303 British case length

[PolarFBear]

CONFUSED: Had a few .303 British rounds to reload. Started with a check of OAL case length. They were originally 2.222. I referenced the Hornady Manual for permissible length 2.158. Trimmed 14 cases with a Lee case trim tool. They tallied out at appx. 2.158. Gave another check for load data from the Lyman Cast Bullet manual. I see Lyman shows OAL as 2.222. If the length should actually be 2.222 why does the Lee tool take them down to 2.158? Why the disparity and have I "ruined" my 303s?

 

[Mike38]

I used to reload for the .303 British. I do not remember what trim length I used, too lazy to look in my notes. But I don't think .064 short is going to hurt anything as long as you make the proper adjustments on the crimp die. The .303 Brit head spaces on the rim, if memory serves me, so you should have no problems at all.

Side note, due to ample (over sized) chambers of the Enfield rifles, if that's what you're using, watch for stretch rings on the brass after 3 or 4 reloads. I never went more than 5 reloads on mine, even if the brass looked ok. Also, try BLC-2 powder if you haven't made a choice yet. I had very good results.

 

[OldManMontgomery]

What I have seen in many manuals and references is a 0.010 inch difference between maximum allowable length and trim to length.

Lyman #50 shows a schematic of the case, showing 2.222 inches as maximum and the details immediately preceding the load data shows a trim to length of 2.212 inches. Hornady #10 show the same information.

Why does the Lee trimmer trim to 2.158"? No idea, unless they measured a different rifle.

What does the difference of .054 inches mean? Probably not much. It may expose the end of the chamber to a bit more chamber temperature from the powder, but a 'few' rounds likely won't be a big deal. That difference will not blow the rifle up with starting loads. The maximum loading with those 'short' cases may or may not be a half grain less, there's no way to predict that small a change.

No. The cases are not ruined. I might segregate those cartridges and see if one finds a discernible difference in either velocity or group size. I seriously doubt it.

 

[RC20]

That is an awful lot of trim and while too much probably ok.

Normal of Max is indeed 2.222

Lyman's own book says 2.212 - 2.200 would be ok and indeed I over trim to avoid having to re-do often (I don't shoot 303)

That said you still have a lot of neck left.

I had a Lyman .223 trim and it shaved way too much, its now a Primer hole clean out tool. I have milled a 223 case down to 1.725 with it and still going!

 

[44 AMP]

First point:

The trim to length is a convenience length, it is not a hard and fast "must do" number, it is chosen as a length that does not interfere with normal function and allows enough room for the case to grow through several firing and loading cycles before reaching max length and needing trimming again.

Lyman uses 0.01" for most rifle cases, but some are less and some cases (short pistol cases, mostly) have a trim to length of 0.005" less than max length.

Second point"

.303 cases have "a mile" of neck to play with. Trimming the end of the neck a few thousandths more than recommended won't hurt anything. The case headspaces on the rim. Varying lengths will make a difference when you are crimping bullets but otherwise, not so much.

Third point:
Lee does what Lee does, and I make no attempt to figure out or explain why.

You did not ruin your cases by trimming the necks a little shorter than recommended.

 

[RC20]

I think 44 AMP severely understates the case (pun) here.

The magnitude (9.5 in Earthquake Terms) of trim the OP is seeing and myself as well as a cross check on the 223 are absurd and well beyond any .010.

It may be ok, as noted 303 has a lot to work with but as a fixed trimmer its junk at best.

While I have other Lyman products that are good, if I based it on their trim thingy I would not ever buy another one.

 

[PolarFBear]

Thanks for the timely, and to the point, replies. On "re-inspection" I have scrapped these 14 RP cases. They were on their 3rd firing getting them prepped for #4. All had a slight ring above the base and some were VERY noticeable. I tried the paper clip scrape to the inside. I never felt any catch or resistance but my technique needs refinement. These 303's are for my son so I'd rather err on the side of safety. My take away --- use a more up to date manual for review. The 2.158 case length came from the Hornady 4th edition; it's got a few years on it. Been reloading for a "while" but faily new to long guns.

 

[Unclenick]

I checked both SAAMI and CIP and both give 2.222" (CIP uses 56.44 mm, but that works out to 2.222"). The SAAMI minimum is 2.202", so normal trim length would target the midpoint value 2.212" and then have an equivalent error tolerance of +/- 0.010.

I don't know where 2.158" came from. My oldest Hornady book, #2, does, indeed, have 2.158". #10, however, has the correct 2.222". So, at some point in time bad information was floating around out there and Mr. Hornady and Mr. Lee both got their information from it. You can probably get Lee to replace your .303 case "gauge" with one the correct length.


Mike38,

BL-(C)2 is canister grade WC846, which was developed in WWII for loading .303 British to supply the allies. It was later adopted for M80 ball for the M14.

 

[Mike38]

BL-(C)2 is canister grade WC846, which was developed in WWII for loading .303 British to supply the allies. It was later adopted for M80 ball for the M14.

Thanks, You jogged my memory there! I guess that's why I tried it and had good results with it.

 

[PolarFBear]

Unclenick. I checked my Hornady 8th edition, page 603, and the case diagram has been corrected: 2.222 inches. I'll take up the short case trimmer issue with Lee.

 

[RC20]

Let us know what their answer is. As my 223 trimmer does short I believe its deliberate but why?

I don't care much as I have gone onto other trim method but its not like you can just trim it till it stops and have it correct.

 

[mikejonestkd]

I just trimmed QTY 5 303 cases with my lee trimmer, and they all came out at 2.214-2.215". something funky is going on with your trimmer. Let us know what Lee says.

 

[Unclenick]

Sounds like that one was out of spec. I've heard a couple of people complain about them sometimes being off. But being off by as much as PolarFBear has and just happening to hit the old number is odd. Maybe he got an old one?

 

[RC20]

As noted, my 223 trimmer does the same thing.

As my hands hurt these days and its a tiny case, I have not gone as far as it will go.

So now you force me to ruin (I say ruin) a 223 case to grip it in the vice and use my drill to run the trimmer via a drill (its right at 1/2 inch so I did not have to break out the corded drill!)

1.685 is where it quit trimming.

Please note that is .065 below the normal trim length let alone pushing .100 below the max length. That is close to HALF the neck gone.

So there is another solid data bit. May the case RIP.

 

[PolarFBear]

RC20: Maybe the Lee trim tools are not quite up to par. Hopefully, others will chime in with experiences with Lee trim equipment, good and bad. When I tried to do .223 cases I never got much success in taking off brass. As my lengths were "good enough for government work" (plinking) I just used it as it was.

 

[RC20]

Agreed and you can check, but my take is the Lee tool has to be used with a micrometer cross check.

Sitting here looking at my sad 223 case with half a neck now is a good laugh.

 

[Unclenick]

RC20,

Sounds like they sold you a 222 Rem "gauge" rod rather than a 223. 1.690" would be nominal trim-to for the triple deuce, and 1.680" is minimum, so you are right there.

 

[RC20]

The rod has 223 Printed on it.