Sigh. Out of oomph at 800 meters

NavyShooter

NavyShooter

CGN Ultra frequent flyer
Rating - 100%
100   0   0
Location
XMU Local .303
Hi Gang.

I come seeking advice.

Here's my sob story, and my possible solutions.

Firing my 24" Remington 700 today, getting set for the summer matches, it's a .308 Varminter that's done very well for me over the years. Fired fine, and repeated the zeros from last year's shooting with my new lot of reloads (168 Moly'd Sierra's on top of 46.0 gn of Varget)

Right out to 700 meters. Dial, point, shoot, wait, hit. Sub MOA out to 700. VERY pleased.

Step back to 800, run out of elevation on dial and hold off (1" tube) holding in the helmet of the Fig 11 to hit in the bull (approximately 2.5 MOA high) This is expected, and repeats last year's performance.

However, accuracy is not there. Not getting consistant shots, or hits. Shots called were not followed by the hits. IE, I'm calling a pull right (bag jump), and getting a left hit. Same thing for vertical errors, the group wasn't a group, it was a pattern.

So, it's becoming obvious to me that the 168's I'm using do not have the legs for 800.

Options open to me that I can see are:

1. Re-barrel with a 26" bbl, and get a little more push.

2. Switch to 190 Sierras

3. Switch to 155 Palmas

Option 1 is a no-go. No time, no money in the budget for a re-barrel job, not to mention throwing away all the zeros I have, and all the fire-formed brass I'm using.

Options 2 and 3 are up for discussion here.

My current 700m zero is 3.9.0 My elevation drum runs out at 4.0.5. I have only 6.5 MOA of elevation to play with above my 700m zero.

Which round is more likely to provide me the best results without running out of my scope's elevation drum? 155's, or 190's?

I've been told that the 155's will shoot flatter, and not have as much recoil management issues as the 190's, so I'm leaning that way, but have no experience with them.

Comments, suggestions?

Thanks in advance,

NavyShooter
 
Have you tried the 175 gr smk they have a higher BC # than the 168 gr does and if you follow the BC of both the 155 and 175 on a computor generated map you will find in all cases the 168 gr bullets are best suited for 600 m in the majority of rifles .Steves right about the Lapua scenars they like to be jammed against the lands
 
The 168 is a 300 meter designed bullet for international free rifle competition, and is not accurate at the longer ranges.
The Seirra 155 palma is accurate out to the longer ranges, and so is the 175.

I don't use the 175 because the twist in my 308's is designed for the shorter , lighter, 155 (1:14 twist)

Yours may have a faster twist, and if it does , try them.
Or, like PGW Steve suggested, you can also try the 154 Scenars.

BTW, I run about 46 grains of Varget in my rifles with the 155, depending on the rifle....
Cat
 
Burris rings with inserts to gain all the elevation you want. 155gr Amax, Nosler, MK, and Scenars. No issue going post 700m. I like Varget and CCI BR2 primers but will use Fed 210M in a pinch.

If it is shooting well at 700m and falling apart at 800m, the problem is the bullet or the scope, not the rifle or you. If you rezero with the Burris rings, you will be moving the scope in the middle of its travel and you might solve your problem. Some scopes will not hold zero when at full turre(I hate it when people put an "n" in "turret")t travel.

I have shot several 168gr bullets and never had them go crazy at such short distances.

If that doesn't solve your problem, go to a 155gr bullet and that should solve your problem. The 175gr MK are quickly becoming old news because recoil is way lower with the 155gr and ballistics are much better.

They fly very well all the way out to 1000m and beyond.

Jerry
 
Last edited by a moderator:
Just a thought, but why not get a tapered base with more elevation. For example if you're running a +20 MOA base try a +25 or +30. If you're running out of elevation this should cure that problem.

If your groups at 800 are really the pits then maybe the Lapua 155's might be the way to go. Something to try anyways. I wonder if having your turret damn near maxed out could be a culprit?
 
I've just picked up a couple boxes of Lapua Scenar 155's from PeterD. I've got them in getting moly'd right now, and am re-measuring the seating depth setting later tonight.

I should have mentioned, that my intent is to keep the rifle as is for now, since it works at everything less than 800. I've only had the rifle out of the bedding once in the past 5 years. The scope has not been dismounted in longer than that. I'm not supersticious or anything, I just don't want to mess up something that's working.

If I do pop the scope off, it'll be to put on a 30mm tube, which will remove all concerns about a lack of elevation available to me.

However, to do that, I'd be swapping the Tasco Super Sniper off the SL-8 I just zeroed too. I might do that, but only as a last resort.

I'm going to work on loads now. Probably a day at the range this weekend for that I guess.

Thanks for all the help folks!

NS
 
Well,

I just loaded up a test batch of 50 155 Scenars.

Looking nice :) Almost a shame to fire them!

Load built up in .5 grain increments from 44-47, all rounds with a nice deep moly coat on them.

Lengths go from 3.055 for most, down to 3.000 and 2.950 for comparison's sake.

This is the longest I've loaded a round out...that's .255" beyond the "spec" for the round. YIKES. I guess I have a long throat, eh?

Thanks for the advice guys, and I should be able to advise RE results tomorrow or Friday.

NS
 
Well,

I found my sweet spot.

Group size with 46 gn of Varget at 100m was .755", outside to outside. Makes it a .447" 5 shot group!!!!

I can live with that.

Tried some other variations, but anything over 46 gn didn't increase velocity (stayed at just over 2800 fps)

Interesting item, it shoots 2 MOA right from my 168's Zero point.

NS
 
Hey guys,

I already have a 15 MOA set of tapered shims in it.

I fired about 85 rounds in testing the other night, in just under 90 minutes. Pretty quick rate of fire for testing accuracy. Lets just say there was only one cold-barrel shot!

Next time, yes, 10 round groups. 3 is statistically insignificant, so I wouldn't go that low, but 5 is somewhat more reliable, and can be fired fairly quickly.

Thanks!

NS
 
gunny - the 168 SMK problem isn't related to elevation or trajectory - the bullet was originally designed to optimize 300m performance, and simply does not work very well out of a .308 at long range.
 
If you like the 155s, try giving the 155 Hornady A-Max and 46gr. of Varget a try. They are nice and cheap, fly well and are consistant.
 
You must log in or register to reply here.
Back
Top Bottom