So i have for years used lee trimmers which only trim to the preset length for my hunting ammo. I recently purchased an rcbs trim pro2 and have been trimming some brass on it. My nosler manual does not list a trim length only a max oal. For the particjlar cartridge max oal is 2.100 so i decided that 2.080 was the appropriate length that i would trim to which i did. However i was thumbing through my lyman manual and found they list the trim length as 2.090. Does 1/100th make any difference that i should be concerned with?

I would like to add that i dont believe it will but feel it is necessary to ask since i dont have any evidence to back it up. My assumption is i likely wont have to trim this brass again...

No.

And it's a NO from me also. Won't make a scrap of difference.

Sometimes the Lee trimmers trim down a good bit shorter than necessary. They probably arent the best for "precision shooting", but otherwise it doesnt matter. I use them all the time.

It's a "no" from me too.

Damn factory brass is usually well under 1/100th below trim length and no on complains too much....or even addresses that.

Way better to be a bit short than spike pressures by being too long.

Zeke

quote:

Originally posted by ZekeShikar:
It's a "no" from me too.

Damn factory brass is usually well under 1/100th below trim length and no on complains too much....or even addresses that.

Way better to be a bit short than spike pressures by being too long.

Zeke

Tell me more about what you mean with pressure spikes due to long brass? Does over length brass allow for to much neck tension?

I cannot believe some do not trim brass, that is dangerous when a case squeezes into the throat of a rifles chamber and pressure sky rockets, and guns lock up, blow brass in half and eved blow some guns up..

I trim when cases are too long and thats with two to 4 reloading's. I do this religiously.

I trim to min spec every time.

quote:

Originally posted by Austin Hunter:
I trim to min spec every time.

I do the same. Always.

Jiri

I’ve got a card, from Lee I believe, that shows a list of popular cartridges max and trim length. I like to trim mine to a standard length to facilitate crimping on the cannelure for both jacketed and especially for cast bullets.

I conceed that factory fired brass and any new brass won,t grow to a dangerous degree until about 4 or more reloads, that is why we have length charts and trimmers..when they get too long its time to trim and annealing is a good idea..max loads grow more and faster of course and require trimming sooner, all that brass has to go somewhere, I would like to hear the negative reasoning to trimming, from those that do not trim??

quote:

Originally posted by Atkinson:
I cannot believe some do not trim brass, that is dangerous when a case squeezes into the throat of a rifles chamber and pressure sky rockets, and guns lock up, blow brass in half and eved blow some guns up..

I trim when cases are too long and thats with two to 4 reloading's. I do this religiously.

Exactly what I meant when I said way better too short than too long!

When the mouth of the case for loaded ammo is jammed at the end of the chamber, that very action tried to crimp the brass onto the bullet and pressures will spike something fierce. At best it will cause erratic groups.

This is why I trim ammo every single time (after they're resized) to uniform them if nothing else

Zeke

Neck only sizing keep the brass stretch to a minimum. FL sizing squeezes the sides of the case making them grow each time they're fired and sized.

I'm anal about all reloading so.... Trimming 100 brass takes about as much time as the commercials in a one hour TV show. De-burr and chamfer takes about that long too but less now with my case prep tools.

Zeke

quote:

Originally posted by sksshooter:
So i have for years used lee trimmers which only trim to the preset length for my hunting ammo. I recently purchased an rcbs trim pro2 and have been trimming some brass on it. My nosler manual does not list a trim length only a max oal. For the particjlar cartridge max oal is 2.100 so i decided that 2.080 was the appropriate length that i would trim to which i did. However i was thumbing through my lyman manual and found they list the trim length as 2.090. Does 1/100th make any difference that i should be concerned with?

The reason some manuals only list max lengths is that 1/100th off max is considered the the standard “trim to” length. In the manuals that only list max…I bet that is stated somewhere in the beginning of the book.

Anyway, now you know. Max-length - 1/100th = std trim-to-length. An extra 1/100th short is not unsafe. But, don’t fool yourself into thinking they will be under max for a longtime — check. In my experience over-trimmed brass stretches a bit faster at first…depending on how you set up your resizing die.

Just about everything I shoot is based on the .30-06 case. Years ago I purchased a .30-06 trim die and ended up keeping one trimmed case as a dummy for setting up my Forster trimmer. To do .25-06 or 6.5-06 I use the same Forster trimmer, but just change pilots. My 6.5-06AI cases will likely never need trimming. When fire-forming from .25-06 or 6.5-06 cases the new case is about 0.012-0.015 shorter than the standard 2.494 and it will likely not grow much ever. Some say that too short of a case can facilitate carbon ring formation. For my .243 and .280 Rem cases, I'll just set aside a factory case in the event I ever need to trim them. I don't think that I'd care to find out what happens if you jam a too long case into the chanber and fire it. I expect that the effect would be less with turned necks since they would be somewhat thinner.

