- Thread starter giannid
- Start date
Test it and find out.
Leave some unchamfered as a control, and shoot it back to back to chamfered ammo. Do it on a couple of different range trips.
Does the chamfered ammo shoot more precisely? Is the ES/SD lower? Are these results repeatable? Are they repeatable over multiple different range trips?
Leave some unchamfered as a control, and shoot it back to back to chamfered ammo. Do it on a couple of different range trips.
Does the chamfered ammo shoot more precisely? Is the ES/SD lower? Are these results repeatable? Are they repeatable over multiple different range trips?
I am doing it so far . whether it seems to need it or not like trimming all my brass gets put through the trimmer just to keep my self doing the same thing to every piece of brass the exact same way all the time . besides I get to zone out and watch old westerns while trimming / chamfer / and de burring my brass it works perfectly ( for me )
Alot of people recommend doing this on new, unfired Lapua brass. Its also not clear to me if you need to do this because Lapua often has slightly thicker case-wall thickness, which may make the neck-wall ever so slightly thicker and stiffer to seat if 'sharp', or if they just use particularly sharp/squared off cutting tools, leving 'sharp' edges. Its very possible that this isn't required for other kinds of brass for various reasons.
For new target-type brass, I uniform the primer pockets and deburr & champher the necks.
I sleep better at night.
Chris
No. With virgin lapua and alpha I dont normally Trim, which includes the chamfer and deburr (henderson). Its really not needed and the difference in SD/Accuracy is more related to virgin brass than the neck prep and is not as much as you will think. Once you are fireformed, every cycle gets hit with Henderson even if its just to clean up the chamfer. Mandrelling on virgin brass is really the only issue with the high amount of friction due to no chamfer and no carbon in neck. May want to put some lube on mandrel for virgin brass to minimize scoring.
I do the following:
Inside chamfer and mandrel new brass always For the above reasons.
Giraud trimmer every firing if I have the cutter head, so that brass gets trimmed and in/out chamfered every time.
If no cutter head and no trim, I will touch the mouth with the inside chamfer tool every time but never outside.
If I trim, it gets in and outside chamfer.
Always VLD tool.
Inside chamfer and mandrel new brass always For the above reasons.
Giraud trimmer every firing if I have the cutter head, so that brass gets trimmed and in/out chamfered every time.
If no cutter head and no trim, I will touch the mouth with the inside chamfer tool every time but never outside.
If I trim, it gets in and outside chamfer.
Always VLD tool.
Only on trimmed brass.
I run new brass thru a mandrel and load it. Lapua and Alpha or Starline in a gasser.
Look at the clearance of your case mouth to chamber wall with a Borescope. You’ll probably see you don’t need to trim as much or if ever.
I chamfer every loading. Consistency
I chamfer every loading. Consistency
Do you ever compare case lengths in the same batch after say 10 firings? I’ve found that cases from the same batch can grow at different rates. That means that I do trim on occasion in order to maintain case length consistency.
Also, I manually ID/OD chamfer each time on my precision brass. It’s not a heavy chamfer and I’ve not done any sort of scientific study, but it works and is what I do.
I trim or at least check length to my variance every cycle.
I debur the flash hole from the inside only once.
I chamfer inside and out and uniform the primer pocket every cycle.
I debur the flash hole from the inside only once.
I chamfer inside and out and uniform the primer pocket every cycle.
So there is no consensus on this, like so many things in reloading. I recently got a Frankford arsenal trimmer that does the trimming and chamfer/ debur all in a couple seconds. I have been running all brass through all 3 steps. I do not see how this can be a bad thing. Most cases, after the first trim aren't hitting the blades when I push them in (the Frankford trimmer trims from the shoulder), but some do. The chamfer and debur thing doesn't seem like it would harm anything either. I'm not hogging out a pile of brass or anything, just kinda smoothing out the rough edges. I have absolutely no idea if this process is giving me better accuracy, but it seems like it will give me more case consistency, and that can't hurt.
At least in theory -- Too much trimming can lead to excess carbon deposition before the free-bore. Its not so much about frequency of trimming, but the average length of brass being fired. If you are trimming to 10 thou under, every firing, you are IMHO timming too much. You can keep a more automated-process and reduce the risk of carbon rings, however simply by shrinking your trim-to length to something like ± 5 thou under.
