Cutting Down A Mold

[Capn Jack]

I've been seeing a number of used 38-55 260gr.molds on the market at a reasonable price and Im wondering, why couldn't I just chuck one up in my lathe and trim about 60grs. off of the back end for my .35 Remington?

[mnovinger]

Chuck it up in the lathe or put it on a surface grinder..... I have an RCBS mold that gives me a 200gr gaschecked boolit. It shoots great in my .35 Rem.

[codgerville@zianet.com]

Better check the diameter, 38-55 should be .375 diameter, 35 Rem should be .358

[Capn Jack]

.02 Is that too large to size them down?

[deltaenterprizes]

.02 Is that too large to size them down?

You only want to size a bullet .002" not .020"

[Morgan Astorbilt]

I trim them down on my Bridgeport, using a 2" or 3" indexible end mill. This is the easiest way. You don't want the top too smooth, it's an air escape.
Morgan

[MT Gianni]

.02 Is that too large to size them down?

You will generally wipe out the lube grooves.

[Capn Jack]

The 250 gr. mold I have in mind, I would be taking off a large base and one lube groove.

[runfiverun]

38-55 molds are usually in the 380 range

[Capn Jack]

Thanks for all of the info. Now all I have to do is buy the mold.

[Lloyd Smale]

heres my experience with doing it. Ive done it to a few. Mostly because the bullet wasnt accurate and figured i wouldnt hurt. In every case it made a bad bullet worse. I think youd be better off buying a rcbs 200. that is a proven bullet that has shot well in about everything ive tried it in. It may cost a few pennys more but at least you wont end up with a paper weight.

[pdawg_shooter]

You only want to size a bullet .002" not .020"

I size .311 down to .301 and .459 down to .451 for paper patching all the time. I used a push through die and have an adverse affects on accuracy at all.

[Capn Jack]

Thanks, I'll look into that one.

[BABore]

I size .311 down to .301 and .459 down to .451 for paper patching all the time. I used a push through die and have an adverse affects on accuracy at all.

Padawg, dude, think about it. Your paper patching and not relying on the lube grooves to carry lube. This guy is. Lyman lube grooves aren't terribly deep to begin with. He's likely to end up with a lube groove depth of 7 to 10 thou when done. Highly likely it won't carry enough to shoot past plinker speed.

As far as sizing it down, that will be a disaster. Yes you can easily do it with a push through die. But, let's look at the original 38-55 boolit (guessing it's a 375248). It has a short front band and a bore ride nose. Likely around 0.366 or so. What's going to happen when that is sized down to around 0.360. It will create one hellava full diameter front band now. One that has to chamber in a 35 Remington. With a short neck. With a PB boolit setting well below the neck. Be way, way better off saving your mulah and buying a 358 mold to begin with.

[jimofaz]

Howdy folks.....If the blocks are all nice & square, and the mould cavity is dead-on perpindicular to the outside of the blocks, then milling, lathe turning, or grinding a bit off the top can be done without losing bullet base squareness. If not, then all bets are off as to how it will shoot. My shooting games mostly begin at 200 meters and can end up at 1000 yards. At those distances, you'll see the effects of an out-of-square rifle bullet base right quick, and especially soon BPCR plain base designs that are a tad long for the caliber anyway. Gas checks are not a fix for an out of square bullet base. On the other hand, I would hazard a guess that base squareness would NOT make any noticeable POI difference at casual plinkin' distances, say for the short & fat pistol boolits we all love to fool around with from time to time, gas checked or otherwise. FWIW....when I got to wonderin' about how a certain design would work if I nipped of a bit, I'd try to shorten enough boolits for a decent range test via lathe turning. A light grip with a collet worked best for me. That way, you could maybe save havin' to try t figure out how to put the metal you just removed back onto the mould blocks when it turned out your brainstorm was more of a brainfart. jimofaz

[Capn Jack]

OK, I'm convinced....I'll spring for the extra money and buy the proper mold. The only molds I've used in the past were for pistol bullets and muzzle stuffers. I sure did love that .50cal. Maxi Ball...You didn't need a spotting scope for that one. I LOVE BIG BOOLITS.

[Ron B.]

Well, the Mods are on my akss's about selling stuff; and not participating. I guess maybe the Lads are right about that. Anyway, the price of molds, IMOO is cheap. Why play machinist, unless you are one? Hades, the time you spend messing up a perfectly good mold (to begin with) you could be out shooting, bird watching, or walking your dog; or something else much less destructive!!!

Anyway, don't mind me. I'm just trying to up my meager posting numbers. They (the Mods), are now referring to me as, The "Dude". Should they wish to add, "Fat Boy" to the 'middle of thier new title given me; I guess I wouldn't mind a bit.

Good shooting, my friends!
GRB

[looseprojectile]

PM me your address and I will send you some 190 grain Ranch Dog gas checked boolits.
Heck, we may be neighbors.
These boolits shoot well in my .357 Rossi carbine.

Life is good

[Capn Jack]

Who could pass up an offer like that? PM sent