Range Report Groups open up at 300 yds?

[silentdave1985]

I reloaded some 165 sierra gamekings for my 308 and at 100 yards I can shoot a half inch group. When i shoot at 300 it opens up to an 8 inch group. Do i need to keep working on a load or could my barrel be bad. It is an older pss. I can shoot my buddies gun into a 1.5 inch group for reference at 300 o his new savage.

Thanks for any advice.

 

[Captain Kirk]

Re: Groups open up at 300 yds?

May need more load development. I try to do my load work at distances of 300+ to get a good idea what is going on, I have had loads that do well at 100 and not as good at longer ranges. Do you check your velocity and ES when working up a load? What do the groups look like?

Kirk R

 

[trailrider121]

Re: Groups open up at 300 yds?

Welcome to the hide. You may want to try some good Federal Gold 308 win factory ammo, to give you a good baseline. If it shoots well at 300 yards, then you know its your hand loads.

 

[VTi]

Re: Groups open up at 300 yds?

Yeah, going to need some more data. Either chrono speeds/spreads or at least tell us if the 8" 300yds groups are mostly vertical dispersion.

When the bullet leaves the bore, the "load" doesn't really matter much anymore. Provided the bullet/load you're shooting is stable at 100, a .5" group can't really turn into an 8" 300yd group. (This is assuming you are loading fairly consistently and don't have horrible velocity swings).

My guess is you probably have an optic set up parallax free at 100, then shooting WITH parallax at 300. If your shooting position/technique is less than perfect, AND have parallax within your optical system, you could very easily open a group up to several inches at 300 yds.

And yes, welcome to the Hide.

 

[MALLARD]

Re: Groups open up at 300 yds?

100y groups are meaningless

 

[silentdave1985]

Re: Groups open up at 300 yds?

I will have to give it all a try. I am using reloader 15 at 41.5 grns averaging 2420 fps and if i remember correctly i am only 10 to 20 fps apart from each shot. Are the bthp gamekings a good bullet for accuracy and hunting or do i need one bullet for each role?

Thanks for the suggestions.

 

[leadbullet]

Re: Groups open up at 300 yds?

just about every load can shoot 1/2 inch at 100 yds and it means nothing. try developing your loads at longer ranges, that is where they get sorted out.
hope this helps.
cheers.

 

[stranded]

Re: Groups open up at 300 yds?

A cheap digital scale weighting bullets can make a difference. SGKBT are good if weight sorted.(1/2gr)

 

[jakelly]

Re: Groups open up at 300 yds?

How does is the group open up? Stringing vertically, horizontally, or just opening all around? How many shots at 100? How many 1/2" groups?

 

[milo 2.0]

Re: Groups open up at 300 yds?

I don't shoot .308, so I'm not the most knowledgeable. What load does your buddies gun shoot well at 300?
The 165 game king has really low bc, the farther it gets from the muzzle, things happen. And from reading on here, your velocity seems way slow. So any breeze at all is going to rock your bullet.
Get a match king or amax and try some.

 

[2Shots]

Re: Groups open up at 300 yds?

I agree with all the above. Get a box of factory loaded match rounds and shoot at 300 or more. Get a load that moves a little faster with a higher bc bullet. Most guys shoot varget in the 43 to 44.5gr range and a 175 bullet or similar. I am assuming your twist rate is ok and have a decent scope and ring/base set up. I wouldn't throw the gun or barrel out yet. But 1/2" to 8" at 300 is pretty extreme.

 

[Tx_Flyboy]

Re: Groups open up at 300 yds?

Silentdave,

I disagree with all the posters so far.

You are likely experiencing what ails most shooters the first time they attempt to shoot at distance...PARALLAX error.

Your problem is likely with the parallax adjustment on your scope.

Perform this simple test:

Whilst looking through your scope at 300yards, move your head just slightly to the left or to the right. Does the crosshairs appear to move in relation to the target? If so, then you are experiencing parallax error. Adjust the parallax on your scope until the corsshairs do not move in relation to the target.

I too experienced the same thing you have when i first went out to 300yards+...my 1/4" & 1/2" groups at 100yards opened up to 6-8in. After correcting for parallax, i was able to get my groups down to 1.5"-2" at 300yards.

There is nothing wrong with load dev. at 100yards...it is preferable in some instances as it eliminates interference from environmental factors.

You mention being able to shoot your buddy's rifle into a 1.5" group at 300yards. Was the rifle already dialed in at 300 by your buddy?

Best