Building a benchrest rifle

[Lee Martin]

May 27, 2018 13:25:12 GMT -5 moosemeat said:

Lee I would be curious to know what your rifle groups at 300 yards with the light bullets. What are the specs on the target?

The 300 yard X is 0.250" inside a 1.5" 10-ring. To be close to the top, your rifle needs to group around 0.75" at 300 (assuming mild conditions). Moderate to heavy wind changes all that.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Lee Martin]

Match #32 – Sulphyr Springs, PA
IBS VFS 100
_________________________________________

Saturday my friend Cyril and I drove to Sulphyr Springs, Pennsylvania for Sunday’s IBS event. Some shots of the range the day before the match:







Hard rain arrived Sunday, but the wind was cooperative. I tied my previous match-best with a 250-21X. Cyril did even better scoring a 250-23X.



Rick Reed was on the bench to our left. He lost his only X on the last bull. A few hundredths closer and he would've had a perfect 250-25X.





Cyril and I shared a bench. In between relays, one of us removed their gun and rear bag:



I also met long-time friend Shinny Shinglock. We’ve talked by phone for years and it was nice to finally meet him. Shinny convinced me to buy my Lab Radar last summer. He takes his to the matches, recording every shot. In time, I may do the same:



Below is a target Shinny and I discussed at length in 2016. That June, he stuck 5 shots in 0.0080” at 100 yards. While not done in competition, it was observed by Bobby Hart of Hart Rifles. By chance, Bobby decided to watch Shinny’s practice bull through his spotting scope. He witnessed, and vouched for, the paper flicking five times as the bullets went one-hole. How small is this? The World 100 yard group record is 0.0077”. Shinny’s was only 0.0003” bigger.



-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[squawberryman]

Beautiful Springtime pics, thank you.

[moosemeat]

Lee,
My F T/R rifle only holds .5 moa. Our target is much bigger with a .5 moa x and 1 moa 10 ring. I have yet to shoot a clean. The accuracy you and your system show is amazing. I have read your complete thread multiple times and tge urge to go full nuts on a build is only stopped by money.
You ever thought about taking your rifle to a midrange F Open match? I think you could do well.

[Lee Martin]

Jun 4, 2018 17:39:01 GMT -5 moosemeat said:

Lee,
My F T/R rifle only holds .5 moa. Our target is much bigger with a .5 moa x and 1 moa 10 ring. I have yet to shoot a clean. The accuracy you and your system show is amazing. I have read your complete thread multiple times and tge urge to go full nuts on a build is only stopped by money.
You ever thought about taking your rifle to a midrange F Open match? I think you could do well.

Haven't thought about F-class yet, but one of these days I may put a rifle together. Right now, I'm focused on short-range group and score (100, 200, & 300 yards. I get to shoot all three yardages this weekend at Thurmont, MD). As you noted, the gun has to be up to the task. 0.25 MOA is pretty much middle of the pack in BR. The guys that win tune their guns to shoot mid 1's in mild air....plus they have wind doping and bag management down pat. Thanks for taking an interest in this thread.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Lee Martin]

Bob Green’s Bullet Comparator
____________________________________

A bullet’s bearing surface length doesn’t affect seating depth. Seaters never contact the ogive’s transition to the shank. Instead it engages the tip, somewhere around the upper third of the ogive. Gunsmith Bob Green created a tool which compares that point relative to where the bullet meets rifling. It’s comprised of a dial indicator graduated in ten-thousandths (0.0001”). The 3/8” stem is set screwed into a gauge bored to match the land diameter. For .30-caliber, that equates to 0.300”. A 1.5 degree lead is machined into the base to mimic the chamber. The indicator is then affixed to a floating brass insert which approximates a seating inlet. A friend lent me his to use on my 114 gr bullets.

