Struggling developing .308 accuracy loads. Help

[Mohawk3a]

I've been trying to develop an accurate .308 load with 175,180, and 185 bergers. I can't get a 10 shot string with less than a 18 es. I keep seeing all these claims of less than 10es and 5 sd. Are there any Berger experts here than can recommend powder, charge, seating depth and neck tension? Ive been using varget and n550, with lapua palma brass. Thanks

 

[fallcreekhunter]

Re: Struggling developing .308 accuracy loads. Help

My experience is that a slightly faster powder is sometimes effective with bergers as their length sometimes takes up case capacity and creates borderline pressure issues as compared to many other bullets. I also have found their accuracy to be much better slightly into the lands like 2 thousandths. Good luck.

 

[81sfo]

Re: Struggling developing .308 accuracy loads. Help

What primers are you using? Sometimes changing primers will give you better SD and ES. Bergers are probably the hardest bullets to find a good load because they usually need to be jammed in the lands or sometimes jumped .For the 175s anywhere from 42.5-45 grains varget will get you where you need to be. I've never used the lapua palma brass though.
What rifle are you using ,scope ?

 

[Mohawk3a]

Re: Struggling developing .308 accuracy loads. Help

Gap hrt, sb scope. I use cci2 bench rest primers.

 

[vman]

Re: Struggling developing .308 accuracy loads. Help

Bear in mind those who get single digit ES probably go to a lot of prep work in order to get the most consistent results.

Sorted brass, consistent trimming, minimal sizing, annealing (probably after every load), brass is fully fireformed, highly consistent charge weights etc etc.

Theres probably way more variables than that but those are to give you an example.

 

[BCP]

Re: Struggling developing .308 accuracy loads. Help

How does it shoot?

 

[tnichols]

Re: Struggling developing .308 accuracy loads. Help

Not trying to be a smart a$$, but maybe try a bullet that is less "finicky" if you are just getting started. I'm fairly new to rifle reloading, so I went with the 175 SMK's because the feed back I got here and from an experienced friend was that the Sierra's just run without alot of fuss. You've got a good rifle, so find a load that shoots and be done with all the developement stuff and go have fun. Just my opinion, I'm wrong alot.

 

[ChadTRG42]

Re: Struggling developing .308 accuracy loads. Help

The VLD's like to be close to the lands, so you have to seat them long. This might be hard to do if you are feeding from a magazine. How far are you from the lands at your max COAL?
If you can't get it to shoot well with the VLD's, then try a SMK, Scenar, or A-max that will tolerate more of a jump.
Anything under a 20 fps ES is pretty good.

 

[Chanonry]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mohawk3A</div><div class="ubbcode-body">I've been trying to develop an accurate .308 load with 175,180, and 185 bergers. I can't get a 10 shot string with less than a 18 es. I keep seeing all these claims of less than 10es and 5 sd. Are there any Berger experts here than can recommend powder, charge, seating depth and neck tension? Ive been using varget and n550, with lapua palma brass. Thanks</div></div>

Can you be sure your chrony is accurate enough for this data to be valid?

 

[Augustus]

Re: Struggling developing .308 accuracy loads. Help

What kind of chrono are you using. I look at chrono results with a lot of suspicion after using multiple chronos in tandem. Also the same load from the same rifle may change in consistancy from one day to the next according to the chronographs. I have started shooting a load at long range to check consistancy in velocity. Shoot your .308 at 600 to 700 yds. in good conditions. If it is holding half min verticles, you are good to go. Anyway 18 fps ES will cause less than 1/2 min of verticle at 700 yds. If you are shooting groups at 100 yds I doubt you will see any ill effects from a load caused by 18 fps ES. I have had 5 shot strings show single digit ES and then have the next 5 go all over the place according to the chrono. A partly cloudy day will drive you nuts as will an overcast day or early morning or late evening when the lighting is changing rapidly. Anyway ES dont matter much, if any, up close. When you go long if your verticles are acceptable to your liking dont worry about ES. It will make you broke and prematurely old. Worrying about it to much MAY in extreme cases cause ones offspring to be born naked.

 

[onlyfineknives]

Re: Struggling developing .308 accuracy loads. Hel

As already mentioned, there are a lot of variables here to look at.

I run the 185 LR Berger in all my 308's. The main things that affected my loads were (in no particular order):

1 - type of primer
2 - neck tension (this is a biggie, both for ES and accuracy!)
3 - powder charge consistency

That said, 18 ES is for sure not a bad number. Could be better depending on your component combination, but it's for sure not terrible.

 

[Mohawk3a]

Re: Struggling developing .308 accuracy loads. Help

Your right, I'm worrying too much. To answer the first couple post, I'm too heavily invested in Berger to go buy smk's right now. I also like bergers. I can get my es around 18 and I'm grouping around .5, with an occasional flyer. I was able to hit steel past 500 with the same ammo, and im no pro. So its definetly working. It's not that I'm completely lost, I just want to be better. I want to get a load worked up with an es around ten. I posted to see if any if you guys had a secret Berger recipe you would share. My chronograph is a 35p so I trust it. I'm going to play around with the seating depth and neck tension a bit more this weekend. Thanks for all the suggesstions. Please let me know if you come accross any info you think I might be interested in.

 

[Supersubes]

Re: Struggling developing .308 accuracy loads. Help

18fps es is absolutely acceptable IMO. Go shoot and stop load developing.

