Kimber Mountain Ascent questions

[luke moffat]

Don't most muzzle breaks reduce recoil AND muzzle flip?

 

[Floorguy]

Don't most muzzle breaks reduce recoil AND muzzle flip?

I would think that with a muzzle brake, if it reduces recoil it would have to in someway affect muzzle flip. The only way to get the flip to be worse would to have a directional brake pointing down. At least that's the only way I could figure it.

 

[bradmacmt]

Don't most muzzle breaks reduce recoil AND muzzle flip?

No. A brake like the Kimber doesn't because gases are dispersed evenly all the way around, the bottom holes essentially counteracting the top holes (gas pushing down and up simultaneously, as well as side-to-side).

The KDF is designed, not as much as a muzzle brake, but as a way to control muzzle flip, having ports on top only. A KDF is not nearly as loud as a "normal" muzzle brake like what is on the Kimber.

The idea that the Kimber's is not designed primarily as a muzzle brake is just "marketing." It's loud, and in no way is primarily designed as a way to control muzzle flip.

 

[Floorguy]

No. A brake like the Kimber doesn't because gases are dispersed evenly all the way around, the bottom holes essentially counteracting the top holes (gas pushing down and up simultaneously). The KDF is designed, not as much as a muzzle brake, but as a way to control muzzle flip. A KDF is not nearly as loud as a "normal" muzzle brake like what is on the Kimber.

The idea that the Kimber's is not designed primarily as a muzzle brake is marketing BS. It's loud.

Kimber saying it doesn't affect recoil is laughable. So is you claim that their brake doesn't affect muzzle flip. Muzzle flip is a result of recoil. Plain and simple. Noise has nothing to do with whether something is a muzzle brake or not.

 

[bradmacmt]

I edited my post slightly while you were typing. But rest assured, the Mountain Ascent sill has muzzle flip as its design is not going to use gases in a way to reduce it... it disperses gases all the way round. That is not a recipe to reduce flip in any meaningful way. Certainly it helps some, but not like the KDF.

 

[bradmacmt]

As to the idea it's not noisy, here's what one "authority" says:

http://www.americanrifleman.org/articles/2014/4/21/kimbers-mountain-ascent/

"Nonetheless, I’d rather go without a brake in these calibers. I’d as soon carry a light rig up a mountain and take a beating behind the gun while firing a handful of rounds than subject my ears to the added abuse. Then again, not everyone does as much shooting in any given year as I do, and so I suspect many hunters will appreciate the brake. Make no mistake: This gun is loud. If a long-range session is in order, wear plugs and muffs (I always do regardless of caliber). In the field, it’s not a bad idea to wear one or the other.

During range sessions, many other shooters approached my bench to ask what caliber I was shooting, or to glance at the box of ammo next to the rifle. I’m sure they were dismayed to see it was only .30-’06 Sprg. In the field, hunters also may opt to unscrew the brake (with an included tool) and replace it with a thread protector (also included). If that’s the case, be sure to check zero with and without the brake installed to confirm point of impact with hunting loads before going afield."

 

[bradmacmt]

Regardless, choices are great. Nice thing about the Mtn Ascent is the brake can be taken off.

Still, having said that, I have no need for a rifle lighter than the "normal" Montana, and really wouldn't mind a bit more barrel weight, say 5 or 6 oz's, on them as well.

 

[tenth1]

In order to reduce "flip" or whip or whatever, you don't need the holes pointed only in a specified direction....

The rifle barrel is actually moving in a concentric movement as that bullet is travelling down the barrel, due to imperfect metallurgy. Depending on load, the bullet will leave headed either down, left, right or up (and any combination 360 degrees) as compared to true barrel trajectory.

In saying that, because all else is equal (break or non), there is absolutely no difference in accuracy, just shorter velocity "nodes". Nodes being harmonic balance with load in question and barrel composition.

 

[GKPrice]

That has to be, uh, interesting to shoot. Definitely wouldn't want to creep on the scope with that one.

My son and I both shoot Montana's in 325 WSM and that particular combo is not uncomfortable at all to shoot, even from the bench - I shoot 220 Sierra SBT and commonly print 3/4" 100 yd groups

 

[GKPrice]

I know I'm repeating myself but a gunsmith in Eugene OR, Richard Buss, has for a lot of years now been making a muzzle brake that he designed and patented quite a few years ago - He has turn OFF or ON models, he has adjustable models, he has plain old muzzle brakes but the defining factor with his brakes is that they are designed (and work, I've used many of them) to be and are no louder to the naked ear than a non-braked rifle - say what you want about them but until you try one you cannot understand that he is on to something revolutionary - I am going to stop by his shop tomorrow as a matter of fact
541-349-1290

 

[husky390]

My son and I both shoot Montana's in 325 WSM and that particular combo is not uncomfortable at all to shoot, even from the bench - I shoot 220 Sierra SBT and commonly print 3/4" 100 yd groups

Interesting because my .300wsm Montana gets annoying after an afternoon session of bench shooting. Granted, this is during the summer months when I'm in a T-shirt. Is the .325wsm more of a push, recoil wise?

 

[luke moffat]

Interesting because my .300wsm Montana gets annoying after an afternoon session of bench shooting. Granted, this is during the summer months when I'm in a T-shirt. Is the .325wsm more of a push, recoil wise?

Did 50 rounds at the range the first time I shot my 338-06 kimber Montana and it weighs roughly 12 oz with a scope on it than your 300 win weighs without a scope scope and rings so likely close to 1.75 pounds lighter than yours scoped. It sure my shoulder was sore the next day but rarely will I be doing much load work anymore since I have a 210 load going nearly 2800 fps and a 250 grain load that does almost 2500 fps. Which is pretty close to what 300 winmag gets for velocity with those bullet weights. But the way I look at it is if it doesn't make me flinch and can still shoot it accurately then that's fine for me. It's a hunting rifle not a plinker from the bench IMO.

