Wind Chart

[littlebang556]

Just wondering if there is a wind guide/chart or whatever that might be suitable for both full-bore and F Class shooting. Something that shows flag strengths and estimates MOA changes required.

regards

Robert A

[balcom]

Littlebang.
Get in touch with your nearest State Assoc office, they should have some of the Jim Sweet books in store, the chart is on the back page, although it is only for 308/7.62, if using a 5.56 mm the wind is about the same up to 600 then after that I add 1.5 to my wind, my load for my Musgrave 5.56 that K Hills built is 25.5 of 2208.
If using a lighter load you might require a bit more wind movement.
PeterH

[littlebang556]

Cheers Peter, never thought about just adding 1.5 but I will certainly give it a try.
My load is very similar to yours and I have but a few times shot beyond 700 yards but will endeavour to put it into practice next year.

Regards

Littlebang556 Rob

[Chris Burdett]

Get them made for any calibre/load at sales@windcharts.com

[pjifl]

Mentally applying a factor works fairly well even over a wide range of distances as long as one does not go to extremes.

Since most of my experience of coaching is with the 7.62 + 155 SMKs or equivalent I simply thing of a rifle as having, say, 60 % of this wind setting.

Peter Smith

[balcom]

Mentally applying a factor works fairly well even over a wide range of distances as long as one does not go to extremes.

Since most of my experience of coaching is with the 7.62 + 155 SMKs or equivalent I simply thing of a rifle as having, say, 60 % of this wind setting.

Peter Smith

Yes Peter, It's all about having the experience which take some time to learn, then comes easy - just wind when you see a change
peterh

[Chopper]

i dont mean to open a can of worms but over the last 3 years or so have done a lot of work and barrel testing on the 223 and load testing,in particular wind differances 223 vs 308,the most interesting results come from shooting them side by side,shot for shot,at this stage i have not compiled all of the information and wonder if i ever will but basically after chronographing the two to shoot the same velocities ,approx 2920fps there was very little if any in wind differences out to seven lines even at a 1000yds where the 223 shot shot a 75.13 which really blew me away, the only time i THINK there was a difference in the grouping was at bendigo range when the range was being continually watered in the hot summer months last year , the morning groups at the longs were great as good as 308 but in the afternoon when the sun was out and the humidity and heavy mirage arose from the ground was the only time i thought that there was any difference in grouping but wind the same ,many still wonder about the differences in 223 vs 308 and say that 308 will buck it better but i say it will BUCK YOU BETTER , i have been a 308 shooter for over 25 years and love them but have to confess that i beleive they have the edge because they are so much easier to use , one of our state team shooters will tell you because he had a problem with grouping his 308 at 300yds even after a regulation scope test of his gear which shot 50.10,i then put him into my 223 shilen with iron sights and he proceeded to shoot a 50.8 ,through shooting the 223 we found that he had a follow through problem, so why dont you have some fun and shoot side byside one weekend and take some groups and remember to shoot the same wind,CHOP.

[balcom]

Chopper,
Haven't tried that but willing to have a go, I have been shooting FB for 38 yrs but the last 7 with a 223 or a 260rem, I can only give the results that I have recorded for my own shooting, maybe it's diff from yours, but I think depending on barrel etc, the wind.elevation the people will make up thier own load, I know that using an Omark for instance will not give you the speed of an LMB or Musgrave etc.
LOL & Cheers
PeterH

[pjifl]

I have been using a 223 from when they became 'legal' for TR. Once the 80 grain projectile was allowed the rifle should, in practice, be considered the same as a 308. The difference is minimal - probably less than what a person can read wind anyway. This is my opinion and another person who has done a lot of coaching.

Statistically there may be one point in 100 difference - but release is better so where does that leave us ??

Peter - I cannot see why a 223 from an OMark would be any different from anything else. Assuming the same barrel and chamber of course.

Why would it be any different ?

The only downside of a 223 is in my opinion

1/ shorter barrel life
2/ markers who are not used to them losing shots occasionally on very large targets.

It would be interesting to see both the 308 and 223 shot on the Open target. It would help to answer some of these questions.

Peter Smith.

[balcom]

I have been using a 223 from when they became 'legal' for TR. Once the 80 grain projectile was allowed the rifle should, in practice, be considered the same as a 308. The difference is minimal - probably less than what a person can read wind anyway. This is my opinion and another person who has done a lot of coaching.

