Ok ! ..really need some help here..!

[jaycee]

Hi all,
I'm hoping someone can figure out what theheck is going on here.

Saturday I took my new Sako 75 Varmint .223 to the range for a little ammo testing. For those who wonder what that is .. Its got a 24inch free floated heavy barrel with a 1 in 8 twist, Walnut varmint stock, adjustable trigger and is a thing of beauty. I have read test reports of these shooting around 1/2 inch -100yd groups.

Back to the story ..

I mainly wanted to check out what would make for good cheap plinking ammo with acceptable results and I'd be prepared to accept the odd flyer or two.

Boy was I in for a surprise !:banghead:

Federal AE FMJ-BT 55 Gr ... would occasionally (Very rare) shoot two in the same hole , and then spread the rest over a 6 inch area. Mostly they would just shoot all over the place .

Remington UMC MC 55.. were much better , not target ammo better but a fast 7 shot string was about 2 inches .. I could have improved if I'd slowed down a tad. But ok for plinking ammo !

So.. I got home , checked the Remington website and then the Federal website .. and guess what ! They both kick out of the muzzle at 3240fps ...
So how come the huge group size difference...?

Over the course of a very long day the pattern was repeated after cleaning , cooling etc.. I am really at a loss !

BTW : If anyone has suggestions for .223 ammo that worked well out of a 1 in 8 twist ..feel free to save me some time and money

Joe

 

[LkWinnipesaukee]

hot barrel?

 

[jaycee]

Nope ,

Wish it was that simple ...

You'd probably need to rapid fire half a box through this one to make it feel warm.. Besides , I kept a check through the day and quit to clean with Forest bore foam a couple of times .. which needs around 20 mins to work .

 

[browningguy]

It may just not like the first load you tried. With a 1:8 twist I'd be shooting heavier bullets. Try some 62's -77's and see how they do. There is no ryhme or reason as to why a gun may only shoot certain bullets well.

 

[jaycee]

OK .. I accept that .

What I can't really figure out is why two pretty much identical ammo types with pretty much the same weights, velocitys and ballistics would shoot so differently... ?

 

[db_tanker]

diffrent powders, diffrent bullets, diffrent brass...

when you get into reloading, you will find that any one of those three items will throw your ammo out like you were gunning for a duck.

Browningguy said what I was going to...


your twist rate is right up the 62 gr bullets alley....go for that or mebbe a touch heavier...

D

 

[jaycee]

Ok Guys,

Thanks for the tips , I will try the heavier bullets.

At the moment , I'm stuck with factory ammo , but I hope to get into reloading maybe next year.

I guess I was a little shocked at how bad it would shoot some of these , made me worry that my new "Tack-driver" was more of a "Post-driver"

Joe

 

[byf43]

db_tanker wrote:

diffrent powders, diffrent bullets, diffrent brass...

when you get into reloading, you will find that any one of those three items will throw your ammo out like you were gunning for a duck.

Browningguy said what I was going to...


your twist rate is right up the 62 gr bullets alley....go for that or mebbe a touch heavier...

Agreed, 100%.

jaycee, Try some Federal 69 gr BTHP Match ammo, or, Winchester 69 gr. BTHP Match ammo. Your groups should shrink. . . immediately!
The point of impact (POI) might be different, or even way off from your original groups, but, you can always move your point of aim (POA) to get the groups where you want them.

When you are ready to start reloading for the .223, there is a plethora of information out there.

Me. . . . my AR-HBAR really likes my load of Hogdon's H-335 and Sierra 69 gr. BTHP bullets in Federal cases and Federal primers.
The same load in Winchester brass is just as good.

This load not close to maximum, but, shows no 'over' pressure signs in my rifle.

 

[rangerruck]

flat base bullets in 100 yds or less USUALLY , i say usually are more acc if made right. I'll give you 2 great suggestions. Plain ol blue box black hills 55 grains. 13 dollars for a 50 round box, and winny 45 varmints, white box 11.00 per. 40 rounds
here lemme show you mine at 100 yds through a cz.






that top little mark up to the right by the black hills is not a bullet hole, but a pen mark
I scratched out, for wind speed. As you can see, the winny's are truly a one hole hit.

 

[jaycee]

Nice shooting ..!

I don't think there is a local supplier for Black hills ammo here,
It's a pity , I have heard some very nice things said of it.

Problem is...Like the guys said , the lighter stuff might not be so good with my 1 in 8 twist.

 

[rection47]

from what ive read 55gr isnt very stable after leaving a barrel with that kind of twist rate, a heavier bullet should do better. But then again, this is just from what ive read, i have no experience with that gun. Or any .223s

 

[jaycee]

managed to pick up some Hornady 75gr Match and some Remington 69gr match,
Can't wait for the weekend to try them out ......stupid job getting in the way of my shooting again,,,..