Secrets of the Houston Warehouse

[Jarhead]

All,

I have been doing some load development work on a new Tikka T3 6.5CM.

I shot at first with Factory ammo to confirm the 1 Tikka MOA guarantee. Result- 0.86MOA/ Tick!

I then set a goal to get it under .5MOA. The plan was to do a seating depth spread with a load the same speed as the factory ammo. This achieved .38MOA. Tick!

I then set a new goal to get it under .25 MOA.....The plan is a coarse powder spread, 7 loads .3 grains apart. I shot a group that was .22 MOA. Tick!

My current plan is to get it under .15 MOA. after this I would call the load development complete. I mentioned this to a friend of mine and he sent me this article.He knows that it will make me change my success point.....

I thought I would share as these guys seem to be the Neil Armstrong's of Benchrest.

secrets-of-the-houston-warehouse-by-dave-scott-precision-shooting-magazine-special-edition-1-1993.pdf

(307.11 KiB) Downloaded 812 times

[marksman]

it has a hell of a lot of good info in the article

"The secret,” Virgil said, “is to get the neck tension — the grip of the brass on the bullet — exactly the same on every case. You do this by firing the case and then feeling the bullet slide in the case neck as you seat it. "

[Bill]

Cool article Jarhead

[SCJ429]

You have done well with your Tikka to shoot 0.22 MOA, what distance did you shoot that group?

What bullet were you using?

[TassieTiger]

Very interesting article - I find it hard to digest...1/millionth of anything is just unmeasurable one my world...he’ll I struggle to work on .030” for seating depths.
So ppl reckon it’s on the level or a bit of local legend status? Same hole shots - time and time again ? I’m not discounting it - I’ve just never seen it.

[Grandadbushy]

Good bit of reading there Jarhead thanks for that mate, just shows that you don't need all the machinery in the world to get better accuracy from your rifle just the normal tools and some knowhow , the usual .5 moa for the 22-250 and .7-.9 moa for the 7mm has been my go to groups but after reading that I wonder if I could do better with the rifles I have by implementing some of the stuff brought up in that read

[Noisydad]

That’s some deep reading alright! My Sharps .40-65 Black powder ammo Is the only one of mine I can say for sure has exactly the same neck tension because it has none at all. The bullets are loose seated On the compressed powder.

[cflake]

Great article, very interesting.

"We discovered that if you want a gun to really shoot, you can’t cheek it, you can’t shoulder it, you can’t hand it, you
can’t thumb it. The only thing you touch is the trigger, and I tried to put my fingerprint on the trigger exactly where my last
fingerprint was. I didn’t even touch the bench. I planted my feet solidly on the floor and kept them right there."

Each to their own and I can see the attraction in BR but in my opinion though.. this isn't "shooting". You may technically be shooting a bullet out of a rifle, but the person that wins these sort of comps aren't the best "shooter". It's more of a competition based on who spent the most money at the gunsmith and the most time in the reloading room.

[Jarhead]

SCJ429,

I am doing all of my load development at Hilltop at 100 meters.

I am using a Hornady 6.5mm 140grain ELD-Match squeezed into a once fired small primer starline case. Bullet is .015" off the lands and sitting on 40.1 grains of AR2209.

I have been measuring OAL at the bullet tip and just bought a proper Hornady ogive bushing to measure this much better. Also bought the OAL gauge and threaded round- previously I measured the "on the lands" measurement with the almost loose bullet in a fire formed case method. I had to measure about 8 times and average as there was a large variance....….

[SCJ429]

You are doing very well with Hornady bullets. The Tikka barrels can produce some outstanding results. I shot a 0.275 MOA group at 300 metres with my Super Varmint. I was using Lapua Brass and Berger bullets which make things a little easier than the Starline and Hornady combination.
Have you tried any Berger bullets?

[ash_hendo]

VERY Interesting, thanks for posting!

I found his experiment on changing powder load quite substantially and not effecting groups fascinating.....

[Jarhead]

Hi SCJ429,

I bought 1000 140Grain ELDs. When I get low I am going to revisit your recommendations on bullet selection!

[TassieTiger]

VERY Interesting, thanks for posting!

I found his experiment on changing powder load quite substantially and not effecting groups fascinating.....

This is why I find it difficult to believe...

