First time loading .30 Carbine: how vital is identical trim length?

[1KPerDay]

I have tumbled a few hundred Aguila and S&B brass. All are once fired. All are at or below 1.284". Some below 1.280". Intend to load IWI 110 SP pills. No cannellure. Using RCBS 3 die set. I generally find rifle reloading tedious and I'm not looking for super pinpoint accuracy which I don't believe my rifles are capable of anyway. I just want something similar to the stuff I was shooting. That works. I have 2400, blue dot, li'l gun, 296, h4195.

Trimming is a PITA so is it vital they're all the same exact length? Even if they're almos all below the trim to length?

 

[Chief 101]

I have never had to trim 30 Carbine brass...

 

[DaisyCutter]

I've never had to trim any once fired brass.

I'd measure some new unfired cartridges to establish some parameters as far as min/max/mean for the cases, and then see if trimming is necessary on any of your once fired brass.

 

[1KPerDay]

I've read .30 grows so you need to keep an eye on length. I was just curious if anyone found it necessary that they all be exactly the same length assuming all were below the trim to length anyway.

Any recommendations on where to begin choosing a load would be welcome also.

 

[gamestalker]

If all are shorter than SAAMI max, and you don't need a roll crimp, you'll be fine.

As for 30 Carb, I don't load it, I may have at some point in time, but not certain I've ever loaded it. Some powders such as 296 don't burn properly without a canelured / roll crimped bullet. Now 2400 & Blue Dot might function alright without a roll crimp.

So the answer here is relative to the following:

Is the brass all within SAAMI max length?

And is the bullet your using typical of what one would find applicable for 30 carb with powders mentioned, and without a roll crimp?

I'll do a bit of research on that and get back to you before the day is out.

GS

 

[gamestalker]

Ok, I just a quick glance in my old Speer #10, and they make no indication of a roll crimp with either 2400 or H110 / 296. Speer shows both canelured and non canelured 110 gr. jacketed bullets used with those two powders, so I would say you are good to go.

BTW, SAAMI case length is 1.290", so anything that length and below is fine.

GS

 

[Sunray]

"...don't need a roll crimp..." Headspaces on the case mouth, so no roll crimping, ever. Your seating die will likely taper crimp anyway.
Never had to trim .30 Carbine either. It's loaded just like a pistol cartridge. Been using IMR4227 with 110 grain FMJ's and HP's(grapefruit size holes in ground hogs) for about 40 years. Tried H110 long ago, but found I get better accuracy with the 4227. And a very satisfying BARK!!! sound.
Absolutely not H4198(or 4895). 2400 is given quite often for cast as well as jacketed bullets. Never used it myself. 296 and H110 are the same thing. So are H and IMR4227, according to Hodgdon's site. Do not worry about compressed loads. And forget cannelure's altogether.
How far below 1.280"?

 

[Walkalong]

I have never loaded .30 Carbine, but some say they trim every time and some say never. I guess you'll just have to check case lengths after firing. They have a max like any other case.

As posted, they headspace on the case mouth, so no roll crimp (Don't remember seeing a .30 Carbine bullet with a cannelure), and don't over do a taper crimp, just remove the bell or a hair more.

 

[Rule3]

As mentioned the 30 carbine spaces off the case mouth unlike other rifle cases. So the length is important,

Size the brass and measure. Yes, trimming is a PITA but cases that are too long or too short will give you problems.

I reload for it and made a big mistake once and trimmed a batch that I misread the case length and trimmed them way to short:banghead: What a waste of almost new brass that was.

Keep them between trim to and max and you are fine. They do not grow that much. Maybe trim them once or twice before you lose them,

 

[cfullgraf]

My 30 carbine cases require trimming. I check the case length after sizing and trim as necessary, usually about 25%-30% of the cases.

As said, 30 carbine head spaces on the case mouth so a roll crimp is not appropriate here.

 

[1KPerDay]

How far below 1.280"?

I measured a few more. Some measure 1.275, some measure 1.288, most are around 1.280. None are over 1.290" which is the SAMMI length I believe. Trim length is 1.284.

