Recently put together a .358 Norma with parts from a few rifles. The barrel is an unknown maker but was originally a .35 Whelen on a MRC 1999 action in a fully floated HS precision stock. In that configuration it shot very well for my buddy that I bought it off of. I was present during load development with the 225 TSX and it was easily MOA or better.
I robbed the barrel and put it on a Model 70 Classic action and used a wood stock from another model 70 Classic. The stock has been pillar and glass bedded to this barreled action. It was also free floated but does not have much clearance. If I grab the end of the stock it easily makes contact with the barrel.
Initial load work up showed lots of vertical stringing with very little horizontal dispersion. A business card jammed between the barrel and the stock settled it right down to between 1 and 1.5 MOA but the card would shift positions between shots. 2 Cards would really send the POI high and groups opened up to about 2 MOA.
I tried several thickness and positions of electrical tape wrapped on the barrel. Like the two cards, heavy layers of tape changed POI significantly (as much as 4-5"). The vertical stringing pretty well disappeared but still had plenty of 2+ MOA groups.
I decided to work more methodically and used just enough tape (three wraps) to almost make full contact with the end of the stock but there was still some play when I grabbed the end of the stock. Dispersion was about 2"+ horizontal and a little over 1" vertical.
Two more wraps gave me solid contact with the stock. It was like turning on an accuracy light switch...
The next four went into .877", the next three with a full cool went .751", the next three with a full cool went 1.045". Average of ten shots was .891" with pretty even dispersion. If I were to overlay all three groups I estimate it would be around 1.25 - 1.5 MOA with 9 of the ten MOA or better. Plenty accurate for anything I plan to point it at.
All shooting was prone off the same bipod and rear bag for consistency.
Between the business card and the tape experiment it is obvious to me this gun will shoot with a little forend pressure. My only concern with adding pressue is potential POI shifts, particularly with a wood stock. I also know the barrel used to shoot well in a stiff composite that was fully free-floated.
My questions are:
Keep the tape and shoot as is?
Have my stock guy permanently bed a "speed bump"?
Get aggressive with the stock and hog it out enough to where it won't make contact even if it flexes?
I am open to all three options just curious what the campfire consensus is.
Thanks
Have an old pencil Bbl'ed M700/270 Win that I bedded the action on long ago.
Was still unhappy with it, so I started adding layers of 1" masking tape across the fore-end channel, a little behind the fore-end cap, until grabbing the fore-end from the bottom and pushing up on the barrel with my index finger took maybe 5# to get it to flex apart.
Took it to the range and it shot great.
Used an Exacto-knife and cut two 1/2" squares out of the piled tape, from ~ 45° from BDC of the Bbl. back down to ~ 30°, and dug into the wood of the stock a little as well.
Then greased the Bbl. lightly with Vaseline, slightly overfilled the pockets with bedding compound, and then mounted the action tight.
After the bedding cured, removed the tape forms and chamfered the edges of the bedding blocks with a little sand-paper to clean them up.
It has shot lights out ever since.
GR
