204 39g SBK Jump or in the lands?

[lmorrison17]

How do they shoot best in your rifle? Jumped or in the lands?
Thanks.
Larry Morrison

[Rick in Oregon]

Larry: Most 204R's I'm aware of are chambered with very long throats, and with most factory chambers it would be most unlikely if you could come closer than .100" to the lands. The factories all chamber with SAMMI dimensions of course, and it appears this was done intentionally, possibly to create a 'non-pressure spike issue'?.

I shoot a Sako M75 Varmint with factory tube, and using the 39 SBK seated way out with only about .100" of bullet in the case neck (neck sized), this rifle shoots in the .3's over RL-10X using Redding Comp dies. With that seating arrangement, I'm still almost a full .090" from the lands.

My second 204R is a custom M700 w/Pac-Nor barrel chambered with a 'match' reamer, and using the 39 SBK in neck sized cases, just kissing the lands, it shoots in the mid-.3's, also with 10X and Redding Comp dies. I'm referring to ideal conditons, early in the morning with about zilch wind. The M700 has just barely been broken-in barrel wise too, with no load development yet (shooting the Sako load for now), so I'm hoping for some improvement once she settles in and a dedicated load has been worked up.

You might want to cruise over to the 204 forum, as there's lots of info and experience over there on the 204R.

[Silverfox]

lmorrison17--Using the Sinclair Chamber Length Gauge in my Savage 12VLP in .204 Ruger, my chamber was 1.877" long after I had shot the rifle for a couple of months. Like in Rick's Sako, I cannot seat the bullets so they will touch the lands and still have enough bullet shank in the casing neck to hold it rock solid, especially on boattail design bullets. If at all possible, I like to have approximately 2/3 of a caliber of the bullet shank inside the casing neck. For the .204 Ruger, that means I want at least 0.163" of the shank touching the inside of the casing neck. For boattail bullets, like the V-Max that have about .100" of boattail, that means the bullet is in the casing neck quite a ways.

I like to shoot my rifles as repeaters, therefore I am also limited in the overall cartridge length that will fit in my magazine. These limitations have not seemed to affect the accuracy of my rifle--at least in my opinion :D However, who knows? Maybe I'd be able to shoot those 0.1" Internet groups if I could kiss the lands with the ogive of the bullets :rolleyes: :rolleyes:

I don't have my exact numbers here at work, but I think the load I have worked up for the 39 gr. Sierras has the bullet seated so it it is about 0.086" from the lands. Other loads I worked up for shorter bullets had the bullets seated so they were at least 0.100" from the lands. I haven't measured the chamber length lately and I would guess there has been a little bit of throat erosion so the bullets are probably a bit further from the lands than when I did my initial measurements.

When I rebarrel this Savage 12VLP, I'll be doing a chamber similar to Rick's with the freebore cut so I can seat the bullets touching the lands and have about one full caliber of bullet in the casing neck. That way, if the throat erodes, and it will, I can chase the lands for quite a while.

Of course, non of our rifles are going to like exactly the same powder charge, primer, brand and type of powder, primer, seating depth, etc. You just have to pay your dues and go out to the range and test loads to see what works best in your rifle. Good luck and give us a report on your progress.

[GrdhgKiller]

With my Rem 700 VSSF II in 204 my 39 BK's are seated .090 off the lands. It shoots quite well. No choice but to jump with its thoat lenght.

[lmorrison17]

Well the bullets finally arrived. This is a Cooper Phoenix single shot. I had no trouble getting to the lands and still have a about a caliber in the neck. My intent is to try some Kissing, .010 in and .010 out. Will be about about the month till I can test as my local public range just shut down for repairs. Thanks for the info gentlemen.
Larry

[Silverfox]

lmorrison17--Please don't wait a whole month for your rifle range to get open again to shoot that rifle!!! Get out somewhere you can set up, even if it is out on the prairie, and do some testing. I'd sure like to see your targets and get a glimpse of how your rifle shoots various loads.

You should be able to chase the lands for a loooong time. That's a good deal! I just checked the throat erosion situation on my Savage 12VLP last night and the throat has eroded between .009" and .010" in the last 2 years, which is about 1,000 rounds worth. Keep in mind, I shoot some of my loads pretty hot, but the rifle is still shooting at a very accurate level.

[lmorrison17]

Prairie OMG I wish. I live in MD. I have been investigating other ranges most seem 1.5-2hrs. But I need to go I have two BR guns with new barrels and have only gotten to fireform the cases no load tuning. The matches are passing me by. The cooper belongs to a friend, he's an elderly gent friend of my fathers, he bought the rifle on advice of a friend of his in ND. He knew I shot a lot and brought the rifle to me to help him set up with proper bench equip. and break-in procedure. He shoots my rifles a couple times and is not satisfied cooper in comparison. As his targets bare no resemblance to the factory test target. I told him you have to handload. SO off he goes with another shopping list for sinclair. But I do his loading for him. My goal is once he sees the benefits plus the satisfaction and fun he'll be ready to do it on his own. Oh and plus I got a new shootin buddy out of the deal.