Trimming tips?

[Mike Matteson]

I have a question? I am looking at Frankford Arsenal Universal Bullet Seating Die set up. This includes set up from .224 thru .338 calibers. Now I have set my bullet with RCBS bullet seating dies for each different calibers. Never used a Mic. die setup. I have the equipment to check the ogive of each bullet. I understand that there are difference between each bullet built and the reason why this is need to be paid attention too. I feel or think that a seating set should be able to detect or seat the bullet to the ogive, and not the tip or close to that, which most basic seating dies do or close to that. I never had much problem with the round being concentric either. I have always been very careful in placing the bullet into the case to seat the bullet. Be sure that the bullet is seating straight. I have been purchasing bushing dies to set dia. to lighten the tension on the bullet being seated. Changing to different bullets, will change the set back from the land for that rifle. Now I generally end up just using a single stile of bullet for that rifle that I use. So once I get set up on a load for that rifle that's what I stay with from then on. If I need to spend the money to get a different seating die for each caliber so be it. It's off to the races! I load for about 20 different rifles presently. No all are mine, son rifles too.

 

[Reelamin]

How often do you trim?

I pretty much don't trim. The only thing I trim are my bulk range brass for the first loading in 223 and 308. Other than that...I dont remember the last brass I trimmed.

Do you trim to saami minimum?

If I do trim I look up the spec and trim it a little long. My 223/308 has the trim length on a piece of tape on my trimmer.

How much do you let brass grow before trimming again?

Until it wont work or I have problems getting it loaded on the bench or in the rifle.

What is your acceptable level of length variation when trimming?

What ever the trimmer turns out after I set it. I may check every few hundred if a bunch of mixed brass I just started with.

Any other tips or tricks?

I found I enjoy it a lot more if I don't detail myself into craziness so I feel like I'm wasting my time and effort. I have people say I am detailed in my reloading. I think I do some things detailed and other things not so much or not at all. Find what works for you after you try them yourself and go with it.

 

[AZShooter]

Wanted to update this thread with a more information.


Straight Shooter's use of a borescope is a great idea. The borescope has to be long enough to reach the chamber from the muzzle end.

OR NOT!

Got to thinking about this as I have an original Hawkeye borescope that is too short to span that distance. I sized a case and drilled out the base on my lathe. Was able to chamber it and look at the end of chamber/end of case to view the gap from the reciever end. While you cannot come up with an actual distance it is nice to SEE the brass is not reaching the end of the chamber.

 

[Mikecr]

Just measure it.
You don't trim to visual

 

[Straight Shooter]

Mike, why not?

 

[Mikecr]

You pick a hard value trim length and log it.
That should not be a book value, and merely validated by some unknown clearance.
The basis of your trimming action should be w/resp to measured chamber end.

It's in my plan (for example) to trim as brass is within 5thou of chamber end.
That's pretty hard to 'see' with a normal borescope.
Sinclair offers a simple tool for measuring this:

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[Straight Shooter]

Got it.

 

[Critter Picker]

I trim to the trim to length in my loading manuL.
Any round that I plan to crimp I am very critical of length. I made an adapter to use my cordless drill to drive my Lyman trimmer. I use a carbide cutter head. I also bought a 2 piece shaft collar to put behind the locking collar on the trimmer shaft so it can't slip.
I read an article on loading 44 MAG for a 8 inch barreled revolver and the author was talking about trimming. In his testing he loaded rounds that varied .030 in length and because of velocity variations POI changes 18 inches at 200 meters.

 

[Critter Picker]

I trim to the trim to length in my loading manuL.
Any round that I plan to crimp I am very critical of length. I made an adapter to use my cordless drill to drive my Lyman trimmer. I use a carbide cutter head. I also bought a 2 piece shaft collar to put behind the locking collar on the trimmer shaft so it can't slip.
I read an article on loading 44 MAG for a 8 inch barreled revolver and the author was talking about trimming. In his testing he loaded rounds that varied .030 in length and because of the velocity change POI moved 18 inches at 200 meters.

 

[Mike Matteson]

After sizing, I chuck them up in my Henderson Gen 3 case trimmer cut to length every time. That way there wondering just how long the case is. They all the same. The Gen 3 cut bevels inside and out. that way I know that all case are consistence.

 

[AZShooter]

MIkeCR I agree measure it or read the reamer print from the reamer that made the chamber. I have many chamber plugs and have measured for many years. Not to be disagreeable, I can see that gap between the brass and the end of chamber easily.

A quick look doesn't hunt anything and if your bore scope is long enough it will instantly tell you the end of the chamber is long and you won't have to worry about trimming for many cycles. Many factory rifles are in this category.

 

[Mikecr]

For basic reloaders to consider:
If you're trimming to book value (arbitrary to chamber), or visual (go/no-go), then that's one part of your reloading that's weak.
It is basic, and safe, but it's stronger to tie all your methods to measure. All actions to plan.
That's just a suggestion.

There is another way to watch for a trim length problem. I do it by habit, as my trim length provides very low clearance.
When a case mouth hits chamber end, that mouth is shiny where contact occurred. I can also feel it.
As I eject each round (I pick them from single shot actions, with eject-delete), I automatically feel the case mouth, and the primer. If I feel anything I look close. There have been occasions where I ran out of clearance, and when I see a shiny spot on a case mouth I STOP. No more shooting until I've put calipers on those cases to find out what I have.
Maybe I had just annealed the batch, or maybe I'm getting too lazy on the bench. Something has changed.
Of course this is not something to rely on to tell you it's time to trim. But it's one of the things you can be watching about your brass -while firing.

 

[Mike Matteson]

I do it a little different. I anneal, size, then set and run them through the trimmer for length. The trimmer will trim them if needed. My old way was check each case and if they were under, I would reload it. If longer or out of spec, I would trim it back about .010. That made my case all generally at different lengths by some. Not a lot but different. That makes my cases inconsistence, which in turn changes the release a little with each case. This way I am not concern about that step, and trying to determine if that could be problem. It's not a problem is shooting deer size animals, but ground squirrels is a different thing. The animal is only about 2" wide, and at 400 to 700 yards it can have effect on how that bullet is going. It's all in what you want to put the time into, and what you want.
Don't get me wrong. I have the greatest respect for mikecr. I have learn a lot from him.

 

[Mikecr]

I find that there is more variance (higher SD) with consistent but higher clearance, than there is with reasonable trim length variances (provided tight clearance). It's one of those deals where consistency in itself does not win over a better plan.
The better plan on my part is to prevent gas from getting between neck and chamber, which would add neck sealing variance, affecting SD.