Accuracy help, factory Kimber Montana 300wsm

Hey all,
I'm diving down the accuracy issue wormhole with my father in laws 10-15 year old Kimber Montana, 8400 in 300wsm. I've been dealing with some pretty significant "flyers" while hand loading for this gun. One round hitting 5-6" off while shooting 100 yards. My ES and SDs are all within 10fps as well so I'm scratching my head. I noticed the barrel isn't "free floated" on this rifle and was wondering if anyone has experience with a similar rifle or gun. Should I try to bed the action or free floated the barrel? Or do I need to keep experimenting with the current set up, my hand loads, or is there something else I'm not considering.
Thanks

As a general rule, if the rifle is factory-intended to have a free-floating barrel yet there's contact past the first inch or so from the breech end of the barrel, a good first try to eliminate flyers is to ensure the barrel is free-floated. One of the product features of Kimber rifles is to have them light for caliber (this is something they focused on more after the early 2000s), and also to have an aesthetically pleasing rifle which implies a reasonably close wood-to-metal fit. Depending on how you rest the rifle at the bench you can get unintentional stock to barrel contact.

Have you pulled the action from the stock to see if there's a thin pad of bedding at or near the forend that contacts the barrel? Sometimes gunsmiths try this... I haven't seen this in a Kimber factory rifle, but my experience runs only from the 1990s to the early 2000s.

I would try shooting the rifle from the bench with the rest being closer to the action and further away from the muzzle/front end of the stock. You could test this theory by having someone hold the rifle so that it rests in various positions from close to the action to close to the end of the forend, and have someone else try to slide a piece of paper (target strip, dollar bill) from forend to action and see if there's any contact. If there is, I'd try to eliminate it as one less variable to worry about.

Check that the front base screw isn't too long and bottoming-out before tightening.

Front action screw can also be a touch long and run into the raceway contacting the lug.

Magazine box can get a little caddywhompus and bind up putting a little torque on the action, not letting it sit properly in the stock when assembled.

The WSMs buck enough in a sub-7lb gun that they can be a little hold sensitive too.

Do a search on trouble shooting Kimber Montana over on 24hourcampfire. There is a list of things to do and check.
Hal

OG-danimal said:

Hey all,
I'm diving down the accuracy issue wormhole with my father in laws 10-15 year old Kimber Montana, 8400 in 300wsm. I've been dealing with some pretty significant "flyers" while hand loading for this gun. One round hitting 5-6" off while shooting 100 yards. My ES and SDs are all within 10fps as well so I'm scratching my head. I noticed the barrel isn't "free floated" on this rifle and was wondering if anyone has experience with a similar rifle or gun. Should I try to bed the action or free floated the barrel? Or do I need to keep experimenting with the current set up, my hand loads, or is there something else I'm not considering.
Thanks

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I purchased a factory Kimber 84L Hunter in .30-06 in 2020, had my GS re-chambered to .30 Gibbs, and installed a muzzle brake. It is not bedded (except for the 20 MOA rail), but I am getting under 1 MOA at 200Y with 190 Bergers during powder pressure testing.

Make sure everything (all screws, including mounts, rings, etc.) is secured/torqued to spec and no interference. Bedding/free-floating never hurts. Good luck!

Hey, all I'll say is good luck. I had the exact same rifle, I tried everything I could think of and ideas I found online. I can't remember how many different loads I tried. After being frustrated for a couple years, I sold it. Best decision ever!
I seriously hope you get it figured out
Take Care

Is the flyer consistent, i.e., is it the same round in the group, or is it random?

If it is the same shot at the end of the string, then, in my experience, it is either a contact point along the barrel, or it is the shooter. Many times it is the latter, especially with lightweight rifles shooting larger chamberings.

If it is random, then check the usual suspects (screws and scope). There was some good advice previously regarding making sure the front action screw isn't too long. The same thing should be checked for the front scope base screw.

If I remember correctly, these sometimes had an issue with the magazine not letting the action sit correctly in the stock.

This first reference also shows the next two. Maybe one will help you.
Best of luck!

If this model has the yellow/green plastic stock with pressure point at the fore end and is hollowed out in the moulding, you will need some serious bedding done to stiffen the stock before free floating the barrel. I had one 8400 Montana, from the 90's, it would always print the third shot 4" away from the first 2. Didn't hang onto it long.

Apart from that, they are a very nice rifle. You could change stocks.

Cheers.

Best day of my rifle owning life was finally getting rid of my Kimber Montana, piece of junk.

A friend bought a Montana in 270 Winchester that would shoot two inch plus groups. I bedded the action from the recoil lug to the tang. Afterwards he reported the groups at one half inch.

MtnTrax said:

Make sure the mag box isn't binding putting torque on the action. I have owned about a dozen Montanas and all shot sub MOA after floating the mag box.

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What do you mean by floating the box mag? Like taking out some metal?