loose groups with 168gr match hpbt

D

DanManOkc

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I currently have a Savage 10FP chambered in .308 with a Bausch and Lomb Elite 4000 6-24x on top. I had glanced at an article online about a guy with the same gun who couldn't get the Sierra Match King 168gr HPBT bullet to print very tight groups. I have the same problem. I have tried working the load between 2600 and 2800 fps with a number of powder combinations and have gotten horrible results with that bullet. I handload all of my loads with RCBS competition dies.
With a Sierra Game King 165gr HPBT I can shoot 1/2-3/4 moa groups all day with a moly-coated bore. The 168gr Match King won't shoot under 1 moa consistently. The twist on my rifle is 1 in 10in and I know many other rifles use a 1 in 12 or 1 in 11 twist. Does that have anything to do with it? My father also has the same problem with his 10FP, so its not just my gun. Well, you know the old phrase, "If it aint broke, don't fix it." I will continue to happily shoot 1/2 moa groups with my Sierra Game King 165gr loads but I was just looking to see if anyone had any ideas. Also, has anyone tried that John Plaster Sniper Stock that Choate makes, is it worth the money? Thanks for your time everyone.

Daniel in OKC
 
I shoot 168 MatchKings, over 40.5gr of Accurate 2520, out of Lake City Brass, out of my 110FP. Unless I mess up I never go over 1/2 minute,and often shoot 5 shot one hole groups. As to your rifling 1 in 10m is faster which means it sould be better at stablizing heaver (longer) bullets. unless there in some differance in the way you are seating the bullet (it should be just short of Contacting the lands) or you are crimping them too much for that style bullet (no Canalure) the Matchkings should get nearly the most out of your rifle. You might play with your crimp and you seating depth and see if that helps.
 
Is your rifle "out of the box"? Or have you done any re-bedding? Any other tweaking?

Some rifles are just more finicky than others, and sometimes tuning helps. There are some other threads on the subject here in the rifle-forum...

Following up on RVDL's comments, vary the seating depth, and try 0.1-grain variations in your powder charge...

I commonly load three or five rounds in each increment of charge, and color-code the cases for testing in load development. You can try the same deal for seating depths.

Think of the hours of fun in trying different primers, and different powders until you achieve perfection! :-)
:-(?
 
Try running a box of factory match ammo. All the big guys use the match-king bullet in their premium ammo. This will narrow down if it's your rifle or the bullet itself and will also help isolate if it is a reloading problem.
 
Thanks for the tips guys, the rifle is brand new out of the box. I'll try seating a little deaper and mabye try some loads using IMR powder or something different than 2230 or 8600. And I have been wanting to run some match ammo through the gun but just haven't shelled out the bucks for it yet. By the way, does anyone have one of those sniper stocks made by Choate? Do you like it?
 
I think there are some variables that should be presented in order to determine if it is mechanical ballistic or human error. When one determines "loose Groups" one should consider what determins loose. Additionally; how many shots are being used to determine the group?

Is the group of a consistent design. By that I mean, is the group together, or do you have one maybe two rnds out of the rest of the group.

How is the group being presented. That is; Are you using an "earth level" machine bench rest?

Are you using sand bags? If so what type, cloth or the army plastic?

Are you using a "cold shot" procedure or fouling then a prescribed number of shots?

You had mentioned that you reload and there are also variables to consider.

This is a "marrying process" and can be tedious to determine which load is correct for the rifle. This is true even when using Factory Loads.

Consideration must also be taken regarding the weather. Temp. Humidity etc. If you are "sandbaging," no pun intended, light, and direction of light has to be taken into consideration.

Within the "stacking principle" of your deteminations, are you recording all of the procedures, combinations and methods you are you are using?

As I remember, you were shooting new out of the box. Again there is a "stackin principle" to consider.

Is the barrel free floated?
If so: is it clear throughout the lenght of the barrel? In my opinion this free float should start @ the receiver.

Is the stock wood or synthetic?

What type of mounting system is provide for the rifle in the stock?

If the stock is from the mfg. does it Fit the shooter?

If a scope is used, is the eye relief the same each time?

Is the trigger finger placed the same place on the trigger each time?

All of these factors can only be ans'd by the shooter and must be ans'd objectively or the results will be inconclusive.

HJN
 
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