I'm a hobbiest gunsmith on my personal collection who quit doing public work a decade ago. I've spun a lot of barrels on from most makers and refits between manufacturers.
All of my experiences have shown me that in 30 plus 10 twist 30 cal rifles at my elevation of 3k-ish feet that there's no issue with stabilization in 200-215 class bullets, at least from berger, horn and sierra.
Last month I built myself 3 rifles all 10 twist, 2 in 300wsm 1 in 300win. The WSM's are a 21" proof stainless on a win classic and a 24" lilja on a sako av. The 300win is a push feed. All 3 are bedded similarly, all floated to at least 20mil and all wear mcmillan stocks. All wear quality, proven scopes in quality proven mounts. By proven, I have shot them personally as well as attached an indicator to the scope and action to measure movement between them.
Every screw is dyed and measured to ensure zero contact and in the case of the 300win, it wears 8-40 and bedded (grit blasted contact points) pic rail....its solid.
The two 300wsm's are boringly accurate and will shoot one hole groups with their best loads and about an inch and a quarter with their worst.
The 300win is my anomaly. I fired it up on the first day with a shoot, clean shoot rotation for 5 rounds and it wasn't pretty, but I hadn't yet shot 3 or more in a row.....when I did so with a charge of h1000 pushing a berger 200.20x my groups were barely staying on a piece of butcher paper.
I immediately assumed the scope it wore was junk and replaced it with a new lrhs and loaded a ladder based on my other 300win successes. The lrhs shot equally poor. I had questioned on of the base screws upon assembly so it was at this point that I took it to 8-40 and bedded the rail.....no change.
With 40 rounds and no two landing within 4" of each other I pulled another lrhs from a very lightweight 300rum that's been very accurate for me tho eliminate the possibility of 2 bum scopes.
Scope 3 shot similarly. Up to this point I've taken h1000 and h4831 from 2700 to 3k fps and from a kiss to .200" off with berger 200.20x, 208eldm and 210 accubonds.
Cleaning, scoping and checking my work has me head scratching. I load up some 165, 175 and 180's....suddenly I can't shoot over an inch. The gun is absolutely what I expect from bartlein....but only to the 180 class.
Checking twist has been a bit inconsistent in my findings but it sure isn't a 14 twist.
I called bartlein and they told me not to expect their 10 twist to stabilize a 200.20x. This threw me for a loop. If every other maker's tube works....why not a bartlein?
My question to you is have you found that a 8 or 9 is required for stabilization of 200 plus class pills?
