SmallCaliberCentral

Hutch20

There definitely is a difference with a custom barrel and chamber. I just shot my new custom rifle for the first time last weekend and it printed groups better than my XR-100 within twenty shots. It took my XR-100 a couple hundred rounds to settle down into the 3's. With the custom rifle I expect it to be able to shoot in the 1's when I find the right combination.

I think the difference with the custom rifle is in how it is machined. All measurements are cut to within .0005 in. tolerance. I can load the bullets jammed into the lands with plenty of bullet left in the case. The action, barrel and chamber are all aligned perfectly with the axis of the bore. The stock is pillar bedded and designed to recoil straight to the rear without any horizontal or vertical movement. Combine all that with a 1 oz. trigger and you're set for shooting some bug holes. You just don't find that kind of fit and finish on factory rifles. The real difference is the cost.

The good side of the story is that the .204 is a very accurate round even with a factory rifle. It just takes a little fine tuning.

this place makes me think WAY too much. That, and the desire to spend large quantities of cash on shootin stuff is drivin me nuts. The thouhts of the one holer, man how can you guys stand it it.

Hutch

Skipper ,I no bench rest shooters have been seating bullets into the lands for a long time and also have been warned that it can spike pressure in a heartbeat , so I no you are going to try it in your new custom 204 , but how do you get around the hi pressure spikes?? Just gradual ladder loading?? Its amazing that a bullet just starting to move in the case mouth at the same time being forced into the rifling doesn't act as a obstruction.

contender hunter

I started from the minimum load with the bullet jammed .005 into the lands and worked my way up the ladder. I don't have a strain gauge so I can't compare it to loading off the lands. I just watched for the signs of excessive pressure like before. I'm using my Chrony to be absolutely sure that I know where to quit adding more powder.

I would imagine that my pressures are higher than they would be having a little jump to the lands like with my XR-100. I was able to work my way to maximum charge and .2 grains over before I started to see reduced velocity. That's where I stopped. I'm looking for one hole groups not max velocity. One of my best groups was with 24.4 gr. of RE-10X with the 35 gr. Berger. That's way down on the low end of the ladder. I did notice that the groups shrunk again at about 25.6 and 25.8 gr. It was kinda like it liked two different charges. I want to repeat that ladder test to see if it was me or the rifle. My very first group after barrel break in put my XR-100 to shame. That just doesn't seem right. Now I'm wondering if the groups opened up at all or it was just my shooting. There just didn't seem to be what I would call bad groups at any charge.

skipper wrote: ...

One of my best groups was with 24.4 gr. of RE-10X with the 35 gr. Berger. That's way down on the low end of the ladder. I did notice that the groups shrunk again at about 25.6 and 25.8 gr. It was kinda like it liked two different charges.

...

This is an area I have been looking at for a while. Not sure if you have seen this or not.

Barrel Harmonics, Pressures and Timing

contender hunter wrote:Hawkeye , did you see an improvement in group size with seating close to the lands??

Contender Hunter
No.. my groups opened up.Thats why I went back to 2.263. I only tried it with the Sierra 39's. Maybe I didn't go far enough We'll give it another try with the LRPV

WrzWaldo

I have not read that particular article but, I am aware of barrel harmonics and nodes. This is not a subject that is discussed much on this forum. I'm not sure why because it is discussed at length on the benchrest forums. I guess it's because this is more of a hunting forum than a benchrest forum. We are all looking for that sweet spot with our load development but just not refering to it in terms of nodes.

My friend uses Quick load to develop his loads and he is always talking about nodes. He is always looking for the next node and to see if he can pack enough powder in the shell to reach it. I wont sit next to him at the range, he needs both hands to lift the bolts.

In my XR100 I tried setting the COL as long as possible, I was able to reach the lands with 40gr Nosler BTs but they didn't shoot well until backed off to .035" off the lands. I seat the 39gr Sierras to 2.395" OAL. This gives me less than the diameter of the bullet in the neck so I am more careful about handling them. Plus my rifle is a single shot so no worries about magazine lengths.

For those of you intent on reaching way out there to the lands I would suggest partial neck sizing. It will help align the cartridge in the chamber and allow it to seal more rapidly upon firing.
I've dabbled with reaching the lands but found no improvement doing so.
Alot depends on your particular chamber I think. Just how far do you have to reach to get there type of thing.
Just as thier are nodes in powder charges there are also nodes in seating depth.

http://www.angelfire.com/ma3/max357/houston.html

The link above is for a very interesting article about some legendary figures from the benchrest arena.

Not to say they had all the right answers, but they did fire thousands of groups to determine the best possible combinations for their rifles and gained a lot of valuable information in the process.

I suppose "individual results may vary" but one thing that stuck with me from this article is the following exerpt.

One thing that IS important is that the bullet be precisely seated against the lands. T.J. Jackson reported this fact in the May 1987 issue of Precision Shooting. In a letter to the Editor, T.J. wrote, “...in all our testing in that Houston warehouse... and the dozens and dozens of groups that Virgil King shot in there ‘in the zeroes’... he NEVER fired a single official screamer group when he was ‘jumping’ bullets. All his best groups were always seated into the lands, or at the very least... touching the lands.

My Cooper .204 is at Cooper being rechambered now, and my M77 Ruger .204 is on loan to a friend.

When I get them back, I plan on doing some extensive chronograph testing on both to determine the most accurate loads for each.

I will answer the freebore question for my guns, although my own personal experience in the last 30 odd years of reloading for many calibers has been to favor the shortest jump possible.

In many cases "soft seating" bullets with oversized expander ball to just touch the lands have provided the best results, although less powder is typically required to achieve desired velocities this way.

DO read the aricle, It's entertaining as well as informative!

Thanks, Sammyc

sammyc
Don't need to read it. I would recognize an excerpt from "Secrets of the Houston Warehouse" anywhere. Your right its a fabulous story. Whether fact or just a gun writers dream I'm not sure.
In most cases I believe its true but not always. I've danced around the lands with my 308 Krieger alot and certain ogive's demand .020 off the lands. Lapua Scenars like to be just touching and Bergers like to be .005 off the lands. So far I have not found any load that likes to be jammed in this barrel. Maybe I have just not found it yet and the blank that came off the machine after mine may love jamming. This is a tight bore Palma barrel not a bench rest tube. A slightly different throat.

Most factory 204 throats are quite long. I think there comes a point of diminishing returns in seating the bullet too shallow in the case trying to reach the lands. To hit the lands with a 39smk in my new barrel I would have roughly .060 still in the case. Thats counting the boat tail. Now if the rifling is more easily accessible with a shorter throat then that changes everything.

The paragraph just below the one you referenced in "The Warehouse" is my favorite. I have seen this work. A horizontal or vertical group can sometimes be fixed by a slight seating adjustment. This has worked for me out of the lands also. Not always though.

Everyone should read that story though. Lots of great info. You just might find the answer to a problem thats been plaguing you.