270 Winchester w/ 150 RCBS GC Boolit

[REDBARON]

Has anybody used the above mentioned mold? I loaded three different loadings using Trail Boss(19.5grs), 5744(22 grs) , and Reloader 7 (24 grs). Absolutely the worst groups this rifle,or I have shot. Trail Boss was by far the worst.. patterns not groups. For the record, the rifle I shot these in has been one of the more accurate that I load for. Also the alloy I use has worked perfectly in every caliber I have cast for. If anyone could send any info-loads, about this specific mold , I would appreciate it.

[ktw]

Try a slower powder. Make sure the bullet fits your throat. Make sure the nose is a good bore-riding fit. You might want to try cleaning it well for copper fouling before shooting cast for groups.

The following gave me something in the range of 1.5 to 2 MOA across 5 shots with that bullet and I suspect an even slower powder might do better yet (e.g. H414)

H4198, 22.0-23.0gr, 1840-1910 fps, oven heat treated and weight sorted RCBS 27-150-SP sized at .278 and lubed with Bullshop Speed Green

IMR3031, 32.0-32.5gr, 2180-2212 fps, oven heat treated and weight sorted RCBS 27-150-SP sized at .278 and lubed with Bullshop Speed Green

-ktw

[GabbyM]

Your Rx7 load should have worked.
One thing with softer alloys and long thin bullets is you can bend them during seating.
I oven heat treat my 270 bullets and use a Lyman M die to help get them seated nice.
What's your bullet nose mic at? My thought is either bullet fit to bore or to soft an alloy.

[jameslovesjammie]

Just a quick question. I know you probably did, but did you make sure you had all the copper fowling out of the bore before shooting cast? I will admit I have forgotten this before and had some HORRIBLE groups.

[REDBARON]

Thanks for all the great info. Yes, I did clean the copper fouling out before heading to the range. Used the Lee lead bullet chamfering die, bullet seating went smooth with no shaving, or any sign of problems. In short used the same technique I use with the other calibers I cast + reload. Actually I have had good luck with my cast boolits thus far....99.9 percent of what I shoot is cast, rifle or pistol. About the oven heat treating...could anyone elaborate.. temp, length of time, do the bullets have to stand up vertical, or can they lay flat in the pan,etc? Thanks again for all the advice.

[ktw]

Oven heat treating:

1) I size and check the bullets in a Lee push through sizer.
2) I set them up verticle on an aluminum camp plate. I cut some two inch tall rings out of a tin can to help keep everything standing up on the plate while it gets moved around.
3) put the plate of bullets in the oven at 450 degrees for 1 hour.
4) drop the plate of bullets into a bucket of cold water. Remove from water and let dry.
5) lube the bullets in a lyman/RCBS size die, the same size or slightly larger than the Lee die used in 1. Don't want to size in this step, just lube.

I neck size with a Lyman 310 tool expander die; same thing as a modern Lyman M die. I think this gives better results than the Lee universal neck expander.

-ktw

[GabbyM]

Here's a link to heat treat process.
http://www.lasc.us/HeatTreat.htm

Noticed he has updated the time and temp charts.
I just lay mine on a cookie sheet single layer. as far as I know I’ve had no issues with bending bullets. Sure standing them up would be better but would be touchy getting 270 bullets stood up. I just use 430* in my gas oven. I did melt the tin out of a batch of 22 bullets with a higher setting. Ovens vary but I do have a thermometer in the oven. 430 seams hard enough and the boolits don’t get overly soft.


Lyman 4th has the RCBS 270-150-SP listed. Rx 7 starts at 19.0 for 1630 fps 20,100 cup top load is 28.0 for 2132 at 30,900 cup.

Your 24 grain loads looks like it would be around 1,900 fps but I suppose it could be a little faster. My RCBS bullet drops a nose on the fat side of .270”. It’s snug in the muzzle end but drops right in at the breach. Barrel has a couple thousand rounds down the pipe. I’ve been burning through some H4198 in my 270 then have ten pounds of Rx7 for it and the 243 and 223. If you were looking for velocities much over 2,000 fps I could see a slower powder but the Rx7 should be good for 1950 fps. You just do have enough pressure for the case to gas seal in the chamber.

I’ve never tried a bullet softer than AC straight 2/6 alloy BHN #15 and most are heat treated 2/6. They ring when I pour them in a pile. I’ve used HT 50/50 with the RCBS bullet but 2/6 gives a fatter nose so I use that. Mostly the bullets are prettier.

[GabbyM]

Shot my 270 today. Rare occasion.

at fifty yards 6 shot group vertical spread was .215". Horizontal was about 3/4". 16 knot quartering wind. Load was 26.5gr H4198 over LR primer and under RCBS 150 grain bullet.
Weatherby Vanguard noodle barrel with Weaver K-4 scope off bench rest. Rifle is pre Wal-Mart walnut stock which I've had since the early seventies. Light was dark with clouds as I could barely make out the target center. Lube is either the excellent LARS Carnauba Red or my rendition of Felix Lube. My records aren’t good enough to know the difference. Load is set up with brass and bullet OL tight. Bolt closed harder than I like. Brass is once fired from unknown rifle and full length resized as tight as my die will go.

Rx7 and H4198 are very close in burn rates. Rx7 show as slower on the charts.
Always had good results with IMR 4198 in 5.56 NATO so bought a can of H4198 since it was advertised as a shorter grain. However it still measures in a problematic way. It will bridge in a 22 caliber neck. I own a powder trickle but refuse to use the things. Rx7 meters well.

Best group this rifle ever turned in was about 28 years ago with a 7/8” at 100 yard with 150 grain Hornady SP. This boolit load works as well at short range as any J bullet load that’s ever been down the bore. And I’ve shot a bunch of them down this tube.