3 shots- good - 5 not so good

dphobby · 07-12-2008, 06:18 AM

hey guys, I finally got out with the omega, wanted to try some crushrib sabots with some 240 xtps.

this one is with 80 gr. t7 fff, first three are ok but then they went south, maybe the barrel was heating up, or the 10-15 mile hr. wind at my back?

this one is with 90 gr t7 fff

then I wanted to try some hornady sst 250's with the low-drag sabots and 100 gr. powder

the first five on this one are ok but had 1 flyer.

everything seemed to load a little too easy, one hand, not tooo much pressure.
Just wondering what everyone's thoughts are on the amount of powder behind a looser fitting sabot,
If more powder or less increases or decreases accuracy?

cayugad · 07-12-2008, 07:21 AM

I would guess the barrel is heating up or you are changing the loading pressure on the sabot with out knowing it. Next time out, try the Shockwaves and shoot, then swab the bore good, and let the rifle rest if it is hot out. I have a shelf under my bench so the rifle can rest in the shade. It will make a difference in the group.

Also try to make loading pressure the same. Some times, as the barrel heats up, the sabots slide easier, so you tend to send them down faster and tighter. Just something to keep in mind.

Actually if the first three are grouping that good, I think you got a real shooter. As for the flyer, even them are not all that bad... Nice shooting.

Kathwacckkk · 07-12-2008, 07:56 AM

I would have to agree with your thoughts about the wind and the barrel heat. However, this still appears to be a pretty tight group. What yardage were these shots fired from? They all appear to be in the kill zone.
I am assuming all of your cleaning or shot routines were the same each time? I ask, because when I really try and get an accurate group, I only shoot once then do a complete clean and let the barrel rest for 15 minutes or so then load and fire again. I do this routine three to five times to figure out what my groups are doing. I figure I will only get one shot in the woods, so I better make sure all the first shots are the same and accurate out of clean and cool barrel. I also bring a couple different guns to the range with me knowing I have to do something while the barrel of the first gun is cooling off.

dphobby · 07-12-2008, 08:10 AM

Ya, I forgot to mention, these were all at 100 yds. Spit patch between every shot. I like to use the spit patch method because it is easy and really convenient when hunting.

Rifle Loony · 07-12-2008, 08:43 AM

I would evaluate your seating pressure.

Are you seating your bullet to a specific mark on your ramrod?

Doesn't really matter how much compression on the load, light, medium, or heavy....as long as each shot is seated withthe same exactamount.

Use masking tape to mark the rod andfind your best seating pressure, then make a permenant mark for future use.

Also, I've seen this sort of thing with volume measured charges, to eliminate that variable I've weighed charges for a long time now.

It could be lots of other things but I'd make sure those issues are looked at first.......no reason for an Omega to shoot flyerslike that if all things are good to go.

As an aside, I've always got 240 XTP's to fly best with Hornady green sabots and T/C Black's..........

Kathwacckkk · 07-12-2008, 08:48 AM

I am assuming your target lines are all one inch spacing? With 80 or 90 gr. T7 fff, you appear to be within 1.5" for three shots at 100 yards. I would eliminateshots 4 and 5 and try just three shot groups again a couple times. As long as you can keep you first three shots of each round as consistent and accurate as above, I think youfound a great load. Nice shooting!

oldsmellhound · 07-12-2008, 10:00 AM

First of all, those are still pretty decent groups. So as far as hunting accuracy goes, I think you'll be fine just the way you are. However, I understand the desire to get the best accuracy possible. I would try some different powder charges - using 5 grain increments (i.e. 85 grains, 95, 105). Try and keep everything as consistent as possible - seating pressure, etc. Let the barrel cool down between shots. These things all should help.

falcon · 07-12-2008, 10:31 AM

Pretty good shooting. A gusting wind at your back can cause vertical stringing like that at 100 yards.So can inconsistent seating of the sabot.

gleason.chapman · 07-12-2008, 11:03 AM

> everything seemed to load a little too easy, one hand, not tooo much pressure.

There is your problem, in my opinion, the tighter the sabot the tighter the group, in general. Too easy or not seated well enough or barrel to hot you will get "blow by", which causes inaccuracy. I like that 250 SW group, and I would work that some more, switch to the black supplied sabot instead of the lo-drag or buy some MMP12s and Harvester Black long sabots and try those. A small sabot change can make a HUGE accuracy gain. Best Wishes
Chap Gleason

falcon · 07-12-2008, 01:19 PM

Quote:

There is your problem, in my opinion, the tighter the sabot the tighter the group, in general. Too easy or not seated well enough or barrel to hot you will get "blow by", which causes inaccuracy.

Very good possibility of that.My Encore likes a very tight fitting sabot and is capable of1" groups or better.The SuperGlideswill not pattern at all, they are all over the place.The Hornady Low Drags make 3-4" inch groups in my gun. Never tried the Crush Ribs.