Loading 308 On Xl650 - Need To Chamfer Casemouths?

[Zak Smith]

I'm loading .308WIN on an XL650 using once-fired Federal brass. Do I need to chamfer the casemouths? I ask because I often get some little slivers of copper from the jacket when the bullet is seated, like this:

Does this matter?

thanks

Zak

[Chriss Grube]

Yes. You still have to do basic case prep. like chamfering and deburring.

[Gun Geek]

Zak:

I think Chriss is right, however, I have a experiment that I am going to try soon (you might try it too).

Try using boat tail bullets. My theory is that the tail will expand the case just enough so that you don't gouge the bullet. Boat tails are just a smidge more in price, but if you're loading short range ammo (say for 3-gun), and need a good volume, then this may work. If you're loading for 1000yd competition, then your volume should be much lower and you have to do lots more to the case anyway (like neck turning), so chamfering is not a big deal.

From my understanding this is a primary reason the Army adopted boats as a standard for the M1-Garand; the ammo manufacturers convinced them that it was critical for accuracy, but the real reason was that they could load boats much faster and cheaper.

30-06 and 223 are my intended victims. Let me know if you try it.

Geek

[ErikW]

Geek, good idea, bad specifics. The tail is smaller than the driven (bore size) part of the bullet and doesn't expand the neck. The smaller tail does enter the neck a little and makes the bullet easier to seat and should avoid Zak's problem.

Zak, if you trimmed the brass, or it's new, you definately need to chamfer and debur. After firing that prepped brass, you might get away without chamfering the reload, at least not with boat-tails. I gar-on-tee you those copper-gouged bullets aren't going to fly straight. You don't have to buy expensive "boat-tail hollow-point" bullets to get boat-tail shapes; a lot of "full metal jacket" plinking bullets are boat-tail-shaped (including some 147-150 gr .308 military bullets?).

A truly progressive reloading press, after resizing, would trim, chamfer and debur. Call it the Dillon 2050, because that's what it would cost.

[Zak Smith]

The pictured bullets are Nosler Ballistic Tip with a boat-tail rear end.

-z

[Gun Geek]

Erik:

What you said about the how the tail would work!

The idea is that using the tail as a wedge, the copper jacket would cause the brass to expand just a little before the bearing surface goes into the case. If you sit a BT on a SIZED case, the case mouth hits on the tail, not the bearing surface (side of the bullet). A little case lube on the bullets might make this thing even easier.

On the trimming/burring/chamferring. I shoot lots of rifle rounds (did that before I got into handguns) and once I have fired a case, trimmed, deburred and camferred, I don't do anything to the mouth (through several firings) until I have to trim it again. No burrs appear if you don't trim and the chamfer doesn't flatten out.

Completely agree about finding reasonably priced boat tail bullets. There's lots of Winchester and Remington bulk stuff out there at a good price. It is BT and shoots excellent groups. They are usally a bit more $$ than a flat base, but not nearly as bad as a the fancy hunting bullets.

On the new press idea - Dillon has the beginning with the trimmer thingy. Check the Blue Press, it looks like a dremmel monted in a die. It even has a shoud so you can hook up a vaccum and suck away the brass trimmings. If you took another station and added a deburr/chamfer tool, say on a low speed cordless drill.

Hmmm. I'm starting into 223 these days...

Geek

[ErikW]

Geek, you need the trimmer after the sizing station but before the powder drop station. In a five-station XL650, for example, #1 must be the sizer and #2 must be the powder drop. You don't have anywhere to put the trimmer. Pipe dreams.

Zak, is that new or trimmed brass in your picture? If not, it blows our theory out of the water.

[Flexmoney]

Pipe dreams on a 650...but what about on that 2050???

[George]

Definitely chamfer it. At least inside, and the outside too if you use a taper crimp. I recommend a Lyman tool called the VLD reamer for the inside mouth because it's shallow angle is a very nice thing for a number of reasons. Any good 45 degree chamfering tool will do the outside well.

Of all of the case prep steps I have checked over a chrono, only case segregation (weighing and/or sorting by headstamp) and "anything" that makes case mouth tension more consistent gave me any measurable/worthwhile results. Chamfering alone showed no results. Chamfering "with" a light taper crimp showed small reductions in velocity variance..

Any time you shave copper from a jacketed rifle bullet you are damaging it before it hits the bore and that can't be good for it's drag coeffecient (wind bucking) over the long haul. Even though that is a lot of copper shaving going on there, I'll bet it doesn't show any problems at 100 yards as long as the jacket isn't cut completely and then peels itself back. It's way downrange where you will find measurable problems with that type of jacket damage.

New brass usually has a ridge around the inside and outside of the case mouth. I usually size, trim and de-burr all new brass. Most commercial 1x 100% processed I have seen is pretty good size and lengthwise but still comes with a little ridge around the case mouth. The Gracey case trimmer is about the only case trimmer that gives you a case that won't shave jacketing without an additional de-burring step.

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Regards,

[Zak Smith]

The pictured brass was commercially loaded Federal GM, fired once.

-z

[dhg2]

There is another trimmer besides the Gracey that does the chamfer od, chamfer id and trim to length all in one step. It is the Giraud Power Case Trimmer. It is a dedicated stand alone unit that does not need a station on the press. It is much more robust and user friendly than the other one. Manually insert the cases, press down and twist. Sort of like an electric pencil sharpener. Can do as many as you can keep up with, 500 to 1200 per hour. Not cheap, but loading good long range ammo never is.

For more information, see the website or contact me for more details.

Doug Giraud

Giraud Tool Company

www.giraudtool.com

doug@giraudtool.com

[Tom Freeman]

I will second the vote for a Giruad. Incredible machine. Hands down better than a Gracey. And, Doug was easier to deal with than the folks that make the Gracey. That classifier Leftys Revenge? Doug designed it.

I trimmed 100 pieces 50 BMG brass and 500 pieces of 6XC in under an hour.

Zak, if you want to touch a Giruad let me know. I will bring mine to the next match. JJ is using it right now to process a bunch of 223.

I like the Holland chamfer tool. The cutting teeth are much smoother than the Lyman. Works for 17-45.

[George]

Hi Zak, I just looked at your photo enlarged 2x and noticed that it shows a pronounced ridge on the outside of the case mouth. If the inside of these case mouths looks similar, I would say you need to de-burr these cases big time. Don't just use a standard 45 degree chamfer tool, use one of the shallower angle ones mentioned.

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Hi Tom, I just looked at the Holland Chamfer Tool and like the idea of the 14 degree cut angle as opposed to the 22 degree angle on the Lyman VLD Reamer Might have to get me one of them. Thanks for the tip.

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Hi DHG, The Giraud trimmer definitely looks good. I got my Gracey back in 87 and it was the best for a long time. But after looking at the Giraud, I have to say that the Gracey is good, but is now the second best. It takes a little fiddling to set the Gracey cutting head up right. and the Gracey is also pretty much a single caliber system. The $110 price difference is definitely providing some value here. I'm gonna try and wear out my Gracey first though.

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Regards,