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bryonbush
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Posted: 7/15/2012 1:10:28 PM EST
Heres whats going on. We loaded up some .308 rounds with 155 gr bullet over a series of powder increases starting from the recomended start load of 45gr to the max load of 48 gr. going in 1 gr incraments. were using normal CCI Large Rifle Primers. we found that the 46 gr cave us the "best" accuracy but even at best, it was roughly a +-2" group at 100 yards which is not that great. the rifle is a new Ruger Gunsite with 16" barrel.
we have talked to others about this and here is what we have been told:
1. try mag primers
2. try using a faster powder like H335
3. adjust bullet seating depth; some guns like the bullet to sit deep and not touch the lands and some like it touching the lands.

whats your thoughts on this.
sdshootermsd
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Posted: 7/15/2012 2:06:34 PM EST
What works for me may not work for you and - or your rifle, but I'd try a different powder.

Right now L'm working with V V 135 and getting slight less than 1" groups, my other powder was IMR 4064

by it doesn't meter well. The V V is smaller grain and is much easier to meter through a powder drop.

sdshooter.......,.....
bigedp51
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Posted: 7/15/2012 2:20:10 PM EST
[Last Edit: 7/15/2012 2:24:08 PM EST by bigedp51]
Rifle accuracy is governed by barrel vibrations and the long and short of it is if you can't get your barrel vibrations "tuned" to the sweet spot of barrel harmonics you will not shoot tight groups. Things as simple as not having the correct torque on your trigger guard screws can screw up your accuracy when tuning your hand loads.



Did you ever noticed the steps cut in a military Mauser barrel, the steps are at the vibration node points of the barrel and used to control barrel vibrations.
(don't try putting Viagra in with your powder it doesn't work)



Ball powders are harder to ignite due to the deterrent coatings used, they are double base powders and these coating are used to reduce the peak flame temperature and they sometimes need a hotter spark to get them burning.

"Sometimes" the seating depth has a effect BUT in most cases your magazine is the limiting factor in bullet seating length unless you are single feeding your cartridges.

I would try different powders and find one that shoots well and then try and fine tune your load from there with seating depths etc.

The groups below were an accident, I was fire forming new cases with the bullets jambed hard into the rifling and varying the loads slightly just checking for pressure signs on the primers on my bolt action .223.


Bottom line, sometimes you work your tail off looking for the best load and sometimes it just falls in your lap when your goofing off.

Scaup58
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Posted: 7/15/2012 3:17:17 PM EST
My AR10 doesn't like H-335 or BL-C(2) or 155 gr. matchkings. It loves 168gr. A-max's, RL-15, 8208XBR and PP2000MR. The right charge of any of these powders under the A-max's will get .6 MOA. Nothing will get 155's under 1 MOA. You'll just have to keep experimenting. One of the 4895's might be a good place to start.
I love the smell of gunpowder, avgas & women.
Trollslayer
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Posted: 7/15/2012 3:51:52 PM EST
[Last Edit: 7/15/2012 4:03:34 PM EST by Trollslayer]
Have you ever shot smaller groups with any other rifle similar to this one and with a similar sighting system?

Has anyone shot smaller groups than 2" using your rifle?

What sights do you have on the rifle?

To me, 2" at 100 yards from a Ruger factory rifle is what you can expect. Do you think the rifle is capable of better?




I have always gotten my best accuracy from extruded powders (not a lot but noticably smaller groups than ball powders). In a 308 bolt rifle, I'd say use IMR4064. Then again, you have a VERY short barrel, so maybe try IMR4895, which is a bit faster.





ETA - bigedp51, that was an awesome post with all the graphics, etc. IMO, any rifle that is sensitive to how tightly the trigger guard screw is torqued is a piece of crap (probably needs to be rebedded).
dcat
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Posted: 7/15/2012 5:07:17 PM EST
[Last Edit: 7/15/2012 5:18:06 PM EST by dcat]
Originally Posted By bigedp51:
Rifle accuracy is governed by barrel vibrations and the long and short of it is if you can't get your barrel vibrations "tuned" to the sweet spot of barrel harmonics you will not shoot tight groups. Things as simple as not having the correct torque on your trigger guard screws can screw up your accuracy when tuning your hand loads.

http://i122.photobucket.com/albums/o254/bigedp51/barrelvibes.jpg

Did you ever noticed the steps cut in a military Mauser barrel, the steps are at the vibration node points of the barrel and used to control barrel vibrations.
(don't try putting Viagra in with your powder it doesn't work)

http://i122.photobucket.com/albums/o254/bigedp51/308mode7.gif

Ball powders are harder to ignite due to the deterrent coatings used, they are double base powders and these coating are used to reduce the peak flame temperature and they sometimes need a hotter spark to get them burning.

