Case Trimming & Crimp Setup For AR Plinking Ammo

[otisrush]

What do folks do with regards case trimming for AR plinking ammo? Do you trim everything to the same length? Or do you do the standard anything-over-1.760"-gets-trimmed-to-1.750" - and live with varying case lengths?

I noticed recently I was getting occasional shoulder crushing. After a bunch of investigation it appears it was due to over-crimping - which was only being encountered when a case on the long side of the spec was going into the die. As I recall I didn't pay attention to what the case length was that I used to set up the die initially.

I'm thinking of setting everything up using a case at 1.759" and then seeing how shorter length cases come out (with regards to case mouth position on the cannelure as well as crimp).

How do folks handle this trimming/crimp balance?

Thanks!

OR

 

[mrawesome22-250]

I trim all new brass once to 1.740" then use an RCBS X-Die and never worry about trimming again.

I've never crimped a bottle neck rifle cartridge in my life.

 

[forty_caliber]

I trim every bottleneck case to the published trim-to-length after sizing every time without fail. A consistent case length works best with your crimping die too.

.40

 

[otisrush]

I trim every bottleneck case to the published trim-to-length after sizing every time without fail. A consistent case length works best with your crimping die too.

.40

I kind of figure that's the road I'll be heading down. I know the key is consistency. And inconsistent case lengths are....well....an inconsistency. It's making me wonder if the Tri-Way trimmer by Giraud might be in order.

The X-Die looks VERY interesting. My processes are set up to intermix range pick-up brass with stuff I've loaded. I don't segregate between the two. So if I go the X-Die route I'll have to think through how I keep stuff I've setup for the X-Die and range scrap separated until I can get it X-Die ready. (I'm sometimes shooting where there is a A LOT of .223 on the ground.)

 

[Walkalong]

Trim every time with a WFT trimmer in a small hobby lathe. The deburr/chamfer with an RCBS tool in the same hobby lathe. Just takes a light touch for a short second.

 

[jmorris]

A lot of my brass is mixed range pickup after matches. For all of it, it’s faster to just size/deprime and trim all of it. If a case needs trimming, it’s trimmed, if it doesn’t the cutter won’t make contact. It’s a fairly quick and easy process, more than a 1000/hour isn’t a problem.

 

[Ironicaintit]

I don’t even bother measuring fired rifle cases any more. I set up the trimmer to length, and they all pass through whether they need it or not. It’s actually faster that way, vs measuring, sorting, then trimming.

I used to be a crimper, but the more I load and learn, the more I’m convinced that it can hurt accuracy, and does next to nothing to keep the bullet from shifting.
That’s not entirely true, I do still crimp some pistol, and tube magazine 30-30, and 45-70.

 

[HDMontana]

My trimmer trims off of shoulder measurement. If it needs it, it trims it. The bullets I use have a cannelure. I crimp slightly into it.

 

[cfullgraf]

I made a "go-no-go" gauge that I use to check my 223 Remington cases. I trim only the ones that do not fit the gauge. I have to trim only about 25% of the cases that I'm working on. See the attached photo.

I do not crimp my 223 Remington ammunition--or any other bottle neck cartridge ammunition for that matter. (side note, the most powerful bottle neck cartridge that I reload for is 30-06).

This includes semi-auto rifles and bolt action rifles.

 

[peels]

Trim every time with a WFT trimmer in a small hobby lathe. The deburr/chamfer with an RCBS tool in the same hobby lathe. Just takes a light touch for a short second.

I use a WFT also, but with a corded drill. It is easy enough where I don't dread the case prep anymore. Makes trimming so much quicker.

I don't crimp anymore.

 

[call1911]

I don't crimp my .223 ammo. Neither for plinking nor for target shooting.
For plinking ammo I do the following:
Range brass is going in the ultrasonic cleaner for an hour.
After drying (radiators in the cold season and in the sun the rest of the year) brass is lubed with Dillon spray.
Then it goes through the Forster Full Size Die/Decapper.
Now all brass is put in my Giraud-Trimmer where it's trimmed (if necessary), deburred and chamfered.
Now a thorough ultrasonic cleaning again.
After drying again it's ready for some of the good stuff (N130 or N140, depending on bullet weight.
Bullets are seated with the Forster Micrometer Die.
Never ever will I put a crimp on.

