Happy Day!

[elkeater2]

I've been frustrated for a long time trying to get my Encore 7mm-08 barrel to group decently. I've tried all the normal things and some abnormal, without much success at all. Today I was shooting Sierra 160 btsp's, which I tried earlier in the week. I'd loaded up a number of them and the weather was great. Vertical spread was at least 4" and Horizontal spread about 1 1/2" off mechanical rest. Moved to just bags and some improvement.

I have bought in to the 'load bullets way out, just shy of the lands' business because it made sense. The Encore allows for that easily, so I had taken full advantage of it with a COL of 2.895". Sierra recommends 2.775". In frustration, I went to 2.755" - just a .140 difference! The first two were on top of each other, the third made it a .236" group. Shot two more quickly and expanded the 5 shot group to .665" and the spread was slightly horizontal. I need to verify in the next couple days, but am really pleased. Now I wish I knew why these short rounds are working, but am not going to lose sleep over it :lol: Has anyone else experienced a gross shortening of seating depth improving accuracy dramatically???

EE2

 

[CatskillCrawler]

Congrats. Feels good when things start to come around. I had to seat 140gr ABs really short to have success in my .270Win. Ya never know.

 

[longwinters]

I have seen that with Hornady bullets, Barnes and Sierra's in several calibers.

Long

 

[dlove]

congratz. my 7-08 like the bullets way off the lands. after finding the length, it will shoot about an inch with almost any powder and any charge.

 

[DrMike]

It is not at all unusual that some loads give the greatest accuracy with a long jump to the lands. I had one rifle (a 270 WSM) that would not live up to anticipated potential. Finally, in desperation, I used a bullet with a longer bearing surface and allowed a 0.250 inch jump to the lands! It was a solid 0.25 inch shooter. I'm working with a 7STW right now that will likely require a 0.100 inch jump to the lands before I'm finished.

 

[elkeater2]

Thanks DrMike and others! I think I learned a little more today :lol:

 

[SJB358]

I've been frustrated for a long time trying to get my Encore 7mm-08 barrel to group decently. I've tried all the normal things and some abnormal, without much success at all. Today I was shooting Sierra 160 btsp's, which I tried earlier in the week. I'd loaded up a number of them and the weather was great. Vertical spread was at least 4" and Horizontal spread about 1 1/2" off mechanical rest. Moved to just bags and some improvement.

I have bought in to the 'load bullets way out, just shy of the lands' business because it made sense. The Encore allows for that easily, so I had taken full advantage of it with a COL of 2.895". Sierra recommends 2.775". In frustration, I went to 2.755" - just a .140 difference! The first two were on top of each other, the third made it a .236" group. Shot two more quickly and expanded the 5 shot group to .665" and the spread was slightly horizontal. I need to verify in the next couple days, but am really pleased. Now I wish I knew why these short rounds are working, but am not going to lose sleep over it :lol: Has anyone else experienced a gross shortening of seating depth improving accuracy dramatically???

EE2

I have done it alot more than I have bullets seated up close to the lands.

My 270WSM is seated 2.860, my 7WSM is seated at 2.850" and both of those are about .100 or better off the lands and they shoot really well. I will start up close to the lands, but more times then not, I back them way off to find consistent accuracy..

2.850"

2.950"

It took me awhile to find it, but once I hit that spot, short on the COAL, it shoots that way, all the time now.

 

[elkeater2]

:shock: :shock:
It did shoot a couple great groups. Went back a week later, and it wasn't going to same POI, and the groups had wild flyers again. Back to the drawing board...

I think I've read nearly everything in every forum discussing vertical stringing with Encores. This barrel, 7mm-08, that's got it bad. It seems that for some this has been a somewhat common problem
I have since the last episode done or verified:
1.pillar bedded one of the old Rynite forearms (not Prohunter). Got the screw holes too close maybe to the screw diameter. Opened them up some Don't want the screws bound in the forearm
2.checked barrel to frame gap and adjusted case sizing to .001 to .002"
3.trimmed all cases to minimum trim-to length
4.have a properly fit hinge pin (barrel and frame)
5.locking bolts are good fit in lug, stronger spring, good engagement with frame
6.using durasight heavy alloy base and rings w/3-9x40 Leupold. Have not tried conversion to six screws or filler under the sight base front overhang - this may be the next experiment
7.am getting what I think is excessive case stretch when firing, but have not found a good definition of an acceptable range. The loads according to the chronograph are at what most people achieve. Maybe it's a slow barrel and the loads too hot....Cases do stretch lengthwise a certain amount in Encores as well as other designs.
8.have checked the PH buttstock for tightness, it is loctited down and doesn't look to be a problem. Other barrels shoot OK.
9.the crown is fine, the throat is centered
Any suggestions? One thing I keep wondering about is the advisability of having two screws holding the forend on. It seems like this introduces the possibility of variable stresses, especially as the barrel warms up. Also some stress potential if the forearm screw holes are not perfectly aligned with the threaded holes in the barrel.
Interested in any constructive suggestions or experiences..

