375 Winchester from 30/30

[Blanco]

A good friend has a 375 and would like to get some more plinking ammo for a reasonable price.
After a bit of searching I see that 375 ammo comes at a premium.
My buddy is not against making a reduced load from 30/30 brass.
As I have never attempted this what would be involved.... Annealing? reforming ? load suggestions?
Any help and or sources would be appreciated.

[GRUMPA]

I have this posted in a thread, I tried it and this is what I found out.

"Well after spending 2 days working on the 375Win and the 375Supermag I found more than a few ways NOT to make them from 30-30 brass. The length of the 375Win case is 2.020-.020 and when forming those from a 30-30 case that's already at 2.020 the case shrinks to 1.980 which of course is to short for my tastes. Everything else is fine after forming but those aren't something I could stand up and be proud of. So needless to say I wont be doing those."

[fryboy]

depends ... new brass no annealing needed , i wouldnt suggest it with very used brass ( annealed or not ) 1x can usually be expanded decently without annealing first but i do suggest annealing after expanding to save from splitting where the shoulder used to be
now for the expanding part .... several ways to do it best i found is a el cheapo lee universal decapper with their newer tapered 375 ruger expanding rod installed ( yes it fits just fine ) but for best results it should be shortened by removing the decapping pin part and about a 1/4" of the bottom of the rod ( up to just before where the taper starts ) done this way it makes the brass in one pass
another way is to just flare enough of the mouth to seat a round ball ( my fav prior way to do it ) load with 8- 10 grains unique and seat the ball just past full diameter and fire , suggest lubing the ball with LLA btw , one can flare enough to seat a regular boolit and use that route or the cream of wheat method if desired but the round ball load is a great plinker !
yes sir low powered cast loadings only for this conversion and the cases will come out short [shrugz] for full power loads trim starline's short 38-55 brass down , their's a vicious rumor that they may start making 375 brass ( something about tooling but other than trim to length and headstamp i dont see much difference between it and 38-55 )

[groovy mike]

38-55 brass can easily be trimmed to work if you can find that.

[Blanco]

Ok so help me out here...
Even though the reformed 30/30 will shrink a bit when formed, is there any huge reason for concern?
I mean what are we talking here .010~.020?
This is not going to be a target round... Accuracy 1MOA of Pig at 100 yards.
Buddy says the reduced recoil would make his shoulder happy

[GRUMPA]

Ok so help me out here...
Even though the reformed 30/30 will shrink a bit when formed, is there any huge reason for concern?
I mean what are we talking here .010~.020?
This is not going to be a target round... Accuracy 1MOA of Pig at 100 yards.
Buddy says the reduced recoil would make his shoulder happy

When I did those I was going to offer the finished product. Folks are just finicky when they pay for things, which.... I can relate too. I just stopped at that point figuring it's just another conversion that didn't meet my expectations. As far as using them? I don't own anything in that cal....

[fryboy]

shrinkage seems more like 1/8" or so , i dont have any cases handy to measure them but it's significant and wider than the cannelure on say a hornady or sierra j-word loading to normal j-word o.a.l.'s you'll never get close to the cannelure , with cast it's no worries ,it's also less problematic in a single shot vs. a lever action ( see that case length to crimp groove aspect again - you'll lose quite a bit of case capacity setting to the cannelure thereby raising pressures even more )
the pressure difference is the most serious aspect , the 375 case was designed for much higher pressures than the 30-30 ( which is why for years i used the 375 case to make various wildcats such as the 7-30, 30 and 357 herret )

[Blanco]

One more thing I am curious about I see J bullets in 2 Diameters .375 / .377 (this will be for a modern Winchester .375
If I were to procure a mold I would assume a .380 bullet and then squeeze it to about 377?
I wonder how well Powder coating would hold up on this?

[fryboy]

in general the bigger j-words are for the older ( and often larger bored ) 38-55 , many current 375 molds wont work for those ( too small ) years ago i had a lee 250 , at the time it was only fair in my only 375 barrel so i sold it but kept quite a few boolits , years later i acquired several more 375 barrels , so of course i tried it in those - one with great results ! so i bought a newer lee mold ...thinking was it was the same thing right ? wrong [sigh] it was much much fatter and sizing it down to .376-7 resulted in quite a bit of displacement ( from .382 ) those didnt work so well for me ,the older mold cast around .378-ish , definitely suggest slugging the bore in this case ,who knows what it will be [shrugz]

[No_1]

Blanco,
Everything the previous posters have said rings true. It is really no different than what we are doing when we load then shoot 38 special ammo in a 357Mag chambered pistol. Take a fire formed 30-30 case, add either a conventionally lubed Lyman 375449, RCBS 37-250 (both GC'd) or Lyman 375248 for a plain base boolit, use a LR primer and 10 grs of unique. It will shoot good. If you are planning to duplicate factory loads then use 375 WIN brass.

[alamogunr]

Why not just get .38-55 brass from Starline. It would have to be trimmed but that should be easier than forming from .30-30, I'm sure it would be at least as strong as converted .30-30. They don't show a ship date but are accepting orders.

