worked the load up to 20.5gr RL-7. Here are some representative groups. As before the lube is Ben's Red and BLL, sized to .2465", WLR primer and OAL of 2.760" for A-Bolt and 2.820" for the 700.

A-Bolt 17.0 gr RL-7 : 1834fps. Holes are still showing obround holes from 1-10 twist. This was my best group of the day!



Rem 700 17.0gr RL-7 1828 fps



A-Bolt 19.0 gr RL-7 : 1988 fps. By this point the holes are round and apparently the 1-10 twist is stabilizing the bullet.



Rem 700 19.0gr RL-7 1983 fps. Groups are starting to come apart. I don't know what the bottom hole is, the shot was good and I know I didn't throw a shot 4" from a solid rest. Hole looks kind of keyholey.



A-Bolt 20.5 gr RL-7 : 2109 fps. 10 round group for your viewing pleasure.





Rem 700 20.5gr RL-7 2010 fps. 10 round group gone bad.
.


Even with the 20.5gr load there was zero leading after all the shooting. The heat treat made a really big difference. There was even a very, very light lube star on the muzzles. I will continue to work with this and would really like to try some H-4895 and see what happens. Like you gentlemen I think I could get the velocity up a little more in both rifles with a slower powder.
Now that I think about it, my success up to 2,900fps in the .222 was probably due to the fact I was using a much slower powder, IMR-4064, and I had no trouble with the same alloy being aircooled.

The really strange thing to me is the velocity readings. Both rifles agreed on velocity within 10fps for each powder load up to the 20.5gr. Then all of a sudden the 700 is 100fps slower than the A-Bolt. Powder was dropped from the measure at the same time for each load and maximum extreme spread was 33fps. Chrono has been working fine with no bad readings and seems to be consistent. Groups fired within fifteen minutes of each other and it was nice and sunny so the light was not variable. Only on the last powder charge was there a difference that big. Perhaps a "Law of Diminishing Returns" thing.

Any comments appreciated. The fliers are bugging me! As Jim said, some could be the nut behind the trigger. I was having a little trouble with my consistency at the range. It was really crowded and I found it hard to get into the groove and stay there.

 

[KHornet]

Have a 2245498, 99 gr. that I never could get to shoot. Maybe I will try some of your Rx7 loads one of these days.

 

[Stonecrusher]

KHornet, the loads aren't mine. I was working off what JWfilips started. I also have as reference an article by Jim Carmichael in "The Art of Bullet Casting" about shooting cast in the sixes. I bought the Rl-7 just for this project, never having used it before. So far I like it better than IMR-4198. It doesn't seem to be near as position sensitive and I don't need a filler, at least in .243. It also meters very well.

Carmichael swore in the article that the 245498 was the most accurate bullet in his rifle, once he started deep seating. His article shows the bullet with all lube grooves in the case neck. In fact the front band is even with the case mouth. He was casting from lino and got his best acccuracy at 15.0 gr RL-7 and 1600 fps.

I will try varying the seat depth soon and see if it makes a difference.

 

[KHornet]

Have probably had that mold for over 25 years or more. Probably never ran to over 1600 or so. Guess I will drag it out, brush the cobwebs off it, and cast a hundred or so. It is a single banger.

 

[Stonecrusher]

Good luck! Let us know how it works.