 

[bearstalker]

Does the mountain ascent rifles come with a threaded cap or just the muzzle brake? Kimber shows the 300 WSM listed and it has me tempted.

 

[Stid2677]

The MA comes with a muzzle brake and cap to use when brake is removed.

 

[GKPrice]

Interesting because my .300wsm Montana gets annoying after an afternoon session of bench shooting. Granted, this is during the summer months when I'm in a T-shirt. Is the .325wsm more of a push, recoil wise?

Sorry husky390 ! this post was just before I was leaving for a long late season elk hunt and I was out of "RokSlide range" I wouldn't call 325 WSM recoil a "push", more like an "angry shove" ... in a package such as the Montana with a FG/Kevlar stock, good pad and efficient cartridge it just seems more palatable than many I've fired, probably a lot of subjective opinion between what "you" feel and what "I" feel too - I seldom shoot any rifle in merely a T-shirt either - I do have a PAST recoil thingy that goes on sort of like a shoulder holster that I often wear when it is warmer out (didn't think of that) but I shoot the 325 WSM Montana well off hand too, just a good combo for "me" it guess

Interesting thread on recoil, "perceived recoil" and muzzle brakes for sure - Richard Buss started deleting the holes on his "varmint" and "tactical" brakes due to dust and some debris being kicked up I know - I've never noticed any directional influence with any of them though - I did MagNaPort a fairly light 338 Win Mag a few years back and I DEFINITELY realized a difference in muzzle "flip" the first time out with it (so did my eyebrow !) I wasn't expecting a change in trajectory ) I think I need to "understand" that accuracy node nomenclature though ...........

 

[GKPrice]

Did 50 rounds at the range the first time I shot my 338-06 kimber Montana and it weighs roughly 12 oz with a scope on it than your 300 win weighs without a scope scope and rings so likely close to 1.75 pounds lighter than yours scoped. It sure my shoulder was sore the next day but rarely will I be doing much load work anymore since I have a 210 load going nearly 2800 fps and a 250 grain load that does almost 2500 fps. Which is pretty close to what 300 winmag gets for velocity with those bullet weights. But the way I look at it is if it doesn't make me flinch and can still shoot it accurately then that's fine for me. It's a hunting rifle not a plinker from the bench IMO.

Nothing like adding my $0.02 3 months late EH ?? Well, I chickened out on reboring this '06, AI'd it instead (I really like Ackley Improved) but you got me hyped on the chambering so I'm watching for that "right deal" to come my way on another to do a 338-06 and I might AI that one too, not for the added "performance" but to check case stretch - I realize it's not likely that I'll be shooting it all that much but there there really isn't much down side to an Ackley chamber IMO (IF it's done right)

 

[VernAK]

I think I saw a threaded bushing on Kimber's website.....the bushing will increase the barrel thread diameter up to can diameter threads....I think.

I don't have time to research hat the moment.

 

[bearstalker]

The MA comes with a muzzle brake and cap to use when brake is removed.

Thank you. I got one ordered!

 

[StephenMills]

Yes, the thread is 7/16 x 28
I own the Kimber Mountain Ascent in .308
The Kimber America site offers Muzzle Thread Adapter SKU: 4700055
This takes their thread from 7/16 x 28 to a 5/8 x 24 threaded muzzle which is more commonly fitting after-market brakes.
* For use with Kimber threaded-barrel mountain rifles.

 

[Odie_7]

Don't most muzzle breaks reduce recoil AND muzzle flip?

Yes. I would die a happy man if no one ever called it "barrel flip" again. Now to the drawing board.

There are 3 types of ballistics: Internal (which we are about to discuss), External, and Terminal (study this too for the sake of your quarry). Internal ballistics are what happen inside your rifle. External ballistics are what happens in flight; this is the main hype for most aspiring LR hunters. Terminal ballistics is what happens when your projectile hits the target. Barrel harmonics are a factor of Internal ballistics.

For every action there is an equal-and-opposite reaction. So, the propulsion of your projectile to peak MV results in two forces: a directional force (opposite of the acceleration of your projectile; basically into your shoulder) and a rotational force (resultant from your riflings causing the rotation of your projectile, also see Gyroscopic Stability). This results in barrel harmonics (aka barrel whip, barrel flip, etc.). From a side-view, this would look like a sine wave of your barrel during firing in ultra slow-motion. If we could watch the crown of your barrel, it would appear to go in an elongated, vertical oval of oscillation, opposite of your rifle's twist (e.g. right-hand twist equals left-hand oscillation).

The "nodes" are the apexes of the elongated, vertical oval that the crown is traveling. If a projectile exits on the long axes of the oscillation oval, slight inconsistencies in MV (also see Extreme Spread) would result in less accuracy. If the projectile exits at an apex of the oscillation oval (aka node), slight inconsistencies in MV will have less affect on accuracy, therefore greater accuracy.

Muzzle brakes reduce recoil and barrel harmonics by reducing the "equal-and-opposite" force that is created by accelerating the projectile to peak MV. The volume of gas in the barrel is forced out of the crown as the projectile accelerates, after ignition. This volume of gas is then redirected by the muzzle brake; this redirection is the 2nd equal-and-opposite force that reduces recoil. Reduced recoil means reduced directional and rotational force from acceleration of the projectile.

Back to the original intent of this thread, installing a suppressor will increase the rifle's overall length considerable, could require a thread adapter to fit the suppressor, and will result in a POI shift if you shoot with and without the suppressor, but I imagine that this is all moot, because the thread is so old....I was just researching the Kimber MA and wanted to squash this frivolous use of the term "muzzle flip".