Triming brass

[BW460]

OK, while I wait for my 450b upper to arrive, I'm trying to get all my toys in order. I have a L.E. Wilson case trimmer. Wilson makes a case holder for the .284 Win. So, here's the stupid question. Is that the case holder I want? They dont make one explicitly for the 450b (at least that I could find).

thanks,
Woody

[Hoot]

OK, while I wait for my 450b upper to arrive, I'm trying to get all my toys in order. I have a L.E. Wilson case trimmer. Wilson makes a case holder for the .284 Win. So, here's the stupid question. Is that the case holder I want? They dont make one explicitly for the 450b (at least that I could find).

thanks,
Woody

While I don't have a Wilson trimmer (RCBS Trim Pro here) if the 284 fits, the 450b will fit. Where they differ plays to the 450b. Probably not so if you were trying to do a .284 case in a 450b specific case holder. I'm guessing on that because I don't know the roll the holder for a Wilson plays in the capacity of a close tolerance fit to the head. My experience with making 284 brass work in a 450b was that one had to reduce the diameter of both the head and the extraction groove a few thousandths to make the 284 case work better with the 450b bolt and extractor. I'm not pressing that hard as early BM production units of the 450b seemed to fit the 284 cases better than my not as early unit and all those subsequent. Custom built 450b's may be more similar dimensionally to the 284. If you're talking about a non-BM rifle, best to ask the builder.

Now, back to the Wilson holder. I'm guessing again, but if it is not a colletting holder, like the Lee trim studs are not a colletting holder, then the 450b case may not center itself properly due to being a little smaller in the aforementioned diameters. That one will have to be answered by someone else, or by just giving it a try.

Here's a Link to another series of links to threads specific to the physical difference between the two cases. Try not to get distracted by tangential discussions within them.We tend to go off on tangents.

Hoot

[Siringo]

The answer to your question is yes. The Wilson holder is the same for 284, 308, 30-06, ect --- any .473 diameter case head. However, I have never found a need to trim 450 bushmaster cases by Hornady (avoid 284 brass -- that is a whole other subject). Many cases have been fired dozen or more times. Upon the first firing, they actually get a wee bit shorter. Straight wall cases usually do not grow.

[pitted bore]

BW460-
Yours is not a stupid question at all. I'll make three points in this post for you to consider. My advance apologies for wordiness.

[POINT #1]
I used a Wilson trimmer for a couple of decades, though I no longer have it. I'm not sure that the 450B case will fit the 284 holder.

From the L.E. Wilson blurb about the trimmer: "Wilson case trimmers are unique in that the case is held by a case holder which simulates a rifle chamber. Cases are held in case holders by their own body taper." Here's an image from the Wilson web site:

.
As you know, the case head and rim diameters are irrelevant to the positioning of the case on the trimmer frame. What is important is that the taper of the case has to match the internal taper of the case holder. Friction between the case and the tapered hole in the holder is what prevents the case from turning when the cutter is applied to the case mouth.

As you also likely know, for some cartridges, taper will differ between fired and sized cases, and different holders are required. For example, with the 308 Winchester, different holders are required for new/sized brass and for fired brass. With the 30-06, firing doesn't change the taper enough to require two different holders, although the case holder will hold fired and sized cases with differing lengths of neck protrusion.

If the SAAMI drawings I have for the 284 and .450B are correct, and if I've operated my calculator properly, the diameter of the 284W case tapers 0.0160 inches per inch of case length. The 450B tapers 0.013333 inches per inch. Both the 450B and 284W cases have the same head diameter of 0.500". My guess is that the 450B case will fit the head end of the Wilson 284W holder just fine. However, the 450B case may not go entirely through the holder, and the mouth my not emerge from the holder so that it can be cut. Even if the case and holder tapers are compatible, the Wilson holder may be set up for the longer 284W case length, and the case mouth may not emerge from the holder.

The answer to this problem of course is to order a special Wilson case holder that costs $22, compared to $14 for an off-the-shelf holder. To make a special-order case holder, Wilson asks you to "send in three cases in the condition in which you intend to trim them (ex. new, fired or sized)".

I think most reloaders of the 450B full-length size their cases in the reloading process, just as in reloading straight-walled pistol cartridges. I've not read or heard of any 450B reloaders who neck size cases. For full-length sizing, you will probably get the best case-to-holder fit for your brass if you send in three fired-and-sized cases when ordering a custom Wilson case holder.

