Page 1 of 1

SEATING AND GROUPING QUESTION

Posted: Mon Sep 30, 2013 1:23 pm
by ALP
Hey guys,maybe you can help with some feedback.1st question is,will seating closer to the lands increase velocity and pressure or decrease it? #2 question with explanation. rifle.Rem 700,26in barrel,12in 1 twist. I been testing some loads using reloader 10x and benchmark.39 gr.sbk. worked my loads up in .2 gr of powder incraments using searra guidelines.Never went up to max loads just midway.Nothing would grourp tight.All the 5 shot groups were about the same.3 would be touching and two would be flyers.The 3 touching would group about .6 in. Iwas seating the rounds at 2.30 so I rechecked the distance with a hornady oal guage and it measured 2.485 to the lands.could this be the problem. Thanks for any help you can give.

Re: SEATING AND GROUPING QUESTION

Posted: Mon Sep 30, 2013 7:54 pm
by Darkker
1) Seating closer to the lands raises pressure, as it doesn't get as good a "run" before contact.
2) 0.2gr of powder change is chasing ghosts, especially with extruded powders, the BR/BD isn't that tight to begin with. Your grouping sounds like a normal factory barrel, shooting long bullets.
Your jump is excessively large, but I don't think that is THE problem, just one of them.
Richard Lee always said he never found a rifle that WOULDN'T shoot with a 0.03125" or 1/32" jump; and I agree. May not be the best, but a darn fine start.
The reason I think you just have a factory barrel is the fact that you DO group, just throw fliers. Sounds like a typical mass produced barrel. Some barrels don't like that bullet, just a part of life.

Re: SEATING AND GROUPING QUESTION

Posted: Mon Sep 30, 2013 8:09 pm
by Bill K
Before you go spending a lot of money chasing things. Take your rifle to a gunsmith and spend some cash, should not be too much, and have the crown redone. You just might be in for a surprise in how it shoots. :D Bill K

Re: SEATING AND GROUPING QUESTION

Posted: Tue Oct 01, 2013 6:03 am
by 204foxguy
ALP,

In regards to the Ruger 204 load testing

When I was load testing I found that as I got closer to the Max Load for the powder I was using the Tighter my groups got.
(I watched for signs of pressure along the way.) I too tested in .2 gr increments - then in .1 gr increments within a small range.
I seated the Bullet at the recommended OAL for the Bullet being loaded.
The Manuals stated Bullet Seating (OAL) is a Long way from the lands on my rifle and it will still group well.

Good Luck

Re: SEATING AND GROUPING QUESTION

Posted: Tue Oct 01, 2013 12:30 pm
by ALP
Bill K,your reply about the crown did make me think.When I first bought the rifle and got it home Iwas cleaning it when I noticed a small scratch across the crown.It barley scratched the blueing off,but did touched the inside of the bore.Could that be the problem even though it seems to be such a minor scratch?

Re: SEATING AND GROUPING QUESTION

Posted: Tue Oct 01, 2013 1:15 pm
by Rick in Oregon
ALP wrote:Bill K,your reply about the crown did make me think.When I first bought the rifle and got it home Iwas cleaning it when I noticed a small scratch across the crown.It barley scratched the blueing off,but did touched the inside of the bore.Could that be the problem even though it seems to be such a minor scratch?
I'm not Bill, but I'm sure he'll agree with me with a single word answer: "YES!"
Have it recrowned, shoot your best load to date and see if we're correct or not. You could still have issues, but that would be the very first place I'd start if it were me. HTH

Re: SEATING AND GROUPING QUESTION

Posted: Tue Oct 01, 2013 1:47 pm
by Bill K
Alp.. Seeing what you said, I would re-crown, as Rick said, this may not do it, but I would just about say you will see a improvement with your best load, to date.. Bill K :)

Re: SEATING AND GROUPING QUESTION

Posted: Wed Oct 02, 2013 12:53 pm
by ALP
Thanks for all the feedback guys.I think I found the problem.I went to the range today and swaped out the scopes.Started shooting groups like they should be. That new scope is now on its way back to Nikon for service or replacement. I still may have it recrowned and bedded. Again thanks for the replies.