[Grandadbushy]

Yes Tassie normally I would agree with you but I've just put a new barrel and action on my sako 22-250 mod 85 and after trying the same load and weight bullet from my old sako 55gr with 31.6gr of B/M2 I found the new one didn't like it so I decided to go to a 50gr for more speed and started at min weight B/M2 up to 36gr max at 3900fps according to the good book but I will chrony it later, now min load was 1moa so went up .5gr it tightened up to.7moa then up another .5gr and it went to what i'm using now but I kept on going and it never changed in 4.5gr to 36gr , I have never had a rifle do that before ,like stay perfect exactly the same groups over a 5gr difference , I moved the seating depth and it all went south different groups for each load put it back to original depth and perfect no change in grouping as at first , what does it ?, I don't know but I think if you are lucky enough to strike the right mix then changing powder weight and to get the same grouping could be possible

[Grandadbushy]

Here is the target I settled on it's good enough for what I do one on the left is my 7mm mag

[TassieTiger]

That’s very nice shooting GDB - very nice indeed - especially with 7mm - that’s very cool. Well done!!!

Thing is with Houston whare house - it was a long time ago when They were doing it and precision was...difficult at best...no cnc machines back then...and - they are talking about 1 hole groups .10” inch...thsts much smaller, then even your brilliant groups above...and I think I read re bumping 1/1,000,000 of an inch ? That’s crazy for bsck then... let alone now. I’m not saying impossible - but...it’s one of those things I’d have to see...

[SCJ429]

VERY Interesting, thanks for posting!

I found his experiment on changing powder load quite substantially and not effecting groups fascinating.....

This is why I find it difficult to believe...

You can try this for yourself. Load a group plus and minus 0.3 grain around your favourite load. Then try another group plus and minus 30 thou seating depth. The seating depth is critical. But notice they also found that jam always produced the best results.

[TassieTiger]

Plus or minus .3gns means .6GNS spread...surely, that had to move poi...especially with oldy timey powders?

[Grandadbushy]

Yeah Tassie i'm hearin ya mate when things are cut that fine it's hard to get ones head around it and would be better to see for our selves

[SCJ429]

Heaps of guys worry about throwing exactly the same amount of powder but don't check the ogive length of the bullet. You could be a couple of tenths of a grain over your load but still be inside of your node. At 100 metres you don't worry about low SD, only the group size. He is saying in the article that the big factors regarding shooting a group was the way the bullet is presented to the lands and consistent neck tension.

Give it a go with your 30/06.

[ash_hendo]

VERY Interesting, thanks for posting!

I found his experiment on changing powder load quite substantially and not effecting groups fascinating.....

This is why I find it difficult to believe...

Understandably difficult to believe, but maybe it has something to do with the uber precise neck tension and being exact in the lands, maybe the "let go" pressure is most important when "in the node" and the little more or less powder is not contributing to velocity. They had pretty short barrels too? probably not burning all the powder anyway? Or it could just be rubbish, surely others have done similar experiments....

[TassieTiger]

Heaps of guys worry about throwing exactly the same amount of powder but don't check the ogive length of the bullet. You could be a couple of tenths of a grain over your load but still be inside of your node. At 100 metres you don't worry about low SD, only the group size. He is saying in the article that the big factors regarding shooting a group was the way the bullet is presented to the lands and consistent neck tension.

Give it a go with your 30/06.

So sell the electric scales and buy a press that measures bull seating pressure and a chamber measure? Cause if this is true, then many ppl (including myself) have not been focussing on the correct things...I mean why bother with OCW or ladder testing at all if .6gns won’t actually matter if you get other higher priority parameters correct?
Can you buy dies or presses that can measure the minute foyer to seat a projectile?

[SCJ429]

You still need to do your load testing to find your node and identify where your node starts and finishes. If your node starts at 41.1 grains and goes to 41.5 grains, for example, you could load anywhere between those figures and the bullet will end up in the same spot more or less. But if you load them short and long or have variable neck tension, your groups will open up.

The best gauge you can get to measure seating pressure is you. You can feel when a bullet needs more pressure to seat it. Put that case aside and recheck and adjust the neck thickness.

Remember that those guys are most likely shooting 6PPC using 60 odd grain flat based projectile from a slow twist barrel. They are not looking for every last bit of speed as they are shooting at 100 or 200 yards.