can't find them except for the gateways, 3rivers only has down to 4"??
I have gotten them at TradTech archery. With EFOC arrows 3 3" feathers stablizes even broadheads well; the main problem I have with them is that I can't see them as well as the bigger fletches, so I've gone back to 4" shield cut.
There are some 3 3/4 real (not imitation) barred trueflight shields on the LW classifieds.
One "trick" Ive used for years is to take packaging tape (the kind you hate because it sticks to EVERYTHING) and put it on both sides of a feather and after sticking it to itself all around the feather and to the feather, I'll take a pair of decent scissors and cut to whatever I want.
When done, grab the tape stuck to the feather and it pulls off very easily since it don't stick to it hard anyway.
The tape on both sides makes it stiff and holds the barbs in place (cutting towards the front of the feather) and easy enough that you can duplicate any type of feather length and shape quite readily.
A person could probably make a stiff, thin cardboard template if he wanted as well but I freehand. No issues.
Just an option. One that has worked for me for decades.
Yankee "injun-uity"
God Bless!
Lancaster has them.
Lost Nation, Larry and Janice have them.