Carry on shooting.

It won’t make any difference.

quote:

Originally posted by sksshooter:

quote:

Originally posted by ZekeShikar:
It's a "no" from me too.

Damn factory brass is usually well under 1/100th below trim length and no on complains too much....or even addresses that.

Way better to be a bit short than spike pressures by being too long.

Zeke

Tell me more about what you mean with pressure spikes due to long brass? Does over length brass allow for to much neck tension?

Ray addressed it well!
Brass that's too long will jam into the end of the neck area of the chamber and actually crimp the brass into the bullet and, when fired, the brass has nowhere to go so it continues to dig into the bullet. This spikes pressure!

Better a bit short than too long!

Zeke

Neck sizing grows brass less? Not sure about that but it does not make since to me?? pressure is the tiger in that cage, fl or neck should be one as bad as the other?? or so it seems.

quote:

Neck sizing grows brass less? Not sure about that but it does not make since to me??

I do not know what ''grows means'. When the case neck is necked up the neck gets shorter and thinner. When the neck is necked down it gets thicker and longer.

And then there are the drop in rerloaders. The Wilson case gage has a datum, the datum means nothing to most. The Wilson case gage measures the length of the case from the datum to the case head and from datum forward to the end of the neck..

All of that means nothing if the reloader is measuring the length of the case from the end of the neck to the case head for trimming.

F. Guffey

Grow is a loose term for lengthening brass.

Come on guys, it doesn't "grow" brass but FL sizing does lengthen it.

When you only neck size you don't squeeze the sides of the case and you're only sizing the neck. Brass doesn't lengthen as much.

When you FL size, it squeezes the sides on the brass and it has to go somewhere. It lengthens and you should/must trim more often.

It's simple. Test it out for yourself if you have the calipers and a neck and FL sizer.

Dang, I thought everyone knew that.

Zeke

quote:

I do not know what ''grows means'.

ZekeShikar, forgive, I was trying to be honest.

F. Guffey

Gotcha sir.
Yes, the slang word "grow" can be inaccurate and misleading.

I should "say what I mean and mean what I say" and use local slang words less often,

Zeke

Zeke, thank you, I do not get many of those.

F. Guffey

I agree with most everything posted above. The precision shooters take everything to the Nth degree and the newest trend is full length size every time then measure and trim as needed. (I'll bet they trim to an exact length (0.0005) every time.

quote:

Originally posted by Michael Michalski:
I agree with most everything posted above. The precision shooters take everything to the Nth degree and the newest trend is full length size every time then measure and trim as needed. (I'll bet they trim to an exact length (0.0005) every time.

I saw one proclaim that he can see the effects of 0.002" case length on target the other day...
This guy also claims that one must trim relative to the neck (not measuring total case length) and that piloted trimmers irreparably damage the inside of the neck.

quote:

Originally posted by Peter Connan:

quote:

Originally posted by Michael Michalski:
I agree with most everything posted above. The precision shooters take everything to the Nth degree and the newest trend is full length size every time then measure and trim as needed. (I'll bet they trim to an exact length (0.0005) every time.

I saw one proclaim that he can see the effects of 0.002" case length on target the other day...
This guy also claims that one must trim relative to the neck (not measuring total case length) and that piloted trimmers irreparably damage the inside of the neck.

This is total bullshit!

I very often get people come in here with what they see on YouTube!

There is some information there, as well as total bullshit.

There is no way in hell what this man is saying is true.

quote:

Originally posted by Saeed:

quote:

Originally posted by Peter Connan:

[ . . . ]

I saw one proclaim that he can see the effects of 0.002" case length on target the other day...
This guy also claims that one must trim relative to the neck (not measuring total case length) and that piloted trimmers irreparably damage the inside of the neck.

This is total bullshit!

I very often get people come in here with what they see on YouTube!

There is some information there, as well as total bullshit.

There is no way in hell what this man is saying is true.

Now, now Saeed . . . this is not the time for being subtle.

Let us know what you really think.

WEll I choose to trim my cases as they lengthen (grow) every time I shoot them...If some refuse to trim Im good with that also, its your decision!

quote:

Originally posted by Saeed:

This is total bullshit!

I very often get people come in here with what they see on YouTube!

There is some information there, as well as total bullshit.

There is no way in hell what this man is saying is true.

Which is why I chose the word "proclaim"

Saeed is dead right of course. And the term Grow, is easy to understand; grow means to get taller or longer. Simple to grasp.
And of course, FL sizing grows brass more than neck. I should not have to explain that.