I have some R-P brass mixed in also. Most are Aguila or S&B though.

I'm having some weirdness with Lee rifle charging die which I'll address in a different thread.

 

[gamestalker]

Interesting, and educational as well. I learned something, which is always good.

GS

 

[FROGO207]

I have a couple 30 Carbines the brass will feed and function in them both if within SAAMI specs. BUT and that is a big BUT the two Ruger 30 Carbine Blackhawks that I own will not reliably load the rounds into the chamber if they are not trimmed to minimum length. Fire carbine level loads in them and the brass will grow enough to lock up the cylinder the next time they are reloaded in some of the chambers of either revolver. So I trim those each reload just to avoid problems. Not worth getting the cylinders headspaced longer if trimming the ammo I use in them works as I load rounds for them lighter anyway.

 

[maxxhavoc]

I have to trim mine, usually about 15-20%. Just use a Wilson case gauge and trim any that fail.

 

[BCRider]

Commonly straight wall cases seldom or never need trimming. At least that's the common mantra. What is different about .30 Carbine that it requires that a portion needs trimming to length with each cycle through the gun?

I'm also wondering at what amount over that trimming is being done. And if it's with previously acceptable and then loaded and fired brass or if it's with new or pickup brass.

 

[crankyoldlady]

After resizing...I trim every case, every time, to precisely 1.285 inches. No crimp required.

 

[col.lemat]

Wilson gauge all, trim required on maybe 10-15% and those are range pick up or have several reloads on them. I use until lost, primer pocket enlarged or case splits. Have used 2400 years ago, now using 296 and never crimped. 110 Gr. with no cannelure.

 

[Rule3]

Straight wall cases do not "grow" and space of the case head. 30 carbine headspaces on the mouth and grows when resized like other rifle cases. I do not find it necessary to trim every time, The actual physics or how and why it grow I do not know, it just does, from working the brass I imagine.

 

[flightsimmer]

I'm loading some .30 carbine range brass now and found one case at 1.270" and several at 1.300".
I always check them the first time around and as long as their 1.275" to 1.287" or there about, I don't bother trimming them.
I also slightly flare the case mouth to ease seating the bullet and then taper crimp them for uniformity.

 

[cfullgraf]

30 carbine cases are a tapered straight walled case.

Since they operate at the high end of pressures for most hand gun cartrigdes coulped with the tapered redizing is probably why the cases grow on the firing/resizing cycle.

Hand gun cartridges like 357 Magnum do grow but at a slower rate than most rifle cartridges. Some serious folks do trim their high pressure hand gun cases to get a uniform crimp between cases. Most do not bother particularly those who run reduced loads.

 

[joem1945]

I shoot a bit of .30 carbine. I do measure them after decap and sizing. For triming I have a Lyman drill press trimmer set up for 1.280. It's fast and does a good job.

 

[TimSr]

As for 30 Carb, I don't load it, I may have at some point in time, but not certain I've ever loaded it. Some powders such as 296 don't burn properly without a canelured / roll crimped bullet. Now 2400 & Blue Dot might function alright without a roll crimp.

H110 was developed for 30 carbine. 3 carbine are normally taper crimped enough to de-bell the mouth. I've never seen a 30 carbine bullet with a cannelure.

To the OPs original question, exact matching case length is not very critical with these rounds.

110/296 function flawlessly in my WWII vintage rifle. Blue Dot works okay in my rifle, but can be borderline in my borother's rifle as far as working the action. I was never able to get my action to function with Unique. 110/296 were the most accurate.

 

[joem1945]

Watch the length od carbine reloads carefully. If over length they may not go into battery and there is a risk of a out of battery firing (really bad thing). Some of the older copies of the carbine will fire out of battery. US GI for the most part will not.

 

[forestswin]

I've attached a paper that seems to be put out by the Civilian Marksmanship Program on reloading the M1-30 Carbine.

it should answer your questions and more

 

[Henry45]

I check and trim after every firing. If it needs trimming, it gets it. But they are ALL checked. Brass length is very important for 30 Carb..