Group Size improvement?

[Willem .243 musgrave]

Hi guys

I want to know if there is anything I can do to make my groups smaller?

My brass prep:
Clean cases inside and out with tumbler
Only neck size cases fire formed in my chamber
Trim case length to same size
de-burr flash hole
Case neck turning
Deburr and chamfer case necks
Use cases from the same manufacturer

I then prime each case with CCI 200 primers from same lott, weigh every charge identically(powder is from same lott and I shot loads that differ in .5grains from min to max load til i got the best result consistantly), and seat the bullet(87 grain hornady V-max) about .002" off the lands.

I can shoot consistent groups of .4" @ 100 meters.

But would like to get them smaller, I have a .243 hunting rifle with a 24" barrel and 10" twist rate, is this the best I'm going to get or can I go smaller?

Any tips or suggestions?

 

[LHSmith]

What type of rest set-up are you using? How are you gauging wind? Does your scope adjust for parallax?
.4 " inch groups will be hard to improve upon.
However, Neck sizing is not the best method for consistency. Minimal shoulder bump with FL die is best. I do not favor neck turning for a factory gun...unless the brass is that bad.....there's enough slop....you're just adding more. Look up the Audette ladder for determining best loads. I would separate my brass according to number of times fired.....the 2nd thru 4th should give best accuracy until the necks become work-hardened and bullet release becomes inconsistent.
If your going to weigh every charge, then I would segregate the cases by weight.
Internally clean cases are said to be necessary for 1000 yard comp....I don't believe in your case that you will see any difference on paper.

 

[Willem .243 musgrave]

I'm just using sand bags to shoot from(prone). I have a 6-18x44 redfield revenge varmint scope that has parralax adjustment. I have to neck turn my cases otherwise some cases prevents me from closing the bolt, even if I do FL sizing. Think my chamber is cut very tight. I normally wait for the time of day when the wind is not blowing at all, or just a light breeze you can barely feel on your skin when I do load tests.

But thanx for the advice, think that I would give more attention to case weight and times fired.

 

[jcampbellsmith]

..... shot loads that differ in .5grains from min to max load til i got the best result consistantly), and seat the bullet(87 grain hornady V-max) about .002" off the lands...

Sounds like you have things in good shape already. Two thoughts, try bracketing your best load by +- 0.2 grains, secondly, try moving the seating in and out gently once you have your ideal powder weight. Finally, try various targets until you get one that really works with your scope reticle and magnification.

Good luck. JCS

 

[Cakes]

.4" for 100m is not that bad, actually fairly average for a production hunting rifle with a 24" barrel IMO. If you're going to "wring out" what it's capable of you need to reduce all the variables; loads, gun, optics, range conditions..and then you might still only get .4"! As stated bumping the shoulders minimally with a Fl die without the resizing button (use a redding bushing of the appropriate size) will go a long way in uniforming your loads. The resizing button can produce significant amounts of run-out in your loads. If you wanted to go to the "nth" degree, use bench/f-class reloading techniques, slap a high quality target scope on it, get a stable front rest with a rear bag and head to the range on a calm morning with ammo that is of target quality..run-out less than .002, consistent light trigger pull and have at it. Trying to make a production hunting rifle into a target rifle can become quite futile IMO. Aside from your loads, a crisp trigger pull and good optics will go along way. Probably better off accepting the 1/2" group and head to the range and practice your shooting techniques...off-hand!! Good Luck, Eric in DL

 

[LHSmith]

So, it is not a factory barrel? Also, way, way more important than any of those preps you listed in your post is the conditions you shoot in. You need to put survey tape at intervals between you and target. It is not unusual at ranges here in the Northeast for breeze/wind to blow in several directions simultaneously at different yardages along the flight path. Be aware shooting off the ground that mirage is heaviest at ground level, and also various light conditions will affect where the bullet goes.

 

[bheadboy]

it seems you have done a good basic job and are getting 95% -- a couple of additional suggestions

weigh your cases and sort to =/-.5gr,
try backing off to jump as much as .020/1000 -- it is almost difficult to consistantly seat .002 off and some may be touching while others are not
shooting prone off bags is not the best test system, if you can get a bench use a front and rear rest with light shoulder pressure
lastly the 10 twist is going to keep you in 90gr or below range and with you using the v-max i assume this is for light game or varmint -try the Sierra 70 gr blitzking, it should give you 3300-3400fps and be accurate.


good luck
Bob

 

[GSPV]

Has the action been bedded?

IMHO, 0.4" is outstanding for prone from sandbags, without windflags, from a hunting rifle.

 

[Corvette0096]

Tony Boyer’s school.

 

[Willem .243 musgrave]

Yes the action has been bedded, the barrel is also fully bedded up to the end of the stock.
Do you guys think shooting from sitting at a bench will give better results?

The weird thing is that my rifle actually shoots at least .5MOA with the Sierra 100gr Gamekings, but maybe it won't be stable at longer distances i still have to do some long range tests.

Thanx very much for all te input from everyone so far, info like this is greatly appreciated by beginners like me!

 

[.260 james]

0.4" is outstanding for prone from sandbags, without windflags, from a hunting rifle.
[/quote]
AMEN

 

[FroggyOne2]

If I had a hunting rifle that shot consistantly like that, I would be very happy!

 

[Larryh128]

About the only thing that you can do better is to anneal your case necks and as you seat the bullet, stop about 1/2 way on the seating, rotate the case 90 degrees and finish seating the bullet. That will help straighten out any mis-alignment. With that said, .4 off of prone bags is very good with a factory rifle.

 

[itchyTF]

The barrel is bedded to the end of the stock? I always thought the prevailing wisdom was free float was the way to go.

 

[bheadboy]

Free floating the bbl from 1-2inch in front of action is prevelant,

your 100% beded bbl is unusual -- but it shoots, if it aint broke dont fix it.

Bob

 

[LHSmith]

The barrel is bedded to the end of the stock? I always thought the prevailing wisdom was free float was the way to go.

Itch- There is actually an AGI VHS ??? that shows how to epoxy bed a rifle stock. In the video they bedded some type of military bolt action and yes....they bedded the entire length of the barrel ???. I know this because a shooting buddy, bedded his Rem.Model 7 this way in a tupperware stock of all things ....and it shoots better than the factory bedded wood stock. Also, some have resorted to filling the barrel channel with silicone caulk (RTV) and reported improved accuracy. Seeing high-speed photo's of how the barrel whips (esp. sporter wt. bbls like these) I can't see how this method works. Go figure.

 

[FroggyOne2]

That is how I understand how they get 10/22's to shoot, bed the bbl and freefloat the action. I know the OP stated that he has it all bedded.. I have to agree, it is the first time I have read of that.

 

[joecob]

Prior to this thread I was convinced that bsdding the action with Devcon and
letting the barrel float was nearly a physical constant and weighing brass was
a waste of time. Now I'm drifting again. OHhh well.....

 

[FUBAR]

Back when I first started precision shooting most of my rifles had wood stocks.

The main reason for free floating then was to make sure the wood did not contract/expand and put pressure on the barrel....

Now all my rifles have free float no matter the stock, but hey I can see how it could work in theory, and evidently it works in his application in practice....

 

[Willem .243 musgrave]

My rifle is a .243 win, with a mauser k98 acton, musgrave barrel and a sako stock, was built by my grandfather custom, don't know why, but he bedded the action as well as the barrel with the same bedding material right up to the en of the stock, shoots consistently .4 MOA groups of 4 shots @ 100m. Also have a supressor on.