The Bob Green comparator and a box of my bullets:



Bullets are gently pressed into the bottom and the dial gives you a number. If they yield the same number, the seater touches the bullet at the same location. Variations in readings depict how much seating depth will differ across the sample. My bullets were within 0.0003” over 100 pieces. That’s damn good. The goal is to hold this window well under 0.001”. I also measured some Sierra Match Kings and found a 0.0025” delta. That amount of spread can impact accuracy, especially if you’re seating to hair line touch.





I’ve ordered a 0001 dial indicator and will make my own shortly.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[bradshaw]

Jun 4, 2018 19:33:44 GMT -5 Lee Martin said:

Bob Green’s Bullet Comparator
____________________________________

A bullet’s bearing surface length doesn’t affect seating depth. Seaters never contact the ogive’s transition to the shank. Instead it engages the tip, somewhere around the upper third of the ogive. Gunsmith Bob Green created a tool which compares that point relative to where the bullet meets rifling. It’s comprised of a dial indicator graduated in ten-thousandths (0.0001”). The 3/8” stem is set screwed into a gauge bored to match the land diameter. For .30-caliber, that equates to 0.300”. A 1.5 degree lead is machined into the base to mimic the chamber. The indicator is then affixed to a floating brass insert which approximates a seating inlet. A friend lent me his to use on my 114 gr bullets.

The Bob Green comparator and a box of my bullets:



Bullets are gently pressed into the bottom and the dial gives you a number. If they yield the same number, the seater touches the bullet at the same location. Variations in readings depict how much seating depth will differ across the sample. My bullets were within 0.0003” over 100 pieces. That’s damn good. The goal is to hold this window well under 0.001”. I also measured some Sierra Match Kings and found a 0.0025” delta. That amount of spread can impact accuracy, especially if you’re seating to hair line touch.





I’ve ordered a 0001 dial indicator and will make my own shortly.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

*****

Amazing dope. Lee.... the SEATING DEPTH caper. I’ve found madness in variations of COL based upon standard seating dies contacting OGIVE of production bullets.

Do good bullets make us better shots? You’re damn right.
David Bradshaw

[Lee Martin]

Match #33 – Black Creek Gun Club
IBS VFS 100
_________________________________

The gun shot well Saturday, allowing me to finish in 3rd place. I took home some money and another “250 Club” sticker. It was a rewarding match.







This weekend I’m shooting the Bud Pryor Memorial in Thurmont, MD. Saturday is 100 & 200 yards. Sunday rounds out with 300 yards. I expect Saturday will be a long day with three relays over two yardages. Since I preload for score matches, I’ve gotten in the habit of weighing charges. Even though I can hold +/- 0.1 grs with LT-30 in my Culver, when I preload, I weigh to within 0.02 grs. Call it placebo effect. I have three lots of fifty .30 Stingrays, but #3 only has two firings on the brass. My preference is to compete with shells fired at least four times. To save time Saturday evening, I pre-weighed 33.0 gr charges of LT-30 and stored them in vials. This method also allows me to load at the range, where trickling powder onto a GemPro scale is tough. 500 vials were quite inexpensive and they’re air tight.





-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Lee Martin]

Match #34 – 24th Annual Bud Pryor Memorial
Thurmont, MD
IBS VFS 100/200/300
_____________________________________________

Last weekend was the 24th Annual Bud Pryor Memorial match in Thurmont, MD. Attendance was high for the two day event, necessitating three relays. Competitors came from Georgia, South Carolina, New York, Connecticut, Pennsylvania, Delaware, Maryland, and Virginia to compete. Saturday was marathon-like since 100 and 200 were done back-to-back. Shooting started at 9:00 and didn’t end until after 6:00. It was hot and sunny, which gave us mirage. Sunday was cooler and by the third 300 yard target, the skies opened up. The downpour was so hard you could barely see the targets (check the videos below). Spotting hits at 300 yards through the storm was next to impossible. My best finish was 4th place at 100 yards. I came in 7th for the Grand Agg (100, 200, & 300 yard score combined). The highlight of the weekend was watching my friend Wayne France set a new three-yardage record. The previous best was a 750-39X. Wayne broke that with a 750-42X. I was one of three referees and it was a privilege to sign his record targets.







