RCBS 7mm 145SIL

I

Intheshop

Banned
Had this mould for too long not to be at least,trying it. Early stages of weighing and mikeing.... but,they're running a touch bigger in both,the nose and body than my Lee mould.

Ran the body of this one down through a inhouse built .287 sizing die..... nose,as cast.

Fresh,factory cases.... pulled JB's,ran the cases up into an M die so that the sized bullet's GC allllllmost is completely down in the expanded case.

Then,without seating any deeper...RAMMED it up into an R700 factory chamber. Which seated and stuck it pretty hard. Knocked it out so ignore tip damage. As measured,the nose section is a touch fat. But you can clearly see the rifling engrave.... and further,can see on the bullet how far it got shoved in the case....

Which gives me at least,a starting point on OAL.

I like the mould's quality,more or less. The RCBS moulds that I have are a little trouble,and that isn't quite the word but...... the sprue plate hold down bolt "could" be better. And the plates,hangover thingy,the part that gets tapped to open is a little short. My RCBS handle's bolt absolutely sucks....needing constant attention.

But will say this.....

Halfarsed cleaned the virgin mould. Ran 3 heat cycles on the kitchen stove,then preheated and started casting. Within a dz casts,it was wanting to "come around"(breaking in)....... interestingly am trying to break in a Lee 309-150F and it's coughing/puking/bucking bad. It's just one of those things that makes it all interesting?

The 7mm alloy is clean range scrap with a bit of Rotometal,dang near lino thrown in. The RCBS,like it..... this particular Lee,not so much.
 
Last edited:
I

Intheshop

Banned
If you look at the upper most drive band you can see where the end of the case neck "witnessed" the jam its arse,seating depth.
 
I

Intheshop

Banned
I almost fell off the wagon the other day..... meaning,actually considered buying some JB's for a 38sp. Got real close to the edge....

Instead,ordered 3 factory RCBS top punches... shooooo,it was close. One of those is the "supposed" correct top punch for this 7-145 mould.

But look at the pic... see how the engraving is heavier twds the bullet tip? Normally that would be the other way round. Heavier twds base,fading to lite twds tip. On this example,the reason is because the bore ride nose got "bumped" during the sizing op. I mean come on,the bullets are basically free so ham fisted gooberness is kinda fun? On my Lee 7 mould,the nose is a cpl "tenths" (.0001's) smaller so bumping them up is Jim Dandy..... not so much with this mould.

If push comes to shove(ha)..... an inhouse "D" reamed top punch can be made. At least,figured...give the factory top punch a whirl first?
 
fiver

fiver

Well-Known Member
I have one and it's heavier 168gr. cousin.
in the 7x57 they are no barn burner but will shoot reliably small groups at a modest pace.
with real soft alloy they do pretty well on the bigger small game.
fox, and chucks are perfect fodder if you can get some expansion or get the bullet to break up.
anything harder on the alloy front and they will penetrate like no tomorrow [16"s of pine log with a dirt poof behind it wouldn't be out of the question] with ww alloy water dropped and pushed with a modest 24grs of 4895.
 
I

Intheshop

Banned
Well this mould's been sucking down too many Cokes or cheap beer cause,she's fat.

153g

And not real consistent but,it's only bout 1/2 way broke in.
 
fiver

fiver

Well-Known Member
iirc RCBS uses 10% tin for their bullet weights. [at least their rifle ones]

I know a lot of guy's don't like or can't use this bullet in their 7-08's because of the slightly over size nose diameter [280?] and a lot of them love it for the positive engraving.
at least RCBS has kept the diameters and design pretty darn consistent so you know pretty close what your getting from them.
 
Ian

Ian

Notorious member
You can make a bump die to put a 1/2⁰ taper on the front half of the nose where it's contacting the lands so hard. This will let you get more of the front driving band into the throat. If you make a D-reamer with the necessary shape you can also kiss a little taper on that front band so it can get up against or at least close to the ball seat and minimize the unsupported length both in the throat and inside the case neck. They may be too long to fit the magazine at that point but only you can tell.

