.351 Win SL bullet mold using .348 gas checks

[10gaOkie]

I am in the middle of getting tooling together to reload for my .351 Win SL carbine. I have had it for 20 plus years and never have shot it yet other than fire forming and the one round I made up using .223 brass which fired and ejected fine.
My concern is about choosing the right gas check. I read where at one time, Lyman had a mold design for the .351 Win using a .348 gas check. I am about to the pull the trigger on ordering a mold from Accurate Molds and fail to see how this 348 gc will fasten to the bullet shank when sizing to .352? If 35cal Hornady gas checks are used and are .358, I dont see them sizing down to .352.
My next problem is deciding what tooling I will need to trim oal length of my 223 brass to 1.380. I have a mini drill press that I could leave set up to do this. This is certainly not a cheap project so I am constantly trying to keep my costs down.

Chris

[texassako]

It might not be the same,but I size down Hornady .30 cal checks to .301" for Carcanos all the time. I do it in a Lee push through sizing die. Same size difference you will face.

[Oklahoma Rebel]

hey! welcome fellow okie! what parts are you from?

[Oklahoma Rebel]

that shank size is the same size the 9.3mm or .366 GC shanks are, they could be sized down I would think, after all, people used .375 checks for the 9.3mm for forever, sages outdoors has them, and so does blammers, if you cant find anything else-Travis

[10gaOkie]

I live in okc. I have built some tough cartriges in the past like the 45/75 and .348, etc. But this .351 takes the cake. So you guys think I can go ahead and get my mold built using the 35 cal gas check? I found some .348 gas checks at Gene Sears. Maybe he will have some 35s too. My mold design at Accurate Molds is 35-180C, .352". It is a plain base, tumble lube bullet but I decided to go with a gc and will change it.

Chris

[10gaOkie]

I have on hand about a dozen full boxes of .348 200gr jacketed bullets. The ones I measured
were .3495. I will eventually get around to trying some in the 07. Maybe they will give acceptable accuracy, maybe not.

Chris

[Oklahoma Rebel]

I think I would go with the .358 so that it can be sized down to the right size, you cant size a gc up ( that I know of) and you want a good seal. wish someone that had experience with that particular cartridge would answer. but I know it is not very common.

[10gaOkie]

According to mold designs listed in the Accurate Mold catalog, for the most part, the 357/358 designs have a .340 gc shank. Also, the .352 designs have a .340 shank. The .348 designs all have a .320 or .319 shank.
I still fail to see the reasoning behind Lyman putting a .348 gc on their old .351 Win. molds.

Chris

[Oklahoma Rebel]

oh, I was mistaken, I thought you said the gc shank was .352. lets see if someone else has an idea. of course accurate molds could make the shank whatever size you want. in fact you should email him ( tom@accuratemolds.com) and see what he thinks, I still think the .358's are your best bet.. see what he thinks about that as well

[runfiverun]

you can squish a gas check up in diameter all you need is pressure.
I push 8mm checks on 8mm boolits up to 358 all the time, it's how I make 140gr gas checked wad cutters.

[10gaOkie]

I have already tried to talk to Tom about this as he was tight lipped about it. Saying he would build whatever I want. He did come up with a nice idea for making a tumble lube design bullet which I wanted. At this point, I think I will go with what he has done in the past on these .351 Win bullet molds which is the .340 shank.
Today, my efforts at making 351 brass from 223 is working out nicely. Just gotta come up with a new supply of non military 223 brass.

Chris

[beagle]

I always used .348 Horady checks on my .351 stuff sized to .352". Worked all right on the Lyman series of moulds and I had no problems. The .351's a strange critter. I had a set of .35 Win SL dies that worked well for me but I normally loaded using a set of .357 Mag tungsten carbide dies. Some .351s will function just fine with .357 Mag brass. Old Grumble had one that did. I'd try that before I went too far. I'd go for a .348 check on a custom designed mould./beagle

[rintinglen]

My .348 Winchester gets .351 GC boolits, either Accurate or RCBS, so I think you'll have no problem if you go that route. In fact, I do believe it is the best route for you to take.

