Building a new 10 1/2 lb RFBR Rifle

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center22

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Finally acquired all the components necessary to build a new 10 1/2 pound RFBR rifle. Don Stith sent me down a very nice looking stock that weighs only 2 lbs 4 oz, including the trigger guard. Bill Swatsworth came through with another XIII action, which has a couple of improvements over my previous two. This action has much heavier striker spring, and the 3/4 x 16 receiver threads extend all the way to the loading ramp. In my opinion, this make it much easier to fit the barrel and set the headspace. The XIII action arrived at my FFL several days before I left for the PSL/ARA Nationals in St. Louis.
Had I not received the XIII before leaving town, I most likely would have ordered a 2500X action from Jerry Stiller at the shoot ... the 2500X's are very nice actions. Just as well though ... because I am very familiar with the XIII's and know how to make them click.

This time I deviated some on my choice of barrels. In the past, I have used Broughton, Shilen and Rock Creek. This time I decided to try a Benchmark 3groove in .900 straight. I already have the Benchmark barrel installed on the XIII action and dropped into my heavy guns stock for initial testing. I will not be able to test the rifle until the middle of next week. I would like to hear from anyone who has experience shooting the Benchmark 3 groove. Thanks, ... John
 
Benchmark barrels

John, I currently have 3 Benchmark 3 grooves on three different rifles, one sporter and two 10.5 guns. On the heavy guns one replaced a Broughton and one replaced a Shilen ratchet that replaced a BM 2 groove. Both heavy gun barrels were put on this year and both have done quite well. I rarely get those unexplained flyers which has really boosted my confidence. All shoot very cleanly, a couple of wet patches after each target has kept the carbon down to just a few trace streaks at the 12 o'clock position over the last 10 matches this year so no brushing has been required as verified by the bore scope. The chambers finish easily and the newly cut leade polishes up to a shine with just a patch and some Isso. My last one in particular had a very nice taper to the bore and has been extremely reliable over a broad temp. range. I like them, have just ordered another one just to have as a spare.

Dennis
 
Dennis, did you ever slug them before instillation? I'd be interested in what current dimensions are running.
 
[. I rarely get those unexplained flyers which has really boosted my confidence.

Dennis, did you feel the 2 groove would give you fliers? Just curious as I have one myself & have wondered if it was me or the barrel?
Keith
 
Benchmark 3 groove

Dennis D. said:
John, I currently have 3 Benchmark 3 grooves on three different rifles, one sporter and two 10.5 guns. On the heavy guns one replaced a Broughton and one replaced a Shilen ratchet that replaced a BM 2 groove. Both heavy gun barrels were put on this year and both have done quite well. I rarely get those unexplained flyers which has really boosted my confidence. All shoot very cleanly, a couple of wet patches after each target has kept the carbon down to just a few trace streaks at the 12 o'clock position over the last 10 matches this year so no brushing has been required as verified by the bore scope. The chambers finish easily and the newly cut leade polishes up to a shine with just a patch and some Isso. My last one in particular had a very nice taper to the bore and has been extremely reliable over a broad temp. range. I like them, have just ordered another one just to have as a spare.

Dennis
Click to expand...

Dennis,
I machined the Benchmark 3 groove and fit it to my XIII action. Chamber is the Eley EPS which I set up .030" short for better engraving. Took it to the range yesterday to test the barreled action in my heavy gun stock. I purposely did not cut the extractor grooves prior to testing, so I had to remove each fired case manually. After the initial sight in at 50 yards with a new Leupold 40X competition series scope, I decided to run some tests without the tuner installed. I shot five shot groups - one with Eley Team, and four other oddball lots of Eley Match. The Benchmark grouped .375" and under without a tuner. I installed a H/H tuner and set it to "225" but the groups still had vertical. When I moved the tuner to "230" the groups began to tighten up. From the preliminary results, I feel the Benchmark 3 groove has some very strong potential for accuracy and like you mentioned, does not show a tendency to throw unexplained fliers. Today, I removed the barrel and milled the extractor slots. Stock work will begin soon. John
 
Benchmarks

I have slugged the barrels but not measured them, the odd 3 grove configuration makes that difficult to get right with just a micrometer. My 2 groove shot very well but was very picky about ammo and tuning. The lots it liked it shot well but the ones that didn't like showed lots of wide shots. That of course was only one barrel and each barrel certainly has it's own little quirks.
John, I, like everyone else has had trouble getting Eley and have been using Lapua this year. When I first chambered it I did a short chamber that engraved to within about .020 of the case, this is the shortest chamber I've ever cut. Upon inspecting the chamber after firing I noticed that the carbon build up was unusual in that it extended into the rifling. It shot well for the first fifteen or so rounds when clean and then started to go down hill. This is the first time I've seen this. I concluded that the chamber was to short and lengthened it until it just comes up to the 2nd canalure. The carbon fouling became lighter, no longer encroaches on the rifling and accuracy no longer falls off. On this particular barrel I used a .224 chamber which seems to work quite well with the Lapua since it doesn't have the heavy lube like Eley does. Building them is fun but I do an awful lot of head scratching trying to figure out what exactly works best.

Dennis
 
Is Longer better?

I read in a post on another site Jerry Stiller put up where he said when he got his chamber out to .660 his flyers went away. I was surprised that nobody engaged him in conversation about it.

Pete
 
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