"Sometimes" the seating depth has a effect BUT in most cases your magazine is the limiting factor in bullet seating length unless you are single feeding your cartridges.

I would try different powders and find one that shoots well and then try and fine tune your load from there with seating depths etc.

The groups below were an accident, I was fire forming new cases with the bullets jambed hard into the rifling and varying the loads slightly just checking for pressure signs on the primers on my bolt action .223.


Bottom line, sometimes you work your tail off looking for the best load and sometimes it just falls in your lap when your goofing off.

http://i122.photobucket.com/albums/o254/bigedp51/May2011-a.jpg


I agree with most of your post and like the groups you lucked into. However, check out the fourth post from top in the attached link. Paul Mauser patented stepped barrels so the barrel could grow forward from heat and still maintain proper bedding, not to dampen vibration modes. I suppose you could argue that proper bedding does reduce the amplitude of the nodes and I would agree that is somewhat true so maybe I would concede the point. Still for those wanting further discussion on this point:

http://24hourcampfire.com/ubbthreads/ubbthreads.php/topics/6566063/6/Reason_for_stepped_military_Ma

I really like your illustration of barrel whip.

OP - I suspect the 155 gr MK does not have enough of a driving band for the barrel on your rifle. The 155 was originally designed for tight bore Palma rifles. Suggest you try a longer bullet (168, 175, 178) or a 150 gr. with a flat base. As far as powders go, with 308 I normally think of either flavor of 4895, Varget, 4064, or RL-15. For something faster to reduce flash with a 16-in barrel, maybe 3031.

Best regards,
dcat

bigedp51
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Posted: 7/15/2012 6:58:33 PM EST
dcat

There are four steps cut in a 8mm 98 action barrel and none of them are at the barrel bands, nor do the barrel bands contact the barrel directly. The patent you refer to is on early Mauser actions that had the barrel bands in direct contact with the barrel which allowed the two stepped barrels to move back and forth in the barrel bands.



Below, my 8mm Mauser has four steps in the barrel and these are at the vibration node points and not for sliding back and forth at the barrel band locations.



There are two ways to tune a rifle.
1. Tune the rifle to standard issued military ammunition for accuracy using stepped barrels or by regulating up pressure at the fore end tip.
2. Tune the ammunition to shoot in the individual rifle as hand loaders do.

NOTE: A standard Remington 700 has 3 to 9 pounds of up pressure at the fore end tip to control barrel vibrations and thus accuracy.



bigedp51
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Posted: 7/15/2012 7:18:09 PM EST
Originally Posted By Trollslayer:
ETA - bigedp51, that was an awesome post with all the graphics, etc. IMO, any rifle that is sensitive to how tightly the trigger guard screw is torqued is a piece of crap (probably needs to be rebedded).


You need to come out of the dark ages and into the shooting Renaissance. (don't get torqued off)



Gunsmithing - How to Torque Guard Screws on a Bolt Action Rifle

http://www.youtube.com/watch?v=CeOL0PTBTDc

Savage Action Screw Torque Tuning

http://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/
bryonbush
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Posted: 7/15/2012 7:54:42 PM EST
Originally Posted By Trollslayer:
Have you ever shot smaller groups with any other rifle similar to this one and with a similar sighting system?

Has anyone shot smaller groups than 2" using your rifle?

What sights do you have on the rifle?

To me, 2" at 100 yards from a Ruger factory rifle is what you can expect. Do you think the rifle is capable of better?


using some off brand 155 gr ammo from a gun show, at 100 yards i stacked 3 shots right ontop of each other. maybe it was just a bad day at the range but ill try some other things that have been suggested. before i purchased a LARGE ammount of the 740 powder and 55gr bullets, i did a lot a reading and there were a lot of positive comments on how they get good accuracy using the 740. wednesday i will be going out again and ive loaded some up with mag primers so we will have to see how they go.