Despite the Wilson trimmer's quality, ease of use, and uniformity of trim, I sold mine because I was reloading a lot of odd cartridges and the expense of ordering custom holders for these was going to be excessive at the time. For reloading a few different cartridges, or if you can afford a bunch of custom holders, Wilson trimmer is great.

[POINT #2]
If you read pertinent threads on this forum, you will find that trimming techniques are rarely mentioned. Case length growth is seldom encountered in 450B reloading, just as it is rare in reloading most auto pistol cartridges. Cases length tends to decrease with repeated reloading and firing. You may find trimming unnecessary, so I'd hold off on ordering a custom Wilson holder until you find trimming is needed.

[POINT #3]
In some of my experimental work reported in this forum, I've used my bolt rifles with 450B loads at pressures exceeding SAAMI max. With some of these loads, case lengths have increased to the point where trimming was needed.

A couple of decades ago, I moved to the Lee system of trimming. (Lee's ideas are good enough that Lyman has recently begun to market their own version of the Lee system.) For cartridges like the 450B for which Lee does not stock standard case trim length gauges, Lee will make a gauge if you pay them enough. Fortunately, the mechanics of the Lee system are simple, and I have been able to cobble together gauges for some pretty odd cartridges. For the 450B, I used the length gauge for the 222 Rem. That cartridge has the same 1.700" length as the 450B. I drilled a washer with a hole to fit closely the gauge stem, and turned its outside diameter to just under .450" to fit inside the case mouth. The washer holds the case centered on the trimmer cutting blades. Trimming is trouble-free if I hold the case vertically, mouth down.

If I've messed up any explanations here, please comment or ask questions, and I'll try to clarify (or retract, if appropriate).

Good luck.
--Bob
edited to remove a major oopsie.

[BW460]

Wow, and all I was looking for was a Yes or No! I love this board! I reload for a 460 S&W mag and have also experienced that case getting shorter after firing. As mentioned, the Wilson case holders use friction to hold the case which means the taper needs to match. I ordered some Hornady brass and was concerned that it might need to be trimed before the first use. Searching on this board can be a little challenging. I looked but didn't see much on the topic. So, for those of you who have trimed, other than the options mentioned above, what do you use?

Thanks for the great responses.
Woody

[Jim in Houston]

I've reloaded several hundred BM450 rounds and don't even own a case trimmer. I would agree with not making any investment in case trimming equipment until you have reloaded a few rounds and can check your results.

[longnkrnch]

I stopped trimming my 450 brass. It just gets shorter and scraps out sooner. I also stopped belling the case mouth. I find
With a little care I can seat bullets fine without the bell. Trying to baby the brass as much as I can as it's longevity is not near as good as bottleneck cases.

[3rdgeargrndrr]

Sorry, but the Wilson trimmer wont work without modification to the holder,
Here is a new case in the 284 case holder,

[pitted bore]

Sorry, but the Wilson trimmer wont work without modification to the holder,
Here is a new case in the 284 case holder, ... {image}

3rdgeargrndrr-
Thanks for your post and the image showing the mouth of a 284 case not sticking out of the end of the Wilson 284 holder. It confirms my conjecture above:

... My guess is that the 450B case will fit the head end of the Wilson 284W holder just fine. However, the 450B case may not go entirely through the holder, and the mouth not emerge from the holder so that it can be cut. Even if the case and holder tapers are compatible, the Wilson holder may be set up for the longer 284W case length, and the case mouth may not emerge from the holder. ...

Wilson will of course be pleased to make a custom holder.
--Bob

[pitted bore]

I stopped trimming my 450 brass. It just gets shorter and scraps out sooner. I also stopped belling the case mouth. I find With a little care I can seat bullets fine without the bell. Trying to baby the brass as much as I can as it's longevity is not near as good as bottleneck cases.

longnkrnch-
My lots of Hornady's brass seem to be pretty tough, at least as much so as any other brass I've got including a lot of bottleneck rifle cases. I've got some small batches of 450B cases that have up to 20 reloads, and are ready for some more. Hoot and some other forum members may have some cases with even more mileage on them. I haven't babied mine in terms of pressure, but they've been used only in my bolt rifles so there's no loading and ejection slam-bang-yanking stress.
--Bob