trim&resize vs. resize&trim

[liber]

Why not actually measure them and KNOW instead of just giving an opinion?

Oh, I have measured a number of them, and all were well below, so I don't do it anymore.

I did measure them when I decided they just couldn't grow enough, but I don't measure them anymore once sized. I have also measured the fired cases and have learned that they do not grow very much or very fast.

As a check, I just measured about 15 fired 308 cases, not a single one is over 2.011, and most were around .2005"-.2008". These cases have been fired twice since resizing.

Thank you for giving me that comfort once again!

[CSACANNONEER]

I'm using Giraud Tri-Way heads in my mill, they cost $90 for each caliber and I have one for 308 and one for 223.

No, I'm not checking them as I trim to .205" and the max allowable is .215". When I size, I only bump it about .001-.002, so there is no way the case can grow enough to exceed the max allowable, IMO.

How long have you been reloading? Do you really feel that your way is safe without remeasuring each one? Do you understand that cutting corners like this is not an approved method since, it is simply not safe (specially to teach to new reloaders). While you have gotten away with it so far, it only takes one time to blow up your gun and possibly injure you.

Trimming after resizing makes your brass consistent. Trimming prior to resizing will give you a bigger variance in OALs which will lead to less precision/larger groups.

[liber]

Why not actually measure them and KNOW instead of just giving an opinion?

Randall,

One thing I've wondered before, and this makes me wonder again is that I was trimming to 2.005" in the past for my 308, and it seems I could trim to .210" or even .215". Because the trimmer is not exact, I have some that are actually less than 2.005, which is why I mentioned in the previous message that most are between 2.005"-2.008". Only one was over in the 15 or so I measured, it was 2.011".

I am not sure if there is any advantage unless I was extending my bullets out to sit close to the lands, which I don't do...mainly because I'm limited to the magazine size.

Do you trim closer to the max case length since you reload for optimal on your chamber?

And, is it better to have a case with max case length so that there is more neck to hold the bullet in?

Curious minds want to know.

[liber]

How long have you been reloading? Do you really feel that your way is safe without remeasuring each one?

Yes, I do, because I have measured enough of them to know that the brass has not stretched even close to max with 2 firings and I have never gone more than 2 firings without TRIMMING again.

I know people like you know better about my reloads.

[bohoki]

i resize then measure the cases any over 1.759 i trim how can you know the final size if you trim first?

[ar15barrels]

Randall,

One thing I've wondered before, and this makes me wonder again is that I was trimming to 2.005" in the past for my 308, and it seems I could trim to .210" or even .215". Because the trimmer is not exact, I have some that are actually less than 2.005, which is why I mentioned in the previous message that most are between 2.005"-2.008". Only one was over in the 15 or so I measured, it was 2.011".

I am not sure if there is any advantage unless I was extending my bullets out to sit close to the lands, which I don't do...mainly because I'm limited to the magazine size.

Do you trim closer to the max case length since you reload for optimal on your chamber?

And, is it better to have a case with max case length so that there is more neck to hold the bullet in?

Curious minds want to know.

What matters is that the cases are shorter than your chamber.
Sinclair sells little spuds that you can put into a shortened case, then chamber the case and the spud to determine YOUR actual chamber's max length.
With that info, trim 0.005" to 0.010" shorter and you are good.

Your variation in trim length likely has to do with your method of trimming.
Any trimmer that locates off of the case shoulder will give trim length variation due to the shoulder length variation.
Shoulder length variation has to do with press frame stretch.
Press frame stretch variation comes from brass hardness variations and from non-uniform lube application.

Hard bumping will eliminate shoulder length variations.

[kingfamous]

Like I said in the O.P. I trimmed some first to 1.750 before resize and then. I took some of those and resized and measured again and got 1.759 +/- I think that would be a decent amount of growth. To close to the max for me. Thank you guys for your comments. Going to take those 500 and have to deburr all of them and resize and trim all over again. Lesson learned.

[kingfamous]

I'm using Giraud Tri-Way heads in my mill, they cost $90 for each caliber and I have one for 308 and one for 223.

No, I'm not checking them as I trim to .205" and the max allowable is .215". When I size, I only bump it about .001-.002, so there is no way the case can grow enough to exceed the max allowable, IMO.

You loading for a bolt gun? .001-.002 is not a lot of bump
Im bumping .004
.006 for hunting rounds

[ar15barrels]

Im bumping .004
.006 for hunting rounds

0.002" is enough for any usage.
There is no reason to be bumping more than 0.003".
0.004" to 0.006" is a LOT of shoulder bump.

Look at it from the gun dimensions angle.
The difference between minimum and maximum chamber length is 0.003" to 0.004".
Bumping more than 0.003" means you are just adding extra headspace to the gun/ammo system.
What do you expect to gain with the excessive headspace?

[liber]

You loading for a bolt gun? .001-.002 is not a lot of bump
Im bumping .004
.006 for hunting rounds

No, for semi-auto. When I try to bump more I can really feel it on the press and it seems easier to get a case stuck when doing FL sizing.

[bsumoba]

You loading for a bolt gun? .001-.002 is not a lot of bump
Im bumping .004
.006 for hunting rounds

0.006" for hunting...wow that's a lot.

maybe 0.003" for hunting and semi-auto and 0.0015-0.002 for bolt actions.

I am doing 0.0015"-0.002" for f-class. I take my firing pin assembly out and make sure that the bolt has no resistance when i close it and a resized piece of brass is in the chamber.

0.002" is enough for any usage.
There is no reason to be bumping more than 0.003".
0.004" to 0.006" is a LOT of shoulder bump.

Look at it from the gun dimensions angle.
The difference between minimum and maximum chamber length is 0.003" to 0.004".
Bumping more than 0.003" means you are just adding extra headspace to the gun/ammo system.
What do you expect to gain with the excessive headspace?

excessive headspace = overworked brass and possible case head separation. believe me...i know from personal experience.

[fguffey]

So i messed up and trimmed about 500 5.56 LC cases that I thought were resized already

Before the Internet trimmers were sold with pilots that did not fit a sized case. A reloader would get into mortal combat trying to push the sized case onto the pilot, then there was that small flare that would get between the pilot and cutter that made it more difficult to remove the case from the trimmer. When the pilot was too large for a sized case I trimmed then sized.

Then there were trim dies, my favorite for accuracy. When using a trim die I use the 'man tool', the file will last forever.

Today most pilots are undersized, I am not wildly indignant about everything, I do not insist trimming must be done after sizing. Most reloaders insist they do not trim pistol cases, the same reloader insist they do not crimp bottle neck cases. I am not indignant about everything.

F. Guffey

[JMP]

Size, then trim. The other order makes no sense as the cartridge should not elongate upon firing only.

[fguffey]

Size, then trim

Size, then trim is an option. Then there are trim dies, another option. Trim dies come with instructions. Trim dies have been with experienced reloaders for decades.

F. Guffey

[Metal God]

Liber :

What you're doing is fine if you are checking on everything once and awhile to be sure you're still in the same place . It's not hard to find a case that was not supposed to be in the lot . I did just that last night . I trimmed 400 LC-10 cases and when finished the very first case I crabbed from the pile was a PPU case .

My point ? S*#t happens , What happens when a case that never got trimmed gets in that lot you feel no need to trim ? better to be safe then sorry .

Also . If your comfortable with your method then that's fine but when giving advice in areas you do not do things by the book . It's very important you explain in detail why you do it the way you do while giving that advice . A noob can easily take it to mean trim once and your GTG . IMHO It's important to know and understand when you do things differently and explain that when giving advice about reloading .

Not a knock , just a friendly conversation .