I have a BDL that will group bullet on bullet at 100 yards and a new .17 VLSF that would have trouble making 2" at the same distance regardless of load.
I'm ging to try and bed the gun and remove the two pips in the front of the stock, but advice from an excellent local smith was this:
The neck tension on the .17 needs to be as low as you can get away with at about 1-2 thou tension.Now my Forster loaded rounds measure .193 . If my bullet is .1715 (berger 25s) and my brass is .014" thick, to get 1-2 thou tension using either Redding or RCBS busing dies, I would need either a .199 or .198 bushing (that is doubling the thickmess of the brass and adding the bullet diameter) Is this right? If so there must be a fair amount now if I have a loaded round at .193

I know the BDL took 300 shots before it would group and the VLSF has done only 150 so far. Is it likely to get better?

1) Your neck thickness is an avgerage of .014". So diameter is .014(2)=.028" + .1715 = .1995". Try the .198" bushing.

2) Yes, you have a fair amount neck tension on the bullet now.

3) Yes, your accuracy is likely to get better. If you're getting copper fouling clean bore every 25 rounds.

4) Seat the bullet closer to the lands.

What is the outside diameter of your fired rounds? What is the neck diameter on the gun/chamber? You need a min of a tho release. I have a 198 chamber neck turn to 195 and size with a 193 bushing. Loaded diameter is back to just under 195. I have found seating the 17s a bit deeper might do the trick. I had a problem with too little neck tension. Wilson bushing can be flipped upside down and give you an extra 1/2 tho of tension. How is pressure? I wonder if it is the neck tension, your pressure might be spikey. I would try starting 2 tho under fired diameter and go in/down from there. You can fine tune with a Wilson bushing more so than a Redding or others. Annealing your cases might fix up some of your release. Bedding is a good idea on all rifles, so that will not be a waste. Hope this helped, keep posting the results.

I'm thinking the the neck diameter on the gun/chamber estimated would be fired case neck diameter plus .001". Just in case the reamer specifications are not known.

17 VLSF? I don’t get around much, what is it?

Mick,

It's a Remington Model 700 Light Varmint Stainless Fluted bolt action rifle chambered in .17 Remington.

Thanks for the advice so far here.
The fired dimensions are .199
I do have a neck turner with a .17 Mandrel, is it worth turning for a factory chamber?
I have, I thought got them right on the lands, but the gauge is in need of replacement and pretty inaccurate at the moment.
Also need to gauge the chamber as I am trimming to SAAMI and expect that is way too short.

I would not turn for a factory chamber. This will cause a sloppy fitting neck. Brass will over work and split. Anneal and use bushings .196,195,194. I would size an empty case. lube the bullet with some imperiel. seat the bullet so the neck has just has enough to hold it and chamber it allowing the bolt to seat the bullet. NO POWDER OR PRIMER. Use that as an OAL gauge. Once you get the seating depth you are most happy with set your dummy there. I use mine to set my seating dies up everytime. I would start there and go in 5 tho at a time on seating depth. Annealing has really helped my neck tension consistancy. All my 17s and 20 get annealed before F/F. The rest get redone about every 5th loading.

I use a .192 or .193 bushing for my 17 Rem. The Rem brass I use has a neck thickness of .0125 to .0115 not worth the trouble to clean up the necks. Since I don't have a tight neck rifle my fired neck dia is .200. I get a load round between .196 and .197. I neck down 221 brass for my 17MachIV and use the same size bushing.

I've had my best luck with IMR-4320 and 25gr bullets at around 3950fps and alot of bullet jump. I still have some of the Rem 25gr bullets and use those plus Hornady's and Berger 25gr haven't tried anything else in that rifle.

Johnny, your second .17 is doing poorly because the rifle gods are angry that you have two and I have none! Can't help with your problem directly due to a total lack of inexperience but I do have a few thoughts.

IF you are striving for a consistant degree of neck tension you will almost certainly have to neck turn. Even good factory brass will have a couple thousants variation between cases. Are you using a neck expander after using the sizing bushing? With a bushing, consistancy of the necks is mandatory. All a neck bushing does is make the outside the same before your bullet expands it, then the variation follow the neck's thickness. An expander does make sure the inside is the same, a bushing die with no expander on unturned necks does not!

Like most rules of thumb, the "seat to the lands" rule is really good for measuring thumbs. A LOT of factory rifles shoot best backed off .010 to .040 inches! Sometimes finding the best seating depth can work magic.

Is that your photo under your handle? If so, you have an amazing resemblance to one of my most respected politicians of all time.

Update.

Sanded the "pips" out of the fore end of the stock and I had the barrel floating. The groups halved (don't get excited yet), but still not as good as the BDL. I then put the moderator back on and it all went to hell again and worse. This is explained by the mod weighing in at 1lb and is pulling the barrel down into the barrel channel. It would shoot, but with no fore end grip at all. Any pressure on the front and it sprayed.
I've left the gun with a local smith to bend and lift the barrel clear of the channel.
I am also concerned that the Dewey SS rod may have damaged the barrel. I have bent 3 rods so far here, 2 Dewey (god bless Sinclair as they replaced free of charge) and one Bore Tech rod. I've nw switched to a pull through for cleaning.

Anyway, I have a Redding "S" set on it's way with a.195/.196/.197/.198 bushings.

Jim C, as you say the necks are not that consistant and have taken the minimum off with the turner.

I like the .17 Rem as I am a fan of the underdog (over here anyway) and the BDL is awesome (I'll get some links to the pictures of the groups)However I spent less than 3 hrs getting a 22/250 AI and 243 AI shooting brilliantly.

Perhaps I should have gone down the 204 route.

When the .17 is back, I'll let you know.

Thanks for the help.