[10gaOkie]

Beagle,
Good info! What is the size of the shank on your bullets that allow for a crimp of the 348 gas checks using a .352 sizer? I still dont see how the 348 gc can get crimped on the bullet with this sizer. I used to own a Blackhawk and a Dan Wesson both in 357 Max. So I have a pile of 357 Max brass if I need to fall back on it. So far, the 223 trimmed is working fine and much easier than turning down rims.

Chris

[beagle]

Don't have that mould anymore or the .351. I always nose first size and this may have helped. I never had any problems with the Hornady checks staying on during sizing. If you can locate some WC820 milsurp powder it goes well in the .351 SL. Only problem I had was the .351 threw case about 20 feet and they were hard to find and recover./beagle

[ScotMc]

10gaOkie,
I have a 351 I just bought. can you give me the details for using used .223 brass?
Thank you,
Scot Mc

[10gaOkie]

Scot
What I did first was I chambered an empty round of 223 brass to see if it would eject with my gun. I didnt trim it or anything. I ejected it as fast as I could by hand and it worked. I did this quite a few times to make sure. I read somewhere that the latter model 07s were more likely to work with the 223 brass as not all 07s will eject the 223 cases. All I know for sure is they ejected fine in my gun which which was made in 1951. I have a pot full of .357 Max brass but found it more difficult and time consuming to work with than the .223. Not to mention that .223 brass is probably the most plentiful of all to be had.
Let me know how this works and if it does, I will go through all the details I went through to reload for it. It is a very expensive project. Even for me as I already had most of the dies, brass, a brick of primers and three to five pounds each of the four brands of powder that work best in the 351.
So far, I have only fired a few loaded rounds through mine checking for good operation using the trimmed 223 brass. I have done a minimum of fire forming also. I have done zero load development as I am still recovering from colon cancer surgery. I plan to drill and tap the receiver for scope top mount base. I just found out the correct bases that are made to fit the 07. I would have to drill and tap for a tang sight as well plus buy the tang sight which isnt cheap. I already have vintage scope and rings. Even when my eyes were younger, I never did much good on 100+ yard shots at deer with open sights./Chris

[10gaOkie]

Scot
This is a list of tools I use to reload 351 using 223 brass at this point.....
Harbor Freight mini chop saw w/ 2" blade
Forster case trimmer
RCBS chamfer tool
.348 expander die
.356 expander die
.357 Max carbide sizing die
.357 Max seating die
9mm taper crimp die
Accurate 3-cavity aluminum bullet mold 35-175BG
Hornady 35 cal gas checks
X-lox 45-45-10 bullet lube
Lee .339 bullet sizing die - opened up to .352
I left out the tools needed to load any cartridge
powders - Lil Gun, 5744, IMR4227, 2400
my mold hasnt arrived yet.

Chris

[ScotMc]

Chris, Thanks for all the information on this. My 351 is a very early model, I believe around 1908 or 1909. I will try the 223 brass when I get home in a few weeks.

[ScotMc]

Hi Chris,
Hope all is well with you and your recovery. My 1909 351 will eject .223 cases with no problems. I'm looking at casting a few boolits from my Lyman 350477 mold. I will check as cast diameters To see if it is viable. I have been eyeballing the Accurate 35-180CG as an alternate in case the .348 mold doesn't work out. Who did your machine work to open up the lee sizing die? Are you still looking for a source of .223 brass? I may be able to help you there. I'm eager to hear your method of using .223 brass into 351 SL.
Thanks

[Wayne Smith]

You guys ought to give Dave Davidson at CH4D a call. I'll bet he has dies set up for this, or will make them.

[10gaOkie]

I am pretty well set on tooling, bullets and brass for the 351. What I need now is loading data for these powders....296, 1680, LilGun, 4759 and A#9. Using a Accurate mold cast bullet that drops 174gr. I already have data for 2400, 4227 and 5744./Chris

Scott....pm sent.

[wolfwing]

Old thread but good info. I'm trying to talk a buddy out of his 351. Hopefully I'll need this info.