Yes, they could be used for cuttings but cuttings root best when taken from active growing canes. Canes with a flower are active growing. Besides, are you segragating the cuttings by variety?
One thought, You stated you're pruning OGRs too. Most OGRs are once bloomers and only bloom on year old wood.If you're pruning them now, you're cutting off your blooms. OGRs should not be pruned, except for obviously dead or damaged canes, until after they bloom.

Thank you, Karl :)

The OGRs are for size and a little more air circulation. They finally had grown so big and thick I had to keep them in bounds! That's all I cut, but it's a lot. It's so fun that I remember them as little tiny bands :D

Oh, I haven't been segregating by variety, but I could if someone would like some cuttings now. It's not that many varieties that are having so much removed. Few bushes, but they're big suckers :D

You most likely removed this year's bloom from the OGRs.
Regardless of the reason, OGRs should not be pruned until after they bloom unless you don't care about a bloom this year. OGRs set buds in late summer/fall.

I didn't prune them 'back' any; I need a better term than either prune or prune back, lol. I cut off parts that aren't allowed to be where they are. Like, it has 10 feet of space and I cut off 10.5 to 13' :D I didn't prune into the 10 foot mass for blooms (except a bit of thinning completely on purpose). No, that wouldn't do for those!

A few of my climbers confuse me regarding old and new wood and which each one likes better, but I think I'm good other than that.

It's good to get it straight! I wouldn't want to mislead anyone into screwing up their season! Thank you :)

A lot of us prune the once-bloomers in spring (or winter). It's easier to see the shape of the plant, and improves the quality of the blooms. Even removing a lot of rose, there always seems to be a lot more to bloom. Just remember this is not a HT style pruning, but proper pruning for the varieties.

I am with MG. I always prune my onceblooming OGRs in winter /spring. Most bloom on the new wood that grows from the old wood. Pruning will encourage to grow more of these laterals and more bloom, not less. Taking 1/3-to 1/2 off each cane never hurts.
Karl, I really respect your knowledge, but I believe you never tried yourself to prune oncebloomers in spring. You probably just repeating what you read in books, etc. This is one of the old wive tales. If you try it, you will change your opinion.
Olga

I have one once-bloomer and I prune it....every other week. Otherwise, SHE starts pruning visitors at the front door.

Seriously, though...I've done it both ways and not noticed much difference. If I tackle her in the spring, I have a much more neatly-shaped monster. If I let her go, lots of the blooms are lying on the ground after it rains. It's still pretty, no matter what.

I have pruned once bloomers in spring, often having no option due to winter dieback. In all cases, depending on how severely I had to prune, I had no blooms that year or had fewer blooms.
What I read in books, I take with a grain of salt. The writer often states his/her experience from a different zone or other conditions that may not apply to me.
What I say is based on my experiences, not books.
Those blooms on the new wood growing from old wood were formed the previously fall. Those new laterals were part of the programing and if the old wood they grow from is pruned away, there will be no new laterals or blooms.
mad_gallica's statement re; proper pruning for the varieties is important to note.
An OGR,if cared for and pruned properly, will have a lot of one year old wood each spring, much of which can be safely removed and still allow a nice bloom.
Newer rose growers should proceed with caution on OGRs until they gain enough experience that they know how much they can safely prune without messing up the bloom.
I try to advise for the newer rose growers. Those more experienced can use their experience taking into consideration their unique growing conditions.
You know what and how much to prune. Many don't.
Meredith stated she's pruning now, and for the first time on many of her roses. This indicates to me she's not all that experienced with pruning?
How do we advise her to proceed with an OGR? Cut away and take a chance she'll cut too much or use caution until she knows what to expect?
Modern roses can often be pruned too much with few bad results. OGRs don't have that luxury.
I have several potted OGRs I'm taking to my local rose society this month for a pruning program. I'll show them how to shape the bushes and remove unwanted growth without destroying the bloom. I'll then show how much to prune after they bloom.

Karl, Thank you. Sorry if I somehow offended you. I don't ever doubt your knowledge. I just see it repeated so often that when you prune oncebloomers in spring you reduce number of flowers. This is so wrong for climates that have little or no winter dieback. The original poster is from zone 7B, even warmer zone than me. She should have zero dieback on old european OGRs. Even if she is completly unexperienced rose grower, she can safely shape her bush and take approx 1/3 off the last year growth w/o ANY decrease of flower production. No experience is needed. Just don't prune them like HTs to 18", this would be a problem, but to reduce 6x6 feet gallica to 4x4 or 3x3 will be very beneficial for bush shape and flower production. This way you will have flowers not only at the ends of canes, but all the way to the bottom, much more attractive in my opinion.
Olga

This is a very interesting discussion!

I did not prune these as they grew from bands, no. Except to remove bad wood and that sort of pruning, of course. I was waiting till they got big enough, then had life get in the way for a bit, and here we are :)

Most of the roses I grow, I'm much more familiar with pruning. I have some old monster ramblers in the woods-edge, too, that I've grown for a long while, but I never prune them. I like the look there :)

Not offended, just stating why I advise as I do. I err on the side of caution in most cases. If one prunes once blooming OGRs after they bloom and does it properly, the bush should not require pruning the next spring except on cold winter areas.
When it's stated that "I'm cutting off so much great new growth" and "I have all sorts of nice fall growth that I'm chopping off, too," I get a little concerned especially when the word "chopping" is used.

Depending on how one is trying to grow them, they can require pruning several times between blooming and frost. Generally I find them much, much more forgiving of bad pruning jobs than modern roses because they will definitely come back. Modern roses can be killed in this climate by overpruning.

Absolutely agree on the "chopping" thing. I wouldn't do it if I had the space to spread out all the laterals and let her go wild. I know I'm sacrificing blooms for the sake of preventing blood loss. I still get quite a few, but I know if I had room, there would be so many more!