 

[MitchAlsup]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mohawk3A</div><div class="ubbcode-body">Please let me know if you come accross any info you think I might be interested in. </div></div>

You might like::

http://home.comcast.net/~jesse99/palma.html

and browse around there for a while.

 

[TDaly25]

Re: Struggling developing .308 accuracy loads. Help

If you do ever give up on the Bergers, below is a load that works amazingly well for me. I load the bullets to jump .0010" to the lands. Here are the stats from the last 3 five-shot strings. Groups at 100 yards were all in the .4s



1/29/2011
.308 Win.
Fired Lapua Brass 43.0 43.0 43.0
168 Gr. A-Max BL-C(2) BL-C(2) BL-C(2) Total
1 2,513 2,500 2,529 --
2 2,491 2,497 2,525 --
3 2,498 2,534 --
4 2,502 2,494 2,525 --
5 2,505 2,496 2,517 --

Max 2,513 2,500 2,534 2,534
Min 2,491 2,494 2,517 2,491
Avg 2,502 2,497 2,526 2,508
ED 22 6 17 43
SD 8 3 6 15
ED as % of Avg. 0.9% 0.2% 0.7% 1.7%
SD as % of Avg. 0.3% 0.1% 0.2% 0.6%

 

[Greg Langelius *]

Re: Struggling developing .308 accuracy loads. Help

IMHO, chronos wear out more perfectly good bores than most other causes. No matter what the numbers are, the true tale is read off the target. For my purposes, the chrono has only limited value, and that's after the target tells me what load to use. The crono gives me a MV number to plug into the ballistic calc, to determine drops. Beyond that, I pretty much work without that particular net.

Greg

 

[Asm1]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">IMHO, chronos wear out more perfectly good bores than most other causes. No matter what the numbers are, the true tale is read off the target. For my purposes, the chrono has only limited value, and that's after the target tells me what load to use. The crono gives me a MV number to plug into the ballistic calc, to determine drops. Beyond that, I pretty much work without that particular net.

Greg </div></div>

I am not alone I see..

 

[Mohawk3a]

Re: Struggling developing .308 accuracy loads. Help

Got it figured out! 175 bergers, avg velocity 2750 with a 9 es. That will work for me. I guess my rifle likes to jump bergers. Thanks for all the tips!

 

[Notso]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mohawk3A</div><div class="ubbcode-body">Got it figured out! 175 bergers, avg velocity 2750 with a 9 es. That will work for me. I guess my rifle likes to jump bergers. Thanks for all the tips! </div></div>

You're still missing the point. HOW DID THEY SHOOT? All of my most accurate loads were not the best chrono shooters.

 

[Mohawk3a]

Re: Struggling developing .308 accuracy loads. Help

No I get you. I had one other group that was a bit better on the chrono, but didn't group quite as tight. The above data is off one of my best groups. I didn't measure, but 5 shots made a pretty small hole. I've got it narrowed down to a couple that I will test more thurough.

 

[Jaxdialation]

Re: Struggling developing .308 accuracy loads. Help

I don't do it -exactly- like that. But perhaps I lucked out. The Chrony and the target have been pretty well correlated. I'm always suspicious when they don't match up, and a better load is generally the result.

Your mileage obviously varies

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">IMHO, chronos wear out more perfectly good bores than most other causes. No matter what the numbers are, the true tale is read off the target. For my purposes, the chrono has only limited value, and that's after the target tells me what load to use. The crono gives me a MV number to plug into the ballistic calc, to determine drops. Beyond that, I pretty much work without that particular net.

Greg </div></div>

 

[tomcatfan]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">IMHO, chronos wear out more perfectly good bores than most other causes. No matter what the numbers are, the true tale is read off the target. For my purposes, the chrono has only limited value, and that's after the target tells me what load to use. The crono gives me a MV number to plug into the ballistic calc, to determine drops. Beyond that, I pretty much work without that particular net.

Greg </div></div>

I agree with you 100%. I deal with instrumentation and the data that it spits out at work all day. People really need to understand that any instrumentation is going to have error, float, a specific resolution, etc. Reading the data given off by any chrono and expecting it to be 100% precise and 100% accurate is just not realistic. There isn't an electronic acquisition system in the world that does this. This is exactly why I don't have any interest in buying a chrony to tell me how fast my rounds are going. There are way to many people that wasting their money here to do that. I'm not shooting past 100yds anyway. I live in Maryland.

 

[BBeyer]

Re: Struggling developing .308 accuracy loads. Help

As was said earlier, a few with very small es and sd figures take a lot of time loading carefully, the rest are lying.

 

[Boomholzer]

Re: Struggling developing .308 accuracy loads. Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">IMHO, chronos wear out more perfectly good bores than most other causes. No matter what the numbers are, the true tale is read off the target. For my purposes, the chrono has only limited value, and that's after the target tells me what load to use. The crono gives me a MV number to plug into the ballistic calc, to determine drops. Beyond that, I pretty much work without that particular net.

Greg </div></div>
Agreed. I use the Chrono for delta MV measurements in load development against target groupings. It's a starting point at 100-200yrds as added target range further skewed reported results. I never had any luck in statistical MV vs target results and I have two Chronos (Pact and CEP).
I also have long adopted using FGMM or a older pet load as a control group in recording reported MV. It allows me some warm up and sanity feedback on the chrony situation.