Reading Groups

B

Birddogjake

Guest
Are there any theads that tell a shooter how to read a group?? My factory 700 .233 BDL groups two holes touching and three holes touching. Is this OAL, Bedding Bullet, 53 BR Sierra, wrong powder or a bad trigger puller??? Thks for any help:
 
reading groups

there will be many MANY more educated replies than mine...but, two 's next to three's (side by side) CAN mean CANT ( vertical crosshair not "plumb" with bore, or crosshair not consistently on a vertical plane to target..) wind , are you using flags...consistent bag positioning, i.e..where on the fore-end is the front bag, EVERY shot...and yes, trigger pull ( I'm assuming that it's not some "challenging" trigger weight/make...???) all assuming that the two's and three's are on an even plane horizontally...
 
one more mini thought, from a mini-brain

STOCK SHAPE! rounded fore-ends will really mess up a theoretically " good " group.
 
It could be any number of about 100 different things.
Maybe you just fired during 2 different conditions.

There is just no telling.
 
Birddogjake: From the description of your "groupings" I want to ask one more question before commenting intelligently on your "double-grouping" BDL.
The question is - what is the average distance between your two sets of bullet holes per group?
Is it 1/3"?
Is it 1/2"?
Is it 3/4"?
Or more?
Something is amiss if you have this double grouping consistently.
Sounds like your Remington wants to shoot - there is just - I am guessing now, ONE thing that needs be corrected for your shots to be all "touching"!
Lets get this one shooting better for ya!
Hold into the wind
VarmintGuy
 
VarmitGuy is correct.

We need more info. Is this a sporter BDL or one of the older Heavy Barreled BDL's? Also, what are the size of the groups, how do they form (ie: 2 shots in one hole and then a move and 3 in another or is it random), does the forming of the groups seem consistant/predictable? When you shoot the groups, does the grouping of the bullets shift back to the original point of impact or does the new group start off where the old one was and then shift to the beginning of the previous group. Also, what powder/bullet/primer/cases are you using.

Hovis
 
Double Grouping Remington

Try a different powder, bullet weight, primer and seating depth combination and shoot it against the old load. If the split group is still there in both groups, it's a safe bet that all is not well with your rifles bedding. If it has dissapeared altogether it was probably conditions on the day. If it is still present in the old group but not in the new one, it is component related. Sometimes it is possible to be on the cusp of a barrel harmonic and get a split group. A change in seating depth and components should get you away from an unfovourable harmonic unless you are very unlucky and find another bad one.:eek:
 
I am using 53 Sierra FB have used H335 H322 BLC2 H4198 Best BLC & H322.
Laupa Brass turned to .012 Bullet seated touching the lands. 20" Factory Varmit Barrell 12 Twist . I have used Wilson neck sizer with .047 Bushing to
2nd group is .750 to 1.00 out from first, some at 10 O'clock some at 7 O'clock.
 
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Birddogjake: Yikes on that latest info - there is a problem for sure!
I am going to think on this one a while.
Hold into the wind
VarmintGuy
 
To Birddogjake

Rem 700s do not always shoot well with bullet touching lands. My BDL sporter in 223 cal won't shoot 53g Sierras unless they are 100 thou off the lands and I have heard of others that do the same thing. If it was my rifle I would move the seating depth back in 4 coarse steps each of 25 thou and shoot each depth to see which shoots best. If your rifle still shoots split groups at each seating depth change or tends to group maybe 4 rounds then pop one, have good hard look at your rifles bedding. I believe that your rifles problem is a lot more basic than tiny changes to concentricity by neck turning and so forth. A set of Lee dies and some quality cases such as Lapua should get you down to around the 1/2" mark without all the fussy stuff. Will be watching this thread with a great deal of interest. Reguards Murphy.:D
 
Groups

I will back off up to .100.. Is it possible that what I should do is forget about neck sizing and full length size only and forget about turning necks??? This H&S stock may be the culprit it may get shipped off to Tom M for bedding. Is it possible some rifles just won't shoot. Thks for all your help.. will quail hunt this week end to alleviate the stress about this rifle..
 
To Birddogjake

HS stocks can be the devil if the bedding blocks are not properly aligned. Had a Rem700 Police in 300 Win Mag that would not shoot untillI had it skim bedded. Enjoy your quail hunting and up the Weimaraners!
 
Possibly the Scope

Parallax was the culprit with my Model 70. Had the scope replace and checked the Parallax and I was back in business. No more double groups.
 
Birddogjake,

I just don't think it's a bedding problem but without seeing the rifle form the groups, I just can't narrow it down. If you haven't tried different seating depths....that's the first thing. Seating depth, I believe, is the single most important factor in accuracy. I would shoot three shot groups and back off .005 at a time and see what happens but I wouldn't waste a lot of ammo. Some guns just won't shoot....that's a fact.

Where do you live?

We really could use some detailed info on how the groups form. Here are a few rules of thumb you might think about. But like I said....just rules of thumb....not exact.

1. Splatter groups....Bedding problem or bad barrel/alignment of action and barrel, loose scope mounts.

2. Walking shots....barrel stress coming from barrel or action/barrel junction.

3. Tossed shots....seating depth/powder charge/primer/bullet (basically something with the load is off.

4. Multi-group groups.....if the gun puts a few in one place - goes to another and then switches back to original point of impact.....try a different scope.


Hovis
 
Just touching could be your problem.
I've always found this the worst seating depth to be at. Many others have luck with it.
Small variations in factory made bullets can have some jumping and some jammed. Granted the variations are small but the effects can be large.
 
Birddogjake

What you describe is common, but has many causes.
First, see that the barrel has clearance under it all the way to the lug.
the old dollar bill thing is not valid, Two business cards is great
insurance. Holding a finger at the barrel and stock tip, gently
tighten and loosen the front guard screw. if the barrel seems to move
a bedding problem may exist. I say maybe, because even with good
bedding, a magazine box to tall can cause big problems. It should
not be tight. Moving to the back guard screw and by feel, test
for up and down at the tang. Another way is to alter the screw tention
while using a bore scope. A dial indicator is probably the best.
Different loads give way different group shapes as does seating
depth.
Gun handling and conditions play hell with great shooters
and 3 and 2 groups can be shot by the best gun around.
Work with one bullet and seating depth, changing one thing at
a time.
 
Groups

I live in KS, Consensus seems to be bedding will try that...
 
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