ETA - bigedp51, that was an awesome post with all the graphics, etc. IMO, any rifle that is sensitive to how tightly the trigger guard screw is torqued is a piece of crap (probably needs to be rebedded).


Trollslayer
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Posted: 7/16/2012 7:25:08 AM EST
[Last Edit: 7/16/2012 7:38:31 AM EST by Trollslayer]
Originally Posted By bryonbush:
Originally Posted By Trollslayer:
Have you ever shot smaller groups with any other rifle similar to this one and with a similar sighting system?

Has anyone shot smaller groups than 2" using your rifle?

What sights do you have on the rifle?

To me, 2" at 100 yards from a Ruger factory rifle is what you can expect. Do you think the rifle is capable of better?


using some off brand 155 gr ammo from a gun show, at 100 yards i stacked 3 shots right ontop of each other. maybe it was just a bad day at the range but ill try some other things that have been suggested. before i purchased a LARGE ammount of the 740 powder and 55gr bullets, i did a lot a reading and there were a lot of positive comments on how they get good accuracy using the 740. wednesday i will be going out again and ive loaded some up with mag primers so we will have to see how they go.




ETA - bigedp51, that was an awesome post with all the graphics, etc. IMO, any rifle that is sensitive to how tightly the trigger guard screw is torqued is a piece of crap (probably needs to be rebedded).




Three shots is not a lot and is typical of how shooters often fool themselves with "lucky" groups (group is not statistically significant). Still, dcat could be right, try another bullet. The 168 SMK is where I'd start. It's a very tolerant bullet that shoots reasonably well unless something is wrong. The flat base Berger bullets are also known to be excellent at shorter ranges (125 to 150 gr, 30 cal benchrest bullets).

bigedp51 is trying to talk me into buying a digital torque wrench for my rifles. :-) What he doesn't know is, I already have one.

The only "dark age" I am in is the result of all my rifles being black (even the bolt actions). I do agree the action screws (and all the screws) and barrel threads need to be tight but if they are super-sensitive to final torque value, something is wrong. For the purpose of this argument, I that this action screw torque "witchcraft" that is a hold-over from the "dark ages" of rifle accuracy.

Then there's that discussion of barrel bands and forearm preload on the barrel. Does anyone even use those, anymore? Maybe if you are still using rifles (and stock designs) from 1898 with barrel bands and forearm pressure on the barrel, maybe it is bigedp51 who is in the "dark ages". Maybe if you are doing that, your rifles are sensitive to torque on the screws. I do not have any of those.

(this is meant to be all in good fun, bigedp51)

Is the barrel of your Ruger Gunsite free floating? I do not see any barrel bands in the images. Is the barrel beded for a few inches in front of the receiver?
dcat
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Posted: 7/16/2012 8:23:18 AM EST
Not to hijack the thread, but there are lots of us still shooting old wooden stocked military rifles which has become very popular in the last few years due to the DMP games matches. The Springfield, and K31 are two commonly seen rifles there that are VERY sensitive to correct torquing of the action screws.
Trollslayer
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Posted: 7/16/2012 8:31:52 AM EST
[Last Edit: 7/16/2012 8:35:37 AM EST by Trollslayer]
Originally Posted By dcat:
Not to hijack the thread, but there are lots of us still shooting old wooden stocked military rifles which has become very popular in the last few years due to the DMP games matches. The Springfield, and K31 are two commonly seen rifles there that are VERY sensitive to correct torquing of the action screws.


I'm sure of that. The thing is, you cannot play with antique rifles and claim that I am the one in the "dark ages".

Truly, we are hijacking this thread.

Please refer to the fine print in my post, above.
bigedp51
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Posted: 7/16/2012 11:51:03 AM EST
Originally Posted By Trollslayer:
(this is meant to be all in good fun, bigedp51)


I know but I may have been off by more than 10,000 years when I said the "Dark Ages".


dryflash3
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Posted: 7/16/2012 12:43:12 PM EST
Was hoping this thread would swerve back on topic. Guess I have to ask.

W-748 in 308 is topic.
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