06 January 2009, 02:23
olguyFree floating barrel/transfer marking medium
I have a M1500 Smith & Wesson(Howa action)in 25-06 for which I worked up promising handload[117gr Horn BTSP, 54.7 gr H4831sc, Win WLR primer, seated @ 3.690"(per Stony Pt. Comp.)in Win brass]for tight 9/16" grp. Then loaded up batch for validation. At range got horizontal stringing with two three shot groups. Did "dollar bill test" & could not get it to slide under barrel. Could slide it in from side for little ways, only about an inch. So, obviously barrel touching stock(a lot). Removed barrelled action from stock. There is pressure point extending back from forend 7/8". In addition, something I have never seen before: what I can best describe as a rib (contoured to the barrel?) centered lengthwise in the barrel channel, extending four" from the front recoil lug recess. Something unique to S&W/Howa? Additional pressure point? I am thinking I will fully free float the barrel. I checked wi a local gunsmith & he ageed with my approach. Is there a good transfer marking medium which I can likely get from my small town hardware store, as opposed to having to mail order. Its been years since I did any inletting. I have used a couple of different things such as lipstick and candle soot, but found them messy and/or cumbersome. Welcome your suggestions. Also, when free floating how much wood should I remove? How much is too much? How much is too little? I understand you do not have to remove too much, just the high spots, so there is no contact?
06 January 2009, 03:14
WestpacI use Grumbachers Prussian blue, however, probably the best transfer marking medium for this job would be an ink pen. Force a piece of paper between the barrel and forend to keep from scratching the barrel and trace the barrel outline on the stock with the pen. Pull the barreled action and commence cutting.
You have to figure that the forend may be applying more pressure on one side of the barrel than the other and so I releive enough material until one of two things occurs. #1. The forend stops moving, at which point I will continue cutting until the amount of gap is even on both sides, or, #2. Until I can palm (slap) the forend in all directions without the forend and barrel making contact (audible sound).
Usually a dollars bill width isn't enough. The barrel will close a "dollar bill" gap pretty quickly as either the barrel heats and moves, or, the barrel and forend collide during recoil. There has to be enough clearance to prevent all contact under all conditions.
06 January 2009, 04:46
Duane WiebeAbout once every five years, I am asked to free float...(gasp)...anyway, I use utility cloth rolls and "shoe shine" with the backing against the barrel and grit against the stock...absoluely even gap all around and will take care of pressure in any direction
06 January 2009, 05:24
kcstottSoot from an acetylene torch works great.
07 January 2009, 23:43
AbobI read in Kinks that someone used his wife's old discarded lipstick, notice I said discard, don't get caught raiding the medicine cabinet
Jim
fur, feathers, & meat in the freezer
"Pass it on to your kids"