I really dont want to cut the barrel for a drop. Is it common for like twist barrels to match across manufacturers? Or do they vary greatly across the board? Would a FF die for a brux 1-20 work in a GM (Knight) barrel? I would like to try full form, and start in my 1-20, but have a few different name barrels. (and guns in twists of 18 and 22 I figure are out also..) If chances are slim, i'll just stick to SF
Somebody will have an answer for you but here is a glimmer of hope for you. At one time I used a die made for a mcgowan (I think) and it fit a pac nor. That may not be the correct combination of barrel vs die but the crux of point I am trying to make is that you are likely to make that work.
Barrel makers internal dimensions are all different, different groove dimensions, land dimensions etc. a drop from the same maker/twist will work fine, it don't have to be from a specific barrel but to be an exact match it is best to come from from the barrel you are using it on, in your case the barrel you have on your gun or one exactly like it..
Imo if the rifling is being made by a button then the differences would be greater than a manufacturer that cuts its rifling... The button is going to wear and its dimensions are being changed the more it is being used.... Looks like you will have an uphill battle in getting a fullform die match....
These guys are correct in saying that the barrels are all different.... Some makers even offer barrels with wide lands and narrow lands, some have 4 grove, 6 grove and even some 8 grove barrels are available. If you want a full form die it will almost 99.9% chance need to be made from the barrel you are forming the bullets for. The only exception would be if you had a drop from lets say a Brux 1-20 and used it to full form for another Brux 1-20 barrel.. That will work because I have done it several times. but the Brux full form die will not even come close to working in a Krieger barrel. Now I don't know about McGowen or pac-nor barrels because I have never used one, nor have I ever build a rifle using a Green Mountain barrel, so you might get lucky and find a die that will work,,,,, but I doubt it. It might be possible to call the barrel maker and ask them if they have a short piece of barrel you could have or even buy to make a die from.. Ask them how close their barrels will match up from one to the next.
pretty much what I figured. GM wont even return messages. guess ill start with the next build. Problem is, Ill probably love it, and have to either consolidate the rest, or start selling and start again. I have barrels all over the board in name and twist.
After reading the comments of those who are more experienced in full form sizing I can see why I might not like my full form die. Jeff made my 2 n 1 die and it works great for me but that's because I only use the smooth die. Tried the full form just didn't like how complicated it was but that probably cause I didn't take the time to fully understand it. With that said I believe Richard is correct unless there is a bullet you want to use and full form is the only way you can. To me for hunting purposes smooth is the only way to go. Just my 2 cents worth.
SF works good for smokeless. My issue is im in a smoke only state. I was thinking a FF might eliminate some obtrusion issues and allow a bigger array of bullet choices. At this point, maybe on the next one. Still works fine with the big lead. But I rarely shoot a cast bullet anymore. Paper patch doesnt seem to want to be pushed hard. It likes it slow at the big lead speeds. I like the modern jacketed style. I gat pretty good results with SF. Just always looking to tinker.
I did have some problems with BH209 and some harder bullets. While a soft Parker or Sierra were simple, a SST and even the little 225gr FTX was not. They needed to be much tighter. A simple way to get them tighter but still "loadable" was, under size, then knurl and then run it through a larger sizing die such as a .452 die.
A .452 knurl will load no problem in a .450 bore. They are a bit snug starting but after that its not bad at all. You could probably even get a .454 knurled OD down. That is a standard Lee sizing die BTW.