I went back to the range today after making some of the changes mentioned.
•all 2x fired brass, trimmed and carefully sized, checked for chamber protrusion
•cleaned both forearm screw holes in the barrel, and made sure the screws were not bottoming out
•remounted scope and bases, cleaning screw holes and verifying screw length. Torqued.
•measured each cartridge for chamber protrusion before and after firing
•BACKED OFF two full grains from the load I was using, 49.0 gr. H414, 120 Nosler BT, CCI 250 primers, 2.775 COL. Loaded up 47.0, 47.5, and 48.0 instead.
•Everything grouped better, no fliers. 47.5 gr. was noticeably the best for 5 shots with lots of time between. Less than MOA for sure at 2985 fps. average.
•Significant to me was that protrusion after the shot was had gone to about .003", max .005" with all loads. It was twice that or more with 49.0 grs. A certain amount is expected.

I know all the admonitions and wisdom from books and forums, but discovered it's still easy to deceive one's self. I think we all want both speed and accuracy, but there is a little voice that tells us we should be able to get to everyone else's max. And if that max velocity is around 3000 fps, we want that magic number too. I didn't think I was seeing "pressure signs" so I went for a load that consistently went 3000 or more. I had gone up to the point of diminishing returns and excess pressure for my rifle without realizing it. The 5 rounds at 48.0 averaged 3K anyway! One more grain wasn't giving me anything but trouble. I do believe the other changes I made contributed as well, but I'm really pleased with the 1.5 gr. less powder load. Need more groups to absolutely verify, but it went so well I'm pretty sure I'm on the right track! :lol: Hope so, I about gave up several times.
EE2

 

[DrMike]

The pursuit of velocity has led many of us into the morass of diminishing accuracy. We were so focused on the holy grail of higher velocities that we were blinded to the need for accuracy. It is most interesting (even instructive) to observe how, in many cases, an increase of 100 fps offers such a small increase in energy.

 

[elkeater2]

The pursuit of velocity has led many of us into the morass of diminishing accuracy. We were so focused on the holy grail of higher velocities that we were blinded to the need for accuracy. It is most interesting (even instructive) to observe how, in many cases, an increase of 100 fps offers such a small increase in energy.

You're so right Doc! Also, all the red flags should be waving when we're loading a cartridge with about 50 gr. useful powder capacity, and it takes 1 1/2 grains more powder (when approaching max) to get 50 -75 more fps. It should be obvious that it's not worth it and the point of diminishing returns has been met.
I do have one question for you - how many groups do you consider adequate to verify you've found a satifactory load? Part of my folly was shooting one decent group and thinking I had it made.
One of the reasons I enjoy this game so much is there is always something to learn, as long as the brain is in gear. :grin: Another reminder to look at all the fundamentals once more when things aren't going right. I just wish the reminder wasn't so long coming! :lol:
EE2

 

[DrMike]

When I reproduce the velocity/accuracy on three separate outings, I'm normally prepared to call it consistent. This will consist of a minimum of nine rounds fired in three three-shot groups. Alternatively, I have shot ten-shot groups and pronounced it good. These would be minimums for me. When I have a group that is reproducible over several seasons, I know that I can speak with confidence.

 

[FOTIS]

You just have to play with all variables until you get there. This is the trick. Persistence.

 

[AzDak42]

Another thing to keep in mind, is that some barrels just aren't moa.

I think we get a little bit spoiled these days when just about every factory barrel can turn in 1.5moa groups with little effort and moa with some work. Sometimes, you just have to call a tent state a tent state and give another tube a try.

Just out of curiosity, what barrel are you running? Is it a premium of factory?