Has anyone ever put an MPI stock on a big bore rifle?? I found a 500 Jeffery for sale that has an MPI stock. The rifle weighs 12 pounds and the seller attributes the rifle weight to the stock.

Apart from the weight, would this be a good stock for a big bore rifle?

They are foam-filled fiberglass.

If the stock is heavy, it is only because of the block of oak put in the foam filling of the butt to attach the recoil pad,
plus the layers of epoxy that had to be applied to the exterior and shaped and sanded to make the forearm look almost symmetrical and with the barrel channel almost centered and straight,
plus all the layers of primer and paint over that, and some steel crossbolts and some pillars hidden inside by the furious fitter of the stock.

That is how I got my one MPI stock so heavy, and I will never do it again.

You can make an accurate-shooter-stock out of one, through major rebuilding, body shop style.

I had the M14 stocks. Best way to describe it is crushed up Styrofoam coffee cups and some wood glue. I was embarrassed to give them away.

McMillan stocks are literally a club as far as strength goes.

I haven't seen a stock MPI stock that would weigh well over 4-5 lbs. the weight is due to additional weights added like lead or merc tubes

12 is a HEAVY 500 jeff. Mine is weigh (pun intended) under 10 and is easy to shoot. Where in Texas are you?

12 is however going to be fairly easy to shoot assuming decent stock layout.

I have used a number of them with varying degrees of success. I have one on my 505 that I beefed up with Devcon steel mixed with lead shot in both the forend and grip and it now weighs around 4 lbs and has held up very well. I also have another one that has a magnum fill and was on an 8 1/2 lb .500 Jeffery ( that now has a fancy wood handle) and I like it enough that I am switching it to a new 458 Win.

I have one on a .416 Ruger (Remington action with drop box) and the whole rifle with scope and empty is 8.5 lbs. I have run about 150 full power 350 gr. at 2555 fps. through it and haven't seen issues. It has held up well.

YMMV

On these forums you can find virtually every product in the gunworld badmouthed,I love the MPI stock on my Norma and wouldn't hesitate to buy another if needed for any rifle.

I would use the MPI only if I had no alternative.
There are so many better stocks, usually,
but you can make an MPI work if you have to.
They are necessary for oddballs, rarely.