Accuracy question...

[MOUNTIN DU]

here's one for ya. i just posted earlier about missin' a nice buck at 75yds chasin' a doe. broadside, trottin', not that hard to do... right?
well, i posted a couple months ago (with pic) about removin' the izzy and replacin' it with a thread protector that a machinist friend made for me. now, after two successful huntin' seasons and honest 1 to 1.5" groups at 100yds my gun shoots 3" low, 3" right at 50yds! could this be a result of the removal of the izzy comp? i didn't adjust my scope until i replace the izzy and shoot it again. i feel like an idiot for not shootin' first but who'd a thunk i would make a difference? is it me, the scope, or has anyone else noticed a change in poi with the removal of the izzy.

[Texas Sheepdawg]

When I swapped out the Izzy for the Ross, my POI did change a bit, but I can't remember for sure. I think it changed impact a bit more to the left and a tadpole higher. But I didn't think to document it. I just adjusted for the change and kept shootin'. But what I did notice was the recoil was more of a push and follow up shots were tighter.

[Texican Hairless]

:shock: here's one for ya. i just posted earlier about missin' a nice buck at 75yds chasin' a doe. broadside, trottin', not that hard to do... right?
well, i posted a couple months ago (with pic) about removin' the izzy and replacin' it with a thread protector that a machinist friend made for me. now, after two successful huntin' seasons and honest 1 to 1.5" groups at 100yds my gun shoots 3" low, 3" right at 50yds! could this be a result of the removal of the izzy comp? i didn't adjust my scope until i replace the izzy and shoot it again. i feel like an idiot for not shootin' first but who'd a thunk i would make a difference? is it me, the scope, or has anyone else noticed a change in poi with the removal of the izzy.

It's normal to see POI change a bit when you swap muzzle devices. 3" at 50 yds is a pretty good distance to have POI shift. What kinda scope/mount are you using?

My POI shifted less than an inch at 100 yds when I installed Ross' brake on my 16" pipe. Sounds to me like maybe your scope got bumped a bit. If you're still shooting nice groups, just low and right then that's probably what happened. Or... maybe a combination of all of the above???

[bushmeister]

When we were testing muzzle brakes, I remember seeing a significant shift with the removal of the Izzy, but I don't remember which direction. Remember that harmonic distortion you were talking about a few months ago?.... you likely changed that when you removed the brake. Easy way to find out is to put it back on and see where it shoots!

[tridentarmory]

IMHO the excellant accuracy of the factory ammo in the .450B is due to a chamber/barrel/twist designed for a specific cartridge/bullet. And, they got it right.
BD

funny you say that, but we found that as soon as we went heavy with projectile, we had to twist it up more/// the 1-16 is our fav.

[Texas Sheepdawg]

IMHO the excellant accuracy of the factory ammo in the .450B is due to a chamber/barrel/twist designed for a specific cartridge/bullet. And, they got it right.
BD

funny you say that, but we found that as soon as we went heavy with projectile, we had to twist it up more/// the 1-16 is our fav.

I think I am gonna like this guy hangin' around......

[wildcatter]

IMHO the excellant accuracy of the factory ammo in the .450B is due to a chamber/barrel/twist designed for a specific cartridge/bullet. And, they got it right.
BD

funny you say that, but we found that as soon as we went heavy with projectile, we had to twist it up more/// the 1-16 is our fav.

Hey Jimmy, how the heck are ya and welcome to our little campfire?

Yup, a 16t barrel is better for bullets heavier than 300gr, but then again when your trying to stabilize all the bullets, in this caliber (which are totally awesome in their numbers), trade-offs are in order. And if I were to make just a moose gun for say a single bullet of say 300-350gr then a 16t would be the better choice, hands-down. But, as their are so many other fine "Moose" bullets that start life out in the 200gr+- area, then a 16t barrel often causes them to self destruct, on some occasions, let's hope that-that occasion, isn't when something bad, is bearing down on you.

Dedicated barrels and specific twist, for specific bullets, aren't for some, but for the Selective Shooter, they can be the only thing..

..t

[tridentarmory]

i aggressively agree, we play with loads frequently, and while loading some stuff at the shop for my 454 casull recently, i used some 185 grain hp ranier projectiles in our 16t 450+p, and they were going through the paper shaped like a star at 50 yards....
not what we wanted... but then again, i bet the soft tissue trauma would be dramatic.

Usually when we go small, we are using a fmj projectile, which definetly helps keep it together at high rpms. thing about a .451 projectile at 2800+, they tend to tumble upon impact... which again makes me smile a little.


Ive been searching for a quality manufacturer of barrel blanks in the 1-18 or 1-20 rates.... havent found anything..
We did bump into an old rifling machine though, ive made an offer.


wildcatter, have you found a happy rpm rate for the .451 projectile...? we have noticed that when people publish data, frequently you will notice potential patterns in the rpm rates for accurate loads within the dimention of the projectile, Not many people pay much attention to this, but none the less, i definetly notice patterns...... (sometimes i do a terrible job explaining things)

[wildcatter]

i aggressively agree, we play with loads frequently, and while loading some stuff at the shop for my 454 casull recently, i used some 185 grain hp ranier projectiles in our 16t 450+p, and they were going through the paper shaped like a star at 50 yards....
not what we wanted... but then again, i bet the soft tissue trauma would be dramatic.

Usually when we go small, we are using a fmj projectile, which definetly helps keep it together at high rpms. thing about a .451 projectile at 2800+, they tend to tumble upon impact... which again makes me smile a little.


Ive been searching for a quality manufacturer of barrel blanks in the 1-18 or 1-20 rates.... havent found anything..
We did bump into an old rifling machine though, ive made an offer.


wildcatter, have you found a happy rpm rate for the .451 projectile...? we have noticed that when people publish data, frequently you will notice potential patterns in the rpm rates for accurate loads within the dimention of the projectile, Not many people pay much attention to this, but none the less, i definetly notice patterns...... (sometimes i do a terrible job explaining things)

Shore Have.. As a matter of fact, I started the notion that rpm is a more important consideration that many other factors and years ago published a formula that is well used in the industry now. Witness, I have twists/rpm's that stabilize the FMJ's at 3000++fps, at speeds where even FMJ's come apart, where they not only stay together, but track straight through very-very thick flesh, without tumbling (as a 25 year PH, Tumbling is a detriment, as in, you can't predict the wound channel and might wound the animal by a deflected bullet, that can then become very dangerous to ourselves, in the aftermath). But is best used by guys like you and I, when incorporated within strategies, that make such knowledge even more valuable, something the Biggies don't understand, yet.

PM me a phone number and a time to call and I'll give you a foot up..

..t

[Hoot]

...snip... have you found a happy rpm rate for the .451 projectile...snip

I'd guess around 75-80K RPM for the 250gr FTX.

Hoot