Point of Impact NOT Changing With Bullet Brand?

[Josh Smith]

Hello,

I have a Savage MkII in .22LR.

When I first got it, there was a definite change in impact with change in bullet brand.

I got to playing around with the barrel - first I just put a Limbsaver damper on it, but then got to thinking about putting a controlled pressure point right in front of the action, so I did <span style="font-style: italic">that</span>, then I read someplace on the 'net about using rubber O-rings to reduce harmonics.

So my rifle looks like this:

Before, I'd have changes in impact if I changed bull type. Since those rubber mods, it's not been doing that, which is something I thought was not possible.

If I have a given bullet weight at a given velocity, I will still hit what I'm aiming at, down to a dime, at 50 yards with another bullet of the same weight and speed, but different brand.

With different weights and/or speeds, I may or may not have to adjust elevation.

Regardless, brand just doesn't seem to matter WRT POI any longer. Group sizes still change, but I can break it in with Blazer and shoot Mini-Mags, Winchester, Federal American Eagle, Federal Champion, Remington bulk, and heck, I don't know what all else I found in my stash.

The one other thing I'm doing is resizing almost everything I shoot to .225". This is what the chamber slugs out to. In other words, I'm sizing the ammo up so that the chamber acts like a semi-match chamber.

Comments?

Thanks,

Josh

 

[TOP PREDATOR]

Re: Point of Impact NOT Changing With Bullet Brand?

i'd also give it a try without resizing the ammo. perhaps that is the factor that is more relevant.

i tried the limbsaver thing (it was on clearance), turns out i put worse groups on paper with it that without it no matter were i put it on the barrel.

dfoosking is right, try the 100 yard thing and see what happens.

 

[Badshot308]

Re: Point of Impact NOT Changing With Bullet Brand?

Better yet, try it at 200 yards. 50 yards is too close to test this at. You'll need a dead calm day or evening to try this though.

 

[Badshot308]

Re: Point of Impact NOT Changing With Bullet Brand?

The OP wasn't talking about using his modifications to find the best load, but that different brands with the same bullet weight and MV were no longer hitting to different points of impact. He was testing this at 50 yds. If the rifle is still accurate out at 200 yds, then testing different loads at this range will really show if POI is changing or not between loads. A lot of shooters are pushing 22 rimfire to 200 and beyond. I don't do any 22 rimfire under 100 except for my GSG5 which isn't accurate enough at 100

 

[Badshot308]

Re: Point of Impact NOT Changing With Bullet Brand?

I was just thinking that 200 yds will show far more discrepancies between loads than 100 due to the ballistic performance of the round. However I agree with you that at 100 yds, they will definately show up much better than at 50. For the OP to test at 200 yds, he'll need a calm, windless day and a very solid benchrest position. Even centerfires usually change POI when changing between brands and even sometimes between different lots of the same load.

 

[Josh Smith]

Re: Point of Impact NOT Changing With Bullet Brand?

Hello,

I used to have to dial in windage for different loads. Now I do not.

I don't understand why.

I would have loved to have tried it at 100yds yesterday, but around here there was a shifting 10mph wind all day. Would have just corrected for a steady wind, but the shifting stuff, not so much.

Anyway, it's been dead calm a lot this summer, especially when humid. I made a set trigger for the rifle, and it's very easy to shoot sub-1.5" at 100yds with most ammo (including Blazer). I've broken 1" a couple times when I slowed down on the iced coffee

It's repeatable and I take squirrel out that far plus some.

I was just very surprised that the combination of the O-rings and the resizing of the bullets had that much effect. It's had the Limbsaver and controlled pressure point for a while now.

Thanks,

Josh

 

[Badshot308]

Re: Point of Impact NOT Changing With Bullet Brand?

Interesting, what are you using to resize the bullets?

 

[Josh Smith]

Re: Point of Impact NOT Changing With Bullet Brand?

Hello,

A feller by the name of D Rock over on RFC sells a kit, similar to Paco Kelly's but more robust.

It resizes to .224" from the box; I polished mine out with some rough sandpaper until it went up to .225.

I'm actually showing where the leads JUST touch the bullet now.

Josh