I'm surprised that someone else didn't suggest this.

[EDG]

You need to slug the bore of the rifle you will be loading for.
.375 Wins are supposed to use .375 j bullets but my Marlin barrel measures .3775.

My .38-55 barrel measures .380. You never know what you will get so measuring a soft sulg or cast of the throat is probably the best idea.

I have blown out like new once fired Remington cases using powder with no bullet. I think it works better if you use a few grains of powder and a filler or a round ball. Some of the cases will blow out with wrinkles if you use only powder.

One more thing I am curious about I see J bullets in 2 Diameters .375 / .377 (this will be for a modern Winchester .375
If I were to procure a mold I would assume a .380 bullet and then squeeze it to about 377?
I wonder how well Powder coating would hold up on this?

[groovy mike]

Why not just get .38-55 brass from Starline. It would have to be trimmed but that should be easier than forming from .30-30, I'm sure it would be at least as strong as converted .30-30. They don't show a ship date but are accepting orders.

I'm surprised that someone else didn't suggest this.

Yep, reply #4

[alamogunr]

Yep, reply #4

I posted too quick. Should have read all the posts.

I remembered that Paco Kelly had written essentially the same thing in one of his books. His reason was that .38-55 brass was thinner than .375 Win and you could get more powder in it.

I don't subscribe to that line of thinking. He advocates a lot of loading practices that I don't subscribe to and I'm not recommending .38-55 brass for the purpose of stuffing more powder in the case.

[fryboy]

Yep, reply #4

or #3 lolz

sadly often starline's brass cost more than actual 375 but ...if it can be found when the 375 can not ....[shrugz]
somewhere long ago i read a blurb that starline stated it should handle 375 pressures but there was also a disclaimer that they wouldnt be responsible should you utilize it as such ( wish i could find it again) the shorter brass requires less trimming , the longer brass would work equally as well ( albeit more work )

[JFE]

I've done this quite few different ways but what I have settled on is opening the case with tapered expander. As others have mentioned, you don't need to anneal the neck/shoulder area if the brass is new, but for work or age hardened brass it's a good idea to anneal first. The cases are 2-3mm shorter than factory 375 cases but use a Lee FCD to crimp your bullets at the correct OAL and it doesn't matter, plus you will never have to trim them. I simply load a 250-300 gr cast bullet over a stiff load of R-7 and use them for hunting or plinking.

One point to note though is that I have found more variation in case capacity of 30/30 brass than any other except for 22 Hornet, so try to use one brand if possible. In general though 30/30 brass is more strongly constructed than 38/55 brass but not quite as strong as 375 brass. I've found PMC 30/30 brass to be very strong but is no longer made.

[Blanco]

I will probably wind up doing just what JFE is doing.
This is just going to be used on Texas piggies and maybe if it is accurate on some whitetail.
That was my original intent, just have some shootable ammo.
I have contacted Tim at accurate about a 230 Gr. grooveless Boolit that I intend to powder coat. And just seat the boolit farther out to the correct length and use a Lee crimp die. I think this will be the easiest workable solution.

[nanuk]

to make Whelen brass from 270, I just dropped a 270Win into my whelen and pulled the trigger.

the neck was almost completely formed.
one run through the FL sizer with a tapered expander button and she was good to go.

any reason one just can't buy cheap 30-30 ammo and do the same?


as for brass thickness, has anyone ever tested 30-30 brass to see if it is thick enough?
just saying, 30-30 is lower pressure round than 375Win, so the brass HAS TO BE thinner doesn't really tell us anything but pure speculation.

I have seen pics of sectioned brass comparing 30-30 to 375, and the difference in one example was minimal. in fact, if they hadn't told us which was which, you'd be hard pressed to tell the difference. (I cannot remember the brand of brass used in that case)

[nanuk]

... you'll lose quite a bit of case capacity setting to the cannelure thereby raising pressures even more )

wouldn't the pressure be lower, all else being equal, as published by Hornady in their discussion on pressure vs seating depth in bottleneck cartridges?

have you tested pressures?

[fryboy]

when one shortens a case and then sets the projectile deeper than standard o.a.l. using the same charge weight pressure will be raised ,in most cases just setting the projectile deeper raises pressures,some ,such as the hi intensity cartridges ,dramatically so ( aka 9 mm and 40 s&w) ,one is reducing case capacity ,setting the projectile out longer ( with the same charge weight ) usually lowers pressure , this is assuming that you arent setting the projectile out to the lands ,weatherby used a long leade ( freebore ) to help reduce his pressure , the running start does tend to reduce pressure to an extent and this isnt what i'd call a bottleneck cartridge more like an overgrown 357 mag that you'll now be trying to load same said mag load in a 38 special case ....yeah pressure would be up

as for actual case capacity ...it varies alot ,as mentioned previously ,in 30-30 cases, try weighing a few keeping in mind that they are close enough to the same length ( before reforming that is )