20190731_102505.jpg
 
Spindrift

Spindrift

Well-Known Member
A nose sizer might be perfect with that bullet. The diminishing nose diameter towards the front driving band would provide a place for the displaced lead to go. Now, if only you knew a skilled machinist who could make a nose sizer of the right size ;)

Edit: Nearly crossposted with Ian, who provided a much more informative post :)
 
Rick

Rick

Moderator
Staff member
Used that bullet to shoot a perfect 80x80 score in an XP-100 7br at the NRA National Long Range Championships. About 1800-1850 fps, would need to look up (meaning see if I can find) the load data to be certain. Was either 748 or H-4895. Is a great bullet and my RCBS mold throws them out like it was raining.
 
I

Intheshop

Banned
Rick how much did yours weigh?

Generally, holding very tight weights on my CB's has been a source of pride.....and why shouldn't it be. Admittedly,this mould isn't broke completely in but..... it's "rangy" on the weights.
 
I

Intheshop

Banned
This is neat.... just got back from my high $$$ heart specialist friend.... so am wearing a heart monitor.Will post elsewhere on that,just saying....

Anyway,before heading out figured I'd cut one of these 153's loose. Did fine,didn't put my eye out,and actually hit kinda close to the 130's. This is neat though....apparently when I jerked the doodoo out of the early seating test,as pictured above. A cpl kernels of H4198 got left in the chamber. They got imprinted into the fired case....one,right on the shoulder/body area the other twds the base,on the body about 1mm down from the other. Plain as day.
 
I

Intheshop

Banned
18g H4198 behind a HARD jammed 153; had some poop behind it. Just sayin,looking at the above imprint... factory Remington primer starting to flatten.....case expansion just fwd of the base.

Not going to waste too much time with the 4198. Need to pursue 4895 and Varget.
 
Rick

Rick

Moderator
Staff member
Ok Shop, ya made me find the load data. Three powders tested, H-4895, W-748, SR 4759. 748 produced 100 fps more velocity than 4759 and shot well, all testing was in a 15" XP. The SR 4759 load @ 18.0 gr and 1855 fps shot so well it was my match load. 4895 had a wider extreme velocity spread, higher S.D. and though not really bad groups it was the lessor of these three powders. 748 (30 gr) and 4895 (28.0 and 28.5 gr) both averaged 1950 fps.

RCBS 145 Sil CCW with 2% Sn @ 154 gr including gas check.
As cast @ .285", Star sized .285"
As cast nose diameter .2785"
Heat treated to 18 BHN
LBT Blue lube
CCI 400 primer
18.0 Gr SR 4759
Loaded cartridge length was seated just off the lands
Three 10 shot chrono tests over a 3 month period averaged
E.S. 12
A.V. 1855
S.D. 6
 
I

Intheshop

Banned
153 was no GC...

Got 8lbs of 4759,well that and another # picked up on a beach vacation a few years ago at this obscenely cool gun store. Wifey and I had packed a lunch and the owners laid out the red carpet.... partied like newlyweds. Picking up the stupid old,cared for can of 4759 was,as they say icing.

18g.... curious'er,and curious'er.

We'll see over the next few days,what the 18g of 4198 does on cold bore conditions.
 
I

Intheshop

Banned
Stay "tuned" on the monitor thing..... not sure these folks know what they're getting into when claiming.... "oh,just go about your daily routine"
 
I

Intheshop

Banned
Heading out with Cocomut for a hike/hunt. Took some coaxing to get her "back" in the house so I could finish the 3 shot group. Once the rifles come out,she starts getting ramped.

Anyway.....18g H4198

Had 2 rds ready to go from yesterday. Grabbed one and it wouldn't chamber....sheet. Grabbed the other and RAMMED it home. Nuthin better than trying to tear a R700 bolt handle off. Uhhh,went into the same hole as the cold bore shot yesterday.

OK,this sucks cause.....I really got to get into the woods and it sorta doesn't count from a hunting rifle standpoint iffin it ain't at least a 3 shot group. So,grabbed the other round and RAMMED it harder this time. OK,as long as the lugs are well lubed,about the only thing that's gonna get F'd up is tearing the silver brazed bolt handle off.... it didn't.

3rd shot was rushed,and technically not a cold bore but. Went 1/2" out of the hole. 3 shot,1/2" group @100... "rushed". First load,first casting with a new mould.
 
You must log in or register to reply here.