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View Full Version : I've Almost Done It IV: A New HELP!



Josh Smith
07-17-2010, 10:11 PM
Hello,

Yes, I skipped the "I've Almost Done It II" & III because the pun was just too good :D

In my ongoing quest to get sub-MOA 100yd groups from bulk ammo, I sort by weight and modify using D Rock's tool. I've recently switched to American Eagle 38gn HP. The bullet weight and powder charge are very consistent, but the cases are not - they seem to vary largely on the amount of priming compound, and some are therefore louder than others.

I come sooo close to sub-MOA 5 shot groups many times, and have broken it numerous occasions if I throw out a flier or two, but there always seems to be one or two that prevent the sub-MOA five shot group.

Here are two of the best groups I managed tonight, out of a total of three groups:

http://i19.photobucket.com/albums/b191/WabashShootist/Guns/hollowpointer/6615a37e.jpg

http://i19.photobucket.com/albums/b191/WabashShootist/Guns/hollowpointer/6cb3f5c5.jpg

As you can see, three are sub-MOA (with one three shot group being almost 1/2 MOA at 100yds!). However, I have vertical stringing.

I need to see if I can get some help with that.

My front rest was the rifle's bipod, and the rear rest was a squeeze sock.

I shot prone, sniper style (vs the one leg bent position I'd been taught).

I know I had a little vertical movement, but this much?

The wind was dead calm. I didn't have to adjust windage at all.

Do you suppose I'm at the mechanical limits of the gun, my own limits, the limits of the ammo due to the inconsistency of the primer charges and the whole sonic barrier thing, or all or none of the above?

My 'scope is a Mueller 4.5-14x APV. The rifle is a Savage MkII BTVS that I pillar bedded. The barrel is definitely free floating.

Torque on the action screws are 55in-lb front (this one has been modified to take a main bolt) and the rear, being stock, takes about 25in-lb or so.

Is there something I should be doing that I am not? Or am I just pressing the limits too much?

What do you all think?

Thanks,

Josh

JKH
07-28-2010, 02:35 PM
Howdy!

I find this very fascinating & recently ran across some forums for .22 benchrest shooting, it is very big in the UK and other places where larger calibers have a dim view taken of them, it seems to be growing in the US as well.

I have a Gun Digest from the 70's with a great aticle about Ed Harris where he and another fellow did some bench experimenting with .22's, they changed a single shot Winny 52 to a clip fed, added a scope and went to town.

Long story short, old Ed claims that bullet diameter is the best way to sort .22 rimfire ammo for accuracy, they went through a significant amount of ammo of all ilk's and his data does tend to prove this out. Its worth a try, I would reccomend using a micrometer but I suppose a good set of dial calipers would work well enough, at least for an initial trial.

I have a CMP USGI Kimber model 82 that I have been playing with, using bulk box Wally World ammo (Federal or Remington) I can put all shots in one little hole at 50 yards but ALWAYS have fliers :^( I had that gun digest out and ran across Ed's article and decided to mic some bullets, WOW! you would not believe the difference in bullet diameter! its no wonder I kept getting fliers. I have 50 rounds that I segregated into groups by diameter (I didnt get too crazy and kept bullets in group as long as they werent more than half a thousandth out) and will see what difference it makes in my old Kimber soon, I'm betting it will be a lot.

In case you're wondering why I would feed a rifle like that cheapo Wal-Mart ammo, well, I am cheap! Plus it is very hard to find good quality match ammo where I live and I wont pay premium price for it plus shipping to get it. I will get some CCI Mini Mags on occasion but want to make the most of the bulk amo I can, without cherry picking ammo it will shoot well under 1/2" all day with this stuff, but I hate having one ragged hole groups ruined by one or two fliers from a 13 pound target rifle with a 32X scope!

Keep us posted, I hope you try this method so I can be lazy for a while longer ;^)

Jeff (JKH)

Josh Smith
07-28-2010, 06:04 PM
Hello,

The accurizer I have makes the bullets a uniform .2245". You might contact D Rock on Rimfire Central and see if he has any in stock yet.

I am finding that rim thickness is very critical. The benchrest shooters I've talked with say to sort the ammo by rim thickness, then by weight. I had been doing by weight only and getting fliers.

What I am finding is this stuff can be very, very accurate, but only if sorted into lots. I usually get three lots out of one bulk box.

Josh