RCBS 7mm-168 SIL help needed.

[HABCAN]

Does anyone have a FULL-POWER load for this boolit in a 7x57? This mold must be an oddball: all my other molds cast my WDWW alloy close to expected weight, but THIS one consistently casts at 184 grs. lubed and GC'd!!

Rifle #1 is a milsurp Brazilian '98 29" with a good bore I bubbaed into a nice long-range piece that shoots Hornady AMax to 1,000m with success. It has a very long throat, and is twisted at 8-1/2" per turn. It will NOT stabilize this RCBS boolit with any load between 1500 and 2500 fps. at any seating depth and I am not interested in a 'plinker' load. The LEE 130 gr. works just fine even when not seated 'out'.

Rifle #2 is a pre-'64 Mod. 70 26" with aftermarket Douglas bbl. sporter, my most accurate rifle, giving 100 yd. 5/8" groups with any benched j-words without too much effort. It has a more-normal (shorter) throat, and is twisted ~11-1/2" per turn. To load this boolit it needs to be stuck 'way down in the case in order to chamber, but I use the LEE 130 gr. in it with no problem. I may never shoot this boolit in this rifle: I only mention it in passing because I DID try it despite its twist rate.

Contender bbls. in 7TC/U 10" and 7-30W 14" WILL shoot this RCBS boolit accurately with a little TLC at low velocities.

What I need is a FULL POWER 7x57 load that will stabilize this keyholin' RCBS SOB for extreme ranges. Does anyone have specific experience/knowledge of THIS boolit in THIS caliber? It seems to have some esoteric problem with MY rifle.

I get no leading with any load tried up to max. It does not seem to matter whether it is sized .284 or .285, nor what method is used to lube it. I even paper-patched a few! So far it just plain WON't stabilize in any of my barrels at anything over about 1200 fps.

[Buckshot]

http://www.fototime.com/51033A5247B82E1/standard.jpg

From my M98/08 Brazilian at 50 yards. The slig is the RCBS 7mm-168. With this alloy, lube and GC it weighed 172grs. There was nothing special done with this loading as it was just a kind of a seat of the pants test so I wasn't going to expend a bunch of time on 'Match' type stuff. The cases were many times fired in this rifle, neck sized. WW primers and the boolit's were visually inspected. Lubed with Javalina (NRA 50/50) and seated to engrave.

The powders shown are surplus. WC860 was a 50 cal powder and WC872 was a 20mm cannon powder, but as can be seen by the velocities they are close. I believe that 3100 is supposed to be similar. In both instances the load was a 'casefull', as in NO airspace :-) The rifle was as issued, sights trigger etc. Fired off the bench.

...............Buckshot

[HABCAN]

Thank you so much Buckshot! I have tried all my powders, the slowest being WW760. Looks like I need a slower one. Like you I'm not looking for anything fancy, just a practical solution.

[Bret4207]

Have you tried sizing them larger than .285? Maybe try some unsized and hand lubed? It had helped in a few of my rifles, but then I never tried doing what you are.

[HABCAN]

Yes Bret, I did. Made little difference. I think I'll just have to find some slower powder despite trying to avoid 'log' types, LOL. Seems I remember giving my daughter supplies of WW WMR for her .257..........................that might be next.

[Buckshot]

................HABCAN, I sure wish I could get a pound of this stuff to ya. I have a 'bit' :-) At one time it could be bought for $3.40/lb and that included shipping and haz-mat.

...............Buckshot

[HABCAN]

Yeah, me Bucko, and diner coffee was a nickel, smokes were twenty-five cents, a loaf of bread was a silver dime and butter was thirty-seven cents a pound. My first real job paid fifty cents an hour for a fifty-four hour five-and-a-half day week of real work. I think mebbe we're going to see those times come again. That's the 'why' behind my searches, if you follow my meaning. Thanks again for your kind wishes. Now, I'll just give my teddy bear a hug and go cast some more boolits.

[HABCAN]

Thanks to the Three B's, Beagle, Buckshot and Bret.
Today I got fullbore power with the above RCBS/760with no tipping.:-D

First, I 'Beagled' the RCBS as per his excellent post here: it now casts ~.288". There IS a small problem now to get the Hornady checks to seat on straight, so some care is needed there.

Then, I honed out my LEE .285 sizing die as per Buckshot's excellent post here:
it now sizes ~.288", virtually 'as cast' whilst seating GC's. Buckshot, rather than wreck some pants, I rolled on a sticky plastic shelf liner on newspaper on the kitchen table. Not messy.

After a light tumble in cut LLA, when dry I recoated the driving band area with more LLA by hand as Bret suggested to be sure my lube didn't run out before the long boolit exited that long barrel.

Having tried a few, I'm sure a IMR4831 load would be good too, but the idea was to be able to just substitute the RCBS for the AMax in the 'standard' load, and now it seems I have been able to.

Now I just have to wait for the weather to warm, and Mud Season to dry up so I can get in to the Ranges!! THANK YOU so much for your insightful helps!!