 

[rdnktrkr]

I check/trim every loading of rifle brass, I use the Lee factory crimp and try to lightly crimp so everything is uniform, I had a loose bullet in a Garand once and have since put a light crimp on any that are shot in a semi

 

[Blue68f100]

All my rifle brass is annealed after cleaning, sized, and run through a lathe mounted trimmer with a 3 way cutter. This measures off of the shoulder so it's best with all brass in the same harness state. The reason I anneal, makes every thing uniform. And I have some brass with 10 reloads on them, never a split neck. But primers pockets are starting to get loose, so #41's are all they see now. If it needs trimmed it happens in not it doesn't. This takes the same amount as time to measure without the extra step of trimming. I only crimp ammo for a tube magazine. As long as you use 0.003"-0.004" neck tension movement will not be a problem. Less than 0.0025" neck tension a BCG can setback the bullet during a jam.

 

[Demi-human]

How do folks handle this trimming/crimp balance?

By not crimping.

With a proper sizing it usually isn’t necessary.
My pistol cartridges are de-expandered, not crimped.

 

[otisrush]

I love hearing the variances in how people approach different aspects of reloading. It always gets my mind churning.

Since I started the thread, I'm giving myself permission for a bit of thread drift.........

For those of you that don't crimp ammo that is magazine fed (let's take single shot bolt action scenarios out of this.....I don't crimp on that stuff either), how do you check that you have sufficient neck tension to prevent bullet movement from recoil while in the magazine?

I've heard of the "bang the bullet tip on the bench 5 or 6 times and see if COL changes" method. I've also been known to fire one or two rounds from a full magazine, then check the unfired rounds that were in the magazine and see if the COL has changed.

Do folks use one of those two methods? Something else?

Thanks again!

OR

 

[call1911]

What I did and something you could do too:
Make like 20 reloads of the same kind with 10 of them with crimp, the other 10 without.

For me this showed that crimping my 223 worsened accuracy.
My best ammo is 11mm grouping with 40gn bullets @100m. And 15mm with 52gn bullets also @100 meters.
Both without crimp out of my 24" bull barrel AR15.
With crimping I had flyers that killed my grouping.

 

[Demi-human]

I've heard of the "bang the bullet tip on the bench 5 or 6 times and see if COL changes"

Or, raise it in your hand, bullet out casehead at your palm, at arms full extension and crush it into the bench with a blow.
Now measure at the ogive with a CBTO tool.
The nose will mash, the bullet shouldn’t move.

If it passes that, an AR is easy.

(Watch your knuckles. Don’t let them impact the bench. You will shear a shard of bone off into the tendons of your finger and it will float around, sometimes jamming in the joint and impeding articulation. Know how I know that?)

 

[Chuck R.]

I shoot a lot of range pick-up brass due to using most of my .223 in 3gun matches.

1. I don't crimp, just rely on neck tension
2. I run every piece of brass into a Giraud Tri-Way trimmer set up on a drill press and trim to 1.748"

I don't even bother to measure it, some gets trimmed, some doesn't get touched. I won't get the same brass back after the next match anyway.

 

[12Bravo20]

I don't bother to measure 223 cases either. I trim them all. It's just as quick to just trim everything even if it doesn't need it. If the case is all ready at or below your target OAL, the trimmer won't cut anything.

 

[Skeptic13]

I trim everything over 1.755 back to 1.752. Why those numbers I really can't tell you. I do want as much bearing surface as possible so don't go below 1.750 but I don't want to push to the max at 1.760. So I just made up a random rule that I am comfortable with and works for me. I think I picked the 1.752 so that if I trimmed a little to much it would still be above 1.750.

I only crimp if the bullet has a cannelure and then only lightly.