Statistically there may be one point in 100 difference - but release is better so where does that leave us ??

Peter - I cannot see why a 223 from an OMark would be any different from anything else. Assuming the same barrel and chamber of course.

Why would it be any different ?

The only downside of a 223 is in my opinion

1/ shorter barrel life
2/ markers who are not used to them losing shots occasionally on very large targets.

It would be interesting to see both the 308 and 223 shot on the Open target. It would help to answer some of these questions.

Peter Smith.

Peter,
I have from experience had trouble extracting shells from an Omark due to the small extractor, thats the diff I am talking about, if you load a round with 25.5 of 2208 you will experience extractor probs then again maybe not but I have whereas with my Musgrave with the large extractor claw I have never had a prob,
PeterH.

[littlebang556]

My load is very similar in that it is 25.4 of 2208 and I also had primary extraction problems, that is until Lynn Otto suggested I talk to her husband to rectify such...I have never looked back and think that even if one wanted to, could load heavier...but my inch load is fine for me.
Just send a private message and I am sure you will be surprised.
I hope the Otto's don't mind and may even post a "suggestion" on how to fix.

Regards

Littlebang556 Rob.

[pjifl]

PeterH,

Sorry, I totally misinterpreted your comment re 'speed' when shooting a 223 from a converted OMark. I thought you meant muzzle velocity.

Just one comment about extraction which probably does not apply in your case - but I will mention it in case someone benefits.

The extractor movement is more delicate with the smaller cartridge.
Sometimes shavings of brass lodge under the claw and in the slot behind the claw and cause problems. It seems more a problem with the 223.

Also, it may be worth examining the bolthead and maybe running a needle file in the extractor slot to allow the extractor fractionally closer to the centre. Of course the extractor needs to be removed for this which is not a trivial job. I dont think some of the boltheads were finished as accurately as they could have been and tidying up the extractor slot may help but dont overdo it. Probably the OMark should actually have a slightly longer extractor spring in the 223 version.

I agree it could be better - but can live with it.

Peter Smith.

[Guest]

Further to Omark extraction problems.
There are several reasons why you experience extraction problems.
1 Insufficient primary extraction.
caused by
a Bolt being set too far back when adaptor is fitted.
b Too much clearance between extractor claw and case rim.
c Combination of both a and b.
Remedy.
a Remove bolt handle and re solder further forward on tube.
Machine bolt handle and insert a hardened steel piece ( bolted on ) and regrind to allow max primary extraction.
b Not a great deal you can do here except make a special extractor with reduced clearance, or as some have done machine bolt head and fit another type of extractor eg Sako.
When increasing primary extraction to an absolute maximum it may be necessary to put a little more chamfer on each bolt lug to assist in bolt turn down.
I recently had an omark that had almost 1 mm clearance between extractor claw and case rim---this is 1mm of lost primary extraction and is nothing short of bad workmanship on behalf of the manufacturer of both the bolt head and extractor.
2[u] Overloading.[/u]
Look for pressure signs, ( well documented) which are not always clearly evident.
Reduce the load to about 10% under max recommended and work up.
Most cases of overloading are brought about by the desire of the individual to extract as much speed ( MV ) as possible. It is well documented and proven that best accuracy is not always at some extreme projectile speed. Of course you need sufficient speed to reach 1000yds with stability. Sometimes this is not possible because of barrel length and increasing the load does nothing more than introduce extraction problems.
3 Buggered cases.
Continual resising, and particularly loading at or over Maximum to achieve speed will cause cases to harden ( over time ) and make extraction difficult or impossible. A good test to determine the state of case metal is that if it won't rechamber easily without resizing, good chance it's had it's useful life.
4 Worn and/or damaged parts.
Replace.

Barry

[pjifl]

Barry Davies mentioned with respect to OMarks

<Bolt being set too far back when adaptor is fitted>.
<Remove bolt handle and re solder further forward on tube>
<Machine bolt handle and insert a hardened steel piece>
< regrind to allow max primary extraction>

Yes. I forgot to mention this. Its the first thing to look for. Coupled with the metal involved in camming the primary extraction of an OMark being soft, its a very commom problem because it wears as well. Very often an old OMark has almost no primary extraction but it can be retrieved.

Someone who knows what they are doing can fix it in a variety of ways and if done in hard metal the whole extraction usually becones a lot smoother.

I am not trying to put people off an OMark. They are a budget rifle which can equal anything - but only if one can address these problems.

Peter Smith