The reloading barn:



The wailing wall:





My gun in between bench rotations:



Looking back from 100 yards:



100 yard results:



Two videos showing the storm’s intensity:





The first page of the Grand Agg results:



After the match, all flags removed:



-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Lee Martin]

Panda Action – Trigger Timing
______________________________________

The railgun arrived and it’s a work of art (looks and function). I’ll photograph it once I barrel the receiver.

Fitting a trigger to the rail’s Panda action - at first I was going to use a Bix N Andy, but switched to a Jewell. I had one on-hand and another Bix would cost $400. As requested, Kelbly’s shipped a BNA hanger. I knew it wouldn’t time correctly and sure enough...pinned in the Jewell and there was significant cock on close. Enter the Dwight Scott designed infinitely adjustable hanger. Key attributes:

• The install screws are slotted, allowing one to precisely time trigger and bolt sear engagement. This eliminates cocking piece slam or cock on close.
• The hanger uses a front mounted set screw to time trigger sear pick-up with the cocking piece. All adjustment is done through that screw. Turn it into the hanger and the trigger sear moves forward in the action. Turn it out and the sear is pushed rearward (just don’t turn it in too far. There’s a chance it could rub against the top lever).
• The hanger is pressed against the front edge of the recess and secured (by way of the slotted tabs).

It requires trial and error, but now the bolt can be operated with one finger.





I also addressed a small amount of trigger creep by: 1) Polishing the side plates, and 2) Polishing the top lever. No metal was removed. I just smoothed the surfaces with Flitz. Sear engagement, over-travel, and trigger pull were adjusted to a scale measured 1.5 ounces.



-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Lee Martin]

Match #35 – Southern Challenge, North Carolina Championships
Ashe County Wildlife Club (Laurel, NC)
IBS VFS 100/200/300
______________________________________________________________

Last weekend we went 350 miles south to shoot the IBS Southern Challenge in Laurel, North Carolina. This was a 100-200-300 yard event covering two days. The weather was gorgeous with highs in the mid-70s. Winds were moderate but the mirage was brutal on Sunday. I shot a personal best at 100 yards landing me 4th place out of 30 competitors (tough crowd too...there were a lot of top shooters in attendance). My 250-23X gave me my first “screamer” decal. IBS awards them for anyone achieving 250-22X or better at 100. A 250-16X at 200 yards or a 250-10X at 300 yards are also considered “screamers”. Saturday’s second half was the 200 yard leg and I finished 14th out of 30.

Ashe County is one of the nicest facilities on the east coast. They have 30 concrete benches in front of a large steel building. The enclosure is perfect for loading and cleaning in between matches.





View from the bench, 200 yard relay:





Me behind my rifle:



Looking back from 200 yards and the mountains behind the range:





Heavy fog hit Sunday morning which burned off once the sun came out. The mirage was some of the worst I’ve ever shot through. Bad enough that you couldn’t see the target rings at 300 yards. Bullet holes were also really hard to spot. The experienced shooters navigated through the blur whereas I struggled. I finished 18th out of 30 at 300 and took 16th place for the entire event.

From my bench Sunday morning. We had to use an umbrella to block the sun.



The 300 yard backstop:



Saturday night entertainment:



We’re headed back to Ashe County in September for the IBS Score 100-200 Yard Nationals.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[bradshaw]

Shaving close, Lee. Is that a drier rag between frond and bag? To throw in just a case of the friction we’ve been talking about? All that coming down to a TACTILE PATCH?
Fine shooting in tough crowd,
David Bradshaw

[Rimfire69]

Great looking facility, and great shooting.

[cmillard]

Job well done and on getting screamer patch!

[Lee Martin]

David - yes, those are dryer sheets on the front and rear bags. Cuts friction even better than stock tape or silicon spray.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"